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Aspergill Us Niger RECOVERY OF COPPER FROM LOW-GRADE ORES BE' ASPERGILL US NIGER PRESENTEDIIi PARTIALFC'LFILL~IENT OF THE REQLIREMENTS FOR THE DEGREEOF ~~XSTEROF APPLIEDSCIENCE CONCORDIAUNIVERSITY MONTRÉAL, QL'ÉBEC. CANADA Nationail Library 6iiiiothèque nationale 1+1 of^^ du Canada Acquisitions and Acquisitions et Bibliographie Seivices services bibiiographiques 395 WeUngton Street 395. rue WeUingdori OttawaON KlAW OibwaON KlAW canada canada The author has granted a non- L'auteur a accordé une licence non exclusive licence allowing the exclusive permettant à la National Library of Canada to BMiothèque nationale du Canada de reproduce, loan, distriiute or seîi reproduire, prêter, distribuer ou copies of this thesis in microform, vendre des copies de cette thèse sous paper or electronic formats. La forme de microfiche/film, de reprodnction sur papier ou sur format électronique. The author retaios ownership of the L'auteur conserve la propriété du copyright in this thesis. Neither the droit d'auteur qui protège cette thèse. thesis nor substantial extracts fiom it Ni la thèse ni des exbaits substanEie1s may be printed or otherwise de celle-ci ne doivent être imprimés reproduced without the author's ou autrement reproduits sans son permission. autorisation. Abstract RECOVERY OF COPPER FRObf LOW-GRADE OmS BY ASPERGILLUS NIGER 31 ahtab Kamali The main concern of this study is to End a feasible and economicd technique to recover metals from oside low-grade ore microbially. Owing to the large quantities of met& that are embodied in low - grade ores and rnining residues. these are considered new sources of metais. On the other hand they potentially imperil the entironment. as the metals they contain may be released to the enlironment in a hazardous forrii. Hence. mining industries are seehg an efficient technique to tiandle these ores. Pyrometidlurgical and hydrornetallurgical techniques are either veF espensive or have a negative impacr ori the en~ironment.That is wh?-, a new environmentiil strates cdled --sustainable development" is coming into perspective. This study employs het erotrophic leaching t hat fds into this nen- emlronmental strates-. in this srudy. by employïng Aspergillus nzger. the feasibility of recoveq of met- als from a mining residue is shown. A. nzger exhibits good potential in generating varieties of organic acids effective for metal solubilization. Organic acid effectiveness was enhanced when sulpbunc acid was added to the medium. Different agricultural wastes w-ere evaluated and the maximum solubilization of 68%. 46% and 34% \vas achieved for copper, zinc and nickel. respectivel. Also iron codissolution of 7% was gained. Acknowledgment s 1 would like to thanlc my supen.isor Dr. Catherine hldligan for her guidance. enthu- siasm, encouragement and Eree donation of ber the. This thesis owes much to her: however. an:- rnistakes are rny onn. Grateful ahowledgment is made for the valuable suggestions and help given by Juliet Dunpliy and Lee Harris. 11'- deepest thanks go to my husband. -4li. for his support and help. Contents List of Fie- es xii List of Tables xvi 1 Introduction 2.1 Introduction ................................ 1 1.2 Extraction metallurgy .......................... 6 1.2.1 Pyrometallur~Techriiques ................... 8 1.2.2 Hydrometalhrgy- Techniques .................. 11 1.2.3 Electrometallurgicai techniques ................. 12 t-i 3.2 Fungal strain and grou-th conditions ................... 47 1.3 Characterization of the mining residues ................. 18 1.4 Chemicai Ieaching esperiments ...................... 49 4.5 Leaching of the mining residue by .1 . niger ............... 19 4.6.1 Determination of organic acids produced by .1 . nzger ...... 56 4.6 .2 Determination of mer& leached by A . niger ............ 57 5 Results aucl Discussion 5 . 1 Chernical leaching ............................ 55 51.1 Copper solubiiization ...................... 58 5.1.2 Zinc sohbilization ........................ 59 5.1.3 Sickel solubilization ....................... 60 .5. 1.4 Iron solubilization ........................ 60 5.2 Organic acid production ......................... 61 5.3.1 pH ................................. 63 5.3.2 Copper solubiiization ...................... 63 5.3.3 Zinc solubilization ........................ 69 5.3.4 Sickei solubilization ....................... 71 5.3..5 Iron sohbilization ......................... 72 .5.4 1Iss balances ................... 6 Conclusions 6.1 Future recomrnendarions ......................... 95 Bibiiography List of Figures -- 1 3Ietai solubilization b~-citric acid. .................... r .i, -- '2 '\letal solubiiization by osalic acid. ................... I a Organic acia concentrztion in medium no. 1 (organic acid concentration at the beginning of esperimem R-as zero.) ................ Organic acid concentraiion in medium no.? (organic acid concentration at the beginning of e~~erimentn-as zero.) ................ Organic acid concentration in medium no3 (organic acid concentration at the bea(rinning of esperiment %-as zero.) ................ Organic acid concentration in medium no.3 (organic acid concentration at the beginning of esperirnent was zero.) ................ 7 Organic acid concentration in medium po.6 (organic acid concentration at the bea- ng of esperiment %*as zero.) ................ 78 Organic acid concentration in medium no.10 (organic acid concentra- tion at the beginning of esperiment n-as zero.) ............. 78 9 Organic acid concentration in medium no.12 (organic acid concentra- tion at the beginning of eqeriment was zero.) ............. 79 10 iariation of pH in medium no.1. medium no . 3 and medium no . 3 . 79 11 1-ariation of pH in medium no.-& medium no . 5 and medium no . 6 . SO 12 Iariation of pH in medium no. 9: medium no . 10 and medium no . 11 80 13 Copper solubilization in medium no.1 ................. 81 14 Copper solubilization in medium no.2 ................. 81 1.5 Copper solubilization in medium no.3 ................. 82 16 Copper solubilization in medium 110.4 ................. 82 17 Copper solubilization in medium no.6 ................. $3 1s Copper solubilization in medium no.5 ................. 83 si 19 Copper solubilization in medium no.7 ................. 84 20 Copper solubilization in medium no.8 ................. M 21 Copper solubilization in medium no.10 ................. 85 2'2 Copper solubilization in medium no.9 ................. 85 23 Copper solubilization in medium no .12 ................. 86 14 Copper solubilization in medium no.11 ................. 86 2.5 Copper solubilizarion in mediuni no . 13 .................. 87 33 Zinc solubiiization in medium no .1 ................... 87 7 Zinc solubilization in medium no2 ................... 88 '2s Zinc solubiIization in medium 110.6 ................... 88 29 Zinc sotubilization in medium no.9 ................... 89 30 Zinc solubilization in medium no.12 .................. 89 31 Sickel solubilization in medium no .l .................. 90 32 Sickel solubi~izationin medium no2 .................. 90 sii 33 Kickel solubïiization in medium no.9 .................. 91 33 Iron solubiiization in medium no.1 ................... 91 35 Iron solubilization in medium 110.2 ................... 92 List of Tables 1 Concentration of metais in the rnining residue ............. 19 2 Sumrnaq- of media content ........................ 31 3 Retentiontinles .............................. 37 4 '\las balance results ........................... 74 5 Surnmary of copper removal results ................... 94 Chapter 1 Introduction 1.1 Introduction In the late 1960s, industrial waste caused hundreds of people to be dected by paral- pis and sensory los dong Minamata Bay in Japan. In the late 1970s, chemically induced problerns of many children in the neighborhood of an elementary schooi were found to be the effect of the waste disposal of Hooker Chernicd Co. Such news heightened public awareness of the disasters which could be caused by industrial waste. Industrial waste not only caused many health problems but also imposed ex- penses. In the United States alone, $70 million were spent on waste disposal in 1980 (LaGrega, 1994). Due to the considerable cost it caused waste management became an important concern for industrial companies. Driven by cost incentives, good en- gineering economics hally came to be characterized by the need to produce salable products rather than waste. This impetus was the first inkling of a very important environmental movement t owardç waste rninimizat ion ( LaGrega, 1994). In the early 1980s, negative environmental consequences which were caused by industrial waste mishancihg became the main environmental issue for industrial se cieties. While waste disposal imposeci expenses were rising, the adverse health and environment consequences of indust na1 wast es were being revealed. These factors encourageci environmental organizations to think of new criteria for the problem of waste treatment. This motivation finally led to the concept of waste minimization, a concept which was introduced in Congress in the 1984 Hazardous and Solid Wastes Amendments to the Resource Consemtion and Recovery Act (RCRA) to legitimize a policy called waste minimization. As it is mentioned in Hazardous Waste Man- agement by LaGrega(l994) waste minimization came into environmental perspective formally when in October 1986 the U.S. Environmental Protection Agency (EPA) in a report to Congress definecl waste minirnization as: "...any source reduction or recycling activity undertaken by a generator that results
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