TECHNICAL NOTE on BEST AVAILABLE TECHNOLOGIES NOT ENTAILING EXCESSIVE COSTS for HEAVY METAL EMISSIONS from NON-FERROUS INDUSTRIAL PLANTS Final Report - May 1991

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I - 2~637t.Pf TECHNICAL NOTE ON BEST AVAILABLE TECHNOLOGIES NOT ENTAILING EXCESSIVE COSTS FOR HEAVY METAL EMISSIONS FROM NON-FERROUS INDUSTRIAL PLANTS Final report - May 1991

*** EUROPEAN This document has been prepared for use within the Commission. It does not necessarily represent the Commission's official position.

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Luxembourg: Office for Official Publications of the European Communities, 1994 ISBN 92-826-5097-9 0 ECSC-EC-EAEC, Brussels Luxembourg, 1994 Reproduction is authorized, except for commercial purposes, provided the Cn,,.C" ir ...-l,..",..,-A,.-A European Commission

Technical Note on Best Available Technologies Not Entailing Excessive Costs for Heavy Metal Emissions from Non-Ferrous Industrial Plants

FINAL REPORT

May 1991

Document This document has been prepared for use within the Commission. It does not necessarily represent the Coomission's official position.

Copyright ECSC-EC-EAEC. Erussel - Luxembourg. 1994 Reproduction is authorized, except for commercial purposes, provided the source is acknowledged. Environmental Consultancy -~

Technical Note on Best Avaliable Technologies Not entailing Excessive Costs €or Heavy Metal Emissions from Non-Ferrous Industrial Plants

Editor: K.-H. Zierock

FINAL REPORT

May 1991

Final Report to etudy contract B 6611-90-6693

CONTENTS PAGE PREFACE 1 PART Ax GENERAL ASPECTS 3 AI Introduction 3 AI1 Legal Provisions of Member States Relevant for Plant Authorisation 3 AI11 Processes and Installations Included in this Technical Note 4 AIV Heavy Metals And Their Compounds Emitted by Non-Ferrous Industrial Plants 9 AV References to Part A 19

PART Bx mVY METAL EMISSIONS CAUSED BY NOH-FERROUS SNDUSTRIAt PLANTS AND THEIR CONTROL 20 BI Introduction 20 BII Emissions of Heavy Metals Caused by Non-Ferrous Industrial Plants 24 BIII Air Pollution Control Technology 21 BIV Cross-Media Aspects 36 BV Monitoring of Emissions 36 BVI References to Part B 60

PART cx CONSIDERATIONS WIT€i REGARD TO PARTICULAR PROCESSES 63 CI Introduction 63 CI I Lead Works 63 CIII Copper Works 79 cIV Zinc Works 93 cv Tin Works 101 CVI References to Part C 110 PART DI ANNEXES 111 DI Examples of the Performance Characte- ristics of Dust Collectors 111 DI I Example of Emissions Figures of Primary Lead Production 117

DIII Plant Authorisation Procedures in ~~ EC Member States 118 -~ DIV Recommended emission limits for lead-, copper-, and zinc-works 148 1

PREFACE The Council of the European Communities adopted a Directive (Com- mission 1984) on June 28, 1984 aimed at the provision of measures and procedures to prevent or reduce air pollution from stationary sources (i.e. industrial process or utility plant). The basis of the Directive is the requirement that a wide range of industrial processes shall be subject to prior authorization by competent authorities in each Member States. A key element of Directive is the concept of the Best Available Technology "that does not en- tail excessive costs" (BAT) to prevent or reduce air pollution, that must be incorporated into a plant prior to the issue of an authorization to operate. Member States were required to bring into force the relevant administrative infrastructure and national legislation necessary for full compliance with the provisions of the Directive by no later than 30 June 1987. An important provision of the Directive (Article 7 ) requires Mem- ber States to exchange (amoungst themselves and the Commission), information concerning (amoungst others) measures forthe prevention and reduction of air pollution as well as technical processes and equipment (including BAT). The principle aim of Article 7 is to ensure that the necessary background information is made available (via information exchange) so as to ensure a harmonious implementation of the Directive in all Member States. In this regard, BAT is to be interpreted as the technology (or set of technologies) which operating experience has adequately demonstrated to be the best technology commercially available as regards the minimisation of emissions to atmosphere, providing it has been proven to be economically viable when applied to the industrial sector concerned. Application for authorizations will generally be deemed to meet BAT criteria if the performance of the proposed plant, under normal operating conditions, in terms of emissions to atmosphere, is guaranteed to be equivalent or better than that of the designated BAT. However, the provisions of the Directive also enable Authorization Authorities to consider whether, because of the individual characteristics of a plant or its local environment, the BAT guidance fully applies and whether the criteria therefore need to be interpreted differently to take account of the particular characteristics of the plant and its environment. It is the Commissions intention, via the information exchange framework, to identify both BAT and the emission values associated with this designated BAT. Such emission values will then become the principle by which future applications for authorization will be judged by the Authorization Authorities in Member States. This will give industry the flexibility to incorporate any reasonable measures provided the proposed plants meet the emission values and conform to broad principles of acceptable design practice. 2

The Commission has taken the initiative in this regard by esta- blishing a Working Group of experts to designate BAT pertaining __ to the production, storage and handling of heavy metals. This ~ technical note summarizes the Working Group’s deliberations and it is intended that it will be used as a set of advisory guidelines by both industry and authorization authorities alike for ~~ the prior authorization of new plants and of existing plants - undergoing major dfication, thereby ensuring the intended and consistent implementation of Directive 84/360/EEC throughout the Community. For existing plants, special circumstances (procedures) apply which are outlined in Article 13 of the above mentioned Directive. As new processes, equipment or technologies are developed, and proven to be economically viable and consistently to better any emissions values associated with the designated BAT, so the inno- vation will become the deaiganted R%!T and the dssion values associated with this new technology would become the emiaeions valuea by which future applications for authorisation would be measured. This is consistent with the evolutionary nature inhe- rent in the BAT concept. 3 PART Ai GENERAL ASPECTS AI Jntroducti0g The European Community (EC) is one of the greatest consum- ers of non-ferrous heavy metals in the world. In addition to the large amount of heavy metals imported from many non-EC countries, substantial production and domestic recovery of heavy metals takes place in most EC Member States (Table AI(a) provides an overview). Of course, the importance and magnitude of production differs among Mem- ber States, as shown in Table AI(b) for a few selected heavy metals. In total, there are about 3000 non-ferrous heavy metal works in operation in the EC Member States, and several hundred are of a size that is worth taking into consideration. However, many of these works are part of larger non- ferrous heavy metal plants, so that the number of important plants within the EC might only be in the order of 40-50. Table AI(c) provides some background figures. This part of the Technical Note provides some background information of general interest concerning:

0 The legal requirements laid down in national legislation on non-ferrous heavy metal plants, as far as the requirements on authorisation and emission limit and guideline values are concerned.

0 The definition of the kind of plants and works dealt with in this note;

0 The emissions associated with non-ferrous heavy metal works and the identification of those which are of greatest relevance for human health and the environment.

AII Leaal Provieions of Member States Relevant for Authoriaatioa Each Member State ha8 authorisation procedures of its own covering installation where non-ferrous metals are processed or where they are packaged and/or loaded in bulk. A brief summary of the relevant national provisions is given in Annex DIII. 4 AI11 Processes and Installations Included in thi s Tec hnic a1

-This technical note covers heavy metal emissions from the following sectors:

i) roasting and sintering plants with a capacity of more than 1,000 tonnes of metal ore per year, ii) plants for the production and smelting of non- ferrous metals, having installations with a total capacity of more than 1 tonne for heavy metals or 0.5 tonnes for light metals. In the following section, a few additional coments are given in order to define in more detail the installations and processes which fall under these two headings. Under point i), all processes concerning the primary processing are included; that is: preparation of raw material, sintering and roasting, and subsequent pyro- or hydroprocessing. In practical terms, all processes and treatments carried out in roasting and sintering plants after the delivery of the raw material and before shipping of the final product are covered. A large number of processes are applied in the non-ferrous metal industry, and in each of the processes a large number of different steps of material treatment are used. It would go far beyond the scope of this technical note to describe them all in greater detail. However, the description of best available technology given in this note in principle includes them all, that means : - with regard to raw material preparation, the storage and handling of material as well as the crushing, screening, pelletising and all chemical treatments are included. Process steps carried out in order to beneficiate ores before entering the work- shop are not included; - with regard to sintering and roasting, all kinds of technologies used in this process step are covered, e.g. downdraft and updraft sintering for lead, or multiple hearth and fluid bed roasters for copper, or multiple hearth, fluidised bed roasters, suspension roasters and sinter roasters for zinc; 5

Table AI(a): Material Balance of a Number of Heavy Metals for 1986 for Europe 12 (Source: Eurostat 1990; figures in 1 000 tomes)

I Avai labi 11ty I Uti1isation I Total I I I d I I I (Utilisation Raw I Mining Dolnestic lnport Decrease I Con- Exports Increase 1 equal material I production recovery in stocks I sunption in stocks I Availability)

Antimny 0.3 8.4 20.4 - 23.0 4.0 2.2 29.2

Chranim 23 114 650 - 739 45 3 707

Copper 53 1048 2463 - 2930 612 18 3564

Lead 176 664 801 18 1477 182 - 1659

Manganese 7 0 1326 0 1139 129 65 1333

Mercury 2.8 1.5 0.8 0.2 3.1 2.2 - 5.3

Molybdenm 0 3.3 31.8 13.7 28.6 20.1 - 48.7

Nickel 18 60 205 24 237 70 - 307

Vanadium - 0.3 7.5 0.1 5.8 2.0 - 7.9

Zinc 609 482 1325 96 1958 554 - 2512 6

Table AI(b) :

Material Production of a Number of Heavy~ Metale €or 1988 for Europe 12 (Source: Euroetat 1990; figures in 1 000 metric tonnee)

Maher State Copper (refined) Lead (refined) zinc Tin (refined)

Belgium 434.2 105.2 2a.1 0.2

Demrk - - - -

F.R. Gemny 426.4 345.1 352.5 0.1

France 43.2 255.7 274.1 -

Greece - 15.1 - 0.2 Ireland - 11.7 - -

Italy 75.4 168.4 242.0 -

Luxarkaurg - - - -

Netherlands - 39.5 210.0 3.7

Portugal 5.4 7.0 5.5 0.11’

Spain 158.8 120.8 245.4 0.8

United Kingdm 124.0 373.8 76.0 16.8

Total 1988 1267.4 1442.3 1703.6 22.0

World 1988 10572.9 5772.4 7254.6 221.5 production

1987 7 8 - the terms pyro- and hydroprocessing, include the various processes which are applied after roasting and sintering in order to purify the product. Under

"pyroprocessing" metal separation by scorifying, ~ lignation, vapourisation, and under "hydroprocessing" metal separation by precipitation, electroly- ~ sis and filtration are covered in this technical note. ~~ However, chemical and mechanical processing of semi-finished or finished products like laminating, forging, cut- ting and surface treatment are not included in this note. It should be mentioned that in some cases the three process steps are not clearly separated. In particular in pyroprocessing there is a tendency to carry out processes like roasting, melting and reduction in one step. With regard to processes covered under point ii), all processes concerning the secondary processing are meant. The broad differentiation among process steps is to a large extent similar to the one given for point i). It is raw material preparation, melting and finally pyro- or hydroprocessing. In mare detail:

0 Raw material preparation: all processes applied in order to prepare scraps or residues €or melting (as far as they belong to the actual plant, e.g. scrubbers operated separately from the plant to which the furnace belongs are not included). This process mainly includes the following steps: - storage - handling (hand sorting, magnetic sorting, gravity-separation) of material - grinding - deflagration of synthetic materials, etc.

0 For melting, various types of furnaces are employed.

0 Finally, as in the case discussed under point i), pyrometallurgical (e.g. remelting, alloying, refining) or hydrometallurgical processes (e.g. leaching by various solvents) are applied. Again, in many cases it is difficult to distinguish between these process steps in practice. 9

AIV Reaw Metals and Their Colrrmounde Emitted bv Non-Perrom Industrial Plants Non-ferrous metal plants are emitters of various heavy metals. In broad terms, one can distinguish between stack gas (or directed) emissions and fugitive emissions. Stack gas emissions occur at confined points (e.g. process vents), and can usually be captured and cleaned easily by appropriate gas cleaning devices (e.g. electrostatic precipitators, scrubbers, fabric filters) and subsequently disposed of. Fugitive emissions occur from sources like outdoor stockpiles, dust from handling or transfer operations, dust blown from dry internal roadways, but also escapes of fumes from inadequate process plant containment. They are difficult to capture but can be controlled by better practices. Both types of emissions are covered by this Technical Note. In the light of the large number of different raw materials used and the various processes applied, nearly all kinds of heavy metals and heavy metal compounds might be emitted from this industrial sector. The quantity of individual heavy metals or compounds actually emitted varies among the numerous processes and, in addition, depends heavily on the composition of the raw material. Some examples of uncontrolled dust load emissions as identified in F.R. Germany are given in Table AIV(a). With regard to fugitive sources, the emissions cannot be quantified at present but are estimated to be significant. Since the emission of none of the heavy metals can be excluded for non- ferrous industrial plants, it is worth- while to study the effects of these substances in order to identify those elements and compounds to whichmost attention should be paid when defining measures to reduce emissions. Directive 67/584/EEC provides some information concerning the classification of dangerous substances. Although the major objective of this Directive is to approximate laws, regulations and administrative provisions relating to substances put on the market, in Annex I it contains a list of classified substances which is also relevant for identifying their effect on human beings and, less exhaus- tively, the environment. It should be mentioned that the Commission is constantly updating the Directive. 10 Table AIV(b) displays those heavy metals and heavy metal compounds which are included in Annex I of Directive 67/584/EEC’.

~ Recently the WHO has published Air Quality Guidelines which are intended to help governments to make decisions - on air quality management, in particular when setting ambient air quality standards, but which are not restric- ~

ted to this use (WHO 1987). They are of relevance in ~~ identifying those heavy metals to which most attention should be given when designing emission reduction measures. On grounds of human health protection, the WHO recommends that attention should focus on Arsenic, Cadmium, Chromium (VI), Lead, Manganese, Mercury, Nickel and Vanadium. By taking into account the potential effects of the substances and the estimated quantity of emissions in EC Member State:, the working group considers the following heavy metals to be the most relevant air pollutants:

1. Antimony (Sb) and its compounds 2. Arsenic (As) and its compounds 3. Beryllium (Be) and its compounds 4. Cadmium (Cd) and its compounds 5. Chromium (Cr) and its compounds 6. Copper (Cu) and its compounds 7. Lead (Pb) and its compounds 8. Manganese (Mn) and its compounds 9. Mercury (Hg) and its compounds 10. Nickel (Ni) and its compounds 11. Selenium (Se) and its compounds 12. Thallium (Tl) and its compounds 13. Tin (Sn) and its compounds 14. Vanadium (V) and its compounds

1 Not all of the substances are heavy metals in strict terms. They have been taken into account because they are quite often considered together with heavy metals in the relevant literature on air pollution. PrOCeSS/ Etutipulll Islwntwlled Range of heavy metals associated with &st missions [a] installation mission dust load volume [d/hl [&?I Pb cu UI Cd Sb AS

Installations for wasting and sintering of lead 100 000 5 - 15 30-45 0.01- 1 1 - 10 0.01 - 1 0.01 - 3 0.01 - 1

Installations for wasting 50 000 5 - 10 0.2- 2 0.4 50 - 60 0.2 0.04 Of ziw

Lead blast furnace mMx) 5 - 15 30-55 0.01-0.04 1-10 0.5 - 10 0.01 - 3 0.01 - 3

Copper blast furnace 100 M)o 5 - 10 4w 0.5 - 70 loperial blast furnace for 80 000 10-15 6 - 70 0.5 zinc

Copper convertor 60 000 10 - 30 20-40 20 - 50

Lead reverberatory furnace 30 MM up to 20 30-50 0.001-0.005 0.01 - 1 0.01 - 0.5 0.1 - 40 0.1 - 10

Furnace for copper refining 50 000 0.1 - 0.2 5-15 15 - 35 5 - 20

i ~I 12

Table A.IV(b)r ~ Heavy Metals and Heavy Metal Compounds, Classified as Dangemue - Substances in Annex I of Directive 67/584/EEC, as of 1.9.1989

Heavy Metal CanpMInds Nature of the Safety advice Indica- special risks concerning dan- tion of attaching to dan- gems chenical danger gerous substances substances R ... s ...

Antimny (Sb) Antimny trichloride [SbCl.] C 34-37 26 Antimny pentachloride [SbCls] C 34-37 26 Antimny canpounds. with the exception of the - trioxicla [SbpOs] - tetroxide [SbpO.] - pentoxide [Sb.O.] - trisulphide [Sb&] - pentasulphide [SbnS.l and those specified elsewhere in the Annex Xn 20122 22 ' Antimny trifluoride [SbF.] T 23/24/25 7-26-44

Arsenic' (As) T 23/25 112-20121-28-44 Arsenic conpounds, with the exception of those specified elsewhere in the Annex T 23/25 112-20121-28-44 Diarsenic trioxide; arsenic trioxide [As~OS] Tt 45-28-34 53-45

Beryllium' (Be) T 6127-37-39 26-2545 Beryllium conpounds with the exception of aluminium beryllium silicates T 6/27-3749 26-28-45

Cadmium (Cd) Cadmium cnpounds. with the exception of Xn 0121122 22 = - cadnium sulphide [CdS]. - cadnium sulphoselenide [xCdS yCdSe]. - mixture of cadmium sulphide with zinc sulphide [xCdS yZnS], - mixture of cadmium sulphide with mercury sulphide [xCdS yHgS]. and those specified elsewhere in the Annex Cadmtum oxide [CdO] 3/25-3340 22-44 . CaWumfonnate [Cd(HCW).] 23125-33-40 22-44 Cadniumcyanide [Cd(CU),] 26127128-32-33-40 112-7-20-29-45 Cadmium fluorosilicate [CdSiFs] 23125-33-40 22-44 Cadmium fluoride [CdF1l 23/25-3340 22-44 Cadmium iodide [CdIpl 23/25-3340 22-44 Cadmium chloride [CdCl-] 45-23/2548 53-44

Arsenic and Selenium are actually metaloides. a Beryllium and Wgnesium are light mtals. ' if appropriate .I. 13

Table A.IV(b)r cont.1

Heavy Metal Conpounds Nature of Safety advlce tha ~~ ~ Indica- special risks concerning dan- tion of attaching to dan- gems chemical __ danger gemus substances substances R ... s ...

Chranim trioxide [CrOl] 0. c 6-35-43 26 Potassium dichronate [KnCrpO,] xi 36/37/3843 22-28 hmnim dichmnate [(NIL)&&) E. xi 1-6-36/37/yl-43 28-35 Sdim dichmnate [Na&r.O,] Xf 36/ 37/ 38-43 22-28 Chrcraic oxychloride (Chwl chloride) [CrO*Cla] 0. C 8-35 718-22-2a POtESSiW chmte [K*CrO.] xi 36/37/3843 22-28 Zinc chmtes including zinc potassium chrmte T 45-22-43 53-44 Calcium chmte [CaCrO.] T 45-22 53-44 Strontium chraMte [SrCrO.] T 45-22 53-44 Chranim 111 chmte [Crz(CrO.),] 0. T 45-8-35-43 53-44

Copper (I) chloride: copper chloride [CuCI] Xn 22 22 Copper (I) oxide: dicopper oxide [Cud] Xn 22 22 Copper naphthenate xn 10-22 -_

Lead hexafluomsilicate [PbSiFo] Xn 20/22-33 13-20 21-24/25 Lead conpounds with the exception of those specified elsewhere in the Annex Xn 20/ 22-33 13-20/21 Lead alkyls [Pb (CMZ.-~). n-1-51 T 26/27/2843 13-25-36/3745 Lead azide E. Xn 3-20122-33 33-34-35 Lead chmte [PbCrO.] Xn 3-40 22

Magnesium alkyls [Mg (CnHlW& n-1-51 F. C 14-17-34 16-43 Magnesium phosphide [ngrPI] F. T 15/29-28 112-22-43-45 Magnesium parder (pyrophoric) [MI F 15-17 7/6-43 Magnesium powder. or turnings [ng] F 11-15 7/6-43

Manganese dioxide [MI&] Xn 20/22 25 Potassium pernrangarate [Kmn,] 0, Xn 6-22 2

T 23-33 . 7-41/ Inorganic cwnds of mercury with the axception of mrcuric sulphide and those specified elswhere in the Annex T 26/27/28-33 1/2-13-28-45 Mercumus chloride (Caloml) [HgXln] Xn 22 2 Organic caapounds of mercury with the exception of those specifie elsewhere in the Annex T 26/27/28-33 2-13-26-36-45 Mercuric fulminate (fulminate of mercury) E, T 23/24/25-33 3-34-35-44 Wcuric owcyanide [Hg(CN)oHgO E, T 23/24/2533 28-35-44 Mercury alkyls [Hg (Cn Mntl)x] 1 26/27/2843 2-13-26-36-45

* Beryllitno and Mgnesim are light metals. .I. 14

Table A.IV(b)a cont.2

- Heavy Metal Carpounds Nature of the .Safety advice Indica- special risks concerning dan- tion of attaching to dan- gerws chemical danger gerws substances substances __ R ... s ...

Nickel (Ni) N icke 1 tetracarbonyl [N i(CO). F, 7 11-26-40- 9-23-45

Selenimt (9) T 23/25-33 20121-20-44 Selenium compounds except cadnim sulphoselenide T 23/25-33 20121-20-44

Thallim (TI) T 26/28-33 2-13-2045 Thal 1 im compounds T 26/28-33 2-13-2045

Vanadim (V) Vanadium pentoxide [V.O.] xn 20 22

Tin (Sn) Stannic chloride [SnCI,] C 34-37 7/8-26 Cyhexatin: tricyclohexyltin hydruxide Xn 20121122 2-13 Fentin acetate: triphenyltin acetate T 23/24/25 2-13-44 Fentin hydroxide: triphenyltin hydroxide T 23/24/25 2-13-44 Trimthyltin compounds. with the exception of those specified elsewhere in the Annex T 26/27/28 26-27-2045 Triethyltin carpounds, with the exception of those specif led elsewhere in the Annex T 26/27/28 25-27-2845 Tripropyltin compounds, with the exception of those specified elsewhere in the Annex T 23/24/25 26-27-2044 Tributyltin compounds. with the exception of those specified elsewhere in the Annex T 23/24/25 26-27-2044 Tripentyltin canpounds. with the exception of those specified elsewhere in the Annex Xn 20/21/22 26-28 Trihexyltin ccnpounds. with the exception of those specif led elsewhere in the Annex xn 26/27/28 26-28 Triphenyltin cnpwnds. with the exception of those specified elsewhere in the Annex T 23/24/25 26-27-2044 Tricyclohexyltin compounds. with the exception of those specified elsawhere in the Annex Xn 20/21/22 26-28 Trioctyltin conpounds. with the exception of those specified elsewhere in the Annex xi 36/31/30 -- Tributyltin oleate Xn 20121122 26-28 .Tributyltin linoleate Xn 20121l22 26-28 Tributyltin naphthenate xn 20121122 26-28

Zinc (Zn) Zinc alkyls [Zn (CnHz,.x)r n-1-51 F. C 14-11-34 16-43 Zinc chloride [ZnCln] C 34 7/8-28 Zinc chmnates. incl. zinc potassim chrumte T 45-22-43 Zinc dimethyldfthiocarbmte Xn 22-38 Zinc powder. zinc dust [Zn] F 10-15 1/8-43 Zinc powder, zinc dust (pyrophoric) IZn] 15-17 7/8-43 Zinc phosphide [ZnsPa] T 28-32 112-20121-22-28-45

' Arsenic and Selenium are actually metaloides. 15

Table A.IV(b)r Legend

Indications of danger

E Explosive F Highly Planunable T Toxic 0 Oxidizing F+ Extremely Flammable Tt Very Toxic C Corrosive Xn Harmful xi Irritant

~ Nature of the special risks attaching to dangerous substances

R1 explosive when dry R2 risk of explosion by shock, friction, fire or other sources of ignition R3 extreme risk of explosion by shock, friction, fire or other sources of ignition R4 forms very sensitive explosive metallic compounds R5 heating may cause an explosion R6 explosive with or without contact with air R7 may cause fire ~a contact with combustible material may cause fire R9 explosive when mixed with combustible material R 10 flammable R 11 highly flammable R 12 extremely flammable R 13 extremely flammable liquefied gas R 14 reacts violently with water R 15 contact with water liberates highry flammable gases R 16 explosive when mixed with oxidizing substances R 17 spontaneously flammable in air R 18 in use, may form flammable/explosive vapour-air mixture R 19 may form explosive peroxides R 20 harmful by inhalation R 21 harmful in contact with skin R 22 harmful if swallowed R 23 toxic by inhalation R 24 toxic in contact with skin R 25 toxic if swallowed R 26 very toxic by inhalation R 27 very toxic in contact with skin R 28 very toxic if swallowed

1. 16

Table A.IV(b)r Legend, cont.1

.- Nature of the special risks attaching to dangerous substances

R 29 contact with water liberates toxic gases R 30 can become highly flammable in use R 31 contact with acids liberates toxic gases R 32 contact with acids liberates very toxic gases R 33 danger of cumulative effects R 34 causes burns R 35 causes severe burns R 36 irritating to eyes R 37 irritating to respiratory system R 38 irritating to skin R 39 danger of very serious irreversible effects R 40 possible risk of irreversible effects R 41 risk of serious damage to eyes R 42 may cause sensitization by inhalation R 43 may cause sensitization by skin contact R 44 risk of explosion if heated under confinement R 45 may cause cancer R 46 may cause heritable genetic damage R 47 may cause birth defects R 48 danger of serious damage to health by prolonged exposure

Combination of R-Phrases

R 14/15 reacts violently with water, liberating highly flammable gases R 15/29 contact with water liberates toxic, highly flamble gases R 20121 harmful by inhalation and in contact with skin R 20/22 harmful by inhalation and if swallowed R 20/21/22 harmful by inhalation, in contact with skin and if swallowed R 21/22 harmful in contact with skin and if swallowed R 23/24 toxic by inhalation and in contact with skin R 23/25 toxic by inhalation and if swallowed R 23/24/25 toxic by inhalation, in contact with skin and if swallowed R 24/25 toxic in contact with skin and if swallowed R 26/27 very toxic by inhalation and in contact with. skin R 26/28 very toxic by inhalation and if swallowed R 26/27/28 very toxic by inhalation, in contact with skin and if swallowed R 27/20 very toxic in contact with skin and if swallowed R 36/37 irritating to eyes and respiratory system R 36/38 irritating to eyes and skin R 36/37/38 irritating to eyes, respiratory system and skin R 37/38 irritating to respiratory system and skin R 42/43 may cause sensitization by inhalation and skin contact

.I. 17

Table A.IV(b)c Legend, cont.2

_- Safety advice concerning dangerous chemical substances s1 keep locked up s2 keep out of reach of children s3 keep in a cool place s4 keep away from living quarters s5 keep contents under ... (appropriate liquid to be specified by the manufacturer) S6 keep under ... (inert gas to be specified by the manufacturer) s7 keep container tightly closed S8 keep container dry s9 keep container in well-ventilated place s 12 do not keep the container sealed S 13 keep away from food, drink and animal feeding stuffs S 14 keep away from ... (incompatible materials to be indicated by the manufacturer ) s 15 keep away from heat S 16 keep away from sources of ignition - no smoking S 17 keep away from combustible material s 18 handle and open container with care s 20 when using do not eat or drink s 21 when using do not smoke s 22 do not breathe dust S 23 do not breathe gas/fumes/vapour/spray (appropriate wording to be specified by the manufacturer) s 24 avoid contact with skin s 25 avoid contact with eyes S 26 in case of contact with eyes, rinse immediately with plenty of water and seek medical advice s 27 take off immediately all contaminated clothing S 28 after contact with skin, wash immediately with plenty of ... (to be specified by the manufacturer) s 29 do not empty into drains S 30 never add water to this product s 33 take precautionary measures against static discharges s 34 avoid shock and friction s 35 this material and its container must be disposed of in a safe way S 36 wear suitable protective clothing s 37 wear suitable gloves s 38 in case of insufficient ventilation, wear suitable respiratory equipment s 39 wear eye/face protection S 40 to clean the floor and all objects contaminated by this material, use ... (to be specified by the manufacturer) S 41 in case of fire and/or explosion do not breathe fumes s 42 during fumigationlspraying wear suitable respiratory equipment (appropriate wording to be specified by the manufacturer)

./. 18

Table A.IV(b)r Legend, cont.3 -

Safety advice concerning dangerous chemical substances s 43 in case of fire, use ... (indicate in the space the precise type of fire-fighting equipment) if water increases the risk, add "never use water" s 44 if you feel unwell, seek medical advice (show the label where possible) s 45 in case of accident or if you feel unwell, seek medical advice immediately (show the label where possible) S 46 if swallowed, seek medical advice immediately and show this container or label s 47 keep at temperature not exceeding ... OC (to be specified by the manufacturer) S 40 keep wetted with ... (appropriate material to be specified by the manufacturer) s 49 keep only in the original container s 50 do not mix with ... (to be specified by the manufacturer) S 51 use only in well-ventilated areas S 52 not recommended for interior use on large surface areas s 53 avoid exposure - obtain special instructions before use

Combination of S-Phrases s 112 keep locked up and out of reach of children s 31719 keep container tightly closed in a cool, well-ventilated place S 319 keep in a cool, well-ventilated place s 3/9/14 keep in a cool, well-ventilated place away from ... (incompatible materials to be indicated by the manufacturer) s 3/9/14/49 keep only in the original container and a cool, well-ventilated place away from ... (incompatible materials to be indicated by the manufacturer) s 3/9/49 keep only in the original container in a cool, well-ventilated place S 3/14 keep in a cool place away from ... (incompatible materials to be indicated by the manufacturer) s 710 keep container tightly closed and dry S 719 keep container tightly closed and in a well-ventilated place s 20121 when using do not eat, drink or smoke S 24/25 avoid contact with skin and eyes __ S 36/37 wear suitable protective clothing and gloves S 36/37/39 wear suitable protective clothing. gloves and eye/face protection S 36/39 wear suitable protective clothing and eye/face protection S 37/39 wear suitable gloves and eye/face protection S 47/49 keep only in the original container at temperature not exceeding ... OC (to be specified by the manufacturer) 19

Commission of the European Communities (1984). Council Directive of 28 June 1984 on the Combating of Air Pollution from Industrial Plants (84/360/EEC). O.J. L 188 / pp 20-25 Commission of the European Communities (1967). Council Directive of 27 June 1967 on the Approximation of Laws, Regulations and Administrative Provisions Relating to the Classification, Packaging and Labelling of Dangerous Substances (67/584/EEC). O.J. 196 Eurostat (1990). Basic Statistics of the Community, 27th Edition. Office for the Official Publications of the European Communities. ISBN 92-826-1498-0 International Lead and Zinc Study Group (1984) Liesegang, D. (1987): "Legislativer und technischer Stand der Luftreinhaltung in der Bundesrepublik Deutschland" in: Staub - Reinhaltung der Luft Vol. 47 (1987), No. 3/4 (March/April), pp. 67-74 Metal Bulletin Books (1985). Non-Ferrous Metal Works of the World WHO (1987). Air Quality Guidelines 20 PART B; HEAVY METAL EMISSIONS CAUSED BY NON-FERROUS INDUSTRIAL PLANTS AND 'PHEIR COhlTRoL

BI ction ~ -~ A large number of production activities are covered under the heading "Non-Ferrous Industrial Plants". This report can neither deal with air pollution problems involved with the production of all non-ferrous ~__ metals, nor can it fully cover all technologies and processes involved in the production of those heavy metals which are included (see part C of the report). Therefore, this part of the Technical Note describes in general terms air pollution problems caused by major process steps (stockpiling, roasting and sintering, production and melting, refining) of the non- ferrous metals industry. Emissions due to primary and secondary processes are included as well as cross- media aspects (see Figures BI(a) and BI(b)). Subsequent chapters of part B provide a general overview of air pollution control technologies and abatement measures for captured and fugitive emissions. As a further limitation, this report outlines only BAT for preventing or reducing the emission of heavy metals. It should be noted that the processes used in the non-ferrous industry cause emissions of other pollutants as well (see Table BI(a)). Additional information is given on monitoring of emissions of dust in general and heavy metals in particular, as well as operational controls. Finally, cross-media aspects are briefly described in broad terms. It should be mentioned that all concentrations given in this report relate to standard conditions (273.15 K, 101.3 kPa). 21

Figure BI(a): Primary Processes in Non-Ferrous Industrial Plants: Overall Scheme and Potential Pollution Problems

Process Step Potential Potential Cross- Air Pollution Media Pollution Prublen ___-_--_--__-__-Problem Water waste

Raw Material I I V - gases waste solid chm{cals -> -I Ore, raw material 1 -+ fugitive fws - dust water waste mechanical energy -n I- preparation I -> (chemicals) I I v - SOt a other gases waste Air -> I Sintering, Roasting I -> fugitive fms - dust water Energy -> I I -> flue gases I1 -1 I I I V I Air -, -> fugitive fums - gaseous pollutants solid I Energy -> Pyroprocessing I 4flue gases - dust waste I Chemicals -> --> (chemicals) I I -V Chemicals -> ,-, -> fugitive fums - gaseous pollutants solid Liquids -> I Hydropmcessing I -> flue gases - dust wast Energy -> & sludge 22

Figure BI(b): ~ Secondary Processes in Non-Ferrous Industrial Plants: Overall -~ Scheme and Potential Pollution Problem6

.~__ Process Step Potential Potential Cross- Air Pollution kdia Pollution Problem __-______-____--Prablem Water Waste

Scrapes. Residues I I V - gases waste solid chemicals - I- Raw material 1 -> fugitive fm - dust water waste rneehanical energy ---r -I preparation I -> (chemicals) I I v - SO. & other gases waste Air -> -I Melting I -> fugitive fms - dust water Energy -> --3 flue gases II -1 I I I V I Air -> ,-, -> fugitive fms - gaseous pollutants solld I Energy -> I Pyroprocessing I -> flue gases - dust waste I Chmicals -> -> (chemicals) I I V Chemicals -> -> fugitive fms - gaseous pollutants solid Liquids -> I Hydroprocessing I -> flue gases - dust waste Energy--, - & sludge 23

Table BI.l(a)c General Overview about missions of Pollutants into the Air Caused by Non-Ferrous Industrial Plants

Industry Process of Operation Air Pollutant Emitted

Foundries Melting Charging Particulate matter including smoke and fwne (cupola) Melting Particulate matter including smoke and fume Pouring Oil, mist, CO Bottm orop Snoke and particulates

Brass and Bmnzs Melting Charging we. particulates, oil, mist Melting Zinc oxide fwne. particulates, yroke Pouring Zinc oxide fume. lead oxide fume

Melting: Charging, Melting, Pouring Particulate matter including smke and fume

zinc Melting Charging Particulate matter including smke and fume Melting Zinc oxide fume Pouring

Magnetic pulley, conveyors & elevators, Particulates (dust) potaw cooler, screening. crusher-mixer Coke-making ovens Organic acids, aldehydes, mke. hydrocarbons

Non-Fermus Smelters. Primary

- Copper Roasting SO*. Particulate matter including smke and fm Reverberatory furnace SOZ. Particulate matter including smoke and fm Converters: charging, slag, skim, Smke, fume, SOp pouring, air or oxygen blar

- Lead Sintering SO.. Particulate matter including smke and fm Blast furnace SO*. CO. particulates, lead oxide, zinc oxide boss reverberatory furnace SOI. Particulate matter including smke and fume Refining kettles Particulates, lead oxide

- Cadmium Roasters, slag, fuming furnaces, de- Particulates leading kilns

- Zinc Roasting Particulates (dust). sot Sintering Particulates (dust). SOo Calcining Zinc oxide fume. particulates, SO*. CO Retorts: electric arc

Non-Ferrous Smelters. Secondary

Blast furnaces and cupolas - recovery Oust, fumes. particulates, oil vapour, smke. CO of metal frm scrap and slag Reverberatory furnaces Dust, Particulate matter including smke and fume. gaseous fluxing materials Sweat furnaces Particulate matter including smke and fume Hire reclanation and autobady burning Particulate mtter including smoke and fum 24

BII Emissions of Heaw Metals Caused bv Non-Fe rrou 9 Industrial Plants

BII. 1 Emissions Due to Roasting And Sintering of Metal ~ Ore -~ BII. 1.1 Stockpiling

Raw materials prior to treatment are stockpiled on - paved outdoor areas which may be surrounded by wind- proof fences or, more efficiently, in closed buildings. Dust generation mainly takes place during discharging of trucks or railway wagons, using belt conveying systems and during material handling. Emis- sion sfrom stockpiles in harbours can be reduced by spraying the raw material. BII. 1.2 Charge Preparation Emissions arise from conveying systems leading from the stockpiling area to the day bins, from the day bins themselves, from day bin hoppers and the mixing unit. BII. 1.3 Roasting / Sintering BII .l. 3.1 Roasting For roasting of sulphidic materials multiple hearth roasters, fluid bed roasters or rotary kiln furnaces are used. The roasting plant consists of charge preparation (proportioning bins, feeder, mixing unit) conveying systems, roaster, a waste heat recovery system in some cases and conveying, crushing, cooling, discharging and stockpiling units for the roasted material. Dust generation can occur in conveying systems leading to the roasting unit, by mechanical dust generation and by evaporation of metals or metal compounds inside the roaster leaving the unit as dust laden process gas also containing alsothe removed S02, and in the discharge, conveying, cooling and stock-piling after behind the roaster. The emissions leaving the buildings via roof openings are so-called fugitive emissions. BII. 1.3.2 Sintering Sintering is mainly carried out on updraft strip sinter machines but downdraft machines are also used. The __ main steps are charge preparation, sintering, breaking and screening of sinter and crushing and cooling of return sinter. Dust is generated during filling and discharging the charge preparation bins and during the conveying and mixing of feed. 25 From the sinter machine a dust containing strong and weak gas with SO2 is produced by the sintering reaction inside the sinter feed bed. Dust is generated at the tipping end of the sinter machine and during conveying and discharging of hot sinter in the sinter and return sinter circuit. Moist waste gas derives from return sinter cooling. Natural ventilation of buildings causes some fugitive emissions.

BII. 2 Emieeione Due to Praduction and Melting BII. 2.1 Pyrometallurgical Unite Production or melting units are shaft furnaces, reverberatory furnaces, electric furnaces, rotary kilns, fuming furnaces, suspension and bath melting furnaces, cyclone melting furnaces. The production and melting units consist of charging and feeding systems, the production and melting apparatus itself, in combination with waste gas cooling or waste heat recovering systems, and tapping areas where the molten products (metal bullion, mattes or slags) are handled and treated in pots and kettles or are granulated. Mechanically generated dust derives from conveying and feeding systems when solid materials are handled. In the case of molten product feeding, fumes can be generated depending on the temperature of the molten phase and the vapour pressure. By chemical reactions and also by the movement of the charge inside the furnaces, fumes and dust-laden waste gas is produced containing SO2 in differing concentrations depending on the sulphur input, the chemical reactions and the degree of sulphur binding in products. Natural ventilating air leaving the buildings via roof openings contains small dust concentrations. BII.2.2 aydrometallurgical Unite Calcine leaching reducing pressure leaching, cemena- tion and electrowinning can be classified as hydrometallurgical units under the category "production and melting" . The leaching step comprises material feeding systems, leaching tanks, thickeners and filtering units. Dust is generated during the feeding of material while in the subsequent steps wet waste gas can result from leaching depending on the temperature in the leaching 26 unit which might sometimes also contain gaseous compounds from chemical reactions. Cementation can be classified under the same category.

During electrowinning in electrolysis cells, electro- -~ lyte spray is formed due to the temperature level and production of gas at the anode and cathode and often leaves the building with the natural ventilation air via the roof. Some companies collect the whole volume ~- of vented air for subsequent particle removal by liquid scrubbers.

BII. 3 BII. 3.1 Pyrometallurgical Refining Pyrometallurgical refining is carried out in steel or cast iron kettles, Harris reactors, reverberatory or rotary furnaces, distillation furnaces (atmospheric or vacuum) and induction furnaces. Dust or fumes can result from filling the furnaces mentioned above with hot liquid metal bullion or from feeding chemicals or reagents into the metal bath in the majority of the refining steps. Chemical reactions produce dust or/and fume containing off gas. In the refining step when using a Harris reactor during hydrometallurgical treatment of salt slagsheavy metal emissions can occur with the moist off gas. In distillation furnaces, the basic metal or impurities are removed from the crude phase by evaporation producing a highly concentrated metal gas which has to be condensed in special equipment. Dust or fumes can de- rive from tapping or transferring the metal phase and from removing intermediate products, for instance drosses, slags etc. Ventilation air from buildings also causes emissions. BII. 3.2 Hydrometallurgical Refining Purification of leach solutions and refining electrolysis are the most important processes. Depending on temperature and reactions, metal compounds containing - wet off gas can be produced in some purification steps. 27 BIII Air Pollution Control Technolouies BIII. 1 Control of Directed Wseione of Heavy Metals Heavy metals, except mercury, are generally not emitted as pure substances but as constituents of dust. Dust from "contained", i.e. closed sources (e.g. a rotary kiln or a shaft furnace) is suspended in a waste gas stream. "Directed emissions" or "point emissions" of heavy metals can only be controlled by reduction of the dust content of the waste gas. Emissions from "uncontained" or "open" sources , such as bulk goods-storage piles or unloading facilities, are called "fugitive emissions". Devices by which the dust content of a gas stream can be reduced are dust collectors or dust arresters. Cy- clones, scrubbers, electrostatic precipitators and fabric filters are the types of dust-collector used in industry. A few examples of the application of dust collectors and their performance characteristics are given in Section D.1 of this Technical Note. BIII. 1.1 Cyclones Cyclones are cylinders or cones in which waste gas is forced to rotate, either by tangential introduction or by axial introduction via guidance blades. Particles whose size or mass exceed certain values migrate, due to inertial forces, to the shell where they are captured. Smaller particles which are entrained by draft forces leave the cyclone. Even well designed and carefully manufactured high performance cyclones have only a likelihood of 50 % to collect 5 m (aerodynamic diameter) particles. But airborne particles released from industrial operations other than mechanical processing are generally much smaller than 5 m; this is particu- larlytrue for fumes and smokes from pyrometallurgical processes. Therefore, in the non-ferrous metallurgical industry cyclones alone cannot be regarded as an appropriate control device. BIII. 1.2 .. Electrostatic Precipitators Electrostatic Precipitators (ESP) are generally of the plate-type with horizontal gas flow. The characteris- tic design feature are plate-shaped collecting electrodes (which are stiffened metal sheets), suspended in parallel at some 0.25-0.35 m distance, in the middle of which the discharge ("spray")electrodes (which are steel tapes or wires) are arranged. Direct current high voltage (60-80 kV) is applied, with nega- 28 tive electrical charge to the discharge electrodes. Certain gas molecules (mainly H20 and 02) after ioni- sation at the discharge electrodes attach to dust par-

ticles, which migrate to the collection electrodes. ~ Every 10-30 minutes the dust is dislodged from the -~ electrodes by rapping. Most of the dust falls into hoppersI but some of it is resuspended and entrained by the waste gas. The DEUTSCH equation relates collection efficiency (T),collection area (A) and the gas flow (Q) as follows :

*w", the so-called migration velocity, cannot be cal- culatedtheoretically but must be determined from operational data from existing installations. It can be derived from the DEUTSCH equation that the collection area has to be increased at an exponential rate with collection efficiency. Modern ESP are divided into several zones (up to 5) or so-called "fields", which are groups of electrodes with their own electric power supply and rapping system arranged behind each other. This electrical subdi- vision is essential for uniformity of performance. The applicability of dry ESP's is linked to certain dust properties, e.g. moderate electrical resistance, non-viscous, capable of forming stable agglo- merates, and a waste gas free of droplets. If these conditions are not met, a wet ESP can be used. In a wet ESP, the electrodes are water-cleaned, either by continuous spraying or by periodic flushing. Due to the low gas velocity, the pressure loss of an ESP is only 200-400 Pascal. However, because of the power consumption of the rectifiers, the overall energy consumption of dry ESPs is 1 - 1.5 kWh/lOOO m3 purified gas (wet ESP up to 2 kWh/lOOO m3), i.e. the same range as with fabric filters. This is the level of operational performance that could be expected even if maintenance was good. There are several reasons for this decay, e.g. that ruptured discharge electrodes (there may be thousands in an ESP) have not been re- - placed, that the electrodes have become misaligned due to material fatigue or the electrodes become scaly. Therefore the internals of an ESP must be overhauled __ from time to time and even, after long periods of operation, completely replaced. 29 BIII. 1.3 Scrubbers Dust collection in scrubbers is mainly effected by inertial forces: Dust particles are made to impact with water droplets, which are orders of magnitude larger than the particles. Due to their size the droplets are more easy to collect by inertial forces (e.g. in a wet cyclone) than dust particles themselves. The droplets may be generated by nozzles (spray tower), rotors (wet fan) or the gas flow itself (venturi scrubber). To make smaller particles impact (on the droplets) requires higher relative velocities and smaller drop1ets.Therefore it is a basic rule that scrubbers consume more energy the finer the particles and the higher the collection efficiency. Venturi-scrubbers have become the most common type of scrubber, because they are able to attain any clean gas concentration required and they have a simple design. They consist of a conical tube ("throat") where the waste gas is accelerated to some 50-80 m/sec. The scrubbing water is delivered to the inlet section of the throat through perforated tubes or wide orif ice nozzles at a ratio of 2-6 l/m3. Usually a wet cyclone is provided for droplet collection, but in cases where very low dust concentrations are required the cyclone should be followed by a mist eliminator (e.g. corruga- ted laminates). Mist eliminators are sensitive to scaling and must therefore be cleaned continuously with fresh water. The overall differential pressure of a high performance Venturi Scrubber is 5000-10 000 Pascal, and the energy consumption between 2.5 and 6 kWh/lOOO m3. Waste water must be treated prior to discharge. BIII .l.4 Fabric Filters (Baghouses) The filtration material is a flexible cloth, e.g. a needle felt or a woven fabric made of synthetic or natural fibres. Due to their higher thermal and chemical stability synthetic fibres such as Polyester, Polya-mide or Polypropylene are more often used than natural fibres (e.g. cotton, wool). There are two methods of bag cleaning, pulse-jet filters and reverse-flow filters. Filters with pulse-jet cleaning generally have cylindrical filter bags (diameter some 0.15 m, length up to 2.5 m) made of needle felt. In the filtration phase the bags, which are pulled on retainers (to avoid flattening), are passed from outside to inside. Dust is dislodged by an air pulse, which is directed into the bags every one to three minutes. Usually 8-10 30 bags, representing 20 % to less than 2 % of overall filtration area, are simultaneously cleaned.

In reverse-flow filters, the bags are arranged in sev- ~ era1 compartments (at least four). During the filtra- -~ tion phase, which is 20 min to one hour, the bags (diameter 0.2-0.3 m, length 3-5 m) are passed from inside to outside. For bag cleaning, the gas flow to one com- ~ partment is reversed by introducing clean gas. The ~- proportionate waste gas flow is diverted to the other compartments. Fabric filter performance stronglydepends on the filter rate, the filter medium (cloth type, workmanship of cloth manufacture) and the method of cleaning. Higher filter rates and more intensive (or more frequent) bag cleaning have a tendency to increase clean gas dust concentration. Lower filter rates, which mean larger and more expensive filters, imply a lower pressure loss (i.e. lower energy consumption) and longer bag life. The filter rate appropriate to a certain application cannot easily be defined but must be based on operational experience from similar applications. Satisfactorily working filters for thermal processes have filter rates between some 0.4 m3/(m2 min) and 1.2 m3/(m2 min), with the lower figures prevailing. Cloth weight of needle felts for pulse-jet filters (which are becoming the usual design) is frequently between 500 and 600 g/m3. Certain casing design features give a tendency for sealings between flanges to fail and for raw gas to seep into the clean gas chamber of the filter. There- fore a rigid, well stiffened casing preventing sealings from mechanical stress should be preferred. At operating temperatures above 12OoC, a welded design should be considered. If carefully designed and well maintained, fabric filters are suitable in certain applications to attain dust concentrations of less than 10 mg/m3.' BIII. 2 Fugitive Emieeione BIII. 2.1 Introduction Dust and metal fumes can escape into the environment by routes other than the controlled emissions from - process vents and chimneys. Sources of potential fugi-

1 Dr. Gsthner emphasized that fabric filters, if carefully designed and well maintained, are suitable to attain dust concentrations of less than 5 mg/m3. 31 tive emissions can be identified and control measures applied. The contribution of fugitive emissions to the total emission from a process site is not readily quantifi- able but it could well be significant and perhaps even exceed emissions from controlled systems. The main potential sources and control measures available are summarised in the following sections. BIII.2.2 Storage and Handling of Raw Materials Raw materials should be received wetted and/or in sealed containers or in enclosed vehicles. These should be inspected before tipping. Appropriate dust control precautions should be taken when sampling. Covered storage provides the best protection against wind-blown emissions. The height of a stockpile should not extend above the retaining walls of the open bays. Properly designed spray systems are required to maintain stockpile surface wetting. Stockpile and access road areas should be hard sur- f aced. Site selection of the stockpile area should consider protection from winds and minimisation of vehicle movements.

BIII. 2.3 Transfer Operations Tipping to stockpiles can be made through chutes equipped with wet suppression systems. Vehicle contact, especially wheel contact, with the stockpile should be avoided. Exposed free fall of dusty material to stock should be avoided. Access roads should be regularly cleaned and kept wet. Reclamation of raw materials from stockpiles can be by: 1 - underfed conveyor, 2 - grab crane, or 3 - front end loader; the best method being 1. 32 Conveyors should be totally enclosed with transfer points extracted to arrestment equipment. BIII. 2.4 Recycling Operations - -~ Drosses, slags and fine dusts from fabric filter arrestment plant have a high potential for dust emission. __ Wetting, as soon as practicable after removal from the process, using a properly designed spray system can greatly reduce dust emissions'. Transfer of drosses and slags for crushing should be in enclosed containers. Crushers should be fittedwith arrestment plant. Fine collected dust can be continuously recycled in a closed system direct from the filter plant. Fine dust can be fed directly into a continuous smelting furnace or wet pelletised before charging. Fine dust can be collected in combustible containers for charging direct to the furnace. The wetting or slurrying of fine collected dust is not good practice. BIII.2.5 Proceee Containment Extraction of fumes followed by arrestment should be applied to sources such as furnaces, launders, melting pots etc. Design extraction volumes should be sufficient to cope with overloads and abnormal operating conditions. Methods of containment could include: - lock chambers on changing systems, - covered launders and ladles, - close hooding at tapping points, - enclosure of hot dressing areas and rotary furnaces. The above emissions should be extracted to filters.

1 Caution is needed when using this method as: __ i) Over-wetting can lead to explosions when the material ie put in the melting pot. ii) Highly toxic gases such as arsine, stibine or phosphine can be formed. iii) Also over-wetting increases energy costs, corrosion and water contamination. 33 High capacity vacuum cleaning systems should be used for housekeeping within the process area. Fabric filter units on hot gases should be located inside a building to reduce emissions during maintenance, condensation and corrosion due to weather effects. BIII. 2.6 Traffic and Roadwaya Roads should be cleaned and kept wet. Wetting without cleaning increases water run-off contamination. A de- dicated, purpose built vehicle should be used. Vehicles should be restricted to designated functions and areas and their use should be prohibited outside the site. Access of private vehicles to affected areas should be prevented. Careful on-site traffic management is required. Roadways should be well defined, well maintained (even-surfaced), kerbed, cambered and gulleyed to obtain maximum water run-of€ and collection. Drains should be fitted with interceptor points to prevent blocking. Vehicle exhausts should preferably not point down- wards. BIII. 2.7 Wheel Washing A well designed wheel wash system, before the weigh- bridge, would include: - a spray system capable of cleaning tyre surfaces and wheel arches; - water trough to at least half the depth of the tyre. Rumbler bars submerged in the trough along its full length; - an irrigated exit ramp and draining off area using clean water draining to the trough should be provided; - automatic jet operation by pressure pads; - solids recovery system; - restrictions to prevent by-passing the wheel wash system. 34

BIII .3 Operational Cantrole

The air pollution control measures referred to in __ Parts BIII.1, BIII.2 and C of this note should be effective in either preventing or reducing dust, fume -~ and gas emissions to an acceptable standard. These measures are smarised as follows:

0 Plant and process control measures such as: - exhaust ventilation hooding, enclosures etc. and arrestment plant, - pressure, temperature, moisture and liquid spray controls;

o Materials handling and storing measures such as: - enclosed containers or hechanical/pneumatic conveying systems, - enclosed material storage areas and water .spray systems;

0 Cleanliness control measures such as: - vacuum cleaning systems, - road cleaning and vehicle washing facilities. Such operational control measures should include the maintenance, examination and testing of equipment to a satisfactory standard, prompt action to deal with malfunctions or breakdowns, proper supervision of the process and provision of sufficient training of staff at all levels. BIII.3.1 Maintenance of Equipment The objective is to secure the efficiency of control measures and that any defects which could result in loss of efficiency are detected and remedied. Maintenance procedures should be established and detail the following: - which control measures require maintenance, e.g. a basic inventory of the system; - how the maintenance should be carried out; - when it should be done, e.g. a planned preventive - maintenance schedule; - how defects which are identified should be remedied including provisions for replacement, repair and remedial action within specified time limits according to the degree of risk; - the person(s) responsible for maintenance. 35 The maintenance methods used for exhaust ventilation and arrestment plant should include:

a) A general visual inspection at frequent intervals to identify obvious defects in the equipment, such as damage, wear, malfunctioning etc., which could result in ineffective extraction and leakage of dust, fumes or gases from the system, for example : - exhaust ventilation hooding, - enclosures etc., - dampers, ductwork, arrestment plant, dust collection, fans and discharge stacks.

b) A more thorough examination of the system should be carried out both internally and externally by a competent person. The performance of the system should also be assessed by carrying out appropriate measurements such as: - static pressures at hoods or enclosures, - the pressure differential across the filter or arrestment plant, the air velocities at the face of hoods etc., - and the air velocities in ductwork. The frequency and extent of the inspection, examina- tions and testing depend upon the conditions of senr- ice, the hazard being controlled and the size of plant. BIII. 3.2 Malfunctiona and Breakdowns Malfunctioning and breakdowns likely to give rise to contamination problems should be dealt with promptly to minimise the risk of contamination. BIII. 3.3 Superviaion and Training The process should be adequately supervised, and staff at all levels should receive proper training and instruction in their duties relating to the control of the process and emissions into the air. Special empha- sis should be given to training for start-up, shut- down and non-routine activities likely to give rise to contamination problems. Staff should be able to recog- nise and take appropriate action in the event of any contamination risk arising from routine operations. 36

The term "cross-media aspects" covers pollution pro-

blems arising when pollution is transferred from one ~ medium to another, e.g. from air to water or soil. -~ When uncontrolled heavy metal dusts/fumes are generated from point source chimney stack emissions and from diffuse source fugitive emissions through the ___ handling, movement, storage and disposal of materials, they can be transported away from the source and eventually deposited or washed out into soil and/or water. Heavy metals can also reach water by leaching from soils, by surface run-off and by direct discharge, e .g . the improper storage of materials , disposal of 0olid waste and the discharge of liquid effluent from scrubbers etc. A cross-media environmental management approach should therefore be adopted in order that heavy metal discharge levels in the context of recognised environmental standards relative to the medium concerned are controlled and monitored. Figures BI(a) and (b) illus- trate the potential cross-media pollution problems arising in primary and secondary non-ferrous processes; guidance on control measures is given in part BIII.l to BIII.2-7.

Bv Bv. 1 Baeic Requirements for Sampling Before adopting a defined sampling/analysis method, it is necessary to determine, at least qualitatively, some characteristics of the emission. Bv.l.l Weeion Definition An emission of pollutants to the atmosphere can be defined by the following characteristics:

0 Physical Nature: The selection of the sampling - method depends on the physical constitution of the emission. From this point of view, emissions can be classified as: i) Pure gaseous emissions: Those which consist exclusively of gases and/or vapours. ii) Mixed emissions: Besides gases and/or vapours , they may contain solid particles and/or aerosols. 37

0 Chemical Nature of Pollutants: Any pollutant may be present under different chemical forms, (element, salt, oxide etc). The selection of the analytical procedure may depend on the chemical species.

0 Process Conditions. In most industrial operations the process conditions vary, thus causing a variation in the characteristics and quantities of gaseous effluents. Also there may be more than one in-plant source exhausting to the same stack and this will cause additional fluctuations. The source sampling process requires a substantial length of time; therefore consideration must be given to altering the sampling method and/or conditions to account for the changes in process conditions. The extreme case is that of the batch-type operation as shown in Figure BV(a) where it can be seen that the quantities emitted may vary depending on the timing of sampling (Brenchley et a1 1973). Bv.1.2 Selection of the Sampling Point/e A sampling point must be placed far enough from any element which could modify the turbulence conditions of the effluent gas so as not to be affected by it. This is compulsory in the case of a mixed emission, its importance is less in the case of pure gaseous emissions. In order to obtain representative data for emitted pollutants and/or volumetric flow, from stationary sources, the sampling point must be located in a place where the gaseous flow has a known direction; the stack cross area will be divided, in order to obtain a number of identical areas, and a traverse point will be located at the center of each area.

0 Selection of the Sampling Point: Many reports (for example: US-EPA 1971a, Brenchley, Ministerio de Industria, BS 3405 : 1983) have described the location of the sampling point (Figure BV(b) ) . For a rectangular duct, the following equation should be used in relation to Figures BV(b) and (c)- equivalent diameter = 2 x (a x b) / (a + b) Experience has shown that 100 mm ports, fabri- cated from standard pipe couplings (see Figure BV(d), are the easiest to work with. Figures BV(e) and (f) show the location of these caps depending on the stack geometry. 38

0 Determination of the Number of Traverse Points: If the test is to meet EPA standards (see US-EPA), Figures BV(g) and (h), along with Table BV(a), should be used. However, if the stack or duct is less than 0.61 m in diameter, the numbers obtained from Figure BV(h) can be multiplied by a factor of 0.67. In no case should a sample be taken at a distance closer than 2.5 cm from the interior stack wall. To use Figure BV(h), measure the distance from the chosen sampling location to the nearest upstream (L2) and downstream (Ll) disturbances. Then use Figure BV(h) to determine the corresponding number of traverse points for upstream and downstream conditions. For circular stacks the number of traverse points should be increased, so that it is a multiple of 4. As shown in Figure BV(g), left side, the sampling points should be located on at least two diameters; when a large number of traverse points are required, they can be located on 4 diameters. In every case, the traverse axis should divide the stack cross section into equal parts. When a rectangular stack is encountered, the cross section should be divided into equal areas, as shown in Figure BV(g). The areas should be of such dimensions that the ratio of the length to width is between one and two. The traverse points should be located at the centre of each area. Some producers of sampling devices use different versions of Figure BV(h), depending on the interior diameters of the effluent ducts and the emission class (gaseous or mixed). BS 3405 : 1983 describes a similar, but simplified procedure. It leads to results with an accuracy of 0 25 % which is very similar to that obtained with EPA's method. BV.1.3 Measurement of Gaeeoue Flow Parametere In order to perform a correct sampling and express the analytical results as absolute quantities (weight) or concentration, we must know some of the characteristics of the gaseous flow:

0 Gas Velocity and Flow Rate: Measurement of these parameters supply the necessary information in order to calculate the concentration and emitted mass of the pollutant. Previously, the cross area of the effluent dust has been calculated, as indicated in Section V.1.2. 39 There are many suitable methods for this kind of calculation, but US-EPA No. 2 (US-EPA 1971b) and BS 3405 : 1983 are the most widely used.

0 Other Parameters: Many of the analyses necessary to evaluate an emission need to have information relating to some parameters which are complemen- tary to those already indicated in this section. The most common ones are: i) Molecular weight. The procedure most widely used is EPA method no. 3 (US-EPA 1971c, Brenchley). It is based on the Orsat analy- ser. ii) Moisture content determination. Most sampling methods measure the dry volume of the gas. That is why it is necessary to know the gas moisture content using, for example EPA no. 4 method (ref. US-EPA 1971d, Brenchley). There are other parameters which may be of interest; their determination methods may be found and are compiled in the specialised literature (Brenchley). 40

Figure BV(a)r Time Variation of Air Pollutant EmiSSiOnS

OD aOD E

I I I I I 2 3 4 TIHE, HOURS 41

Figure BV(b)t Sample Point Location

L2 2D 42

Figure BV(c)r Rectangular Duct or Stack ~ -~

I I

'1a 43

Figure BV(d): Standard Pipe Couplinge

Standard 100 m nominal Metal external wall (4in) BSP socket fixed to 100 external face of wall Standard m naninal

(a) In metal flue or duct wall (b) In metal flue or duct wall with internal lining

Weld is not to penetrate to block internal diameter ket

Liner tube

Standard 100 m I /(4in) ESP socket diameter of socket Weld on bracket

Bolt or flxing device to prevent socket and liner turning when rming plug

Dimensions are in millimetres. 44

Figure BV(e): Location of Caps in a Circular Flue

Access fiinb

Sanpling pint Distance fmwall Sanpling point Distance from wall at access f itmnt at access fitaent

0.15 0 0.065 D 0.85 0 0.250 D 0.750 D 4 0.935 D

a) Four sanpling points b) Eight Sanpling points In a circular flue in a circular flue 45

Figure BV(f): Location of Cape in a Rectangular Flue

0 AlterMtive posit ions for access holes

c) Four sanpling points in a rectangular flue

d) Eight sanplinq points in a rectangular flue 46

Figure BV(g)r Equal Sampling Areas for Traversing Ducts ~ -~

+ +

t + +

(a) Circular duct (b) Rectangular duct 47

Figure BV(h)t Minimum Number of Traverse Sampling Points a8 a Function Of Number of Duct Diameters

Number of duct diameters upstream. Distance LI 50 fn E H 0 % 40

14 0 - t 1 I I I I I I I 1 2 J 4 5 6 I a e 10 Number of duct diameters downstream. Distance LI 48

Table EV(a): Location of Traverse Points in Circular Stacks ~ (Figures given indicate percentage of stack diameter from -~ inside wall to traverse point)

I NUMBER OF TRAVERSE POINTS ON A DIAMETER I + ------I 12 -41 61 8 10 12 14 16 I8 20 22 24 I I I I * I I 1 I 14.6 6.7 i 4.4 i 3.2 2.6 2.1 1.8 1.6 1.4 1.3 1.1 1.1 I I I 2 I 85.4 25.0 I 14.6 I 10.5 8.2 6.7 5.7 4.9 4.4 3.9 3.5 3.2 I I I31 75.0 I 29.6 L 19.4 14.6 11.8 9.9 8.5 7.5 6.7 6.0 5.5 I I I41 93.3 I 70.4 I 32.3 22.6 17.7 14.6 12.5 10.9 9.7 8.7 7.9 I I I51 I 85.4 I 67.7 34.2 25.0 20.1 16.9 14.6 12.9 11.6 10.5 I 161 ;1 95.6 1 80.6 65.8 35.6 26.9 22.0 18.8 16.5 14.6 13.2 le1 '1 I 89.5 77.4 64.4 36.6 28.3 23.6 20.4 18.0 16.1 Irl 81 I 96.8 85.5 75.0 63.4 37.5 29.6 25.0 21.8 19.4 O1 91 91.8 82.3 73.1 62.5 38.2 30.6 26.2 23.0 97.4 88.2 79.9 71.7 61.8 38.8 31.5 27.2 93.3 85.4 78.0 70.4 61.2 39.3 32.3 97.9 90.1 83.1 76.4 69.4 60.7 39.8 94.3 87.5 81.2 75.0 68.5 60.2 98.2 91.5 85.4 79.6 73.8 67.7 95.1 89.1 83.5 78.2 72.8 98.4 92.5 87.1 82.0 77.0 95.6 90.3 88.4 80.6 98.6 93.3 88.4 83.9 96.1 91.3 86.8 98.7 94.0 89.5 96.5 92.1 90.9 94.5 96.8 98.9 49 Bv. 2 Sampling Procedures The evaluation of heavy metal emissions evaluation can be carried out by measuring their concentrations in the emitted particles and condensed fractions. In some cases, the presence of pollutants in vapour form (mercury, antimony trichloride etc.) makes a sampling method identical to the one used when gaseous pollutants have to be sampled compulsory. In practice, there are not any direct measurement methods, and this means that heavy metals determination must be carried out using a previously taken sample. Bv.2.1 Sampling of Gaeeoue Pollutants There are many types of devices for sampling gaseous pollutants. Some of them are shown in Figure BV(i) . The oDeration of these devices and their comDonents does ;lot pose any difficulties (Brenchley, Dejorkin, US-EPA 1971(e)). Figure BV(..j) shows a US-EPA sampling train, also shown in Figure BV(i) as 'EPA Absorption Train'. This device is used in the US-EPA Method no. 6 for sampling SO2 emissions. This device can be used for the absorption of volatile, gaseous or vapourous pollutants such as Hg, SbC13, AsH3 etc. In spite of the fact that many of these pollutants are retained by cold water without any difficulty, in some cases e.g. mercury, oxidant compounds, contained in the three last impingers, should be used. It is also convenient to have hydrogen peroxide in the first impinger in order to prevent the interferent action of 502, if present, over the other reagents (NATO-CCMS). Bv.2.2 Sampling of Particulate Pollutants Most heavy metals emissions are formed by powdered solid materials and/or aerosols. Figure BV(k) shows some of the most widely used devices for particulate matter sampling from a gaseous stream (Dejorkin, US-EPA 1971f, ASTM 1978, Karels). The main sampling procedures for particulate matter are :

'0 US-EPA Method no. 5: This device is shown in Fi- gure BV(1). Its operation does not present difficulties (US-EPA 1971(f)) and also suitable reagents intended to absorb gaseous or vapour pollutants can be introduced in the impingers. This allows this method to be used for every kind of emission. 50

0 Other Methods: There are other methods for particulate matter sampling, which have been compiled in the specialised literature (NATO-CCMS). The main interest of those procedures is the possibi- ~ lity of obtaining information on the granulome- -~ tric distribution of particles. BS 3405 : 1983 shows a simplified method, similar to EPA no. 5. BV.2.3 Components of Sampling Devices __ As shown in Figures BV(i), (j), (k), and BV(l), a sampling device consists of several instruments. Every one of them has its own specific function. The operation of those instruments (thermometers, manometers etc.) is described in many handbooks and specialised publications, e.g. Brenchley, BS 3405 : 1983). BV.2.4 Absorption of Pollutants

0 Solid Particle Pollutants: Sampling solid pollutants does not offer any difficulty, because if the filter has a suitable porosity, they will be retained over the surface of the filtering materials (see Figures BV(k) and BV(1). The fibre glass media used as a filter is required to be at least 99.7 % efficient for 0.3 microns dioctyl phtalate particles (Brenchley). However, if analytical interferences are not expected, paper filters or other materials can be used (Kolthoff et a1 1971). In any case, it is advisable to carry out a blank assay using a "virgin" filter.

0 Gaseous or Vapourised Pollutants: Some of the elements considered produce or may produce volatile or gaseous compounds which are not retained by filters. That is why they have to be absorbed by means of a suitable reagent, contained in the impingers of the sampling devices. Generally an acid and/or an oxidant solution is used as an absorption reagent. When the gaseous effluent contains aerosols, a filter is not a good retention material because once the filter has been "moistened" by the aero- sol, it is transformed into a source of micro- drops because of the dragging effect originated by the gas crossing through it. This makes it compulsory to analyse not only the filter but also the solution in the impingers. 51 Bv. 3 Determination of Pollutante The selection of an analytical method depends on many factors, accuracy and reliability being the most relevant. Both factors must keep an equilibrium with economic and operational factors. From a technical and methodological point of view, the available analytical methods can be classified as:

0 Non-instrumental methods: They are the basis of conventional chemical analysis and are based o# procedures like gravimetry and volumetry. Because they are slow and laborious, these methods are not used very often nowadays. However, they are used on some occasions due to technical and economic reasons.

0 Instrumental methodsr These methods are based on a physical property of the element to be dealt. with, and on the fact that this property depends mathematically on the concentration of the element. Due to the progressive implementation of these methods, and to their reliability, in this report only these kinds of techniques will be considered. There are a large number of these techniques, which are applicable to the determination of the pollutants which are the subject of this report. Many of them are listed in the specialised literature (NATO-CCMS). In spite of the fact that all these techniques may be used for the determination of pollutants, Atomic Absorption Spectrophotometry (AAS) is al- most the only one that we propose in this report, due to its reliability and to the positive economic factors associated with it (for example, seC Verein Deutscher Ingenieure, VDI Richtlinien 2268, Blatt 1/2/3). BV.3.1 Antimony Sampling particulate matter, forming part of a gaseous stream, can be carried out by means of a filter paper and/or an impinger. Stibine can be absorbed in an impinger containing a 6% aqueous solution of mercuric chloride. Antimony can be oxidised to the pentavalent state by means of ceric sulphate and then be evaluated using the technique which is described below. 52

Figure BV(i) x Devices for Sampling Gaseous Pollutants at Source

a.-LA APCD Absorption Train

3 1

6 4 1 9 10

be-EPA Absorption Train

4 6 c.-EPA Grab Sampling Train

1.-Probe 7. -Valve 2.-Pilter 8.-Pump 3.-Thermometer 9.-Gas Drier Column 4:-Wet Collector 10.-Gas Flow Rate Meter S.-Manometer 11.-3-Way Valve 6.-Total Volume Gas Meter 12.-2-Way Valve 13.-Purge Bulb 53

Figure Bv( j 1 : Gaseous Pollutants Sampling Device (U.S - EPA)

1.-Probe, (end packed with 7.-Silicea Gel Drying Tube quartz or Pyrex wool) 8. -Pump 2.-Type S Pilot Tube 9.-Needle Valve 3.-Stack Wall 10.-Rotameter 4.-Pilot Manometer 11.-Thermometer 5.-Glas Wool 12.-Dry Gas Meter 6.-Impingers 13.-Ice Bath 54

Figure BV(k)r Source Sampling Trains for Particulate Matter

1. -Nozzle 1 5.-In-stack filter 3. -Probe a.-Joy WO-50 Particulate Train 4.-Condenser S:-Thermometer 6. -Valve 7.-Total volume gas meter 8. -Pump 1' 11 L+/+HT* 9.-Wet collector 10.-Dry collector 11.-Manometer 12.-Condenser and drier column b.-LA APCD Particulate Train 13.-Gas flow rate meter 14.-Vacuum gage ss - 1

c.-EPA Particulate Train

d.-ASTM Particulate Train

e.-SF APCD Particulate Train 55

Figure BV(1): Sampling Train for Particulate Matter (EPA Method 5)

I ¶

1. -Probe 9.-Thermometer 2.-Reverse type Pilot tube 10.-Check Valve 3.-Stack wall 11.-Vacuum line 4.-Pilot manometer 12.-Vacuum gauge 5.-Heated area 13. -Valve 6.-Filter holder 14. -Pump 7.-Impingers 15.-Dry test meter 8.-Ice bath 16.-Orifice 56 The method is based on leaching the sample with a mixture of nitric and hydrochloric acids, adjusting the acidity, suitable dilution and measurement of the atomic absorption at a wavelength of 217.58 nm if lead is not present or at 231.15 nm if lead is present. Standards are prepared from pure antimony-potassium tartrate. In some cases, other methods intended to dissolve the sample, have to be used (Kolthof et al. 1988). When the antimony content is lower than 0.05 %, it is necessary to use more sensitive techniques, such as Atomic Absorption Spectrophotometry combined with Hy- dride Generation, which allows a detection limit of 0.005 micrograms, (Kolthoff & a. 1988) to be reached. Sample preparation can be carried out as it has been described above, but in order to avoid interferences, standards and samples must be prepared in a similar way, and the final solutions must have a similar chemical composition. Bv.3.2 Arsenic Arsenic (and its oxidised derivatives), dust and mist can be collected by means of the usual sampling methods. In order to absorb arsine, one or more impingers containing an oxidising agent (e.g. potassium permanganate) must be used. The simplest method is based on the spectrophotometric determination of arsenic, with previous arsine absorption with silver diethyldithiocarbonate, at a wavelength of 540 nm, this can be used for the determination of arsenic contents in the range of 1-20 micrograms (Kolthoff 1988, ISO). Because other elements may interfere, it is advisable to isolate arsenic. The most usual method is based on the distillation of arsenic tribromide or trichloride. Arsenic can be determined by using Atomic Absorption Spectrophotometry, combined with hydride generation, but in many cases, it is advisable to previously isolate arsenic by distillation. Bv.3.3 Beryllium Samples can be taken using filter paper, fibre-glass filters and millipore filters. Beryllium determination by Atomic Absorption Spectro- photometry at the wavelength of 234.9 nm does not present difficulties (Hertz). Other associated techniques 57 (graphite furnace) can be used with better detection limits (Owens). Bv.3.4 Cadmium Samples can be taken using filter paper, fibre-glass filters and millipore filters. Sample solubilisation depends on its chemical composition, but generally it consists of acid leaching. There are several methods for cadmium determination; the most widespread procedures are those based on Atomic Absorption Spectrophotometry. BV.3.5 chrrmlium Chromium and its derivatives can be collected by means of the usual sampling methods. There are several methods for chromium determination; the most widespread procedures are those based on Atomic Absorption Spec- trophotometry. Bv.3.6 Copper and its derivatives can be collected by means of the usual sampling methods. There are severdl methods for copper determination; the most widespread procedures are those based on Atomic Absorption Spectrophotometry. Bv.3.7 Lead Lead and its derivatives can be collected by means of the usual sampling methods. However, it is necessary to note that only one impinger alone cannot totally absorb lead fumes. Therefore, at least two impingers are needed. Samples are dissolved in acids, and lead can be determined by Atomic Absorption Spectrophoto- metry. Bv.3.8 Manganeee Samples can be taken using impingers, filter paper, fibre-glass filters and millipore filters. There are several methods for manganese determination; the most widespread procedures are those based on Atomic Ab- sorption Spectrophotometry. BV.3.9 Mercury Mercury determination is one of the most complex analyses. If mercury is present as a vapour, the procedure is based on absorbing it in an oxidant solution, and determining the mercury content by means of the technique known as "Cold Vapour Atomic Absorption Spectrophotometry" (NATO-CCMS). 58 If mercury is contained in particulate matter it must be dissolved, but this operation has to be carried out very carefully in order to avoid losses due to volati-

lisation, preferably by means of a pressure device. ~ When solubilisation has finished, the mercury content -~ can be evaluated by measuring the atomic absorption of its cold vapour. BV.3.10 Nickel Samples can be taken using impingers, filter paper, fibre-glass filters and millipore filters. There are several methods for nickel determination; the most widespread procedures are those based on Atomic Ab- sorption Spectrophotometry. BV.3.11 Selenium Fumes and dusts can be taken using impingers, filter paper, fibre-glass filters and millipore filters. Se- lenium hydride requires an impinger containing an oxidising agent such as aqueous solutions of iodine or bromine. The measurement can be carried out by Flame or Hydride Generation Atomic Absorption Spectrophoto- metry. BV.3.12 Thallium Dusts and mists containing thallium can be collected by means of the usual sampling methods for particulate matter. There are several methods for thallium determination; the most widespread procedures are those based on Atomic Absorption Spectrophotometry, combined with the Zeeman system and/or graphite furnace (Grognard a1 1985). BV.3.13 Vanadium Samples containing vanadium can be taken with an impinger containing a 10 % nitric acid solution. Vana- dium can be determined by Atomic Absorption Spectro- photometry. Solid samples can also be analysed by means of the usual methods for ores and concentrates (Roy et a1 1984). BV .3.14 Tin Samples can be taken using impingers, filter paper, fibre-glass filters and millipore filters. There are several methods for tin determination; the most widespread procedures for tin contents in the range of 50 ppp to 1 % are those based on Atomic Absorption Spec- trophotometry (Meusik et a1 1974). For lower concentrations, Hydride Generation is suitable. 59 Bv. 4 Continuoue Monitoring As stated in chapter V.2, there are usually no direct measuring methods for heavy metal emissions. However, in some cases continuous monitoring can be carried out, and quantitative or semi-quantitative results can be obtained. When a pollutant flows through a duct, it is possible to establish important differences in the physical properties of the gaseous stream, depending on the concentration of the pollutant. For example, in the case of a gaseous stream acting as a carrier of a single pollutant (e.g. metal fumes), depending on the concentration of fumes, a variation in the optical properties of the gaseous stream will be produced (e.g. opacity, refractive index, absorption of elec- tromagnetic radiation, etc.). Therefore it is possible to establish a correlation between the physical properties of the carrier gas and the concentration of the pollutant. One of the most widely used procedures for mercury determination consists of measuring the absorption produced by a gaseous stream when a W light beam produced by a mercury vapour lamp crosses it. This method has reduced credibility since all mercury has to be in the form of elemental vapour. Other pollutants, such as sulphur dioxide, must be removed before the measurement because they produce interference. Another limitation of these kinds of procedures is that one must be sure that the pollutant is always present in the same chemical and/or physical form; otherwise errors will be produced. Furthermore, all these methods require frequent cali- bration, using conventional discontinuous procedures, and therefore this means duplicate equipment. However, they can at least be used as semi-quantitative monitoring systems for routine controls. Bv.5 Fugitive wssione Fugitive emissions cannot be absolutely measured. The only possible approach consists of measuring the pollutant concentration in the environment. In order to do this, methods described in V.2 can be used, taking into account that gas flow and velocity mea-surments are neither necessary nor possible. The analytical methods will be those described in chapter V.3, but larger sampling times and/or more sensitive analytical procedures should be used. 60 BVI ASTM (1978). Test Method for Particulates Indepen-

dently or for Particulates and collected Residue ~ Simultaneously in Stack Gases. ASTM D 3685-78 -~ ASTM (1980). Standard Test for Total Mercury in Water. ASTM D 3223-80 Brenchely, D.L., Turley, C.D and Yarmac, R.F. (1973). Industrial Source Sampling. Ann Arbor Science Publi- shers. Ann Arbor, Michigan British Standards Institution (1983). British Standard Method for Measuring of Particulate Emission Including Grit and Dust (Simplified Method). BS 3405 : 1983 Dejorkin, H. et al. (1965). Source Testing Manual. Los Angeles Country Air Pollution Control District , LOB Angeles, California Grognard, M., Piolin, M. (1985). Acid Pretreatment- Fusion Method for Determination of Thallium in City Waste Incineration Fly Ash by Zeeman Atomic Absorption Spectrometry. At. Spect. Vol. 6, no. 5, pp 142-143 Hertz, R.K. (1987). General Analytical Chemistry of Beryllium. Chemical Analysis of Metals. pp. 77, 81, 82, Francis T. Coyle (ed.), ASTM STP 944, Baltimore International Organization for Standardisation (ISO). Norme Internationale IS0 2590. Methode generale de dosage de l'arsenic - Methode photometrique au diethyldithiocarbanate d'argent. Karels, G.C. (1971). Improved Sampling Method Reduces Isokinetic Sampling Errors. 12th Methods Conference in Air Pollution and Industrial Hygiene Studies. University of Southern California. Los Angeles (Cal.), April 6-8, 1971 Kolthoff, I.M., Elving, P.J. and Strass, F.H. (1971). Treatise on Analytical Chemistry. Part 111, Vo1.2, Section B "Industrial Toxicologic and Environmental Pollution and its Control", pp. 75-105. John Willey Sons, Inc., New York - Kolthoff, I.M., Elving, P.J. (1978). Treatise on Analytical Chemistry. Part 11, Vol. 10, pp. 312, 324, 325, 328, 329. John Willey Sons, Inc., New York Mensik, J.D., Siedemann, H.J. (1974). Determination of Tin in Mineralised Rocks and Ores by Atomic Absorption Spectrophotometry. At. Absorption Newslett. Vol. 13, no. 1, pp 8-10 61 Ministerio de Industria (1976). Orden de 18 de Octubre de 1976 sobre Prevencion y Correccion de la Contamina- cion Industrial de la Atmosfera. BOE no. 290, 3 de Diciembre de 1976 (Spain) NATO-CCMS (1983). Air Pollution Control of Heavy Metal Emissions from Stationary Sources. Committee on the Challenges of Modern Society. No. 144, Chapter 3 Owens, J.W., Gladney, E.S. (1975). Determination of Beryllium in Environmental Materials by Flameless Atomic Absorption Spectroscopy. At. Absorption Newslett. Vol. 14, no. 4, pp. 76-77 Roy, N.K., De, D.K., Das, A.K. (1984). Determination of Trace Levels of Vanadium in Chrome Ores by Chelate Extraction Atomic Absorption Spectrometry. At. Spect. Vol. 5, no. 3, pp 126-128 US-EPA (1971a). Standards of Performance for New Stationary Sources. Method no. 1. Federal Register, Vol. 36, no. 247, December 23, 1971 (USA) US-EPA (1971b). Standards of Performance for New Stationary Sources. Method no. 2. Federal Register, Vol. 36, no. 247, December 23, 1971 (USA) US-EPA (1971~). Standards of Performance for New Stationary Sources. Method no. 3. Federal Register, Vol. 36, no. 247, December 23, 1971 (USA) US-EPA (1971d). Standards of Performance for New Stationary Sources. Method no. 4. Federal Register, Vol. 36, no. 247, December 23, 1971 (USA) . US-EPA (1971e). Standards of Performance for New Stationary Sources. Method no. 5. Federal Register, Vol. 36, no. 247, December 23, 1971 (USA) US-EPA (1971f). Standards of Performance for New Stationary Sources. Method no. 6. Federal Register, Vol. 36, no. 247, December 23, 1971 (USA) Verein Deutscher Ingenieure (1987). Chemical Analysis of Particulate Matter. Determination of Ea, Be, Cd, - Cor Cr, Cu, Ni, Pb, Sr, V, Zn in Particulate Emissions by Atomic Spectrometric Methods. VDI 2268, Part 1

Verein Deutscher Ingenieure (1987). Chemical Analysis ~ of Particulate Matter. Determination of Arsenic, Antimony and Selenium in Dust Emissions by Atomic Absorption Spectrometry after Separation of their Volatile Hydrides. MI 2268, Part 2 62 Verein Deutscher Ingenieure (1988). Chemical Analysis of Particulate Matter. Determination of Thallium in Particulate Emissions by Atomic Spectrometry. VDI 2268, Part 3 63 PART C: COIVSIDgRATIONS WITH REGARD TO PARTICULAR PROCESSES

CI Introduction This part of the Technical Note deals with air pollution problems associated with lead, copper, zinc and tin works. The production of these four metals, and of nickel, is considered to be the most relevant source of heavy metal pollution from the sector in the Comu- nity. Unfortunately, nickel works could not be included in this note. Every effort has been made to describe properly the best available technology for the various processes contained in this technical note. However, the reader is advised to establish with any stated technology with particular interest, that it is commercially available and has demonstrated under normal working conditions processing the various materials intended by the use of appropriate assessments of recognized performance criteria, its reliability, consistency of environmental performance and the economic factors involved at its operated capacity.

CII Lead Worka CII .1 Primary Lead CII. 1.1 Introduction World consumption of refined lead amounts to about 5.6 million metric tonnes of which about 2.2 million metric tonnes derives from secondary sources. About 27 % or 1.5 million metric tonnes from the figure mentioned above are produced in the EEC, representing about 04 % of total production in Western Europe. In the past, the lead smelting industry ha8 improved its technology not only with regard to profitability but also in the reduction of heavy metal emissions. In the following sections, problems associated with the production of lead are outlined, as well as the BAT to prevent or reduce air pollution. CII.1.2 BAT €or Traditional Plants Primary lead production is traditionally to be under- stood as the production of lead from lead concentrates but today so called primary lead smelters also treat different types of secondary materials to a certain extent. 64 The process route is based on sintering, reduction of sinter in a shaft furnace and refining of bullion from which the latter can be carried out pyrometallurgical- ly or hydrometallurgically. CII. 1.2.1 BAT for Sintering Dust emissions associated with discharging, handling and stockpiling of raw materials or by-products can be reduced by displacing the activities mentioned above in completelyenclosed buildings whichmay be equipped with ventilation and dedusting facilities, spray systems or other suitable controls. When stockpiling in unroofed areas the material stockpile surface should covered by lime solution spray or other protecting liquids, forming a thin layer after binding has been completed. Stockpiling areas and roads have to be kept clean by using a sweeping machine and should be kept wet to reduce dust emissions. Conveying and charge preparating systems should be covered with specially designed hoods to collect dust emissions, ventilating off-gas containing dust should be cleaned in fabric filter units, and buildings should be equipped with vacuum floor cleaning systems.

0 Downdraft Sintering: Downdraft sintering is not "state of the art" technology due to the weak off gas produced which is unsuitable for sulphuric acid production. If downdraft is still used it should operate with recycling of weak gas to ensure a strong gas with an SO concentration of more than 4 % suitable for SA2 conversion in a sulphuric acid plant.

0 Updraft Sintering: Due to the updraft system and the reduced volume of air leakage, a higher concentrated strong gas is produced, but nevertheless weak gas is also present in updraft sintering in the rear part of the machine, containing SO2 at about 1 % concentration. By recirculating the emissions of SO2 the production of weak gas can be avoided. The updraft sinter technique has become accepted sinter technology and replaced most of the downdraft machines. The advantages of the updraft technique include: - the production of higher concentrated strong gas - a smaller volume of off-gas - the possibility for treating a high lead bearing charge 65 - higher throughput - improved sinter quality In sinter plants, conveying systems and material handling machinery are covered by hoods and ventilated to avoid dust emissions. The off-gas is cleaned in fabric bag filter units to less than 10 mg/q3 dust content. Off-gas from return sinter cooling is dedusted in wet systems or in bag filters requiring a gas temperature of more than 100°C to avoid condensation of water vapour . Strong gas from sinter machines is cleaned in hot electrostatic precipitators followed by an additional cleaning step in a wet electrostatic pre- cipitating system preparing the strong gas for utilisation in a sulphuric acid plant. All recovered dusts are recycled to the charge preparation plant by closed conveyors. Ey automatic control of the pressure inside the sinter machine gas collecting system respirable dust emissions can be avoided. CII. 1 .2.2 RAT for Lead Bullion Production in Shaft Furnace All feeding systems are covered with hoods and are ventilated. Prom tapholes and launders fumes and dust are collected by hoods which are ventilated via bag filter fans. The shaft furnace off-gas is cooled by the additon of air, water sprays or indirect cooling before dedusting in bag filter units. Waste gas collecting is carried out at the furnace top by hoods located in the centre- line of the upper shaft or by closed top constructions in combination with waste gas dusts leaving the furnace shaft at the front end shaft side underneath the top construction. Dust recovery is carried out in bag filters using fi- brous filtering material by which low dust contents in cleaned gas can be achieved. Moist waste gas from slag granulation is cleaned by a wet electrostatic precipitator to a dust content of less than 10 mg/mN. The high performance of the shaft furnace enables a lead smelter with a lead capacity between 100 000 and 200 000 tons per year to produce lead bullion with only one furnace leading to an overall reduction of the volume of off-gas in comparison with a two-furnace operation. 66 Vacuum systems have to be provided in buildings for floor cleaning.

0 Dedrossing / Decopperisingr Dedrossing and decop- ~

perising can be carried out in batches or conti- ~~ nuously in kettles producing dry drosses. The kettles are covered with ventilated hoods and the dross can be removed by mechanical or vacuum ~- dross removal equipment usually integrated into the hood. Continuous dedrossing is possible for some specific bullion compositions by using a specially designed reverberatory furnace combining dedrossing and dross remelting €or matte formation. Furnace off gas and kettle ventilation waste gas from charging, drossing, tapping and launder areas are sent to bag filters for dust removal. Under these conditions it is possible to minimise gas volumes from decopperising and dross treatment. CII. 1.2.3 BAT for the Boliden Electric Furnace Process This process comprises roasting and reduction in one unit and requires high grade lead concentrates for direct conversion to lead bullion, which contains a percentage of sulphur requiring desulphurisation in a converter. The lead level of the slag is higher than in shaft furnace slags. Energy cost is the dominant factor influencing the profitability of this process. Concentrates and fluxes have to be dried prior to treatment. Conveying systems and bins are covered with ventilated hoods or completely closed conveyors are used. The dryer off gas is cleaned in a filtering unit. The electric furnace top is covered by a big hood of the dimensions of the furnace that collects leakage gas from electrodes and the furnace arch which is cleaned in bag filters. Tapping areas and launders are also provided with hoods €or dust and fume collection, connected to a bag - filter. Furnace off-gas is cleaned in a waste heat boiler and electrostatic precipitator prior to SO2 conversion. Waste gas from the converter for lead bullion desulphurisation is collected and cleaned in bag filters but conversion of SO2 needs an overdimensioned sulphuric acid plant due to the low SO, concentration in converter off-gas and the changing volumes. 61 CII. 1.2.4 BAT for Refining CII.1.2.4.1 Pyrometallurgical Refining

0 Final Decopperieingr Final decopperising is carried out in batches or continuously in kettles by addition of elemental sulphur or sulphur/pyrite mixtures. The kettles are covered with hoods connected to a ventilation system via a filtering unit in order to collect all generated dust. For dross removal vacuum systems or different types of machines are used which are integrated into the hood construction to ensure dust-free dross recovery.

0 Softening: Softening comprises oxidation and the removal of antimony, arsenic and tin. Today, four processes are generally available, carrying out softening in a reverberatory furnace (continuous or in batches), in kettles by oxygen injection via a lance respirator by addition of caustic soda and sodium nitrate in a batch operation or using a melt formed from caustic soda and an oxidising agent such as sodium nitrate, held in a special reaction tank inserted in the kettle. Lead is pumped in batches through the salt melt recovering the impurities. (Harris process).

0 Reverberatory Proceeer The furnace itself and the lead tapping area respiratory launders are connected to a dedusting filter. Dosing and holding kettles are covered with ventilated hoods. Drosses formed on the lead bath in these kettles are removed from time to time by mechanical devices. Antimonial slag from the furnace flows into pots which are located adjacent to the taphole launder under a ventilated hood. After slag solidifica- tion pots are emptied by a special fork lift for further treatment. Depending on the capacity of the refinery and the Sb/As content of the bullion in the batches, softening in a reverberatory furnace requires more than one furnace leading to higher total off-gas volumes in comparison to continuous softening, which can handle large quantities of lead bullion with only one furnace, as the oxidation rate is about ten times higher than during batch operation. On the basis of a certain quantity of lead bullion and concentration of antimony, arsenic and tin continuous softening has greater advan- 68 tages also due to the reduced volume of off gas and emissions (15 000 - 20 000 q3/h per furnace ) .

~ 0 Oxygen Softening: Oxygen softening is a more simple method which can be carried out continu- - ously or in batches in a normal kettle covered with a ventilated hood. The volume of off gas is much lower than from a reverberatory furnace. The __ Sb content in slag runs about double of that in slags from continuous reverberatory softening reducing the campaign length of antimonial slag treatment. In spite of the high specific oxidation rate total softening capacity per kettle unit is lower than in continuous reverberatory softening due to the small reaction surface area of the reaction cylinder. Depending on the desired capacity, two softening kettles may be necessary. But even with two units off-gas volume is significantly lower in comparison to continuous reverberatory softening (3000 - 5000 m,,3/h per unit).

0 Caustic Soda Kettle Refining: The refining kettle is covered with a ventilated hood while dross is removed by mechanical or vacuum devices which are integrated into the hood construction. As softening capacity is low this process is not suitable for big lead smelters.

0 Harris Proceee: Due to the salt melt used for the oxidation of impurities dust emission does not occur from this step.

0 Deailvering: As the scum formed during desilvering consists of intermetallic crystals with entrained lead dust is not generated and therefore kettle ventilation is not necessary. o Deaincingt Dezincing takes place in a kettle with a water cooled cover which ensures a high vacuum above the distillation surface. During operation emissions are negligible. Dust is not formed in this step.

0 Removal of Bismuth: Prior to the removal of bismuth step cleaning of the lead from impurities like zinc, antimony etc. has to be carried out by oxidation. A covered ventilated kettle is used. Dross formed during operation can be removed by mechanical devices or by vacuum removing systems. The removal of bismuth itself is similar to desilvering but the reaction between calcium and magnesium with molten lead at the beginning of 69 the procedure generates dust which is collected by a ventilated hood. o Finishing: The final refining step prior to casting is an oxidation of the rest of impurities i.e. zinc, antimony etc. The kettle is covered by a ventilated hood with an integrated mechanical or vacuum system for dross removal.

CII.l.2.4.2 Hydrometallurgical Refining The economic advantage of hydrometallurgical refining depends on the tonnage of lead to be treated, the bismuth content of the lead and the level of energy costs. After decopperising, anode casting takes place with special casting machines, while cathode starting sheets are produced from refined lead by different methods. Dust is not generated in the cell house. How- ever, this clean technology is not of interest in the majority of smelters due to the higher costs associated with it. Anode slimes have to be treated pyrome- tallurgically in smaller units (see chapter CII.1.4). CII. 1.3 New Lead Smelting Technologies (Direct Smelting Technologies) During the last 20 years several new pyrometallurgical lead smelting processes have been proposed to replace sinter plant and shaft furnace operations. Some of them are now in a pilot stage or in industrial development or operation. All of them operate in two steps: a smelting and a reduction step. The initial aim of these processes was to follow the routes progressively developed for copper smelting, where the heat generated by the roasting of the sulphide raw materials is now used in most processes to smelt the charge in one single stage (autogenous smelting). Environmental control of emissions has also become a key aim of the new lead smelting technology and the direct autogenous smelting processes will probably be considered "state of the art" in future. These processes also claim to offer energy, investment and operating cost savings over traditional smelting technology. All these advantages are now at a of demonstration stage for some of these proposed processes. Raw material stockpiling, charge preparation, SO2 conversion, lead bullion refining and by-product treatment have to be carried out by unchanged established technologies. In the following sections, only the new part of the proposed smelting technologies and their 70 present state of the development are described, the above mentioned unchanged areas being omitted.

It is important to note the information given in the ~ following section with regard to the demonstration of the full industrial capabilities of the new lead ~~ smelting technologies. CII.1.3.1 KiVCet PrOCeBB __ This process has been in operation at an industrial scale at one European plant since 1987 (capacity 84 000 t/year), where it is used according to the following technology. The feeding and discharging area of the feed dryer respirator and the dryer itself are ventilated and the waste gas is cleaned in bag filters. Closed or pneumatic systems are used for conveying the dry feed. Bins are connected to filter units. Process gas from the reaction shaft is cleaned after passing a waste heat boiler in a hot electrostatic precipitator and in a wet electrostatic precipitator and then sent to the sulphuric acid plant. Dust is recycled in closed conveyors to the reaction shaft burner. Primary lead and prereduced primary slag formed in the reaction shaft flow into the electrothermic part of the Kivcet furnace where final reduction of slag takes place. Electric furnace off gas contains vapourised metals mainly in oxide form which are recovered in bag filters after cooling. This dust can be recycled to the reaction shaft in closed conveyors or sent to a zinc smelter. Slag and lead bullion tapping areas are covered with ventilated hoods. Waste gas from slag granulation is cleaned in wet gas cleaning units while lead tapping off gas including launder ventilating gas is cleaned in bag filters. Buildings are equipped with vacuum floor cleaning systems. Information released by the company developing the process in Europe enables us to conclude that the performances are promising and that demonstration of the full capabilities of the process should be possible in the near future. - CII.1.3.2 Boliden (Top Blown Rotary Converter) Proceee This process is in operation in one European plant. The scale is industrial but the furnace operates as a - complement to the Boliden Electric Furnace Process and the smelting of lead concentrates has actually only taken place in pilot tests. The company developing the process intends to apply it now for its full production of lead. The technology is described as follows. I1 Dry feed is injected by compressed air and oxygen through a lance into the tiltable and rotating Kaldo- furnace. Roasting and reducing reactions take place during batch fed operation in two separate steps. Furnace of€ gas is cleaned in hot and wet electrostatic precipitators or in venturi scrubbers before entering the SO2 conversion plant. Dust is recycled to the furnace in closed conveying systems. The furnace itself is located in a large ventilated hood in which furnace tilting and pouring of lead bullion and slag into large pots occurs. Slag granulation is carried out in covered granulating facilities ventilated by bag filters where dry fumes are generated and by wet cleaning systems where moist waste gas is produced. Information released about the process enables us to conclude that the trials are promising enough to permit the use of the installation at full industrial scale. Information about this operation will probably become available soon if demonstration of the full capabilities of the process can be achieved within an acceptable period of time. CII .1.3.3 Outakumpu Praceee This process has been operated at a pilot scale for a limited period. The technology is described as follows : Dry feed is fed into the flash furnace, via a special burner with oxygen by closed and ventilated conveying systems. Waste gas from the flash furnace enters a waste head boiler and a hot electrostatic precipitator. After waste gas cooling and final cleaning in a wet electrostatic precipitator gas is sent to the SO2 conversion plant. Dust is recycled in closed conveying systems to the flash furnace. The primary lead and slag tapping area at the flash furnace settler is covered with ventilated hoods, and connected to heated and closed launders leading to the electric furnace where slag cleaning by powdered coal takes place. Furnace off gas contains vapourised metals mainly in oxide form which are sent to a bag filter after cooling for dust recovery. Electric furnace dust can be recycled to the flash furnace in closed conveying systems or sent to a zinc smelter. Lead bullion and slag tapping areas are covered with ventilated hoods. Waste gas from this part 12 of the electric furnace is cleaned in bag filters. Moist off-gas from slag granulation is sent to Wet cleaning systems. Buildings are equipped with vacuum floor cleaning systems. - - From the information released by the company developing the process performances at pilot scale were promising enough for preparing it for industrial application. Considering the process as an alternative avail- ~__ able technology, the Outokumpu process has not yet been adapted for operation at an industrial scale. CII.1.3.4 Q8L Process This process has been operated for a limited period at pilot scale and several industrial plants are under construction, some of them due to start operation in the near future, of which one is in Europe. The technology is described as follows: Feed drying is not necessary. Moist feed is transported from the charge preparation plant by covered or closed and ventilated conveyors to a ventilated nodu- liser and then to the feeding area of the horizontal longitudinal QSL vessel. Conveyors and feeding area are covered with ventilated hoods. The QSL furnace can be equipped with one or two waste gas uptakes leaving the furnace at the oxidising zone or at the oxidising and reduction zone. Strong gas from the oxidising zone is cleaned after passing a waste heat boiler in hot and wet electrostatic precipitators and sent to SO2 conversion. Reduc- tion zone waste gas can be mixed either with the oxidation zone waste gas or can be removed from the furnace via a separate uptake leading to a gas cooler and to a bag filter. Dust from oxidation zone waste gas cleaning is recycled by closed conveyors to the charge preparation plant. Dust from reduction zone waste gas can be sent to a zinc smelter. Lead bullion and slag tapping areas and launders are covered with ventilated hoods connected to a bag filter. Buildings are equipped with vacuum floor cleaning units. - Information released by the company developing the process enables us to conclude that the performances at pilot scale were promising enough to permit the construction of industrial plants. Information on their operation will soon become available although the demonstration of the full capabilities of the process at an industrial scale will take some time. 73 CII.1.3.5 Isaemelt Process The first step in the process is operated in one Australian plant at semi-industrial scale of limited capacity as a complement to the main sintering-shaft furnace circuit. According to the available information, pilot tests of the second step of the process have been carried out in an additional vessel using both batch fed and continuous feeding. The company developing the process has decided to increase its application by building a new industrial facility of 60 000 tons per year lead bullion capacity, which will still operate in complement to the main sintering-shaft furnace circuit. The technology of the process is described as follows. Drying of feed is not necessary. Moist feed is fed into the vertical and cylindrical reaction vessel. Waste gas is sent to a waste heat boiler and is afterwards cleaned in hot and wet electrostatic precipitators prior to SO2 conversion. Dust is recycled by closed conveyors to the reaction vessel. Primary slag from the first reaction vessel is continuously tapped into a second vessel where reduction is carried out. Waste gas from the reduction vessel passes a waste heat boiler and is cleaned in a bag filter. Dust is recycled by closed conveyor to the first vessel or sent to a zinc smelter. Feeding and tapping areas are covered with ventilated hoods. Buildings are equipped with vacuum floor cleaning systems. Information released about the process enables us to conclude that the test performances are promising enough to increase the application of the process at an industrial scale. The new plant will operate in two full steps. After the completion of construction, the demonstration of the full capabilities of the entire two step process will probably require several years. CII. 1.4 Treatment of By-Products CII. 1.4.1 Copper Dross Copper-containing droases are treated in reverberatory furnaces, short rotary furnaces, blast furnaces or electric furnaces. Stockpiling should take place in a closed building adjacent to the furnace area. Feeding is carried out by conveyors or by front end loaders and special fork lifts with boxes. Conveying feeding systems and the feeding area of the furnace area should be protected against dust emission by ventilated hoods. The furnace tapping area should also be equipped with ventilated, 14 sometimes moveable hoods for efficient capture of dust and fumes.

Furnace waste gas is normally mixed with the off-gas ~ from the feeding and tapping area to quench the tem- -~ perature prior to final cooling and cleaning in a bag filter. Pressure control of the furnace and adequate dimensioning of gas volume for ventilation of auxili- ary equipment should avoid uncontrolled dust emis- __ sions . Floors inside the building should be kept clean by sweeping machines and/or other vacuum cleaning systems. C11.1.4.2 Antimonial Slag This material can be processed to antimonial bullion by reduction in a short rotary furnace, a rotary kiln or in a shaft furnace. See chapters for measures for reducing dust emissions CII.1.4.1 and CII.1.2.2. CII.1.4.3 Salt Slage from the Harris Proceae Granulation of salt slag and the concentration of sodium hydroxide containing solution by evaporation is carried out in facilities or tanks covered with hoods. The water vapour is released to the atmosphere after passing through mechanical separators or a condensation pipe or a washing device. CII. 1.4.4 Pb-Xn-Ag Cruet from Deeilvering The crystalline crust is remelted in a small kettle so as to separate most of the entrained lead or directly treated in distillation vessels to remove the zinc. A chlorine containing salt slag on top of the molten bath helps to avoid too much zinc oxidation. Dust and fumes generated by agitating and removing the dried salt slag are captured by special ventilated hoods connected to a bag filter. The triple-alloy produced in this step has to be de- zinced using a vacuum dezincing or a retort furnace. As the dezincing takes place by distillation and the zinc vapour is condensed in special condensers no dust is emitted from the inside of the dezincing furnace. Feeding and tapping areas are covered with hoods to collect dust and fumes escaping from the furnace during charging and tapping activities. Lead silver alloy from the dezincing step is treated in a cuppellation furnace 75 - i.e. a small reverberatory or a TBRC furnace and bottom blown converter - by oxidation of lead producing a lead oxide bearing slag. Furnace off-gas is mixed with the gas from hood ventilation of the tapping area and sent to a gas cooler prior to cleaning in a bag filter. CII. 1.4.5 Bismuth-Cruets Bismuth containing crusts from the bismuth removal step can be enriched in bismuth content by remelting and additional debismuth removal in a kettle (see chapter CII.1.2.4.1). Oxidising or chlorination of the enriched crust in a kettle leads to a Pb-Bi-alloy. The kettle is covered with a ventilated hood and dross removal is carried out by mechanical devices integrated in the hood construction. Bismuth removal can be obtained by complete chlorination of lead in a small ventilated unit or by electrolysis, CII. 1.4.6 Flue Duets Dusts from the gas cleaning systems are normally recycled to the sinter plant or to the lead smelting unit using closed conveyors and transportation systems. If cadmium is concentrated in the dust (in the roasting or/and reduction steps), the Cd-rich flue dust is leached to remove cadmium and to lower the Cd-level in the recycled dust or sold to companies, possessing leaching facilities. Cadmium can be recovered as Cd-carbonate or Cd-concentrate. In the latter case the cementation tank has to be well ventilated with regard to possible arsine generation. Of€ gas is cleaned in a special wet cleaning system. CII. 1.4.7 Shaft Furnace Slag Slag can be used for different purposes, for instance bituminous layers in road paving, concrete or cement production. Screening or drying facilities have to be equipped with well ventilated hoods connected to a bag filter. 76 CII. 2 Secondary Lead Production CII. 2.1 Proceee Description of Secondary Lead Production

Secondary lead production is aimed at recycling raw - materials containing lead, mainly battery scraps as well as metal sheets and pipe scraps and sludges or drosses. ___ The amount of battery scraps is regularly increasing along with the development of batteries and a decrease in the share of the other products on the total lead market. The process route is based on breaking up the old batteries and separating the paste, metallics and organ- ics (ebonite, polypropylene), melting and reduction in different types of furnaces, and refining of lead depending on the required quality: antimony-lead or soft lead. After washing and grinding, polypropylene can be recycled as a secondary raw material for the plastics industry. Ebonite can be used as a fuel. An alternative process route provides the treatment of complete and undismantled batteries but without sulphuric acid. One process step, i.e. battery breaking and separating of metallics, paste and plastic, is not required, and the plastic material replaces a significant part of the fuel necessary in the reduction step. CII. 2.2 BAT for Battery Scrap Preparation CII. 2.2.1 Penarroya Proceee After crushing, the components are separated in a ro- tative screen. Pines (or paste) are directly sent to the melting operation, other intermediate products are crushed under water and treated in hydraulic separators to recover metallics, ebonite and polypropylene. Only the first screening operation could generate some dust emissions, however the machine is installed in a ventilated hood connected to the air cleaning system of the plant. - CII.2.2.2 m Process After crushing and wet screening, the different products are separated by hydraulic classifiers. As all - the operations are performed in wet conditions, no problem occurs as far as dust emissions are concerned. 77

CII.2.2.3 Tonolli-CX Proceee As in the MA process, after crushing, screen and hy- drodynamic separators work in a wet medium, and any environmental problems are transferred to problems of waste water treatment. In addition, a further leaching of the paste with sodium carbonate can eliminate about 95 % of the SO4 ions as sodium sulphate. After filtration with a filter press, the mixture of lead carbonate and lead oxides can be sent to a melting operation. CII .2.2.4 Varta Proceee Complete acid free batteries are fed into a blast furnace with coke, scrap iron and returned slag. Addition of other secondary material is possible. Part of the plastic material is used as fuel in addition to a reduced coke rate while the other part of the plastic is volatilised. Furnace off gas has to pass through an afterburner to oxidise the organic components prior to filtration. The process produces antimonial lead bullion, a discardable slag and a lead iron matte which can be treated in primary lead smelters. CII. 2.3 BAT for Melting After preparation, the different raw materials to be treated are mainly: - metallics (from batteries and pipes, sheets etc.), - lead oxides, - lead sulphate, - lead carbonate (after a CX-type pretreatment), - sludges and/or drosses. Today, the industrial production of secondary lead is processed on a pyrometallurgical basis. The operations to be performed during the “melting phase” are: - fusion of metallics, ‘- elimination of SO4 ions, - reduction of the oxidised compounds, to produce lead bullion, slag and gases. However, clean scraps can be melted in a kettle and liquid lead introduced directly at the right stage in the refining according to the final production grade. I0 In Europe, the major part of production is made use of by rotary furnaces when only one plant treats batteries in a shaft furnace similar to the primary lead ones (cf. C11.1.2.2). - -~ In the USA, the main process consists of melting the different products in a first furnace to recover lead and slag and then treating this slag in a reverberatory or electrical furnace to recover lead bullion and ___ a final slag which can be disposed of. As this process is more expensive than the European ones, and does not have any advantages from an environmental point of view, it cannot be regarded as a BAT. CII.2.3.1 Short Rotary Furnace Raw materials, fluxes and reductants are charged in batches in a short rotary furnace where sulphur is finally fixed in a soda slag preventing any emission of SO, in the process gases. At the end of the cycle, liquid lead bullion is tapped and transported to the refinery while slag is tapped in pots or granulated and disposed of in a controlled dump. Dust emissions come on one hand from mechanical generation during handling and feeding of raw materials and on the other from the generation of fumes, depending on the temperature of the melting phases and the vapour pressure. All these emissions have to be collected by ventilated hoods connected to a filtration system that generally also receives the process gases. The gases are cleaned in bag filters which permit low dust contents to be achieved. CII. 2.3.2 BAT for Long Rotary Kilns Contrary to the short rotary furnace, the long rotary kiln is operated on a continuous basis. It requires a more constant quality of charge but the environmental conditions are the same as for the short rotary furnace.

~ CII 2.4 BAT for Refining The impurities contained in lead bullion from secondary production which may require elimination or ad- - justment are mainly copper, antimony and tin. Then the operations for refining are generally limited to : 79 - decopperising with addition of sulphur (see CII.1.2.4.1); - removal and adjustment of antimony to the required level to produce antimony lead or soft lead by addition of oxygen, nitrates and soda; - elimination of tin by chlorides. All these operations are conducted in kettles covered with ventilated hoods connected to a filtering system in order to collect all the dust that is generated. The removal of dross or by-products uses vacuum or mechanical devices integrated into the hoods to ensure a dust-free recovery before recycling.

CIII G0D-r Works CIII. 1 Primary Copper CIII.1.1 Introduction About 10 % of refined copper production worldwide takes place in EC countries. Of this, about 60 % is of primary origin, part having been smelted in Europe and part resulting from imported blister. The following deals with the main points of heavy metal emissions from the pyrometallurgical processing of copper concentrates up to blister and following refining and recovery of cathode copper. CIII. 1.2 Smelting Technology Sulphidic copper ore concentrates are the most important raw material for primary copper production. The processing of oxidized ores is only of minor importance and is not included here. The main steps in copper metallurgy based on sulphidic ore concentrates are: - concentrate smelting to matte - matte converting to blister copper

CIII.1.2.1 Handling Wet Concentrates Dust emissions, which are connected with the unloading, handling and stockpiling of copper ore concentrates, can be avoided by the use of storage bins (and weighing bunkers) ventilated by baghouse units, covered conveyor belts and covered stockyards. 80 When stored in the open air, the stockpiles are surface secured. The material stockpile is - if the concentrates tend to give out dust emissions - covered by

lime solution spray or another protecting liquid, ~ which forms a thin layer after binding is completed. - Stockpiling areas and roads have to be kept clean by using a sweeping machine, thus avoiding dust emissions. CIII.1.2.2 Drying Smelter Feed With the exception of smelters with green (not dried) feed smelting where concentrates with 6-10 % moisture are processed, rotarv drvers or rotary flash dryers are preferably used, which are in the main heated direct by oil or gas. The desired moisture level after drying is dependent on the subsequent smelting technology - at best 0.1 % maximum and moisture. To remove the dust from the dryer's off-gases not only electrostatic precipitators but also bag filters or wet scrubbers are used. With the above mentioned off-gas cleaning facilities the heavy metal emissions can be reduced to: - 20 mg/m3 for dust, - 5 mg/m3 for copper. Slimes separated in the cleaning facilities are transferred to the drying process whilst dry dust is transferred to the smelting process.

CIII.1.2.3 Partial Roasting before Smelting of Concentration The more traditional technique of processeing sulphidic concentrates consists of roasting in a separate step before smelting. In this step some sulphur is removed by the introduction of air, with simultaneous drying and heating of the concentrate, to achieve a sulphur content favour- able for matte smelting. In cases where the concentrate already has a suitable sulphur content, this step may not be applicable. - This processing technique has been ousted in recent decades by processes in which roasting and smelting are both part of one process step (direct matte smelting). __ Fluid bed roasters are mainly in use in smelters with partial roasting before smelting. The principle of this roaster is characterised by the fact that the concentrate is suspended in a stream of 81 hot air. As much as 35 % of the calcined concentrate leaves the roaster in the form of flue dust which has to be recovered in dust collectors for further processing. Fluid bed roaster gases typically contain 10-14 % SO2 and are channelled to sulphuric acid plants after cleaning. The calcines are transported in closed systems into the smelting furnace to avoid dust and SO2 emissions. Whilst in the past only reverberatory furnaces were used forthe smelting process, today electric furnaces are also in use. Reverberatory smelting tends to be declining worldwide. CIII.1.2.4. Smelting to Matte During matte smelting two liquid phases are formed, a sulphide matte melt and an iron silicate slag. The silicate slags are made up of gangue, ferrous oxides and flux additives (silica and limestone). Sul- phur, copper and iron combine and form the copper matte which concentrates most of the precious metals and some insignificant elements. CIII.1.2.4.1 Smelting in Reverberatory Furnaces This process is not used anymore in EC countries. The process is being progressively abondoned worldwide, due to its extensive SO2 emissions and poor energy utilization. CIII.1.2.4.2 Electric Furnace Smelting In the electric furnace smelting process the roasted ore concentrates are transferred on to the liquid melt either through the top of the furnace or sideways by individual chargers. The smelting temperature is obtained by means of electric resistance heating. De- pending on the size of the furnace 3 to 6 electrodes immersed in the liquid slag layer are used. Tapping procedures are similar to those of reverberatory furnace. CIII.l.2.4.3 Flash Smelting As mentioned above, in these processes the matte forms in one step roasting and smelting taking place in one single step. In flash smelting the concentrate is dispersed in an air andfor oxygen stream. Smelting and converting occur and are substantially completed while the particles are in flight. 82 Two processes are currently in commercial use: - the OUTOXUMPU process, - the INCO process. - -~ The OUTOXUMPU process is the most widely used, in fact the only one of both processes used in EC countries. With this method the dried concentrates together with flux and preheated air (150 to 1000°C) are blown into ~- the furnace through nozzles at the top of a reaction shaft . The melted particles are separated from the gas flow and fall on to the molten bath. The matte (approx. 50 to 70 % copper content) is tapped and transferred to the converter. The flash furnace slags which are discharged at the other end of the furnace are further processed to lower their Cu-content. Some characteristics of the OUTOXUMPU process are: - high SO2 concentration in the effluent gas, - efficient use of energy, resulting in low fuel consumption, - production of a high grade matte, resulting in a short blowing time in the converter, - high throughput per reactor unit. With the OUTOXUMPU process it is also possible to produce blister copper directly in the furnace, although this possibility is only practised in exceptional cases with smelters. In the INCO process oxygen is used for smelting copper ore concentrates which are blown horizontally into the furnace from both ends. The concentrates are roasted and melted in the hot atmosphere of the furnace. The heat produced by roasting is sufficient for an autogenous smelting process. The slag low in copper flows out continuously at one end of the furnace and the matte is tapped periodically at the centre of one sidewall. The process gas contains 75 % SO The advantages of this process are similar to txose of the OUTOKUMPU process discussed above. CIII.1.2.4.4 Other Smelting Proceeeee The TBRC method (top blown rotary converter) uses oxygen and concentrate blown through a lance system on top of the bath in a vertical rotating vessel. The operation is batchwise, with sequential tapping of slag and matte. The rocess was developed due to the special features of the ores to be treated. The process has at present been discontinued. 83 The NORANDA urocess is currently used in Canada and in the U.S.A. The process uses a cylindrical converter- type smelting furnace. Pelletised concentrate and additives are charged on to the bath of molten slag at the top end of the furnace. Burners fired by natural gas or oil situated at both ends produce the heat necessary for processing. Oxygen-enriched air is blown into the molten bath through the converter tuyeres, causing sulphur and iron to oxidize. During continuous smelting in the furnace the melt segregates into three liquid phases: slag and matte. The matte is tapped periodically from the bottom of the furnace and the slag flows out continuously opposite the charging end. The basic idea was direct smelting to blister copper; the operating practice today is to produce a copper-rich matte for further converting. The MITSUBITSHI urocess is currently used in Japan and in Canada. This process produces blister copper continuously by employing three interconnected furnaces. The dried concentrates, air, oxygen and additives are charged into the smelting furnace by means of consum- able lances and subsequently melted to form matte (60 to 65 % copper content) and slag. This mixture flows continuously into an electric slag resistent furnace which serves as a settling vessel. There the matte is separated from the slag. The latter is discharged from the furnace, whereas the matte flows through a syphon into the converting furnace where it is continuously processed into blister copper: the converting slag is granulated and recycled to the smelting furnace. The ISA-SMELT (Mount ISA, Australia) is a new process for smelting concentrates to matte which has been in commercial use at Mount Isa for the last two years. In a standing refractory-lined vessel moist concentrate and flux are fed by conveyor and air/or oxygen enriched air blown via a lance under the bath surface into the melt. As a result slag and copper matte form. The separation of the molten phases takes place in the fore-hearth. The resulting high grade matte is further processed in the converter to produce blister copper and the slag discarded. Some characteristics of the ISASMELT process are: -- - Produces high SOz concentration in the off-gas, - very high specific smelting rates, - reduction of fuel consumption, - a variety of fuels can be used, - low copper content in discard slag, - can treat concentrate feeds with high megnetite content, - low dust carryover in off-gases. 84 Cvclone Smeltina Processes were invented by Lurgi/ Babcock and further developed by Norddeutsche Affi- nerie (Flame Cyclone Reactor) and by KHD (Contop) to

a point where they can be considered for commercial ~ scale production. With these high-intensity processes -~ the copper concentrates and flux are smelted with oxygen in cyclone-type combustion chambers. In the Contop -process, the cyclone is disposed vertically. In the FCR-process, the combustion takes place in vertical __ reaction shaft and the separation of the liquid from the gas formed phase occurs in a horizontal cyclone. Slag and white metal or copper rich matte are separated in the fore-hearth and tapped. The white metal or matte is processed in the converter. effluent gas is processed in a sulphuric Theacid p ant.

CIII.1.2.5 Environmental Requiremente Feeding systems (conveying, charge preparation) of all the described processes are covered to avoid dust emissions. The dust emissions occurring at the material transfer points are sucked off and separated in fabric filters. The dust collected in the filter units is transferred to the feeding systems again via enclosed conveyors. Feed openings in the furnace are covered with hoods which are connected to the cleaning systems. Effluent gases from roasters and smelting furnaces are cooled either directly or indirectly (e.g. waste heat boiler), dedusted in cyclones and/or hot electrostatic precipitators followed by additional cleaning in a washing and cooling system. The gas thus cleaned is channelled to a sulphuric acid plant to process the SO,. The separated flue dust is recycled. Tapholes and discharging systems are equipped with hoods. The ladles are positioned in ventilated chambers while they are filled with the molten material (slags, mattes). Both the chambers and the hoods are connected to the ventilation and gas cleaning system. All the recovered dust is recycled either to the process, from which it originated, or it is treated in another plant (e.g. shaft furnace). The floor of the smelting plants must be kept clean. Dust contents below 20 mg/m3 are achieved with the filter units. 85 CIII.1.2.6 Slag Cleaning Depending on the smelting process, when its Cu-content

justifies it, the primary slag which is produced du- ~ ring matte smelting is either channelled to an elec- -~ tric slag resistant furnace for further copper extraction or submitted to floatation after crushing and milling. ~__ In the electric slag cleaning, a C-bearing agent is added to the slag and the decopperized slag is either granulated or tapped into ladles. The sulphide phase (matte) collected at the bottom is further treated in the converter process. If CO occurs owing to the copper extraction process of the slag, the furnace off- gases require afterburning. This is followed by a gas cleaning system (e.g. fabric filters) yielding a re- sidual dust concentration of < 20 mg/m3. The separated dust is reprocessed or sold for further processing. Scrubbers can also be employed to clean the off-gas. Tailings from slag flotation plants are dumped.

CIII.1.2.7 Diecarding Decopperieed Slag6 The decopperised slag is either produced in a granulated form or as lump slag. Water used for granulation is usually kept in a closed circuit. Cooling towers can be employed to cool the water. Ladles filled with cooled slag are emptied in so-called crushing towers for the manufacture of lump slag and reduced to a suitable size as required. To avoid diffuse emissions, crushing and screening facilities are covered by hoods and sucked off. Filter facilities are available to dedust the waste air. CIII.1.2.8 Matte Conversion to Blister Copper The trend towards increasing matte grades continues worldwide, mainly due to the growing use of oxygen for enrichment of the air during smelting. Just as the matte grades depend from case to case on the raw material feed and the selected process, data regarding converter operations and their technological requirements can vary as well. The Peirce-Smith converter is by far the most common copper matte converting vessel. Some smelters use the Hoboken converter. Both converter types operate batchwise. The converters are charged with liquid matte via ladles. The slag produced during converting is tapped periodically through the converter mouth via ladles. The blister copper is tapped in a similar way at the end of the converting cycle. 86 During these operations fugitive emissions occur, which can be reduced by the use of additional suction facilities (e.g. secondary hoods), by proper control of the converter position system and by charging side- ~ ways, reducing the need to tilt the converter at the off-gas hood for charging purposes. When the secondary - hoods are used, the collected diffuse emissions are cleaned in fabric filter units or washed and sent to an acid plant. __ Hot process gases produced during the blowing periods and are collected by means of hoods over the converter mouth. Well-designed closed fitted hooding and proper working practices will avoid large volumes of process gases and consequently increase SO concentration and improve the efficiency of the acicl plant. The use of oxygen for enriching the blast air will also result in higher SO2 contents. The SO, concentration varies considerably during the processing cycle. In order to ensure that the acid plant operates efficiently when processing converter off-gases, two alternatve concepts are practiced: multi-converter operation and single converter operation in combination with a stea- dy SO, gas source resulting from concentrate roasting or concentrate to matte smelting. With the Hoboken converter the escape of process gas which usually occurs when the converter is tilted for charging and to tap slag and blister is avoided. The process gas is sucked off through a syphon flue at one endside of the converter. The syphon minimizes gas ecape during all phases of operation. The converter is charged through a small mouth near the top of the casing. Charging is also possible during blowing without tilting the converter. Dilution of the process gases due to infiltrated air is reduced so that the average concentration of SO2 is in principle higher than for the Peirce-Smith. However, the SO, concentration will still vary throughout the cycle. Problems, for example, may arise from smaller charging mouths due to slag build-up, or with scrap charging or syphon block- age as well as at higher throughputs. Converter off-gases have to be cleaned from dust before collection of the SO2 in the acid plant. The dedusting takes place in settling chambers or flues, followed by electrostatic precipitators with a subsequent wash. The latter is possible as a final treatment or serves as the first stage of the preparation for sulphuric acid plants. Dust collected in,the filter units is recycled to the smelting stage or has to be processed separately. Owing to its relatively high copper content, converter slag is either recycled directly in liquid form to the 87 smelting stage or to an electric furnace for separate decopperizing. The slag may also be cooled down for crushing and milling, the copper-rich particles being separated from the rest of the slag components by flotation. The thus recovered secondary Cu-concentrates are fed to the smelting stage. CIII. 1.3 Refining Operations Blister copper first undergoes a pyrometallurgical refining step - often with addition of copper scrap - and is then cast in anode shapes for transfer to a tankhouse for electrorefining. The impurities of the blister are removed partly in the pyrometallurgical step (in the so-called anode furnace) and then finally in the electrolytical refining. CIII.1.3.1 Anode Furnace Operations Melting, refining and casting can be carried out batchwise or continuously and two stages can be dis- tinguished in the process: the oxidation and the poling stages. The type of fire-refining furnace in use mainly depends on the specific situation of the smelter/refinery. Rotary drum-type furnaces are mostly used for refining molten converter copper as feed; reverbarato- ry furnaces are applied for solid charge - also when small amounts of molten copper are added. Both process systems are operated batchwise. However, in respect of solid charge the continuous Contimelt process has been developed, especially for high throughput levels. The furnaces are heated with fossil fuel, partly using additional oxygen. Depending on the selected technology, heat recovery from the furnace off-gases may occur by means of waste heat boilers or by preheating of the charge when this consists of cold solid blister/scrap. The impurities oxidized during the first stage are mainly discharged via the slag. The reduction of excess oxygen resulting from the oxy- dation of the copper is realized by immersion of tree trunks (poles) into the molten bath for hearth furnaces or by injection of reducing gases, for example, natural gas (CH4), for converter-type furnaces. In case CO-bearing off-gases are produced during the poling process, an afterbuming chamber is connected to the furnace. The afterburnt off-gases are dedusted, preferably in fabric filter units, if necessary after cooling. There are two methods in use for casting anodes from refined copper: the casting wheel and the continuous caster based on the Hazelett concept. 88 In case diffuse emissions occur when the anode copper is cast, tapholes and launders are fitted with suction hoods and connected to the fabric filter units.

~ Anode furnace slag contains substancial quantities of copper and has to be treated further. In general the - slag is cast in ladles and separates into metal and slag phases while it slowly cools down. The cooled down slag is often added to the charge of copper blast ~- furnaces in lumps. The anode furnace slag may also be recirculated in liquid or solid form to the matte converting step.

CIII.1.3.2 Electrorefining of Copper Anodes The final refining of the anode copper is carried out in electrolytic cells in a tankhouse. During electrorefining the copper is dissolved from the anode and deposited on the cathode. Two tankhouse concepts are applied: - The conventional system using as cathodes thin copper starting sheets produced from one day deposits in separate cells - The permanent cathode concept applying stainless steel blanks on which the copper is deposited. The deposits are stripped periodically and the cathode blanks recirculated to the electrolytical cells. The electrolyte in the cells consists of copper sulfate and diluted sulphuric acid. Small amounts of organic agents are added to control the deposition reaction. By applying a direct electrical current the anode copper is dissolved and is then deposited on the cathodes in a pure form. The impurities contained in the anode copper such as precious metals, selenium, tellurium, lead and antimony form the so-called anode slime which settle in the tankhouse cells and are then separated. They are further treated to recover the pure metals. Other elements in the anode copper, mainly nickel and arsenic, concentrate in the electrolyte, from which a bleed is separated for processing. From the bleed electrolyte, nickel can as an example be produced in the form of nickel sulfate and arsenic as As203. Nickel as sulfate and sulphuric acid are normally recovered from bleed after decopperization in electrolytic cells with insoluable lead anodes, the acids being recycled to the tankhouse electrolyte. To control the copper content in the electrolyte regulator cells are used, also equipped with insoluble anodes. 89 In these cells owing to the anodically formed oxygen, which is in the form of extremely fine bubbles, an electrolyte-bearing spray can occur. This contains inter alia nickel and arsenic. The spray formation can be prevented by covering the cells with a protective layer, e.g. oil, or by fitting suction hoods connected to a scrubber. The final tankhouse product is the copper cathodes. These cathodes are converted into continuous cast shapes such as cakes and billets, wire rod or used for preparation of alloys. CIII. 1.4 Flue Duet Handling The separated flue dust in the filter units with the fine particles must be treated in enclosed systems. It is either channelled back to the process again where it originated or processed in other plants, e.g. by reducing smelting in shaft or electric furnaces.

The removal of the dust from the filter units is discharged by rotary vales or screw conveyors. For the transportation screw conveyors, totally enclosed conveyor strips or covered buckets are used. Occasionally flue dust is conveyed pneumatically. In any case fugitive emissions must be avoided. This also applies to storage. Flue dust must be stored in closed bunkers unless it is of a thicker type, e.g. as pellets or briquettes. There are various hydro/pyrometallurgical methods to process flue dust, for example reduction smelting in the blast or electric furnace. When using hydrometallurgical methods it is important to use the solutions in a closed circuit to avoid waste water. Any waste water resulting despite these precautions must be treated.

CIII. 2 Secondary Copper CIII.2.1 Introduction About 17 % of refined copper production in the Western world and as much as 46 % of EEC production (on the basis of 1987 data) is produced from various secondary materials, e.g. metal scraps in the form of: - copper scrap such as fabrication rejects, wire scrap, plumbing scrap, apparatus, electrical systems, products from cable processing etc.; - alloy scrap such as brass, gunmetal, bronze in the form of radiators, fittings, machine parts, turnings, shredder metals; 90 - copper-iron scrap like electric motors or parts thereof, plated scrap, circuit elements and switchboard units, telephone scrap, transformers and shredder material. Another large group of metal containing materials is composed of by oxidised materials. These are drosses, ashes, slags, scales, ball mill fines, catalysts etc., as well as materials resulting from pollution control systems as filter dusts and sludges from the purification of waste water. Their copper content varies in a wide range from only 10 % up to nearly 100 %. The associated metals which have to be removed are mainly zinc, lead, tin, iron, aluminium and nickel, as well as certain amounts of precious metals.

CIII.2.2 Process Description of Secondary Copper Production In a first step, copper anodes are produced by combined pyrometallurgical processes (Verein Deutscher Ingenieure [VDI] 1985). These anodes are refined in a second step by electrolysis, the process being similar to primary copper production (see chapter CIII.l). Direct hydrometallurgical processing of copper scrap is of little significance as it is used by very few industrial plants (United Nations 1979). Depending on their individual chemical composition, the raw materials of a secondary copper smelter are processed in different types of furnaces: - blast furnaces (approx. 30 % Cu in the average charge) , - converters (approx. 75 % Cu), - anode furnaces (approx. 95 % Cu). The blast furnace metal ("black copper") is treated in the converter, the converter metal is refined in the anode furnace. In each step, additional raw materials with corresponding copper content are added. Most of the accompanying metals are oxidised by this pyrometallurgical treatment. Zinc, lead and tin are volatised and can be recovered from the off gas. Iron and aluminium are slagged. Shaft furnace slag can be used as a material for construction purposes. Converter slag and anode furnace slag are recycled to the blast furnace. 91 The off gas filter dust from the blast furnace and converter can be treated for the recovery of zinc, lead and tin. The anode furnace filter dust is recycled to the blast furnace. In addition to these combined processes, high-grade copper scrap is charged together with cathodes in a wirebar furnace, the type of furnace and the kind of treatment resembling that of anode production. Another technology makes use of TBRC (top blown rotary converters) for both the functions of the blast furnace and the converter. After smelting the accompanying metals are oxidised. Lead and tin are slagged off and recovered in another TBRC as a lead-tin alloy by a reduction process. Zinc is volatilised, iron and silica are slagged. CIII .2.3 BAT for Blaet Furnace Operation In the blast furnace a mixture of raw materials, iron scrap, limestone and sand, as well as coke is charged at the top. Air which can be enriched with oxygen is blown through the tuyeres, the coke is burnt (corresponding to the Boudouard- reaction) and the charge materials are smelted under reducing conditions. The off-gas is cooled first in a waste heat boiler, then in an air cooler, and finally dedusted in bag filter units. The dust content, being initially 5-10 g/m3 in the raw gas, can be reduced to 20 mg/m3. Black copper and slag are discharged from tapholes. Dust emissions from charging and tapholes can be reduced with hoods which are associated with the ventilation and filtering system. But in the case of old plants, the installation may be difficult and the effect may be poor, particularly at the charging area. CIII. 2.4 BAT for Converter Operation Black copper from the shaft furnace is charged together with additional raw materials, flux and coke or other fuel which initiates the reaction. After charg- - ing, air is injected. The aim is that after smelting the charge materials should oxidise the accompanying metals.

~ The off gas from the converter mouth is collected with a hood and ducted to bag filter units. To avoid emissions during charging and discharging, the hood should not only cover the mouth. The best arrangement is either a secondary hood or an enclosure of the converter with the minimum possible operating opening. 92 The dust content of the of€ gas depends on the amount of additional air which is sucked off from the enclosures. Typical values are 5-20 g/m3 in the raw gas and 20 mg/m3 in the clean gas. CIII. 2.5 BAT fat Anode Furnace Operation Converter copper is charged together with copper raw materials. For smelting the charge, oil, coal dust or lignite dust is used, mainly in reverberatory furnaces. After smelting, air is blown on the bath to oxidise the remaining impurities. The oxygen content of the liquid copper charge after the blowing period is removed by a subsequent reducing period in which the reduction is achieved by the use of wood (poling logs), hydrocarbons or ammonia. The fire-refined copper is cast into anodes. Low quantities of remaining impurities, mainly lead, nickel and precious metals are removed by electrolytic refining. The off gas is cooled (using a waste heat boiler, or if necessary air cooler) and dedusted in bag filter units to 20 mg/m3. If the cooling capacity is not very high , ther normal filter materials can cause problems. In those cases, teflon and glass fibre have proven to be suitable filter materials. If necessary, emissions of fumes from the charging hole, poling hole and taphole should be collected by ventilated hoods. CIII. 2.6 BAT for Wirebar Operation The design and operation of wirebar furnaces is similar to that of anode furnaces, resulting in a similar control of emissions (see chapter 111.2.5). CIII. 2.7 BAT for Top Blown Rotary Converters In the TBRC a mixture of raw materials, limestone and sand are charged. The material is heated by natural gas and oil and is smelted under oxidising conditions by oxygen-injection. The accompanying metals are oxidised and slagged off. These slags can be processed in another TBRC to recover lead and tin. After this reduction operation the slag is granulated and can be used for construction purposes and sand-blasting. To treat other oxidic materials such as drosses, ashes, slags, fines etc., another TBRC can be used. The material together with ferrous copper is smelted by natural gas and air or oxygen under reducing conditions. 93 Black copper is discharged and treated further in the first TBRC together with metallic materials. The slags of this furnace are treated and used as mentioned above. The off-gases from the TBRC are collected with a hood, cooled in a steam- boiler or air-coolers and filtered in bag-filters to 20 mg/m3 dust in the end- gases. The furnace is totally enclosed to capture emissions from charging and discharging. These gases are also filtered off to an end-value of 20 mg/m3.

CIV Zinc Work0 CIV. 1 Introduction In 1987 annual zinc production in the Western world amounted to 4.9 million tonnes, ?: 1 million tonnes i.e. 20 % originating from remelted zinc and secondary raw materials. EEC production amounted to 1.66 million tonnes, i.e. f 80 % of the overall production in Europe and f 34 % of the production in the Western world. Virtually 80 % of the primary zinc production in Europe is extracted by hydrometallurgical treatment. The remainder, as well as secondary zinc, are extracted by thermal processes.

CIV. 2 Primary Zinc Metal Production Primary zinc is mainly won from two types of concentrates : - sulphides, mainly zinc sulphides (blendes), - oxides, mainly zinc carbonates and zinc silicates . In Western Europe it is mostly a mixture of blendes that constitutes the feedmaterial for the hydrometallurgical process. In the thermal process (Imperial Smelting), the feed is constituted by a mixture of Zn- blendes and Pb-concentrates or Zn-Pb-mix-concentrates. This process enables an easier treatment of oxidic materials. 94 crv.2.1 BAT for aydtomoetallurgical Process CIV. 2 .l. 1 Roasting Blende Concentrates Virtually all roasters used in the hydrometallurgical process are "fluosolid" furnaces. In order to avoid dust formation when handling raw materials, their hu- midity content is preferably 6-8 %.Covered storing areas for concentrates also provide a minimum of dust emissions, thanks to ventilation and dedusting installations. In case of storing materials in the open air, dust formation can be avoided by sprinkling the piles with a fixing solution.

Sulphides are injected into the I' f luosolid" furnace where they react in a fluidised bed with the oxygen from the air, converting ZnS into ZnO and burning S to so*. Roasting gases containing 5-15 % SO2 are cleaned in electrofilters and gas scrubbers; SO is then converted by catalysis on vanadium pentoxiie into SO3 to be further converted with water in the absorption tower into sulphuric acid. The nature of this extensive gas treatment reduces to dust emissions to virtually nil from this type of combined roasting and sulphuric acid production. SO2 is the only emission that occurs. During the transport of the calcium it is possible that fugitive dust emissions occur. cIv.2.1.2 Hydrometallurgical Xinc winning Process Roasted concentrates are leached in different succes- sive steps in ever stronger sulphur acid mediums, after which Zn, Fer Cu, Cd, Ni, Cor and T1 elements en- ter into solution. The nature of the technology (aqueous medium) in covered reactors means that, in principle, these operations can neither cause dust nor noxious gas emissions. However, a central scrubber system for treating the harmful water vapours is recomended if specific dust and/or noxious gas emissions could occur. The various other existing elements should be removed from the Zn-bearing solution that is obtained: Fa can be removed by three different processes: - the goethite process, in which Fe(II1) sulphate from the solution is first reduced with Zn sulphide concentrate and in which iron is then re- oxidised with oxygen, that is diluted in the solution, and deposited as a hydrated iron oxide (= goethite); 95 - the jarosite process, in which iron is deposited with ammonium in the shape of a hydrated alkali- iron sulphate (=jarosite); - the haematite process, in which, comparably with the goethite process, reduced iron (Fe 11) is first deposited under high pressure and with O2 injection in autoclaves in the shape of pure Fe- oxide: Fe20g (=haematite). The rich Fe-residues obtained are deposited in land- fill sites provided with membranes (jarosite-goethite) or rather exceptionally further processed in the cement industry (haematite). The other metals except zinc are removed from the solution through so-called cementation processes, pre- cipitating these elements as metals by means of zinc powder. This precipitate is further treated for the recovery of secondary metals (cf. CIV.2.1.5). The purified Zn sulphate solution is sent to the tankhouse cells, equipped with anodes of lead-silver alloys and aluminium cathodes. ZnSO4 is decomposed by electric current, depositing pure Zn metal on the aluminium cathodes, liberating oxygen at the lead anode and producing sulphuric acid in the solution. Heat is given off simulatanously in the process. Atmospheric air coolers are used to cool down the electrolyte. The exhaust air is saturated with steam and carries drops of electrolyte (Zn sulphate and sulphuric acid). In order to avoid emission of these elements, the towers are equipped with demisters. crv.2.1.3 Smelting Cathodes Zn cathodes have to be smelted into appropriate commercial shapes and alloys. The smelting takes place in induction furnaces, providing a flux on the metal bath, mostly with ammonium chloride. Through the presence of this flux on the bath, only very limited quantities of vapours are released. The greatest dangers for emissions occur when the Zn bath is skimmed. All furnace vapours are conveyed through exhausters at the skimming place to bag filters where they are processed before being released into the atmosphere. CIV. 2.1.4 Manufacture of Zinc Powder Part of the molten zinc is converted into Zn powder that is used as a reagent in the above mentioned purification steps (IV.2.1.2). 96 Molten zinc is therefore pulverised into fine powder that is collected in the canisters and on the bag filters . The powders are then sifted, the air being purified in bag filters. CIV. 2.1.5 Processing Secondary Products Lead sulphate, often enriched in silver, is the main component of the leaching residue and is further treated in lead smelters. In some cases a first drying is necessary, depending on the equipment used for filtration. This drying takes place in a rotary furnace; the dry gases are sent to filter bags with the aim of complete dedusting. The purification cements - particularly copper, nickel, cobalt - with the exception of cadmium which is traditionally recovered in zinc works (cf. CIV.2.1.6), are further processed in other non-ferrous companies. They are enriched by leaching in a light sulphuric acid medium, bringing the remaining zinc metal largely into solution. This operation needs to be done in an aqueous medium in covered reactors. A multiple stage scrubber is required if Arsenic is used in the purification stage. CIV. 2.1.6 Cadmium Winning Cd can be cemented in a sufficiently concentrated and pure shape with a zinc electrolyte with Zn powder (cf. CIV. 2.1.2). In this case the Cd cement obtained is compacted into pellets and directly smelted in a furnace, provided with a covering layer of molten sodium hydroxide. This sodium hydroxide prevents the release of dangerous metal vapours. The molten metal is directly cast into commercial shapes. Cadmium can also be produced by vacuum distillation from Cd-briquettes. In order to avoid any Cd emission, the Cd furnace, smelter and caster are under permanent air exhaustion. Any Cd emission is prevented by processing this exhaust air in a filter. Less pure and poorer Cd cement are brought into solution again, the Cd electrolyte obtained being further purified by precipitation (for iron) and cementation and finally recovered by electrolysis in the same type of cells as the Zn electro-winning. The cathodes obtained are treated in the same way as described before for the Cd pellets. 97 A further production line for producing high-grade Cadmium may be via refining in a vacuum distillation unit, where the above mentioned pellets are briquetted, melted under a layer of caustic soda and distilled under vacuum in a completely closed process. CIV.2.2 BAT for Pyrometallurgical Processes In Western Europe the Imperial Smelting process is the only pyrometallurgical process applied for primary zinc winning. This relies on a type of blast furnace for which a sintered load is necessary. The typical charge of the blast furnace contains f 20-22 B of lead. cIv.2.2.1 Roasting and Sintering The same techniques as described under CIV.2.1.1. apply for the treatment of raw materials. The sintering line is composed of a slow forward moving roaster on which the charge is placed and ignited, the temperature being increased further during the process by the heat generated from the roasting process. Due to the high temperature the charge on the line agglome- rates. The combustion air is blown from below through the sintering line and the roast gases are collected, together with the dust, in the exhausters at the top of the line. The roast gases are further dedusted and finally treated in a contact department, as already described in Section CIV.2.1.1. The sinter is cooled and broken at the end of the line, thereby freeing large quantities of dust which are exhausted together with the air through bag filters. The dust is recycled via closed conveyor belts towards the feed of the sinter line. Thanks to efficient exhaust and dedusting installations (mainly bag filters) , dust emissions are reduced to a minimum in the overall installation. cnr.2.2.2 Pyrometallurgical Process (Imperial Smelting Process) The Imperial Smelting process is based.on the principle of the blast furnace. Zinc oxide is reduced at high temperature with carbon to produce Zn metal. The sintered charge is loaded in alternative layers at the top of the furnace, together with cokes preheated at 8OO0C and the products of melting. Preheated air at 75OoC is blown from below into the furnace, converting the coke into CO, which reacts in turn with ZnO. The zinc metal vapours obtained leave the furnace together with the gases and the vapours are condensed on 98 molten lead metal drops in the so-called splash-condenser. A pump drives the molten metal mass through a series of pipes in which the solubility of Zn in lead

is decreased by cooling; this yields 2 molten metal ~ layers, the floating liquid zinc metal then being separated from the liquid lead that is recycled to the -~ condenser. Zinc metal is cast into ingots or further sent for thermal refining (cf. CIV.2.2.3). On one hand, metallic lead is tapped at the bottom of the furnace and cast into ingots. For further treatment of this lead, refer to Section CII.1.2.4. On the other hand , slags are tapped , granulated and either dumped or sold. The main risks of emissions in this process are: - feeding of the blast furnace: where a double bell is provided to restrict to a maximum all emissions through the furnace mouth. The exhaust gases are sent to bag filters; - slag and lead casting: emissions occurring here are under strong exhaustion and all gases pass through adequate dust filters. All gases exhausted at the slag granulation section are treated in wet electrofilters; - outlet splash-condenser and decanting basin of the lead-zinc separation stage: dust in these gases, particularly metal oxides, are exhausted in bag filters; - the off gases , containing CO, are thoroughly scrubbed with water. The cleaned gas is either used as a fuel to preheat the air for the blast furnace, or released to the atmosphere via a burner. CIV. 2.2.3 !!!hemal Zinc Refining For some applications it is necessary to proceed to a further refining of the zinc obtained by thermal treatment. . This refining takes place in distillation columns of the reflux-type, i.e. by fractioned distillation. This process relies on the fact that zinc and cadmium have a rather low boiling point in comparison with other metals. The process in fact involves two steps: - zinc and cadmium are separated from the other metals in a first distillation column, yielding zinc with a cadmium content; 99 - a further separation is made in the second column between pure zinc metal on one hand and, Zn-Cd- alloy on the other. A traditional unit includes two similar distillation columns, consisting of distillation trays made of si- licon carbide. In the lower part of the columns, the trays are heated from outside. Similar installations used to refine zinc can be used to produce zinc oxide by introducing air into the system. The zinc metal to be refined is melted in a feeding furnace and flows at half height in the first column. The distillation residue, leaving this column at the bottom, is composed of a metallic Zn solution with, among other substances, lead and iron, whereas the distillate, composed of zinc and cadmium, is used as feed in liquid form, to the second column via an intermediate condensor. At the bottom of this column the very pure Zn metal is tapped, whereas at the top the Zn-Cd alloy is collected through a condensor. This zinc-cadmium alloy can be treated still further to extract pure cadmium, inter alia by vacuum distillation. Although the columns are heated from outside and the released gases are in principle pure gases, the composition of which depends on the fuel used, deformations of the distillation trays are caused by the high temperature in the columns, giving rise to metal vapour infiltration in the gases through small slits and cracks and finally to metal oxide emissions too. Therefore, the waste gases may require filtration if the required emission standards could be exceeded. An industrial example is given in part D of this note. CIV.3 Secondary Zinc Metal Production For secondary zinc sources a distinction can be made between purely oxidised, mixed oxidised/metallic and purely metallic products, mostly from other metallurgical activities. Flue dust from smelting processes are the most important of the oxidic products. CIV.3.1 BAT for Treatment of Oxidic Products Oxidised products are mostly processed, together with roasted and sintered zinc concentrates, in primary thermal zinc smelters, in particular using the Impe- rial Smelting process. Oxidised products are mostly subject to thermal pretreatment in rotary thermal furnaces (clinkerisation) to eliminate halogens. The gases that are produced are 100 sent over a scrubber to collect the halogens in a metallic oxide material.

The oxides are pelletised in preparation as the feed ~ for the Imperial Smelting furnace. -~ Very poor residues and flue dusts (e.g. flue dusts from the steel industry) are first treated in rotary furnaces (Waelz-furnaces), in which residues and cokes __ are heated together; as a result non-ferrous metals first reduce and vapourise to oxidise again later to metal oxides in the gases. The gases pass through bag filters, where the metal oxides are collected again, in a more concentrated and purer form this time, which allows them to be treated later in the same way as described before. CIV.3.2 BAT for Processing Metallic Products Residues and metals for recycling are melted again in the melting furnaces, which are either induction type furnaces or furnaces with direct or indirect heating by natural gas or fluid fuels. The molten metal is mostly treated at the first stage in a liquating furnace, where due to a difference in density and the varying solubility of the metals associated with zinc, lead and iron for example, can be partially separated from zinc, depending on temperatures. The partly purified zinc is cast into shapes and either reused at this quality (for instance for galvanisation) or is further distilled to fine zinc in thermal refining columns, as already described above (Cf. "2.2.2). Prior to smelting, zinc metal is either first reduced through shredding waste zinc roofing, waste zinc gut- ters, etc. ) or, in the case of galvanisation of ashes, first ground and sieved in order to separate the grains of metal from the oxides. The oxides are then further processed, as described in Section CIV.3.1. When processing shredder scraps a separation is first made between pure non-ferrous metal fractions and light metals (aluminium, magnesium) based on their different specific density, prior to smelting the zinc fraction in a furnace. The molten zinc is cast into moulds and afterwards refined into fine zinc in distillation columns, as described in section CIV.2.2.3. The main emissions from all these operations are those of metal oxides; they are mainly caused by the SO- called "descratching" of the melting baths. The units are always used with under powerful exhaust systems and all gases pass through bag filters to eliminate the metal oxides before they are released to the atmosphere. 101 cIv.3.3 Treatment of Ozidic/Metallic Secondary Pxoducte It is possible to treat a large variety of oxidic and metallic secondary materials simultaneously in vertical New Jersey Retorts. The oxides, mixed with bituminous coal and sulphite liquor as a binder, are briquetted and coked. The hot briquettes with a zinc content of 42-46 % are charged into the natural gas heated retorts together with metallic materials such as drosses, metallic ashes, scrap and other sources. The splash condensed metal contains 99.8 % Zn. The CO-rich reaction gas is used for retort heating after having passed through a scrubber. The waste gas from the retorts is filtered in a bag filter before being released into the atmosphere. The residues from this process may be treated by a thermal process to produce a lead-zinc oxide, a matte collecting copper, nickel and silver, and a non-polluting slag. cv Tin Works cv. 1 Introduction The world production of tin from primary sources was about 170,000 tonnes in 1988. Tin was recycled to about 16 % of primary production in 1981, but the amount has fallen in recent years because of the sharp fall in the price of tin in 1985. As a result a figure of 6 % was estimated for 1988. It is unlikely to rise substantially because the uses of tin are generally dispersive, e.g. in tinplate or chemicals, and recovery is not possible. On the other hand, the recovery of tin from previously dumped industrial residues may be necessary because disposal is no longer permitted. Smelting of tin is now virtually limited to two sites in the EEC, though the recycling of tin-lead alloys (solders) is carried out at several other small sites, as is the recycling of tin-copper alloys, bronzes and brasses. Tin intermediates are isolated at many lead and copper smelters and refiners. Production of tin metal in the EEC was estimated to be 23,500 tonnes in 1987, with estimated consumption of 51,500 tonnes estimated in the same year. Mine production of tin concentrates is limited at present to Cornwall in the UK with 4,000 tonnes of tin, 102 in Portugal with 5000 tonnes and Spain with 100 tonnes each, annually. The European industry smelts primary and secondary tin together, the refining techniques are the same, so they are considered together in this Note. 07.2 BAT for Traditional Technology As in the case of lead, European primary tin smelters treat some recycled materials with tin concentrates, frequently intermediate products produced in the course of refining lead or copper. Because of the relatively high value of tin much lower grades of concentrate are economically treated than of say, lead, and the lower grades of tin concentrate also contain more impurities. Low-grade smelters usually handle the by-products of lead and copper smelters containing tin, and use techniques meeting the requirements for lead. The following impurities occur in secondary tin smelters: arsenic, zinc, cadmium, selenium, tellurium, antimony, bismuth, halogens and sulphur, as well as lead. The presence of radionuclides of the uranium and thorium series requires special attention, usually in non-alluvial ores. There are four main smelting technologies in existence: i) High-grade smelting (> 65 % tin in feed) reverberatory furnaces ii) Medium-grade smelting (65-45 % tin in feed) electric arc furnaces iii) Medium-grade smelting (65-45 % tin in feed) rotary furnaces iv) Low-grade smelting (20-45 % tin in feed) sinter plant and blast furnaces High-grade smelting does not concern EEC companies within Europe, as the concentrates are not exported from the countries of origin. The other process routes differ considerably. Broadly, medium-grade smelters have reasonably pure feed and little refining is necessary. Low-grade smelters have an intake of lead which can be as high as 50% and which may contained the impurities listed above; to all intents and purposes they should be treated as lead smelters. cv.2.1 BAT for Low-Grade Tin Works cv.2.1.1 Roasting or Sintering See CII.1.2.1 concerning BAT for sintering, in respect of the control of dust in handling, stockpiling, charge preparation, feeding and discharging; CIV.2.1.1 on BAT for roasting zinc concentrates. 103 The sulphur content of tin concentrates is low both as a percentage and in terms of absolute quantity; it is far below the amount required for an acid plant, and recognised methods of disposal must be used. Off-gas must be cleaned to remove particulate emissions; this gas is corrosive because of the presence of chlorides and fluorides, and sulphur oxides. Selenium is removed at this stage. Gaseous metallic species must be removed at low temperatures since bag-filters and precipitators will not arrest them. A wet final stage gas cleaning train is required; this is made up of an electrostatic precipitator followed by an absorption tower to remove gaseous arsenic, fluoride and sulphur oxides from the sinter plant. For the smaller volume produced by the roaster, a high- energyventurior wet-disintegrator is used. The solution produced must be neutralised before disposal. All recovered dusts are recycled to the charge preparation plant; at intervals the level of radioactivity of the precipitator dust must be checked for the presence of the radionuclide polonium 210, an alpha-emit- ter with a half-life of 138 days. If necessary the dust can be treated by isolation to allow time for decay before recycling. Work within the precipitator must be subject to control of exposure to ionising radiation. The precipitator must operate wet or be capable of being washed down to clear toxic dust before entry for maintenance is attempted. cv.2.1.2 Metal Production in the Blast Furnace See CII.1.2.2 BAT for lead bullion production in the blast furnace, except that in the case of halogens being present and pyrophoric dusts being produced the wet gas cleaning methods are preferred for the process gas, either high-energy venturi scrubbers or a wet disintegrator should be used. The dust fromthetapping-fume bag-filter is subjected to an acid leaching process to reduce its cadmium content, which otherwise would be recirculated. The slag produced in the first stage is granulated and

will require further treatment to reduce its tin con- ~ tent. Steam produced during granulation is ducted from the workplace to a stack for dispersal. cv.2.2 BAT for Medium Grade Tin Works - See CIV.2.1.1 BAT for zinc roasting works. Medium and high-grade tin concentrates are frequently supplied in canvas bags, or loose in containers. Dust emissions must be contained within buildings with ven- 104 tilation and dedusting facilities in bag-emptying, tipping, and stockpiling areas. Roads should be kept clean by mechanical sweeping and spraying. Dusty materials such as recycled fumes are pelletised for handling and re-charging. Smelting takes place in short rotary or electric furnaces, the technology selected being on the basis of the comparative prices of fuels. Furnace off -gas is cleaned by dilution with air and use of a bag-filter or dry electrostatic precipitator. In the case of electric smelting, combustion of the carbon monoxide generated at the electrodes has to be completed by secondary air in a refractory chamber before gas- cleaning. The sulphur dioxide content is low. Tapping areas and launders are provided with hoods for dust and fume collection and connected to a bag-filter. These fumes are mixed with the off-gas cleaning fumes and pelletised for recycling. As stated in CV.2.1.2 above, the slag needs further treatment. CV.2.3 BAT for Droesing and Decopperieing Production of an iron phase by any of the smelting processes combines much of the arsenic present in the charge: this is later separated for treatment for arsenic removal by roasting (see chapter CV.4.2). The remaining iron in the metal, with any copper, is removed by drossing continuously or batchwise at temperatures between 500 and 3OO0C, using dross-removal equipment which reduces the liquid metal content. Drosses drained of liquid metal are discharged through sprays to a quench and handled in enclosures. The iron drosses are recycled to the smelting stage where the iron is eventually removed from the system in the final slags. Copper drosses must be treated for copper extraction and the tin residue recycled.

CV.2.4 BAT for Refining It should be noted that the presence of bismuth in any of the products of refining by any technique will require a precautionary examination of the bismuth pro- . duct for its level of radioactivity due to the asso- ciation of the radionuclide Po 210 with bismuth. CV.2.4.1 Lead Removal Three methods are available for the removal of lead in tin: Distillation of lead (and some other elements), fractional crystallisation or electrolysis. The presence of silver or gold usually determines the process 105 since distillation and crystallisation are not completely effective in removing them. CV.2.4.1.1 Vacuum De-Leading A vacuum distillation unit is fed from a small kettle containing molten tin at a low temperature (350°C), and using one of two available plant designs, the metal is heated within a high-vacuum enclosure to 1200-1400OC. Lead and some other elements including Bi, As, In, evaporate and are condensed into a tin- lead solder phase, leaving pure tin. Both are removed as molten metal via barometric columns. The high-temperature part of the plant is totally enclosed, and presents no hazard or toxic emissions. The tin-lead alloy containing the impurities requires further treatment by electrolysis; see chapters CV.2.4.3 and CV.4.3. CV.2.4.1.2 Lead Removal by Fractional Crystallization A spiral crystalliser designed and manufactured in the People's Republic of China by the Yunnan Tin Corpora- tion is filled with impure tin and at 180-230°C pure tin crystals are deposited on the spiral arms and are continuously removed as a crystallising mass. A reser- voir fills with the impurity-rich liquid solder. The technique is non-polluting and is preferred to chlorine removal of lead except where the objective is the manufacture of tin chlorides. In presence of lead, bismuth is also removed. The impure liquid requires further treatment; see chapters CV.2.4.3 and CV.4.3. CV. 2.4.1.3 Electrolysie Electrolysis is undertaken for the removal of lead when recovery of precious metals and bismuth is possible. Other impurities, e.g. antimony and tellurium, are also concentrated in the slimes. Indium is only 50 % removed and, if present, requires separate treatment. Anodes and starting sheets are cast from decopperised metal and recycled cathodes, respectively, and electrolyzed in one of a choice of electrolytes at temperatures between ambient and 8OOC. Alloys of tin- lead can be refined directly to pure solders, or electrolysis to pure tin can be undertaken. Dust is not generated in the cell-house processing, butthe kettle used for melting cathodes requires hooding and installation of a bagfilter to collect dusts. Fumes should not be generated at the required operating temperatures. Anode slimes have to be treated in further pyro- and hydrometallurgical stages; see chapters CV. 2; 4.3 and cv. 4.3. 106 The economic advantage of electrolysis is based on the recovery of gold/silver; the method requires the retention of a much larger quantity of tin than the py-

rometallurgical techniques. Therefore though it is ~ more effective, it is not normally used. -~

CV.2.4.2 Removal of Antimony and Arsenic See CV.4.1.3 above. Antimony and arsenic are removed from tin and tin-lead solders by treatment at 250-260° with metallic aluminium or sodium. The reaction is carried out in a hooded, stirred kettle with enclosed dross removal. The drosses produced must be handled with great care into special receptacles, which are removed immediately to a furnace to avoid the risk of wetting and the production of toxic arsine or stibine. The furnace product is treated for recovery of antimony and arsenic after the drosses are "sweated" or "drained" in a reverberatory furnace at 800°C to recover tin or solder; the use of aluminium must be regarded as an inferior technology to the use of metallic sodium.

CV.2.4.3 R-val Of Bismuth See sections CV.2.4.1.2 and CV.2.4.1.3, as well as CII.1.2.4.1 on the removal of bismuth from lead. The same reaction is used for tin at 270 OC. In treating the bismuth drosses, the level of activity of Po 210 must be checked on an alpha-particle spectrometer. If the level is above 15 Bq/gm, the material will require treatment in accordance with the regulations for ionising radiations. The use of the Kroll-Betterton reaction cannot be regarded as BAT, now that the mechanical crystalliser (see chapter CV.2.4.1.2 on BAT for lead removal) is available. It may be necessary to add some lead if the bismuth:lead ratio of the tin is too low. The metallic concentrate produced by impurities from the crystalliser must also be examined for the presence of Po 210. CV.2.4.4 Removal of Indium Indium is removed by a reaction of tin with gaseous chlorine, conducted in a hooded kettle using a special reaction tank inserted in the kettle. High efficiency is achieved leading to a complete absorption of chlorine. Indium is removed as a molten slag at a low temperature through a hooded off-take. It is treated for indium recovery. 107 cv. 3 New Technologies for Tin Smelting The use of single-lance vertical injection of air- or oxy-fuel mixtures into a melt in a fixed vessel, in which both controlled reduction and oxidation and slag fuming take place, has been developed, it is called "Sirosmelt". This technique is in commercial development at present. A similar system using the TBRC technology developed in the secondary copper industry is in use in one low- grade smelter in the USA. Refractory problems have hindered adoption of this equipment. The feeding, handling, gas treatment and metals treatment of these furnaces is unchanged from existing practice. The main advantage is the ability to carry out consecutive treatments of metals and slag in the same vessel, avoiding transfer of the hot phases and reducing the opportunity for fugitive emissions. No special charge treatment is needed, but large lumps must be broken down.

CV. 4 Treatment of By-Products CV.4.1 Slap Treatment The tin content of concentrate smelts is too high for discard because of the metal value. Three methods of treatment are used: - Smelting with scrap lead or a lead-containint residue to give a tin-lead alloy and a low-tin slag. The product must be de-leaded as in CV.2.4.1 above, or used as solder. - Smelting slag at a higher temperature and reducing tin with iron. The iron has then to be oxidised into slag in the concentrate smelt. This places a strict limit on the iron content of the concentrates. - Fuming tin from slags or low-grade concentrates and collecting the tin as tin oxide fumes. Sul- phur in the form of pyrite is the reagent, producing a low-sulphur gas in amounts too small for acid production. CV.4.1.1 "Washingn with Lead Lead oxide residues or scrap metallic lead are smelted together with granulated slag in strong-reducing conditions. A blast-furnace or a short rotary furnace is used for this treatment (see chapters CII.1.4.1 and CII.1.4.2). The slag can be used; see chapter 108 CII.1.4.7. The tin is mostly contained in the resulting lead rich material. CV.4.1.2 High Temperature Reduction The slag produced in the first-stage smelt is mixed with carbon and extra limestone flux and smelted at a high temperature in a rotary or electric furnace. The slag can then be reduced to a discard level and is then used (see section CII.1.4.7). The tin is recovered as "hard-head" or tin-iron compound. It is returned to the first stage smelt where the iron is oxidised into slag. The extent to which this is possible places a strict limit on the iron:tin ratio of the original concentrates. The furnace is equipped as in CV.2.1.2 and CV.2.2 above. CV.4.1.3 Slag Fuming Slag fuming exists because it separates iron and tin by the volatility of tin sulphide. This also enables low-grade tin concentrates to be worked for tin recovery, even where they are very high in iron. A slag-fuming furnace is oil- or natural gas-fired by submerged combustion in the molten slag and can be charged with granulated or molten slag. Use of lump pyrites minimises dust production; conveying and charge mixing follow the notes in BIII.2 of this Note (Fugitive Emissions). Process gas can contain gaseous arsenic oxides, as well as tin oxide, sulphur dioxide and products of combustion. Tin oxide can be separated first by an electrostatic precipitator or baghouse running at a high temperature (30O-35O0C), arsenic at a lower temperature (EOOC). Sulphur dioxide because of the very cyclical nature of the process and the small quantities involved is not economically recovered. A wet scrubber using limestone slurry as a reagent will neu- tralise sulphur dioxide and fluoride if present, and react with any remaining arsenic to produce calcium arsenate which is filtered off in a cake containing calcium arsenate, calcium fluoride and a calcium sulphite/gypsum mixture. Note: The amounts of these oxidised products depend on the tin content of the slag and the impurities present in the charge material. The definition of BAT is difficult under these circumstances. The separation of tin and arsenic by high- temperature capture of tin allows the recovery of arsenic trioxide - white arsenic - in a separate bag filter. The operation of such a plant must meet the hygiene standards for As20 The product is impure and not saleable, so it must ge refined. The amounts in- 109 volved are not sufficient to lead to an economic operation. If the capture of tin is carried out in a baghouse, e.g. at 100°C, arsenic oxide condenses with the tin oxide and is smelted into the metal, though some is still in the gaseous condition and a wet scrubbing system is required to reduce the emission. If the arsenic is ultimately to be deposited, it is better practice to use a wet catching system which greatly reduces the hazards posed by arsenic within the plant.

CV.4.2 Arsenic Removal Various products containing arsenic have to be treated to recover tin: tin-iron compounds, lump "hardhead", iron-tin drosses arise from smelting, and sodium-tin drosses from refining. The drosses may be heated to remove fluid metallic tin; all these products are then ground in a ball-mill and roasted in a fluosolid roaster to volatilise the arsenic. Addition of iron pyrites may be necessary to achieve this if much iron is present. The materials handling follows the principles of CII.1.2.1 (BAT for Sintering). The calcine produced is quenched for handling and returned to the primary smelting circuit if the antimony content is not too high. The off-gases are cleaned by venturi scrubber or wet disintegrator scrubber to avoid producing dry arsenic trioxide. The aqueous solution of ar-senious acid produced can be oxidised to arsenic acid for disposal as ferric arsenate, or for manufacture of a marketable product if the quantity is suitable. cv.4.3 Lead, Antimony and Bismuth Removal All the refining techniques produce drosses, slimes or alloys containing all three of these, and possibly precious metals as well. These can be smelted with secondary lead and refined or electrolysed directly to give solder cathodes and a slime which is ultimately processed through a secondary lead circuit (see chapters CII .2 on secondary lead production and CV. 2.4.3). cv.4.4 Copper Recovery The treatment of copper drosses follows a similar route to that of lead copper drosses (see chapter CII.1.4.1 Copper Dross). Some cadmium, nickel, arsenic and selenium are also taken out by this route. Because of the value of tin, refining is carried out in spe- cialist secondary plants with intermediates arising from the copper refining circuits, and with final electrolytic refining. 110 CV.4.S Recovery of Zinc The secondary steel and copper industries produce oxide fumes as a result of refining operations which contain both zinc and tin oxides. These are frequently of low metal value especially in the case of those from steel refining, and in earlier times were dumped, despite their lead and cadmium content. Some are recovered via pyrometallurgical treatment (see chapter CIV.2.2.2 Zinc Pyrometallurgical Process), and some via the Waelz Process (see chapter CIV.3.1. BAT for Treatment of Oxidic Products). The general handling of these materials must follow the recommendations in Section BIII.2 (Fugitive Emissions). These residues are treated in Tin Works by hydrometallurgical processing, using dilute sulphuric acid to leave a tin-rich residue for smelting, as discussed in CV. 2.1. The zinc solution can be purified as mentioned in chapter CIV.2.1.2, though usually the amount of tin will not permit economic recovery by electrolysis; the purified solution is used in the manufacture of zinc based chemicals.

CVI References to Part Davenport, W.G. / Partelpoeg, E.H. (1987). Flash Smelting Analysis, Control and Optimisation. Pergamon Press

' von Ropenack, Dr. A. (1990). Integrierter Umweltschutz - Die Aufgabe der Zukunft. Vortrag anlafilich der GDMB- Hauptversammlung vom 26.-29.9.1990 in Miinster von Ropenack, Dr. A. (1991). Die heutige hydrometal- lurgische Zinkgewinnung. Vortrag der Tagung "Lead and Zinc in the 1990's" 5.-7.2.1991, Sao Paulo/Brasilien Sohn, H.Y. / George, D.B. / Zunkel, A.D. (eds. ) (1983). Advances in Sulphide Smelting. TMS-AIME 1983. Metallurgical Society, Inc. Taylor, J.C. / Traulsen, H.R. (eds.) (1988). Proceed- ings of Symposium on World Survey of Non-Ferrous Smelters. TMS-AIME 1988. Metallurgical Society, Inc. VDI-Richtlinie 2102 (1985). Emissionsminderung, Kup- ferschrotthotten und Kupferraffinerien. Entwurf Februar 1985 United Nations Economic Commission for Europe (1979). Guidelines for the Control of Emissions from the Non-Ferrous Metallurgical Industries. 111 PART Dx ANNEXES

DI EXamDleS of the Performance Characteristics of Duet Collectors Example 1: Wet Electrostatic Precipitator

Process : Imperial Smelting, Slag Granulation

Capacity: Zinc 85 000 tla Lead 38 000 tla

Gas flow from slag granulation: 55 000 mN’/h

Horizontal flow plate Wet-ESP

Specific collection area: 68 mz/(m3/sec) Overall collection area: 1284 ma Number of zones: 2 Number of rectifiers: 2 Rated high voltage: 50 kV (arith.) Rated current: 2 x 400 mA (arith.) Liquid to gas ratio: 0.8 iim9 Overall water flow: 45 m9/h (continuous spraying) Number of spray nozzles: 29 Energy consumption: 3 kWh/lOOO m3

Operation results

Raw gas Clean gas [ mg I I

Dust 150 - 5400 < 3.0 Zn 100 - 1350 0.1 - 1.5 Pb 28 - 520 0.1 - 0.8 As 1.2 - 5.4 < 0.05 Cd 0.13 - 0.21 < 0.05 112 Example 2: Wet Electroetatic Precipitator

Process: Tin refining Molten tin in pot furnace is treated with chlorine gas

Gas flow: 10 000 w”/h

Horizontal flow plate Wet-ESP

Specific collection area: 75 mz/(ms/sec) Overall collection area: 210 mz Number of zones: 2 Number of rectifiers: 2 Rated high voltage: 78 kV (peak) Rated current: 2 x 200 mA (arith.) Liquid to gas ratio: 1.7 l/m’ Overall water flow: 17 ms/h (continuous spraying) Number of spray nozzles: 29 Energy consumption: 3 kWh/lOOO ms

Operation results

Raw gas dust concentration: 0.5-2 glmd Clean gas dust concentration: 2-5 mglm’ Dust composition: 30-50 X Sn (Rest: chloride, Zn, Pb) 113 Example 3: Fabric Filter

Process: Zinc distillation in heavy oil fired columns

Capacity: 40 000 - 50 000 tla refined zinc

Waste Gas: flow: 25 400 - 43 900 mN*/h temperature: 190 -210 "C

Filter:

Filtration material: Teflon (PTFE)-fabric; area weight 320 g/mz Bag cleaning: Reverse flow, off-stream Number of compartments: 18 Number of bags: 720 Filter area (net): 1870 mz Filter rate (average): 0.5 m'/(mz min) Differential pressure (av.): 1800 Pascal

Operation results

Raw gas dust concentration: 0.14 - 2.38 glmd Clean gas dust concentration: 1 - 12 mg/m* Dust composition: Zn 15 - 69 x Pb 1 - 13.3 X Cd 0.05 - 0.76 X 114 Example 4: Fabric Filter

Process: Smelting of tin/lead residuals Tinllead ashes and other residuals are processed in a heavy oil- __ fired short rotary furnace. The waste gas at a temperaure of 600-10OO0C at the furnace exit is cooled by water injection (cooling tower, high pressure water atomization) to 400’C and by air introduction to finally 200°C.

Capacity: 9 t batches every 5-6 hours

Waste gas at filter inlet: flow: 11 000 - 27 000 nQ/h temperature: 130 - 240°C

Filter:

Filtration material: Teflon-fabric; area weight 320 g/mz Bag cleaning: Reverse flow, off-stream Number of compartments/bags: 18/560 Filter area (net): 1420 mz Filter rate (average): 0.4 m’/(mZ min) Differential pressure (av.): 1400 Pascal

Operation results

Raw gas dust concentration: 3 - 16 g/mN’ Clean gas dust concentration: 3 - 7 mg/mN’ Zn 0.1 - 0.8 mg/mN3 Pb 0.2 - 0.8 mg/mN* Sn < 0.1 mg/md As 0.1 - 0.3 mg/nkg 115 Example 5: Fabric Filter

Process: Smelting of lead scrap Lead battery scrap is processed in heavy oil-fired short rotary furnaces. Process flue gas and tapping fumes (captured by hood) are mixed and delivered to a gaslair tube-type cooler: reducing temperature from 32OoC to 100°C.

Capacity: Feed 15 t/24 h; output 6 t lead/24 h

Waste gas at filter inlet: flow: 600 - 10 000 m2/h temperature: EO - 100°C

Filter:

Filtration material: Acrylnitrile-needle felt Bag cleaning: Pulse jet, onstream Number of compartments/bags: 2/304 Filter area: 340 ma Filter rate: 1 mgl(mz min) Lifetime of bags: 1 year

Operation results

Raw gas dust concentration: 2.5 - 5 g/mN’ Clean gas dust concentration: 2 - 6 mg/md Clean gas Pb concentration: 0.4 - 3 mg/mN3 Clean gas As concentration: 0.1 - 0.3 mg/mw3 Clean gas Sb concentration: < 0.01 mg1m.3 116 Example 6: Fabric Filter

Process: Lead refinery of a primary lead smelter ~

Lead refining kettles and other pot furnaces have been hooded and - ~ the exhaust gas from the hoods was delivered to a fabric filter.

~ This installation has reduced roof emission of the smelter room __ by more than 95 X.

Cauacitv: 120 000 t lead I year

Waste gas at filter inlet: 52 000 m2Ih at 5OoC

Filter:

Filtration material: Polyester-needle felt Bag cleaning: Pulse jet, onstream Number of compartments: 23164 Filter area: 1500 mz Filter rate: 0.6 m’l(m2 min)

Oueration results

Raw gas dust concentration: 0.11 - 0.35 g/mN3 Clean gas dust concentration: 0.1 - 0.6 mg/nhs Dust composition: Pb 14 - 38 % Zn 3 - 28 X 117 DI I Exmule of Emissions Fiuures of Primarv Lead Production DII. 1 Introduction In the following Table, emission figures are outlined for primary lead production concerning the traditional route sinter plant / shaft furnace operation and the new or direct smelting technologies. The emission figures do not include emissions from raw material stockpiling facilities, refinery and by-product treatment, as these areas in primary lead smelting will be replaced by new technology. The emission figures presented in the papers are referring only to stack emissions. Emissions from roof operations and fugitive emissions are excluded. The figures are pre- senting examples for a traditional smelting technique (actual figures) and a QSL plant (proposed figures) and a Kivcet plant (actual figures). It is important to refer to chapter C, section 11.1.3.1 (Kivcet Process) and to section 11.1.3.4 (QSL Process) with regard to their full industrial capabil- ity when comparing the plant performance data shown below.

DII. 2 Table I Stack Emissions of an 80 000 tpy Primary Lead Smelter (Examples)

Unit

Sinter plant I Shaft furnace 264 000 12 083 4979 654 105 30

QSL plant ’ 180 000 4 205 1233 292 8 3

Kivcet plant 168 000 2 792 915 228 4 no data available

’ Operating tim 8300 / 8400 h/a Operating tim 7730 h/a ’’ Operating tim 7960 h/a 118 DIII plant Authorieation Procedures in E.C Member States DIII.l According to Article 16 of Directive 84/360/EEC, Mem- ber States shall bring into force the laws, regulations and administrative provisions necessary to com- ply with its provisions not later than 30 June 1987. At that date, only Greece had failed to communicate its internal measures to the Commission, so that noth- ing can be said about the actual legal situation in that country. With regard to the other countries, the situation is smarised Table DIII.l(a). DIII. 2 Installations for which Authorieation is Required in Member States All Member States except Greece claim that their national legislation covers all aspects of the Direc- tive. Some countries have laid down in their legislation a detailed list of installations which have to undergo a licensing procedure prior to operation. In Belgium, a "List and Classification of Dangerous, Dirty and Noxious Industries" is given in the General Regulation for the Protection of Labour, Chapter 11, Title I. All installations mentioned there must be subject to an authorisation procedure prior to construction, conversion, relocation and, consequently, operation. According to the danger emanating from these installations, they are divided into three cate- gories : - source of major hazard, approval at provincial level; - less important, small installations, approval at local government level; - notifiable installations which by virtue of their inferior importance do not require any formal approval. All installations covered by this Technical Note are part of the first category. Table DIII.2(a) provides an overview of the relevant installations listed in the Belgian legislation. In Denmark, the Environmental Protection Act contains a "List of Enterprises, Plants and Activities" which - need authorisation prior to operation, under heading A "Production and Manufacture of Iron, Steel or Met- als" point 5.2 "Iron Foundries, Steel Foundries, Non- Ferrous Metal Foundries and Refineries" are included. More detailed descriptions are not provided. In the P.R. Germany, the Fourth Order implementing the Federal Immission Control Law (Order on Installations Subject to Licensing) contains a list of installations 119 which have to go through a licensing procedure. The order distinguishes between installations which have to undergo the full licensing procedure according to Article 10 of the Federal Immission Control Law and installations which have to undergo the simplified procedure laid down in Article 19 of the Federal Im- mission Control Law. Table DIII.2(b) lists the installations relevant for this Technical Note. In France, the act of 19.7.1976 lists some 400 "clas- sif ied installations", divided into two main catego- ries: installations in class 1 are subject to authorisations and have to meet certain requirements governed by prefectoral decrees. Notification by the owner or operator of installations suffices for the other class. Table DIII.2(c) lists those installations mentioned in the act which are relevant for the sector non-ferrous industrial plants. In Ireland, in accordance with 1988 Regulations made under the Air Pollution Act, 1987, all plants must be licensed from 1.2.1989 by local authorities. The regulations also specify certain classes of existing plants which are licensable from 1.3.1989. Article 6 (1) of the Act defines the term "industrial plant" as follows :

I' 'Industrial Plant' in this Act means any plant, equipment, appliance, apparatus, machinery, works, building or other structure or any land or any part of any land which is used in the course of trade, busi- ness or industry €or the purposes of, or incidental to, any industrial process specified in the Third Schedule. 'I The Third Schedule mentioned in this Article is to a large extent identical with Annex I of Directive 84/360/EEC. Table DIII.2(d) lists the installations mentioned there which are of relevance for this Tech- nical Note. Existing plants licensable from 1.3.1989 include plants specified at Code no. 27, in Table DIII.2(d). In Italy, trade and industrial processes which cause air pollution are classified into two groups. The first relates to industrial installations which must - be established far away from residential areas; the second relates to trade activities. As a rule, the Ministry of Health issues a new list of classified installations every three years. Unfortunately, such ~ a list has not been made available to the working group. In LUX^"^, Annex I of Directive 84/360/EEC has been transplanted literally into national law (Regle- ment ministeriel du 22.8.1987). However, of more im- 120 portance for the practice of licensing is the list of classified installations attached to the law of 16.4.1979, relating to dangerous, dirty or noxious installations. The establishments are divided into three classes. The existence, operation, transfer, extension or conversion of establishments in classes 1 and 2 is subject to authorisation; class 3 establishments are subject to a written declaration to the Inspectorate of Works and Mines. Table DIII.Z(e) lists the installations relevant for this report. All installations mentioned there belong to class 1. In the Netherlande, the Air Pollution Act requires that no establishment belonging to a list of about 400 industrial installations may be set up or operated without a permit issued by the provincial authorities. Table DIII.Z(f) lists the installations relevant for this report. In the Portugueee legislation, Administrative Order no. 110/85 requires that all establishments where one of twenty-four activities listed in its Annex is carried out, must have a special authorisation from the General Directorate for Environmental Quality in all air pollution matters. All installations covered by this Technical Note are included in the category "In- dustries of non-ferrous metals" of the Annex in the Administrative Order. In the Spanieh legislation, the Royal Decretes 1302/86 and 1131/88 detail special conditions that apply to activities that pollute the atmosphere concerning installation, extension, modification or relocation. These activities are classified in three groups A, B and C, according to the degree of potential pollution. Authorisations are granted by the central administra- tion, regional or local authorities through a corresponding licence. Table DIII.Z(g) provides an overview of the installations which require authorisation prior to operation. In the United Kingdom, the Environmental Protection Act 1990 has recently become law, and the relevant regulations under this Act came into force on 1 April 1991. Those types of processes with the greatest pollution potential or the most scope for cross-media control will be subject to a system of Integrated Pollution Control (IPC) which covers releases to air, water and land. Operators of processes scheduled for IPC will require an Authorization issued by Her Majesty's Inspectorate of Pollution (HMIP) specifying the use of BATNEEC to prevent the emission or discharge of pollutants were required by UK and EC legislation. For processes where there is potential to release pollutants to more than 121 one environmental medium the operator must satisfy the national inspectorate that he is employing the Best Practicable Environmental Option and that pollution to the environment taken as a whole is minimized. Proces- ses prescribed for air pollution control only will be regulated by local authorities. All new and substantially modified scheduled processes are subject to IPC; existing processes will be brought under IPC in a phase programme. Existing smelting processes come under IPC from 1 January 1995 and existing non-ferrous metal processes from 1 May 1995; until then regulation of such processes will continue to be based on the pre-IPC legislative framework. Table DIII.Z(h) lists the installations which come under points 2.1 and 2.4 of Directive 84/360/EEC.

DIII. 3 Emission Limits and Guideline Values Applied in Member States for Non-Ferrous Industrial Plants Two types .of emission values are of importance for the industrial sector concerned: - values for specific heavy metals or groups of heavy metals; - values for dust emissions. Limits for dust emissions can in principle not replace the specific values for heavy metals because the quantity of metals associated with dust emissions differs from one process to the other. However, these limits nevertheless contribute to the reduction of heavy metal emissions in many cases. Moreover, emission reduction measures usually aim at reducing dust emissions to the degree found to be necessary in order to avoid dust and/or heavy metal emissions. Therefore, limit and guideline values for dust are presented as well. The values are separately presented in the following section, starting with those for heavy metals. Legally binding national emission limits for the industrial sector concerned are laid down in only two countries: F.R. Germany and Spain. In two other coun-

tries, more or less exhaustive emission guideline va- ~ lues exist, Italy and United Kingdom. In the remaining countries (Belgium, Denmark, France, Ireland, Luxembourg, the Netherlands and Portugal)', ~ no emission limits or guidelines are fixed. Very often, the values are subject to negotiations between the operator and the authority responsible for

1 No information is available for Greece. 122 granting licenses. In some countries, these authorities are of local character, so that even within one and the same country, different air pollution requirements may apply for comparable plants. In the Benelux countries the licensing authorities take into account emission limits applied in other countries, in particular those laid down in German law, in their negotiations with operators. With regard to heavy metal emissions, the sitution is as follows: In Belgium, no legally binding emission limits are laid down for non-ferrous metal plants. The emission limits are defined for each individual plant in the operation permit. When defining these limits, the licensing authorities take into account limit and guideline values applied in other countries, in particular in F.R. Germany. In Denmark, no legally binding emission limits are laid down. However, new air pollution guidelines will regulate the emission of all substances mentioned in Annex I1 and all installations mentioned in Annex I in the near future. In the F.R. Germany, legally binding emission limits relevant for this report are laid down in sections 2.3 and 3.1.4 of the Technical Instruction on Clean Air. In strict terms, the Instruction is just an administrative regulation and only binds administrative authorities. However, indirectly it has a certain binding effect to the operators of plants as well via the approval procedure. The emission limits in force which are relevant for the industries concerned in this Technical Note are displayed in Table DIII.3(a). It is notable in the German approach that emission limits are laid down for a large number of heavy metals, irrespective of the industrial process. The approach adopted is substance-oriented rather than source-oriented. The heavy metals are separated into three classes, depending on their harmful potential for human health and the environment and with regard to the applicability of advanced control technologies by taking into account the applicability of advanced source- specific control technologies. In France, no legally binding emission limits for heavy metals emitted by the processes regarded in this report are laid down. The emission limits are defined for each individual plant in the operating permit. No information about emission limits for heavy metals applied in Greece has been made available to the working group. 123 In Ireland, no national legally binding limit values for heavy metal emissions, relevant for the sectors concerned, are laid down. The Air Pollution Act of 1987 requires the application of "best practicable means". Legally binding emission limit values are applied at a local level by the relevant licensing authorities. These values are being reviewed in the context of licensing relevant plants under the 1988 Reg- ulations. At present it is still necessary for local authorities to make themselves familiar with the current state of technical knowledge, performance standards achieved by various emission control technologies, processes, operating methods and other alterna- tives which have been developed for various plants, so that they are in the position to attach effective and realistic emission limits to licences. However, direc- tions specifying the "best practicable means" in relation to particular classes of industrial plants are in preparation - taking into account the German TA Luft and other international standards to assist in implementing the licensing regulations. In Italy, according to Article 20 of Law 615, all industrial plants must have installations and devices for the abatement of air pollutants to the lowest technically feasible levels, i.e. adopt the "best technical means" available. Moreover, according to Article 3 of the technical regulation DPR number 322 of 15.4.1971, all sections of an industrial factory which can contribute to air pollution must have an abatement plan. Legally binding emission limits are not laid down in the Italian legislation for non-ferrous metal plants. However, there are emission limits for lead mentioned in Article 8 of DPR 322 which have the character of guideline values (see Table D111.3(b)). The approval document to be issued by local authorities may contain more detailed emission limits to be met by the individual plants. In Luxembourg, no legally binding emission limits for heavy metals are laid down. Those of the German Tech- nical Instruction are unofficially applied as guideline values. In the Netherlands, the permit to be obtained by all industrial plants causing air pollution (either under - the Air Pollution Act for large installations or under the Nuisance Act for small ones) sets limits to per- missible emissions for individual plants.

~ In Portugal, no legally binding emission limits are laid down for non-ferrous metal plants. The emission limits are defined for each individual plant during the licensing procedure. When defining these limits, the licensing authorities take into account limit and guideline values applied in other countries. A new law 124 concerning air quality protection is under discussion and will establish legally binding emission limit values for several industrial processes, as well as emission limit values of general application. In Spain, legally binding heavy metal emission limit values are laid down for a few processes in the decree of 6.2.1975. Table DIII.3(c) provides an overview of these values. In the United Kingdom, no legally binding uniform emission limit values for the non-ferrous metal industries are laid down. However, legally enforcable limits are set on a site-by-site basis; these limits being based on achievable levels of releases of particulate heavy metals to air are given in "Chief In- spector's Guidance to Inspectors - Metal Industry Sector" (Table DIV.3(d)). The duty to use available techniques not entailing excessive costs also requires control over those emissions which are not capable of being measured and for which therefore no emission limit can be set (fugitive or uncontained emissions). In addition industry is required not only to provide equipment and systems for the prevention of emissions, but also to ensure proper and effective use and supervision of all operations where harmful or offensive substances may be involved. With regard to emission limits for duet, the situation looks similar to that for specific emission limits for heavy metals: o Legally binding emission limits are laid down in F.R. Germany and Spain. o Guideline values are available in Italy and the United Kingdom. o Neither kind of nationally binding value applies for Belgium, Denmark, France, Ireland, Luxem- bourg , the Netherlands and Portugal'. - In F.R. Germany, in addition to the emission limit values for specific heavy metals, dust emissions are also included in the Technical Instruction (see Table DIII.3(e). In addition to these limit values, general rules concerning the reduction of emissions of dust due to treatment, production, transport, handling and storage of dusty materials (which might contain heavy metals ) are given in section 3.1.5. Finally, some spe-

Insufficient information is avaliable for Greece. 125 cia1 requirements are laid down in chapter 3.3.3 (see Table D111.3(e)). - In Italy, guideline values for dust emissions are laid down in Article 8 of DPR 322 (see Table D111.3(f)). - In Spain, the emission limits given in Table DIII.3(g) are laid down in the decree of 6.2. 1975. - The "Chief Inspector's Guidance to Inspec- tors - Metal Industry Sector" of the United Kingdom also provide guideline values for dust emissions (see Table DII1.3(h)). 126

Table DIII.l(a)r Laws, Orders and Regulations Considered Relevant for the Implementation of Directive 84 / 3 6O/ EEC

Member State Name of Law, Order or Regulation __

Bslaiurn' - reglementering op als gevaarlijk. ongezond of hinderlijk ingedeelde inrichtingen, zijnde. titel I van het Algmn Reglant van de Arbeidsbescherming. R.E. 11.2.1946 - wet van 28.12.1964 op de bestrijding van de luchtverontreiniging, B.S. 14.1.1965 - KE 13.12.1966 betreffende de voorwaarden en modaliteiten voor de erkenning van de labora- toria en instellingen die belast zijn mt de mnsternemingen. ontledingen. proeven. en onderzoekingen in het kader van de bestrijding van de luchtvervuiling - KE 26.7.1971 tot oprichting van zones vwr speciale bescherming tegen luchtvervuiling - KB 8.8.1975 ter vwrkaning van luchtvervuiling door SO. en stof, afkmtieg van industri- ele verbrandingsinstallaties - KB 25.9.1978 tot regelantering van het gebruik der benamingen en kenmrken van zware minerale olien, bestemd am als brandstof te worden gebruikt. - Nov 10. i988: Arrete de I'Executif regional wallon mrdifiant le titre premier, chapitre premier du R6glmnt general pour le Protection du Travail - Nov 18. 1988: Arret6 royal relatif a la d6namination aux characteristiques et a la teneur en soufre de combustibles residuels (alroge I'AR du 15/Sept/78) - Dec 29, 1988: ArrW royal concernant la prevention et la reduction de la pollution de I'air par l'amiante

-Denmark - Lov nr. 178 of 24. maj 1972 am bortskaffelse m.v. af olie- og kemikalieaffald - Lovbekendtgbrelse no. 05 af 8. marts 1985 om miljbbeskyttelse - Lov nr. 329 af 4. juni 1986 om sndring af lov am miljbbeskyttelse, og - Miljbministeriets bekendtgbrelse nr. 783 af 21. november 1986 am godkendelse af saerligt forurendende virksomheder m.v. - Milj+ministeriets bekendtg+relse nr. 68 af 24. januar 1989 af Lov om Miljabeskyttelse

FA Germany - Gesetz zum Schutz vor schadlichen Urrmelteinwirkungen durch Luftverunreinigungen. Gerau- sche. Erschiitterungen und ahnlichen Vorgilngen (Bundes-lmnissionsschutzaesetz - ElmSchG) vm 15. Marz 1974 (EGE1. I S. 721. 1193). zuletzt geandert durch Art. 5 der Dritten Zu- standigkeitsanpassungs-Verordnung vom 26. November 1986 (EgE1. 1 S. 2089) - Vierte Verordnung zur Durchftihrung des Bundes-lmnissionsschutzgesetzes (Verordnunq uber qenehmiqunqsbedurftiqe Anlaqen - 4. BImSchV) (BGB1. I S. 1586). zuletzt getindert durch Verordnung zur Neufassung der Ersten und Vierten Verordnung zur Qurchfiihrung des 8undes- Imnissionsschutzgesetzes van 15. Juli 1988 (BGB1. I S. 1059) - Neunte Verordnung zur Ourchfllhrung des Eundes-Imnissionsschutzgesetzes (Grundsatze des Genehmiaunasverfahrens - 9. ElmSchV) vam 18. Februar 1977 (EGBI. I S. 274). geilndert - durch Verordnung van 27. Juni 1980 (EGEI. I. S. 277) - Qreizehnte Verordnung zur QurchfUhrung des Eundes-lmnissionsschutzgesetzes (Verordnunq ubar Groefeuerunqsanlaqen - 13. BlmSchV) vam 22. Juni 1983 (EGBI. I S. 719) - Erste A1 Igmine Verwaltungsvorschrift zum Bundes-Imnissionsschutzgesetz (Technische An- ~ leitunq zur Reinhaltunq der Luft - TA luft) vom 27. Februar 1986 (GMEI. S. 95, 202)

-France - Decret 74-414 du 23.5.1974 - Loi 76-663 du 19.7.1976 relatif aux installations classees pour le protection de I'environnmnt - Decret 77-1133 du 21.9.1977

It should be mntioned that the three administratively indenpendent regions of Belgium have the possibility to impose particular requimnts for the establishment and operation of plant. .I. 127

Table DIII.l(a) - continued Laws, Orders and Regulations Considered Relevant for the Implementation of Directive 84/360/EEC

Member State Name of Law, Order or Regulation

~~~~~~~ ~ ~ - Oecret no. 80-813 du 15 octobre 1980 relatif aux installations classees pour la protection de 1 'environneuent - Circulaire du 21 mars 1983 - Circulaire du 22 juillet 1983 - Loi no. 85-661 du 3 juillet 1985 mdifiant et cmp1Btant la loi 76-663 du 19 juillet 1976 relative aux installations classees pour la protection de I'environnmnt - Circulaire du 30 aolit 1985 - Arrete du 9 juin 1986 - OBcret du 26.9.1986 - Decret no. 87-279 du 16 avril 1987 relatif aux conditions d'application de la loi no 64-1245 du 16 dec. 1964 aux installations classees pour la protection de I'environnmnt - Arret6 du 4 fevrier 1988 - Circulaire ininisterielle du 7 mars 1988

- Air Pollution Act of 1987. - Licensing of Industrial Plant Regulations of 1988.

- Legge n. 615 del 13.7.1966 - D.P.R. n. 322 del 15.4.1971 - O.P.C.M. n. 30 del 28.3.1983 - O.M. n. 105 del 10.3.1987 - 0.P.R.no. 203 del 24.5.1988

Luxenhourq - Loi du 16 avril 1979 relatif aux Btablissements dangereux. insalubres et incomnodes - Reglement grand-ducal du 23 decembre 1987 relatif aux installations de combustion alimn- tees du combustible liquide ou gaseux - R€glmnt ministeriel du 22 juillet 1987 portant publication de la Directive 84/360

Netherlands - Besluit van 6 septder 1972 tot uitvwring van de artikelen 21, eerste en derde lid. 24, eerste en derde lid. 32. 33, tweede lid, 34. derde lid, 40, eerste lid, en 73, eerste lid, van de Wet inzake de luchtverontreiniging (Stb. 1970, 580) (Vergunningenbesluit inrichtingen luchtverontreiniging) - Besluit van 28 decerrber 1977 tot wijziging van het Inrichtinqenbesluit artikel 19, eerste 1 id, Wet inzake de luchtverontreiniging - Vergunningenbesluit luchtvemntreiniging (statutory instrument, 23-4-1980. Stb. 407) - Beschikking van de Minister van Justitie van 21 augustus 1980. houdende plaatsing in het - Staatsblad van de tekst van het Hinderbesluit (Stb. 1953, 36). zoals dit laatstelijk is gewijzigd bij Koninklijk besluit van 23 april 1980. Stb. 303 - Hinderbesluit (statutory instrument, 12-1-1984. Stb. 7) - lnrichtingenbesluit ex. art. 19 Wet Luvo. 28-12-1984. Stb. 709, 25-8-1978, Stb. 444, __ statutory instrument) - Hinderwet (29-8-1985, Stb. 494); - Wet inzake de luchtvemntreiniging (12-12-1985, Stb. 655; entered into force 1-2-1986) Netherlands cont. - Wet algemene bepalingen Milieuhygiene. 23-4-1986, Stb. 211 - Besluit va 10 april 1987. houdende emissie-eisen stwkinstallaties Wet inzake de luchtverontreiniging - Richtlijn "Verbranden" van 21.8.1989

.I. 128

Table DIII.l(a) - continued

Laws, Orders and Regulatione Considered Relevant €or the ~ Implementation of Directive 84/360/EEC -~

~ ~~ or Menber State Nam of Law, Order Regulation __ Portuqal - Law no. 1947 of 12 February 1937 - Decree no. 29 034 of 1 October 1938 - Decree-Law no. 46 923 of 28 March 1966 - Decree-Law no. 46 924 of 28 March 1966 - Order no. 24223 of 4 August 1969 - Decree-Law no. 446176 of 5 June 1976 on the licensing of electricity generating plants. - Decree-Law no. 255180 of 30 July 1980 - Administrative Order no. 110185 of 20 November 1985

- Decree no. 2414161. 30 NOV. 1961. Rules and Regulations for Annoying, Insalubrious, Noxious and Dangerous Industries. - Law no. 33/72, 22 Dec. 1972. Protection of Atnospheric Environment. - Decree no. 833175, 6 Feb. 1975. Development of Law 38172. Inmission Levels, Characteris- tics and Functions of the National Net for the Vigilance and Prevision of Air Pollution, Definition of Polluted Areas, Emergency Situations, Emission Levels, Catalogue of Poten- tially Air-Pollutant Activities, Regulations for Installation, Enlarge"., Modification and Operation of the Air Pollutant Activities. - Order 18 October 1976. Prevention and Correction of Atmspheric Pollution from Industrial Activities. Procedure and Regulations for the Authorization of New Plants and Vigilance of Actual and New Plants. Sampling Methods. Calculation Methods for Stack Height. Re- quirements for Cooperating Laboratories. - Royal Decree Legislative no. 1302186, 28 June 1986. Enviromnt and EEC. Evaluation of Envirmntal Impact. Authorizations. - Royal Decree no. 1131188. 30 Sept. 1988. Rules and Regulations for the Implentation of the Legislative Royal Decree no. 1302186.

United Kinadom -Acts: - Alkali etc. Works Regulation Act 1906 as it applies to Great Britain (this is further amended by the Health and Safety (Emissions into the Atnosphere) Regulations 1983) - Alkali etc. Works Regulation Act 1906 (as it applies to Northern Ireland) - Health and Safety at Work etc. Act 1974 - Enviromntal Protection Act 1990

Requlations and Orders: - The Alkali etc. Works Reaulation- Order (Scotland) 1933 - The Alkali etc. Works (Registration) Order 1957 - The Alkali etc. Works (Registration) Order (Northern Ireland) 1981 - The Health and Safety (Emisslons into the Atnosphere) Regulations 1983 - The Alkali etc. Works Order (Northern Ireland 1987) - The Control of Industrial Air Pollution (Registration of Work) Regulations 1989 - The Health and Safety (Emissions into the Atmsphere) (Amendrent) Regulations 1989 - The Enviromntal Protection (Prescribed Processes and Substances) Regulations 1991 (SI 1991/472) - The Envirormental Protection (Applications, Appeals and Registers) Regulations 1991 (SI 1991/507) - The Envirormental Protection (Authorization of Processes) (Determination Periods) Order 1991 (SI 1991/513) - The Enviromntal Protection (hnhntof regulations) Regulations 1991 (SI 1991/836) - Public Health, England and Wales and Scotland, The Disposal of Contmlled Waste (Exeptions) Regulations 1991 (SI 19911508) 129

Table DIII.2(a)r List of Classified Installations of the Belgian Law Relevant for the Sector "Non-Ferrous Metal Plants"

Code nmer of installation Name of installation according to Belgian law

136 (174) Facilities for desilvering copper

137 (171) Extraction or refining by resmelting of the copper content of scrap fran workshops where copper or its alloys are worked

138 (172) Manufacture of copper by hydmprocessing (chloridation process)

165 (41) Manufacture of tin foil and loaf. Silvering of mirrors

184 (216) Foundries ... Enamelling of cast metals. See: Sheet and plate

259 (220) Pickling of metals

260 (221) Refining of precious metals

261 (222) Manufacture. refining and processings of metals by pyrogenic methods:

1. Blast furnace (Ore stack yards, blast furnaces, blast air heaters, gas filtering and scrubbing equipent) 2. Steelworks (Pig iron mixers, cupclass converters) 3. Ironworks (Furnaces, rolling mills, hamrs) 4. Zinc foundries (Furnaces) 5. Works: Lead, silver, copper and other netals (Furnaces, tanks, converters, leaching or electrolysis equiprent for the mnufacture and refining of metals) 6. Rolling mills for imn. steal, zinc and copper (Furnaces, tanks, rolling stands hmrs) 7. Forges (Furnaces, drop hamrs. presses).

263 (84) Treatment of ores and the like

a) Washing and concentration, not including anciliary facilities in the imne- 165 (41) diate vicinity of mines b) Mechanical preparation, not including anciliary facilities in the (&late vicinity of mines c) Roasting ... d) Calcination and sintering ...

270 (2341 Nickel production

304 (150) Lead product ion

305 (195) Production of lead alloys 130

Table DIII.Z(b): List of Classified Installations of the German Law Relevant ~ for the Sector "Non-Ferrous Metal Plants" -~

3.1 Installations for roasting (heating with air supply to convert into oxides). smelting or sintering (pelletizing of fine- grain materials by heating) of ores

3.4 Smelting plant for zinc or zinc alloys Smelting plant for zinc or zinc alloys for a for a charge of 2000 kg or mre smelting charge of 50 to less than 2000 kg or smelting plant for other non-ferrous metals, in- plant for other non-fermus metals. including cluding refinery installations for a refinery installations for a charge of 50 to charge of 500 kg or mre. excluding: less than 500 kg. excluding: - vacuum smelting plants: - vacum melting plants: - smelting plants for low-smelting point: - smelting plats for low-smelting point cast - cast alloys of tin and bisnuth or of alloys of tin and bisnuth or of high-purity high-purity zinc. aluminim and copper: zinc. alminium and copper: - smelting plants which are part of pres- - smelting plants which are part of pressure sure or gravity dye casting machines: or gravity dye casting machines: - smelting plants for precious metals or - smelting plants for precious metals or alloys consisting solely of precious alloys consisting solely of precious metals metals or precious metals and copper: or precious metals and copper: - flow soldering baths. - flow soldering baths.

3.0 Foundries for non-ferrous metals. exclu- Installations consisting of one or mope ding: pressure casting machines with locking - foundries for bell or art casting forces of 2 meganewtons or mre - foundries in which metallic imulds are used for casting - foundries in which the metal is melted down in travelling pots, and - foundries producing drawing dyes fma cast alloys melted down in 3.4 - 3.14 Installations for the crushing of scrap Installations for the crushing of scrap metal metal by rotor milling with a minal ca- by rotor milling with a ncininal capacity of pacity of the rotor drive of 500 kilaratts the rotor drive of 100 kilowatts to less than

or mre 500 kilaratts ~ 131

Table DIII.2(c): List of Classified Installations of the French Law Relevant for the Sector 'Won-Ferrous Metal Plants"

~ ~~ ~~~~ Code nlmber of installation Name of installation according to French law

60 Manufacture of antimony sulphide. Roasting of antimony ores: see 294

143 Manufacture of derivatives of chraniun such as chmtes, chranic acid. chraniun oxide

161 Manufacture of copper sulphate:

1. with roasting of pyrites. 2. by washing of oxidized pyrites, 3. by the action of sulphuric acid on copper wtal or scrap or wastes.

Copper, brass and bmnze foundries: see 284. Grinding and crushing or copper canpounds: see 89 bis. Roasting of copper or nickel ores: see 292.

162 Treatment of copper or nickel ores otherwise than by masting:

1. In shaft furnace or reverberatory furnace 2. In electric furnace ...

163 Treatment of copper or nickel mtte

279 De-tinning of wtals with chlorine

283 Manufacture of metals and alloys be pyrogenic electrolysis. where aggregate furnace pwr exceeds 25 kW

284 Metal and alloy foundries:

1. with treatment, even incidentally. of scrap such as swarf. fillings etC., or of mare scrap metal or alloys, impregnated. steeped or coated with various foreign substances such as oil. paint, insulants, etc.. or mixed with various substances foreign to the desired and product

a) in the case of lead and if lead-containing dust, smke and gases are not recovered: b) in all other cases ...

2. In all other cases ...

285 Tenpering. annealing or quenching of wtals and alloys

.I. 132

Table DIII.2(c) - continued List of Classified Installations of the French Law Relevant for the Sector "Non-Ferrous Metal Plants"

Code nurber of installation Nmof installation according to French law

207 Treatment of metals with acids

1. Pickling by imnersion (see 288) 2. Pickling by spraying, sloshing, foam and gel:

a) where the amunt of acid solution in use exceeds 1500 litres: b) where the amunt of acid solution in use does not exceed 1500 litres.

3. Vapour-phase pickling ... 4. Other treatments ...

292 Sintering of iron ore

293 Washeries for ores, minerals or metallurgical residues, with a treatment capacity exceeding 10 t/day

294 Roasting of ores containing sulphur or arsenic:

1. With gas condensation and dust recovery: 2. In all other cases ...

295 Hot treatment of ores with sulphuric acid for mtals extraction or preparation of mtal Iic sulphates

348 Refinining or cupellation of lead

349 Oesilvering of lead by zinc addition

416 Reduction of zinc ores 133

Table DIII.2(d)r List of Classified Installations of the Irish Law Relevant for the Sector "Non-Ferrous Metal Plants"

Code rider of installation nam of installation according to Irish law

4 The roasting and sintering of mtal ores in plants with a capacity of nwre than 1,000 tonnes per year

7 The pmduction and mlting of non-ferrous mtals in installations having a capacity greater than 1 tonne for heavy mtals or 0.5 tonnes for light mtals

9 The production of a conpound or alloy of magnesium

27 The extraction or recovery, by burning or by the application of heat, of aluminium. zinc. copper or lead. fmn any scrap mtal or alloy, waste material or residue including scrap or waste cable 134

Table DIII(e):

List of Classified Installations of the Luxembourg Law ~ Relevant for the Sector "Non-Ferrous Metal Plants" -~

.~ Code nunber of installation Nane of installation according to Luxdouq law

35 Manufacture of arsenical substances

118 Manufacture. extraction and refining of copper

121 Pickling of metals. See: Metals 229

141 Electrolytic treatmnt (Extraction, refining and protective coating)

151 Production of tin

229 Production, mnufacture. refining, treatmnt and processing of m?talS

231 Ores and the like (Treatmnt. washing and concentration, mechanical preparation. roasting. calcination and sintering)

261 Manufacture of lead or lead campounds 135

Table DIII.Z(f): List of Classified Installations of the Dutch Law Relevant for the Sector "Non-Ferrous Metal Plants"

Code nuher of installation Name of installation according to Dutch law

709. Besluit 28.12.77 a. 1'. Installations for the grinding. roasting. pelletizing or sintering of Inr ichtingenbeshit ores. with a total capacity of 1000 t or mre per annum:

2'. 2'. Installations for the production of pig iron, crude steel or primary non-ferrous netals. with a total capacity of 1000 t or mre per annum:

3'. Installations for the loading, unloading or storage of ores. with a storage area for ores of 0.2 hectares or over:

4'. Installations for the snelting or casting of aluminium alloys or copper alloys, with a total capacity of 4000 t or mre per annum;

5'. 5'. Installations for the snelting of lead, with a capacity of 2500 t or mre per annum, with the exception of printing works. 136

Table DIII.2(g)i List of Classified Installations of the Spanish Law Relevant __ for the Sector "Non-Ferrous Metal Plants" -~

.___ Code nu&r of (nstallation Nane of Installation according to Spanish law

Group 1.4 Lead production by shaft furnace

Lead refining

Lead production by secondary sirelting (recovery of scrap lead)

Zinc pmduction by reduction or distillation

Production of crude or black copper by shaft, reverberatory or rotary furnace

Copper production by converter

Copper refining by electrolysis

Production of antimny. cadmium, chrmium. magnesium. manganese, tin and mercury

Production of metals and alloys by igneous electrolysis when the furnace is rated at mre than 25 kH 137

Table DIII.l(h)r List of Classified Installatione of the British Law Relevant for the Sectors aRoastinqn and “Non-Ferrous Metal Plants”

The Enviromntal Protection Act (Prescribed Processes and Substances) Regulations 1991 (SI 1991/472) came into force on 1 April 1991. Part A of these regulations lists those processes prescribed for Integrated Pollution Control by the national inspectorate and Part B lists those prescibed for air pollution control by local authorities. Non-ferrous metal production and welting processes are covered in sections 2.2 and 2.3 of theses regulations which are reproduced below:

Non-Ferrous Metal Plants Part A

(a) The extraction or recovery fran any material- (1) by chemical means or the use of heat of any non-ferrous metal or alloy of non-ferrous metal or any conpound of a non-fermus metal; or (11) by electrolytic means. of aluminium. if the process nay result in the release into the air of particulate matter or any metal, metalloid or any metal or metalloid canpound or in the release into water of a substance described in Schedule 5 or does not fall within paragraph (b) of Part E of this Section. In this paragraph ‘material‘ includes ores. scrap and other waste.

(b) The mining of zinc or tin where the process may result in the release into water of cachium or any conpound of cadmium.

(c) The refining of any non-ferrous metal or non-ferrous metal alloy except where the process is related to a’ process falling within the description in paragraphs (a), (c) or (d) of Part E of this Section.

(d) Any process other that described in paragraphs (b), (e) or (d) of Part E of this Section for making or melting any non-ferrous metal or non-ferrous metal alloy in a furnace, bath or other holding vessel if the furnace, bath or vessel enployed has a designed holding capacity of 5 tonnes or mre.

(e) process for producing, melting or recovering by chemical mans or by the use of heat any of the elemnts listed below or any alloy whatsoever, if the percentage by wight of any of those elenents which the alloy, in mlten form, contains weeds the relevant percentage specified below. and the process nay result in the release into the air of particulate matter or smke which contains any of those elements- antimny 1% arsenic I% beryl 1 ium 0.1% chranium 2% lead when alloyed with copper 23% lead when alloyed with any metal other than copper 2% magnesium 10% manganese when alloyed with copper 15% manganese when alloyed with any metal other than copper 42 phosphorus 1% platinum 1% selenium 0.5% 138

Table DIII.2(h) - continued Liet of Claaeified Inetallatione of the British Law Relevant for the Sectore "Roastingn and VX"Ferrou8 Metal Plants"

~ Any process for producing, melting or recovering (whether by chemical means or by electrolysis or by the use of heat) cadmium or mercury or any - ~ other alloy containing nure than 0.05 per cent by weight of either of these metals or both those metals in aggregate. __ Any nanufacturing or repairing process involving the use of beryllium or selenium or an alloy of one or both of those metals if the process may oc- casion the release into the air of any substance described in Schedule 4.

The heating in a furnace or other appliance of any non-ferrous metal or non-fems metal alloy for the purpose of reimving grease, oil or any other nonmetallic contaminant (including such processes as the removal by heat of plastic or rubber covering from cable), if related to another process descrikd in this Part of this Section.

Any foundry process (including ancillary foundry operations such as the manufacture and recovery of nuulds, the reclamation of sand, fettling. grinding and shot-blasting) if related to another process described in this Part of this Section.

Any other process otherwise falling within a description in paragraph (a), (b), (d). (e) or (f) of Part B of this Section if the carrying on of the process by the person concerned at the location in question is likely to produce 1000 tonnes or mre of special waste in any 12 rmnths period.

Part B

The makinp. or melting of any non-ferrous mtal or non-ferrous metal alloy in any furnace, bath or other holding vessel with a designed holding capacity of less than 5 tonnes (together with any incidental refining).

The extraction or recovery of copper, aluniniun or zinc from mixed scrap by the use of heat.

Melting zinc or a zinc alloy in conjunction with a galvanising process.

Melting zinc or aluminium or an alloy of one or both of these metals in conjunction with a die-casting process.

Any such process as is described in paragraph (h) of Part A above, if not related to another process described in this Part.

Any foundry process (including ancillary foundry operations such as the manufacture and recovery of mulds, the reclamation of sand, fettling, grinding and shot-blasting) if related to another process described in this Part of this Section. -

Smelting processes Part A

SPlelting or calcining sulphides or sulphide ores. including regulus or mattes. 139

Table DIII.3(a): Limit Values Laid down in F.R. Germany €or Heavy Metal Emissions of Non-Ferrous Metal Plants (extracted from “Technische Anleitung zur Reinhaltung der Luft“)

3.1.4 Inoraanic Dust Particles

The inorganic dust particles listed below shall altogether not exceed the following mass concentrations contained in the waste gas. even if several substances of the smclass are present:

Class I Cadmium and its canpounds. indicated as Cd Mercury and its ccmpounds. indicated as Hg Thallium and its cnopounds. indicated as TI at a mass flow of 1 g/h or mre 0.2 mglfl

Class 11 Arsenic and its canpounds. indicated as As Cobalt and its ccmpounds. indicated as Co Nickel and its conpounds. indicated as Ni Selenium and its conpounds, indicated as Se Tellurium and its canpounds. indicated as Te at a mass flow of 5 g/h or mre 1 qIn5

Class 111 Antimny and its compounds, indicated as Sb Lead and its ccmpounds. indicated as Pb Chmium and its conpounds. indicated as Cr Cyanides easily soluble (e.g. NaCN), indicated as CN Fluorides easily soluble (e.g. NaF), indicated as F Copper and its conpounds. indicated as Cu Manganese and its canpounds. indicated as Mn Platinum and its canpwnds. indicated as Pt Palladium and its canpounds. indicated as Pd Rhodium and its carpwndJ. indicated as Rh Vanadium and its compounds. indicated as V Tin and its canpounds. indicated as Sn at a mass f IDW of 25 glh or mre 5 WID?

Inorganic dust substances which are strongly suspected to cause cancer shall be assigned to Class 111: reference is made to Part 111 of the MI\K-value-list.

If substances of several classes are present, the mass concentration in the waste gas shall not exceed - irrespective of 5-1 - a total of 1 mg/fl for coinciding class I and I1 substances as well as a total of 5 nqlfl for coinciding class I and 111 or class 11 and I11 substances.

Physical conditions (pressure. temperature) during the discharge of waste gases which cause essential parts of the substances to became vapaurs or gases will make it necessary to evaluate, whether, considering the aspects Of each individual case. the mass concentrations given in 5 1 can be mtalso in the case of total vapoumus. gaswus and particulate missions. 140

Table DIII.3(a)r continued Limit Values Laid down in F.R. Germany for Heavy Metal Emissions of Non-Ferrous Metal Plants (extracted from "Technische Anleitung zur Reinhaltung der Luft" )

2.3 Emission Standards for Carcinoaenlc Substances

The emissions of carelmgenic substances which are contained in the waste gas shall be limited to the largest possible extent by giving consideration to the principle of proportion.

Reference is made to Part I1 A 1 adA 2 of the MAK-value-list (list of the nuuir" values at wrking places of the Senatskmission of the Deutsche Forschungsgminschaft for the testing of harmful substances).

The carcinogenic materials listed below uust not exceed the following concentrations in the waste gas. also if several materials of the sam class are present:

Class I Berylliton and its conpounds in respirable form, indicated as Be at a mass flow of 0.5 glh or nure 0.1 WJInP

Class I1 Arsenic trioxide and arsenic pentoxide, arsenious acid and Its salts arsenic acids and its salts (in respirable form), indicated as As

Chromium (VI) ccnpounds (in respirable form), as far as calciun chmte. chromium (111) chrmte, strontium chrmte and zinc chtwute. indicated as Cr

Cobalt (in form of respirable dustslaerusols of cobalt metal ad cobalt salts of low solubility), indicated as Co

Nickel (in form of respirable dustslaerusols of nickel metal, nickel sulfide and pyritifemus ores, nickel oxide and nickel carbonate, nickel tetracarbonyl). indicated as Ni

at a mass flow of 5 glh or mre 1 win'

In the event of the presence of substances of several classes, the following shall apply irrespective of 5 3: If substances of classes I and I1 coindde.the MISS concentration in the waste gas nust not exceed a total of 1 rglm'. if substances of classes I and I11 or classes I1 and I11 coincide. the mass concentration in the waste gas nust not exceed a total of 5 ugh?. - 141

Table DIII.3(b)r LMt Values in Italy for Heavy Metal Emissions of Non- Ferroua Metal Plants, as Given in the Ministerial Decree of 12.6.1990

Guidelines for the content of polluting emissions from industrial plants and the fixation of maximum emission values associated with dust.

Plants for the second smeltine of other non-ferrous metals and of their allovinas

Comer and its compounds As regards the lime kilns. during- the smeltine - of electrolvtic comer._- the emission value is of LO mglms 142

Table DIII.3(c)t Limit Values in Spain for Heavy Metal WLissions of Non- Ferrous Metal Plants, as Given in the Decree 833 of 6.2.1975 -

.~__ Industrial processes Emission limits concerned

Antimony

-voltare flow of stack gases 45 q Sbz Os/+ for installations that started operation before 1975 above 2500 cbn'lsec 30 q Sbr OdnP for installations that started Operation after 1975 20 q Sbr OdnP for installations that started operation after 1980

- volum flw of stack gases 120 q Sbr 03/nP for installations that started operation before 1975 below 2500 d"/sec 80 q SbZ Odi? for installations that started operation after 1975 60 q Sb. O./nP for installations that started operation after 1980

Arsenic production

-volm flow of stack gases 45 q As* OJnP for installations that started operation before 1975 above 2500 d"/sec 30 q As0 O~/irr' for installations that started operation after 1975 20 q As2 Os/nP for installations that started operation after 1980

- volum flow of stack gases 120 q Asz O.h? for installations that started operation before 1975 below 2500 d"/sec 80 q AS. Oh? for installations that started operation after 1975 60 mg As2 Odm' for installations that started operation after 1980

Cadmium production 40 q/nP (expressed as Cd) for installations that started operation before 1975 25 q/d (expressed as Cd) for installations that started operation after 1975 17 q/d (expressed as Cd) provisions for plants that started operation after 1980 (total Cd emission: less than 13.6 kg/week)

Lead production

- volum flow of stack gases 20 rg/d (expressed as Pb) for installations that started operation before 1975 above 300 d/min 15 q/nP (expressed as Pb) for installations that started operation after 1975 10 q/d (expressed as Pb) provisions for plants that started operation after 1980

- volum flow of stack gases 120 q/d (expressed as Pb) for installations that started operation before 1975 below 300 m'/min 100 q/d (expressed as Pb) for installations that started operation after 1975 ~ 80 q/d (expressed as Pb) provisions for plants that started operation after 1980 143

Table DIII.3(d): Achievable Levels of Releases of Particulate Heavy Metals to Air in the UK, as given in "Chief Inspector's Guidance to Inspectore - Metal Industry Sector"

The concentration of pollutants in emissions to air are in the specified conditions:

For non-coubustion gases: no correction for water vapour content or oxygen content, tempwatures OOC. pressure 100 kPa.

Non-ferrous Metal Processes

Tin and its compounds (as tin) Molybdenum and its compounds (as molybdenum) Copper and its canpaunds (as copper) Lead and its compounds (as lead) Antimny and its compounds (as antimny) Arsenic and its compounds (as arsenic) Chromium and its compounds (as chrmium) Platinum and its compounds (as platinum) Selenium and its compounds (as selenium) Cadmium and its compounds (as cadmium) Mercury and its canpounds (as mercury) Rhodium and its colnpounds (as rhodium) Beryllium and its compounds (as beryllium)

Smelting Processes

Tin and its conpounds (as tin) Molybdenum and its compounds (as mlybdenum) Lead and its cMnpounds (as lead) Antimny and its ca~pwnds(as antinmy) Arsenic and its compounds (as arsenic) Selenium and its cMnpounds (as selenium) Cadmium and its cMnpounds (as cadmium) Rhenium and its cmounds (as rhenium) Mercury and its canpounds (as mercury) 144

Table DIII.3(e): Emission Guideline Values and Special Requirements for Dust in F.R Germany, as Given in the Technical Instructione of 1986

Emission limits: 50 q/fl for mass flow of rare than 0.5 kg/h

150 ng/d for mass flow of up to 0.5 kg/h

Special requirements for dust emission: - For facilities producing non-ferrous unrefined metals, it is said that "particles containing waste gases shall be collected and fed to a deduster. Particles emlssions in the waste gas shall not exceed 20 q/ms, in lead works 10 ng/m3".

- For smelters, Including facilities for refining non-fermus mtals and their alloys, it is required that "particles containing waste gases shall be collected and fed to a dedusting system. Particles emissions in the waste gas shall not exceed 20 q/d for melting or refining plants as well as 10 mglP for plants melting or refining lead or its alloys. when smelting cathode copper in shaft furnaces, emissions of copper and its conpounds in the waste gas shall. indicated as copper. not exceed 10 q/m'.

- For foundries of non-ferrous metals, the following requirements are laid down for particles:

"a) Particles containing waste gases shall he collected as far as possible and fed to a dedusting system.

b) When utilizing filter dedusters. particles containing emissions in the waste gas shall not exceed 20 ngIP at a mss flow of 0.5 kg/h or rare." 145

Table DIII.3(f)r Emission Guideline Values for Dustin Italy, as Given in the Ministerial Decree of 12.6.1990

Guidelines for the content of polluting emissions from industrial plants and the fixation of maximum emission values for dust.

Plants for the Drimarv Droduction of non-ferrous metals

The flue gas must go through a scrubbing plant. The emission values are: for the lead foundries 10 mg/m’ in other cases 20 mg/ms

Plants for the second smelting of other non-ferrous metals and of their allovings

The flue gas must go through a scrubbing plant. The emission values are: for second smelting plants of iron or its alloyings 10 mg/m’ for other plants if the mass flux is equal to or greater than 0.2 kg/h 20 mg/m’

Plants for the production of lead batteries

The flue gas must go through a scrubbing plant. The emission value is: if the mass flux is equal to or greater than 5 g/h 0.5 mg/m* 146

Table DIII.3(g)r mission Guideline Values for Duet in Spain, as Given in the Decree 833 of 6.2.1975

Cadnium pmduction 600 q/nP for installations which started operation before 1975 500 ugld for installations which started operation after 1975 300 mg/d provisions for plants which started operation after 1980

Copper production 400 ug/d far installations which started operation before 1975 (1st and 2nd melting) 300 q/d for installations which started operation after 1975 150 q/d pmvisions far plants which started operation after 1980

Copper production 600 q/nJ for installations which started operation before 1975 (refining) 500 q/m” for installations which started operation after 1975 300 ng/nP provisions for plants which started operation after 1980

Lead production (all 200 q/d for installations which started operation before 1975 processes but ref ining) 150 q/m3 for installations which started operation after 1975 50 q/dprovisions far plants which started operation after 1980

Lead production 300 q/d for installations which started operation before 1975 (for refining) 200 q/d for installations which started operation after 1975 100 ng/d provisions for plants which started operation after 1980

Zinc production 600 q/m3 for installations which started operation before 1975 500 mg/d for installations which started operation after 1975 50 q/dprovisions for plants which started operation after 1980 147

Table DIII.3(h): Achievable Levels of Dust Releases to Air in the UK, as given in "Chief Inspector's Guidance to Inspectors - Metai Industry Sector"

The concentration of pollutants in missions to air are in the specified conditions:

For non-conbstion gases: no correction for water vapour content or oxygen content, temperatures 0°C. pressure 100 kPa.

Non-ferrous Metal and Smelting Processes

Particulate matter 50 mgld 148 DIV Recammended emiesion limits for lead, comer and zinc works DIV. 1 scope The recommendations given below cover - roasting and sintering plants with a capacity of more than 1000 tonnes of metal ore per year - plants for the production and melting of non- ferrous metals having installations with a total capacity of over 1 tonne. The recommendations are valid for new plants and existing plants undergoing major modifications. They cover directed and fugitive emissions. The recommendations are equally valid for primary and secondary works. Consideration should be given to the problem faced by existing plants in the control of air pollution. Ba- sically the recommended emissions limits can also be applied to existing plants, after an appropriate period of time necessary for the adaptation. However, the full application of the recommended emission limits depends on many plant specific characteristics. This includes the plants technical characteristics, its rate of utilization, the length of remaining life, the nature and the volume of polluting emissions and the desirability of not entailing excessive costs for the plant concerned having regard in particular to the economic situation of undertak- ings belonging to the category in question.

DIV. 2 Emission limits and recommndatione DIV.2.1 Directed emiesions As far as technically feasible and economicallybear- able particulates containing gases must be captured and conveyed to waste gas purification plants. DIV.2.l.l Guideline values and special requirements for particulate emissione Emissions are indicated as mass of emitted materials related to the volume of waste gas under standard conditions (273.15 K, 101.3 kPa) after substraction of the water vapour content, expressed as mass concentration in the unit m~/m,,~.The quantities of air which are fed to a system in order to dilute or cool the waste gases shall not be considered when determining mass concentrations. 149 DIV.2.1.1.1 Lead works For facilities which extract, smelt, refine, or otherwise process lead, it is required that dirty waste gases shall be collected and fed to a gas cleaning system. Particulate emissions in the waste gases of lead works, measured under normal operation conditions, shall not exceed 10 mg/~n,,~. DIV.2.1.1.2 Copper works For facilities which extract, smelt, refine, or otherwise process copper, it is required that dirty waste gases shall be collected and fed to a gas cleaning system. Particulate emissions in the waste gases of copper works, measured under normal operation conditions, shall not exceed 20 mg/~n,,~. DIV.2.1.1.3 Zinc works For facilities which extract, smelt, refine, or otherwise process zinc, it is required that dirty waste gases shall be collected and fed to a gas cleaning system. Particulate emissions in the waste gases of zinc works, measured under normal operation conditions , shall not exceed 20 ~ng/m,,~. DIV.2.1.2 Guideline values for inorganic duet and fume particlee i) The inorganic dust particle listed below shall altogether not exceed the following mass concentrations contained in the waste gas, even if several substances of the same class are present :

Class 0 Berylium and its compounds, indicated as Be at an emitted mass flow’ of the metal listed above of 0.5 g/h or more: 0.1 mg/q3 Class I Cadmium and its compounds, indicated as Cd Mercury and its compounds, indicated as Hg Thallium and its compounds, indicated as T1 at an emitted mass flow’ of all the metals listed above of 1 g/h or more: 0.2 mg/~n,,~

The mass flow is the product of waste gas flow at standard conditions times the concentration of the metals. 150 Class I1 Arsenic and its compounds, indicated as As Nickel and its compounds, indicated as Ni Selenium and its compounds, indicated as Se at an emitted mass flow' of all the metals liste! above of 5 g/h or more: 1 mg/% Class I11 Antimony and its compounds, indicated as Sb Lead and its compounds, indicated as Pb Chromium and its compounds, indicated as Cr Copper and its compounds, indicated as Cu' Manganese and its compounds, indicated as Mn Vanadium and its compounds, indicated as V Tin and its compounds, indicated as Sn at an emitted mass flod of all the metal; listed above of 25 g/h or more: 5 m9/" ii) The emissions of Beryllium which are contained in the waste gases shall be limited to the largest possible extent by giving consideration to the principle best available technology not entailing excessive costs. iii) If substances of classes I to I11 are present, the mass concentration in the waste gas shall not exceed - irrespective of what is said under i) - a total of 1 mg/n~,,~for coinciding class I and I1 substances as well as a total of 5 mg/%3 for coinciding class I and I11 or class I1 and I11 substances. iv) Physical conditions (pressure, temperature) during the discharge of waste gases which cause essential parts of the substances to become vapours or gases will make it necessary to evaluate whether, considering the aspects of each individual case, the mass concentrations given in i) can be met also in the case of total vapourous, gaseous, and particulate emissions.

For the time being, there is no commercially available control technologywith regard to shaft furnaces for the melting of electrolytic copper. The emission value for comer may not exceed 10 mg/q3 if the maximum mass flow exceeds 25 g/h. Further research to reduce these specific emissions should be undertaken. The mass flow is the product of waste gas flow at standard conditions times the concentration of the metals. 151 DIV.2.2 Fugitive duet and fume emLeeions In order to reduce fugitive emissions the following requirements should be met: Fugitive dust: i) Raw materials which could cause dust emissions should preferably be stored and handled in closed buildings. Open air stockpiles of such raw material, if unavoidable, should be equipped with well designed spray systems to maintain well wetted surfaces at all weather conditions or appropriate sealing techniques should be used. ii) Stockpile areas and access roads should be hard surfaced and periodically cleaned by wet vacuum cleaners. iii) The wheels and tires of road vehicles should be cleaned, preferably by wet systems, before leaving the work.

DIV. 3 Monitoring Direct particulate emissions shall be continuously monitored when the appropriate technology is available and when emissions of dust exceeds 5 kg/h, or emission of Cd, Hg or T1 exceeds 5 g/h, or emission of As, Ni or Se exceeds 25 g/h, or emission of Sb, Cr, Pb, Mn, VI or Sn exceeds 125 g/h. The concentrations of the metals in the cleaned waste gases shall be determined periodically. - 152 -

LIST POF PARTICIPANTS OF THE WORKING GROUP

Mdreaa

Mr. A. Arongaeno Dgm del hkix c/ CasteIlona 67 Madrid / Spain

Mr. H. AIIekotte Ruhr-Zink CmW Bittener Str. 1 0- 4554 Dotteln

Mr. J.4. Bartolre EEC ffi XI A3 Rue de la Loi 2m B - 1M9 Brusaela

Mr. P. Clarletta Vieille Montagne Fabriekaatraat 144 B-39WOverpalt

Mr. T. Carnell Brltmnla Refined Ustala (EWCMTNX) Botony Rood u( - Northfleet (Kent)

Mr. F. vm der Cruyaaen Miniateria r/d Vlaane Ganeernciap Bsatuur vwr Leefmi I leu krblsrsatroat 1 B - loo0 Brusasla

Mr. F. Durand Miniatbra de I 'envi rmnanent SEI/cEppR - 14. M du G6q6ral Ceclerc F - 94126 Neui 1 ly

Mr. S. Ferquel KTALElKP-FR4KE 44, rue Roper Salengro F - 94126 Fontenoy aou8 Boia

Mr. Rul N. OancoIves Direccao Geral do Ouolidade do knbiente R. do SSCUIO51-3 P - 1200 Lirh

Mr. C. Gather Umeltbundesant Elnarckplatr 1 D - l[xx) Berlln 33

Mr. P. Halaall 13 Park Rood Weltm. Brough iK - Horin iimbersiae iUl5 iW - 153 -

LIST POF PARTICIPANTS OF THE WORKING GROUP

None Mdrerr

Mr. Peter Klotz kbtoll Eurcp Weser Blei r3rS-I Johonnastr. 2 D - 2890 Nordenhan 16

Mr. Leo ECffi 111 E3 Rue de Io Loi 200 B - 1M9 Brusrels

Dr. R. Mae. Eurarutaux. Asrociaticn Internat ionale Rue Montoyer 47 B - 1040 Bruraels

Mr. C. MBmald Dept. of the Envirormant Roan 8.550 45 Marahan Street U( - London W1P Wi

Dr. G. C. kbi WI Farnaci dl Barga I - 55352 Lucca

Or. C. Meyer-Wulf Mttenwerke Koyser A.C. Postfoch 1580 D - 4670 LOnen

Mr. C. Van Cktgsvul Mlnlatry of Eccnanic Affairs de kbusaquare 23 B - 1040 Brussels

Mr. J. M. Pmcet Aaturlono da Zinc % bartodo 178 E - 35400 Avlies (Asturlar)

Mr. Steil Berzlius MstalhOtten Qnttl Ff 281180 D- 4100 Dulrburg 28

Dr. H.J. %'elten Marddeutsche Affinerie AS. Postfoch XI 39 26 D - 2ooo hburg 36

Mr. H. Wwterschoot Eurcmstaux Aaaoclation Internat ionale Rue Lbntoyer 47 B - 1040 Brussels

European Commission

Technical note on best available technologies not entailing excessive costs for heavy metal emissions from non-ferrous industrial plants Final report - May 1991 Document

Luxembourg: Office for Official Publications of the European Communities 1994 - VI, 154 pp. - 21.0 x 29.7 cm ISBN 92-826-5097-9 Price (excluding VAT) in Luxembourg: ECU 19.50 Price (excluding VATJ in Luxembourg: ECU 19.50

ff. OFFICE FOR OFFICIAL PUBLICATIONS OF THE EUROPEAN COMMUNITIES *: *: *.. L-2985 Luxembourn