T1-Kovler-Purification-Of-Phosphogypsum-Israel.Pdf

Prof. Konstantin Kovler is Head of the Department “Building Materials, Performance and Technology”, National Building Research Institute (NBRI), Faculty of Civil & Environmental Engineering, Technion - Israel Institute of Technology. His research focuses on recycling industrial by-products in construction, PURIFICATION OF PHOSPHOGYPSUM FROM high-performance cementitious materials, radioactivity of building materials, and radon mitigation. Fellow of RILEM, Editor of Materials & Structures, Cement & Concrete Composites. Chairs committees “Ecological Aspects of Construction”, “Radioactivity of Building Products,” Israeli Standards Institution. 226Ra AND HEAVY METALS FOR ITS FURTHER Director of Technion Recycling Initiative. UTILIZATION IN CONSTRUCTION: Eng. Boris Dashevsky is Research Fellow, the Department “Building Materials, Performance and TECHNOLOGICAL UTOPIA OR REALITY? Technology”, NBRI. His research interests are in technologies of manufacturing building materials using mechano-chemical activation, recycling industrial by-products (phosphogypsum, coal ash, copper slag, carbonate rock waste of dimension stone factories and quarries, construction and demolition waste – including asbestos-cement, acid tar, sulfur- and sulfonate-containing wastes) in construction. Konstantin Kovler1 , Boris Dashevsky1, David S. Kosson2 1National Building Research Institute – Prof. David S. Kosson is Cornelius Vanderbilt Professor of Engineering at Vanderbilt University, Nashville, Tennessee, US, where he has appointments as Professor of Civil and Environmental Faculty of Civil and Environmental Engineering Engineering, Chemical Engineering, and Earth and Environmental Sciences. His research focuses on energy and water sustainability, management of nuclear energy production and industrial wastes, Technion - Israel Institute of Technology including leaching assessment and contaminant mass transfer applied to groundwater, soil, sediment, waste, and cementitious materials systems. 2Department of Civil & Environmental Engineering, Vanderbilt University, Nashville, TN, USA

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ENVIRONMENTAL PROBLEMS WITH PG PHOSPHOGYPSUM (PG) (Hilton, 2010) • 5.6 –7.0 bt of PG produced in lifetime of industry to In the manufacture of phosphoric acid phosphate rock is date (5 t of PG per t of acid) digested with H2SO4: • Some 3 - 4 bt (Hilton 3 bt, Birky 4 bt... What’s a bt between friends) now available, of which >1.1 bt in [Ca (PO ) ] CaF 10H SO  20H O 75-80C  3 4 2 3 2 2 4 2 Florida, ~0.1 bt in Israel 6H (PO ) 10CaSO 2H O  2HF 3 4 4 2 • “Stacks” in 52 countries, and rising

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PG STACKS PG STACKS

Belaruskali (https://belarusdigest.com/story/belarusian-privatisation-and-the-future-of- Fort Meade, Florida (courtesy: Harvey Henkelmann) belaruskali/)

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1 PG STACKS PG STACKS

• The Phosphate Manufacturing Complex of Huelva, Spain, including PG Stacks (~100 Mt)

Sarasota, Florida (image: Jim Damaski/Tampa Bay Times via AP File)

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PG STACKS PG STACKS

• S. Korea S. Korea (2002)

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ENVIRONMENTAL PROBLEMS WITH PG (Hilton, 2010) • PG holding growing at ~150-200 Mt/yr at present with prospect of 250 Mt/yr by 2015, in Israel – 3 Mt/yr • Total global holding will probably double sometime between 2025 and 2040 CHEMICAL CONTAMINANTS • Stacks are taking up an unknown, but increasing quantity of land… • Often in prime, highly sensitive, increasingly populated areas, such as central Florida

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2 CHEMICAL CONTAMINATION OF PHOSPHOGYPSUM AND REQUIREMENTS CHEMICAL CONTAMINATION OF FOR BUILDING GYPSUM PHOSPHOGYPSUM Phosphogypsum Requirements for building  part of the impurities present in the phosphate is gypsum carried off with the gypsum stream after the total P2O5 1.0% <0.4% separation of phosphoric acid and gypsum water soluble P2O5 0.2% <0.01%  small amounts of soluble impurities (traces of free acids, acidic phosphates and silicofluorides; total F 1.0% <1% 0.1-1%) affect the quality of the gypsum much water soluble F 0.14% <0.05% more strongly than the insoluble impurities in natural gypsum, whose concentration may be as Na 0.17% <0.05% organic 0.15% <0.10% much as 10% (clay, CaCO3, SiO2, iron oxide - inert >2% <2% present as inert fillers) pH 4 >5 i nert

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TYPICAL CONTENT OF RADIOACTIVE ISOTOPES IN GYPSUM, pCi/g (1 pCi/g = 37 Bq/kg)

238U 226Ra 232Th 40K Radium equivalent Natural gypsum 0.4 0.6 0.2 2 1

Phosphogypsum 4 22 0.5 6 23 (maritime RADIOACTIVE CONTAMINANTS phosphate) Phosphogypsum <1 3.2 0.6 7 5 (magmatic phosphate) Nitrogypsum 4 2 2 10 3

Fluoroanhydrite - - - - <0.1

FGD-gypsum 0.1 0.1 0.06 0.3 0.2

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Dose criterion Country Index Decision values End-use of building materials (mSv per year) EU countries EU 푪 푪 푪 푰= 푹풂 + 푻풉 + 푲 퐼≤1 1 CE 2014 ퟑퟎퟎ ퟐퟎퟎ ퟑퟎퟎퟎ Austria 퐶 퐶 퐶 (Austrian Stand. Institute, 2009) 퐼= 1+0.07휀휌푑 + + 퐼≤1 1 880 530 8800 ÖNORM S 5200: 2009 퐼 ≤ 0.5 Bulk material (e.g. brick, concrete, gypsum) 퐶 ≤ 150

Czech Republic 퐶 퐶 퐶 퐵푞 I≤1 퐼 = + + ; 퐶 ( ) Raw material (e.g. sand) 0.3 (Hulka et al., 2008) 300 200 3000 푘푔 퐶 ≤ 300 퐼≤2 Superficial material (e.g. tiles) 퐶 ≤ 300

퐶 퐶 퐶 퐼 ≤1 Bulk material 1 퐼 = + + Finland 300 200 3000 퐼 ≤6 Superficial material (STUK, 2010) 퐶 퐶 퐶 퐶 퐼 ≤1 Bulk material for road constructions 퐼 = + + + 700 500 8000 2000 퐼 ≤ 1.5 Superficial material for road constructions 0.1

푆 푆 푆 푓 = + + ; 푓 +Δ푓 ≤ 1.2 Poland Dwelling: for civil engineering construction 300 200 3000 1 (Poland Government, 2007) 퐵푞 indexes can be multiplied up to 4 times 푓 =푆 ( ) 푓 + Δ푓 ≤ 220 푘푔 Non EU countries

퐶 퐶 퐶 퐼 = + + 퐼 ≤1 Bulk material EXISTING REGULATIONS Albania 300 200 3000 1 (Albania Government, 2011) 퐶 퐶 퐶 퐶 퐼 = + + + 퐼 ≤1 Bulk material for road constructions 700 500 8000 2000 퐼 ≤ 1.0 Bulk material China 퐼 ≤ 1.0

(Chinese Standardization 퐶 퐶 퐶 퐶 퐼 ≤ 1.0 Superficial & 25% hollow bulk material for 퐼 = + + ; 퐼 = 1 Administration, 2010 ) 370 260 4200 200 퐼 ≤ 1.3 dwelling constructions GB 6566-2010 퐼 ≤ 1.3퐼 ≤ 1.9 Superficial material for industrial constructions 퐼 ≤ 2.8 Superficial material for outside use

퐴 퐴 퐴 퐴 퐼≤1 Bulk material Israel 퐼= 1−휖 + 휖+ + 퐴 퐴 퐴 퐴 퐼 ≤ 0.8 Superficial material (Kovler, 2011) – SI 5098: 2009 0.3 퐴 퐴 퐴 퐼 ≤ 0.4 Bulk material 퐼 = + + 퐴 퐴 퐴 퐼 ≤ 0.32 Superficial material Russia Aeff + ΔAeff ≤ 370 Dwelling/public constructions (Russian Committee for Standards 퐵푞 퐴 ( )=퐴 + 1.3퐴 + 0.09퐴 ≤ 740 Industrial construction 1 and Metrology, 1994) 푘푔 GOST 30108-94 ≤ 1500 Road constructions 퐶 퐶 퐶 퐼= + + Bulk material 300 200 3000 Serbia 퐶 퐶 퐶 퐼= + + 퐼≤1 Bulk material for outside use 1 © K. KOVLER ET AL. ©Official K. GazetteKOVLER of Serbia ET 86/2011a AL. 400 300 5000 퐶 퐶 퐶 퐼 = + + Bulk material for road constructions 700 500 8000 17 18

3 a) DH CONTAMINANTS IN PG: b) HH PROBLEMS FOR USE IN CONSTRUCTION c) AH

 Chemical impurities CURRENT SOLUTIONS • injurious to the setting time and strength of building binders • To create phase changes (P O ) 2 5 between hemihydrate (HH) and • result in efflorescence and spots on the surface dihydrate (DH) • result in corrosion of steel or glass reinforcement in building products • Can purify from phosphates, • may exceed requirements for environmental protection but not from radionuclides,  Radioactive impurities because RaSO4 crystallizes first and cannot be washed out • 226Ra concentration  0.7-1.0 Bq/g

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THE DISTRIBUTION OF IMPURITIES ACROSS THE PHOSPHOGYPSUM FRACTIONS AFTER WET PROPOSED APPROACH PURIFICATION (SEPARATION BY GRAIN SIZE)

Fine Medium Coarse Phospho- <30µm 30-200 µm >200 µm gypsum (removed (removed by by filtration) flotation or • Chloride complexation at moderate temperatures with hydro- followed by neutralization cyclones • Chloride complexation with Ra to prevent precipitation Wt. % of the gypsum 20 70 10 100% of Ra salts Total P2O5 0.8 0.5 7.6 1.3%

SiO2 0.45 1.0 8 1.3% • High chloride concentration (recycled) lowers Na 0.15 0.07 0.30 0.15% transition temperature for the crystal states Fe2O3 + Al2O3 0.5 0.45 1.8 0.7% F 1.4 0.5 7 0.2% • Initial acidity achieves heavy metal extraction Organic C 0.3 0.05 0.2 0.2%

Ra (Bq/kg) 1258 544 646 748 © K. KOVLER ET AL.

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PROPOSED APPROACH SOLUBILITY OF CHLORIDES AND SULFATES (g/100 mL)

• Chloride complexation at moderate temperatures Fe2+/ Cr2+/ Ra Th U Sn Zn Cd Ni Ca Mg Zn Ba Cu Pb Se followed by neutralization Fe3+ Cr3+

• Chloride complexation with Ra to prevent precipitation 62.62+ 24.5 125 * 39.5 432 113.7 250 74.5 54.8 367 36.2 74.2 0.98 * 56.2 /96.93+ Chloride of Ra salts Solubility

26.562+/ 12.4/ • High chloride concentration (recycled) lowers 2·10-4 1.38 10.9 18.8 54.1 76.4 38.4 0.206 31.5 54.1 0.00022 20.5 0.0045 37.6 81.53+ 64 Sulfate transition temperature for the crystal states solubility

2.36/ • Initial acidity achieves heavy metal extraction 122500 90.6 - 2.1 8 1.488 6.51 361.65 1.74 6.78 164500 3.62 217.8 - 1.49

ratio 1.18 Solubility Solubility

* the data are not available, reacts with water, dissolved in acidic medium © K. KOVLER ET AL. © K. KOVLER ET AL.

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4 SEM – ROTEM PG (BEFORE AND AFTER TREATMENT GAMMA RAY SPECTRA OF PG SAMPLES IN CHLORIDE SOLUTION), TECHNION, 2012-2013 (ROTEM), BEFORE AND AFTER TREATMENTS

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GROWTH OF 226RA CONCENTRATION IN TIME EFFECT OF CHLORIDE CONCENTRATION

Rotem PG - effect of CaCl2 concentration in the solutions with different L/S ratios (1 and 3 L/kg) 1.2 800

700 1 600 L/S = 3; T = 90 C; t = 30 min

0.8 500

400 0.6 300 0.4 200 Ra activity activity Bq/kgRaconcentration, Relative Ra-226 concentrationRa-226Relative 226 0.2 100 L/S = 3; T = 90 C; t = 30 min 0 0 0 10 20 30 40 50 60 0 7 14 21 CaCl2 concentration, % Time after closure of Marinelli beaker, days L/S = 1; T = 90 °C; t = 30 min © K. KOVLER ET AL. © K. KOVLER ET AL.

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EFFECT OF TEMPERATURE EFFECT OF CaCl2 CONCENTRATION

Rotem PG - effect of the solution temperature (L/S = 1; CaCl2 = 40%; 30 min. mixing) 700

600

500

400

300

200 Ra activity activity Bq/kgRaconcentration, 226 100

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5 Technological Scheme of PG Installation

Dewatering slurry by Solids to streamed tank Neutralization of HF from PG slurry hydrocyclone (screw feeder for wet PG) APPLICATIONS exhauster gases by CaCO3 slurry and condensation of Clean gases water vapor in to scrubber/hydrocyclon atmosphere • Gypsum and gypsum based building binders and finished products

Closed streamed heated (90 – 120 C) tank - rotating drum concentrator • Purified HH can be further dried and commercialized as gypsum to achieve ~1:1 40% CaCl solution 2 Flue gases to solid volume ratio; heating – by Pool to cool water and binder direct contact with flue gases in Liquids returned back to precipitate CaF2 with limestone phosphoric fertilizers plant countercurrent powder • May be further processed and commercialized as high-quality

Boiler - Separation between the solution and heat Clear water CaF finished gypsum products HH by heated and thermally insulated 2 15% - 20% CaCl solution exchanger 2 centrifuge(s); washing of HH by superheated water (100 ˚C - 110 ˚C) • Recovered contaminants include

HH residue to neutralization of Precipitation of phosphoric Separator (press-filter or • Rare earth elements Cooling Drying phosphoric acid with lime in acid with limestone powder centrifuge for fine cleaning tank HH thermally insulated mixer (≥ from particles < 5 m) in the tank 100˚C) • Radionuclides

Solids – DCP for use at Manufacture of finished gypsum Solid waste to disposal • Phosphates phosphoric fertilizers plant Final product - dry HH products by Ca (PO ) (~40,000 Bq/kg) 3 4 2 casting/pressing/extrusion • Fluorides

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APPLICATIONS OF PURIFIED HH DISPOSAL OF REMOVED CONTAMINANTS

• Can be easily hydrated and used as a source of • Fine fraction of PG (but some gypsum lost) gypsum for gypsum and cement industry • Natural zeolites • Can be further dried and commercialized as • Artificial zeolites gypsum plaster • Geopolymers • May be further processed and commercialized as high-quality finished gypsum products

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THANK YOU HOW TO PROCEED? ВИ БЛАГОДАРАМ ХВАЛА СПАСИБО Consumer TAK VIELEN DANK MERCI GRAZIE GRACIAS

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