The solvent extraction of copper and iron from bioleaching solutions of PCBs with LIX 860N-IC and next stripping test with H2SO4 were investigated. In test the effect of varying sulfuric acid concentration on stripping rate of Cu and Fe and also phase ratio (O : A) were determined. It was found that the stripping rate of copper increases with the sulfuric acid concentration. The optimal concentration of H2SO4 is suggested to be about 150 g/L and phase ratio O:A = 1:1

A. Fornalczyk

J. Willner

English

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228   METALURGIJA 53 (2014) 2, 228-230J. WILLNER, A. FORNALCZYKEXTRACTION OF COPPER FROM SOLUTION AFTER BIOLEACHING OF PRINTED CIRCUIT BOARDS (PCBs)Received – Prispjelo: 2013-07-26Accepted – Prihvaćeno: 2013-10-25Preliminary Note – Prethodno priopćenjeISSN 0543-5846METABK 53(2) 228-230 (2014)UDC – UDK 669.3: 66.066.1:62.004.8=111J. Willner, A. Fornalczyk,: Silesian University of Technology, Depart-ment of Metallurgy, Katowice, Poland The solvent extraction of copper and iron from bioleaching solutions of PCBs with LIX 860N-IC and nex t stripping test with H2SO4 were investigated. In test the eff  ect of varying sulfuric acid concentration on stripping rate of Cu and Fe and also phase ratio ( O : A) were determined. It was found that the stripping rat e of copper increases with the sulfuric acid concentration. The optimal concentration of H2SO4 is suggested to be about 150 g/L and phase ratio O:A = 1:1. Key words: copper, solvent extraction, electronic waste, bioleaching, LIX 860N-IC.INTRODUCTIONPrinted circuit boards (PCBs) are the main carrier of valuable metals in the electronic waste. For example, metal content in these elements of mobile phones is about 28 %, including 10 - 20 % of copper , 1 - 5 % of lead, 1 - 3 % of nickel, content of precious metals (Ag, Pt, Au) about 0,3 - 0,4 %, and the rest are plastics (19 %), bromine (4 %), glass and ceramics (49 %) [1]. The quantitative composition of polymetallic electronic ele-ments makes this type of wastes, an attractive material in terms of valuable metals recovery . Printed circuit boards (main component of many portable electronic devices) are an example of a source of valuable metallic constituents.In addition to traditional methods of electronic scraps processing (pyro- and hydrometallurgical meth-ods), new solutions are searched, which could replace or improve current practice processes. It is important that efﬁ  cient metal recovery and the principles of envi-ronmental protection must be kept.  Well known is ap-plication of biohydrometallurgical methods in recovery process of metals (such as Cu, Au, Ni, U, Zn, Pb) Over the past few years bioleaching–solvent extraction–elec-trowinning (BL–SX–EW) process has been conducted in hydrometallurgical production of copper from low grade ores. About 20 – 25 % of the world’s total copper production originates from solvent extraction followed by electrowinning processes [2,3]. In recent years, much attention has been paid to the possibility of using microorganisms in the extraction of metals from a variety of waste. A small number of pub-lications is dedicated to the possibility of further recov-ery of metals from solutions after bioleaching. As a re-sult of bioleaching of electronic waste, a multi-compo-nent solution is obtained, containing various metal ions, of which copper is predominant component. Due to the presence of additional metal cations, especially iron cations, direct recovery of copper is much more hin-dered. In this case, an ef fective method that allows the separation of desired metal (Cu) from their mixture may be solvent extraction [4,5].Not many studies have been undertaken for the sol-vent extraction of copper from polymetallic post-bi-oleaching electronic scrap solutions [6]. Experimental works using bacterial leaching for the extraction of some base metals (Cu, Zn, Pb, Ni, Sn) from electronic waste were carried out with the partici-pation of Acidithiobacillus ferrooxidans and Acidithio-bacillus thiooxidans.[7-9]. It was indicated that in the presence of these strain and at the ambient temperature, 99 % of copper can be extracted into solution during bioleaching. Typical polymetallic solution after bioleaching of PCBs form used mobile phones consists (g/L): 3,228 - 4,525 Cu, 2,084 – 3,437 Fe, 0,061 Sn, 0,0005 Pb, 0,0695 Ni. The solvent extraction allows selectively separate copper from solution and next further recovery of Cu from a loaded organic phase requires the stripping op-eration.The aim of this study was to determine the prelimi-nary conditions of the copper and iron stripping rate from loaded organic phase, using H2SO4 at varying con-centrations and varying phase ratio O :  A. Achieving this goal required set of operation which consisted of the preparation of test material (PCBs milling), bi-oleaching of waste and the extraction process in accord-ance with the methodology presented in this article.229 METALURGIJA 53 (2014) 2, 228-230J. WILLNER et al.: EXTRACTION OF COPPER FROM SOLUTION AFTER BIOLEACHING OF PRINTED CIRCUIT...EXPERIMETAL WORK Materials. The research was conducted on printed circuit boards (PCBs) derived from spent mobile phones. PCBs were ground with the cutting mill to a particle size < 0,5 mm.Bioleaching. Bioleaching were carried out in Erlen-meyer ﬂ  asks by using a rotary shaker (130 rpm) at am-bient temperature. In this study  Acidithiobacillus fer-rooxidans strain was used. The culture was maintained in a standard Silverman/Lundgren (9K) medium. Sam-ples of the waste were 2 g, the volume of solution was 200 mL, whereas the quantities of bacteria culture was 10 % (v/v). Bioleaching was carried out within 40 days. Solutions were ﬁ  ltered, combined and then subjected to solvent extraction. The metal content (Cu and Fe) in the solution after bioleching was determined by atomic ad-sorption spectrometry (SOLAAR M6-UNICAM Atom-ic Absorption) and was as follows (g/L): 3,228 Cu; 2,084 Fe.Extraction. The organic solvent such as LIX 860N-IC obtained from the supplier (BASF , Ireland), was used in studies. It was found (data not illustrated) that the optimal concentration of LIX 860 N-IC is suggested to be about 5 %, phase ratio O:A  = 1:1 and pH = 1,9. Therefore extraction experiments were carried out in these conditions by using separatory funnel and manual mixing of organic (O) and aqueous phase (A) for time period of 5 minutes. Stripping. Stripping test was carried out with H 2SO4 with the varied concentration from 37,5 g/L to 300 g/L. Experiments were carried out in separatory funnel by manual mixing for 5 min. Dif ferent phase ratios O:A  were used from 1:3 to 3:1. Concentration of Cu and Fe in solutions during extraction as well as striping experi-ments was determined by  AAS. Stages of studies are illustrated in Figure 1.RESULTS AND DISCUSSION When 5 % LIX 860 N-IC was used, the extraction rate of copper was in the range of 97-98,5 % and iron from 2,5 to 3,8 %. The loaded organic phase came from the solvent extraction was stripped by H 2SO4 solution. The results of stripping experiment are shown in Figure 2. In test the ef fect of varying H 2SO4 concentration on stripping rate of copper and iron were investigated. The stripping rate of copper rises with increasing of H 2SO4 concentration and reached above 92,8 % with respect to sulfuric acid concentration of 150 g/L. Iron stripping rate is constants in all tested range of sulfuric acid con-centration and equaled about 24 %. The inﬂ  uence of phase ratio (O:A) on the copper and iron stripping is shown in Figure 3. With the increase of O:A ratio, copper stripping rate increased.  When the O:A rose from 0,33 to 1,0 the copper stripping rate in-creased from 67,7 % to 92,8 %. In the highest ratio slightly rise to 98,1 % was observed.  The iron striping Figure 1   Diagram of research regarding recovery of copper from solution after bioleaching of PCBsFigure 2   Eff  ect of H2SO4 concentration on copper and iron stripping rate, (O:A=1, contact time 5 min.)rate was in comparable equilibrium level during all test. SUMMARYResearch on solvent extraction and stripping test of copper and iron from polymetallic solution after bi-oleaching of e-waste was carried out. It was shown that copper can be separated and recovered by solvent ex-traction using LIX 860 N-IC. Extraction rate of copper was in the range of 97 – 98,5 % and iron from 2,5 to 3,8 %. It is easy to strip copper from loaded organic phase. About 93 % of Cu was stripped by sulfuric acid with concentration of 150 g/L and phase ratio O:A  = 1:1. Iron 230   METALURGIJA 53 (2014) 2, 228-230J. WILLNER et al.: EXTRACTION OF COPPER FROM SOLUTION AFTER BIOLEACHING OF PRINTED CIRCUIT...REFERENCES[1]  C. Ludwig, S. Hellweg, S. Stucki, Municipal Solid  Waste Management: Strategies and technologies for sustainable solutions, Springer, Berlin, 320–322 (2003).[2]  S. Panda, P.K. Parhi, N. Prahan, U.B. Mohapatra, L.B. Su-kla, K. H. Park, Hydrometallur gy 121-124 (2012), 1 16-119.[3]  J. A. Munoz, D. B. Dreisinger, W.C. Cooper S.K. Young, Hydrometallurgy 88 (2007), 3-18. [4]  L. Gotfryd, G. Pietek, Physicochemical Problems of Mine-ral Processing, 49 (2013) 1, 133-143.[5]  S. Panada, P. K. Parhi, N. Prahan, U.B. Mohapatra, L. B. Sukla, K. H. Park, Hydrometallurgy (2012) 121-124, 116-119. [6]  CH. Zhang, J. Wang, J. Bai, W. Mao, 2010, Production of high purity copper from bio-leaching solutions of waste printed circuit boards, IEEE 1-4.  The 4th International Conference on Bioinformatics and Biomedical Enginee-ring, June 18-20, 2010, Chengdu, China.[7]  J. Willner, Biological leaching of copper from electronic scraps by pure and mixed cultures of acidithiobacillus,  The 4th International Conference on Engineering for  Waste and Biomass  Valorisation (WasteEng12) Proceedings, 1616-1622.[8]  J. Willner, Journal of Achievements in Materials and Ma-nufacturing Engineering, 55 (2012) 2, 860-863. [9]  J. Willner, Metalurgia 52 (2013) 2, 189-192.Note: Foks P. is responsible for English language, Katowice, Poland stripping rate was constants in all experiments and equaled about 24 %. AcknowledgementsThe research was conducted within the work: BKM-324/RM1/2012 (Poland).  The authors are grateful to BASF (Ireland) for supplying or ganic solvent LIX 860N-IC used in the research. Figure 3   Eff  ect of phase ratio (O:A) on stripping rate of copper and iron (H2SO4 concentration 150 g/L, contact time 5 min.)

Extraction of copper from solution after bioleaching of printed circuit boards (PCBs)

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228  METALURGIJA 53 (2014) 2, 228-230J. WILLNER, A. FORNALCZYKEXTRACTION OF COPPER FROM SOLUTION AFTER BIOLEACHING OF PRINTED CIRCUIT BOARDS (PCBs)Received – Prispjelo: 2013-07-26Accepted – Prihvaćeno: 2013-10-25Preliminary Note – Prethodno priopćenjeISSN 0543-5846METABK 53(2) 228-230 (2014)UDC – UDK 669.3: 66.066.1:62.004.8=111J. Willner, A. Fornalczyk,: Silesian University of Technology, Depart-ment of Metallurgy, Katowice, Poland The solvent extraction of copper and iron from bioleaching solutions of PCBs with LIX 860N-IC and nex t stripping test with H2SO4 were investigated. In test the eff ect of varying sulfuric acid concentration on stripping rate of Cu and Fe and also phase ratio ( O : A) were determined. It was found that the stripping rat e of copper increases with the sulfuric acid concentration. The optimal concentration of H 2SO4 is suggested to be about 150 g/L and phase ratio O:A = 1:1. Key words: copper, solvent extraction, electronic waste, bioleaching, LIX 860N-IC.INTRODUCTIONPrinted circuit boards (PCBs) are the main carrier of valuable metals in the electronic waste. For example, metal content in these elements of mobile phones is about 28 %, including 10 - 20 % of copper , 1 - 5 % of lead, 1 - 3 % of nickel, content of precious metals (Ag, Pt, Au) about 0,3 - 0,4 %, and the rest are plastics (19 %), bromine (4 %), glass and ceramics (49 %) [1]. The quantitative composition of polymetallic electronic ele-ments makes this type of wastes, an attractive material in terms of valuable metals recovery . Printed circuit boards (main component of many portable electronic devices) are an example of a source of valuable metallic constituents.In addition to traditional methods of electronic scraps processing (pyro- and hydrometallur gical meth-ods), new solutions are searched, which could replace or improve current practice processes. It is important that effi cient metal recovery and the principles of envi-ronmental protection must be kept. Well known is ap-plication of biohydrometallurgical methods in recovery process of metals (such as Cu, Au, Ni, U, Zn, Pb) Over the past few years bioleaching–solvent extraction–elec-trowinning (BL–SX–EW) process has been conducted in hydrometallur gical production of copper from low grade ores. About 20 – 25 % of the world’s total copper production originates from solvent extraction followed by electrowinning processes [2,3]. In recent years, much attention has been paid to the possibility of using microorganisms in the extraction of metals from a variety of waste. A small number of pub-lications is dedicated to the possibility of further recov-ery of metals from solutions after bioleaching. As a re-sult of bioleaching of electronic waste, a multi-compo-nent solution is obtained, containing various metal ions, of which copper is predominant component. Due to the presence of additional metal cations, especially iron cations, direct recovery of copper is much more hin-dered. In this case, an ef fective method that allows the separation of desired metal (Cu) from their mixture may be solvent extraction [4,5].Not many studies have been undertaken for the sol-vent extraction of copper from polymetallic post-bi-oleaching electronic scrap solutions [6]. Experimental works using bacterial leaching for the extraction of some base metals (Cu, Zn, Pb, Ni, Sn) from electronic waste were carried out with the partici-pation of Acidithiobacillus ferrooxidans and Acidithio-bacillus thiooxidans.[7-9]. It was indicated that in the presence of these strain and at the ambient temperature, 99 % of copper can be extracted into solution during bioleaching. Typical polymetallic solution after bioleaching of PCBs form used mobile phones consists (g/L): 3,228 - 4,525 Cu, 2,084 – 3,437 Fe, 0,061 Sn, 0,0005 Pb, 0,0695 Ni. The solvent extraction allows selectively separate copper from solution and next further recovery of Cu from a loaded or ganic phase requires the stripping op-eration.The aim of this study was to determine the prelimi-nary conditions of the copper and iron stripping rate from loaded organic phase, using H2SO4 at varying con-centrations and varying phase ratio O : A. Achieving this goal required set of operation which consisted of the preparation of test material (PCBs milling), bi-oleaching of waste and the extraction process in accord-ance with the methodology presented in this article.229METALURGIJA 53 (2014) 2, 228-230J. WILLNER et al.: EXTRACTION OF COPPER FROM SOLUTION AFTER BIOLEACHING OF PRINTED CIRCUIT...EXPERIMETAL WORK Materials. The research was conducted on printed circuit boards (PCBs) derived from spent mobile phones. PCBs were ground with the cutting mill to a particle size < 0,5 mm.Bioleaching. Bioleaching were carried out in Erlen-meyer fl asks by using a rotary shaker (130 rpm) at am-bient temperature. In this study Acidithiobacillus fer -rooxidans strain was used. The culture was maintained in a standard Silverman/Lundgren (9K) medium. Sam-ples of the waste were 2 g, the volume of solution was 200 mL, whereas the quantities of bacteria culture was 10 % (v/v). Bioleaching was carried out within 40 days. Solutions were fi ltered, combined and then subjected to solvent extraction. The metal content (Cu and Fe) in the solution after bioleching was determined by atomic ad-sorption spectrometry (SOLAAR M6-UNICAM Atom-ic Absorption) and was as follows (g/L): 3,228 Cu; 2,084 Fe.Extraction. The organic solvent such as LIX 860N-IC obtained from the supplier (BASF , Ireland), was used in studies. It was found (data not illustrated) that the optimal concentration of LIX 860 N-IC is suggested to be about 5 %, phase ratio O:A  = 1:1 and pH = 1,9. Therefore extraction experiments were carried out in these conditions by using separatory funnel and manual mixing of organic (O) and aqueous phase (A) for time period of 5 minutes. Stripping. Stripping test was carried out with H2SO4 with the varied concentration from 37,5 g/L to 300 g/L. Experiments were carried out in separatory funnel by manual mixing for 5 min. Dif ferent phase ratios O:A  were used from 1:3 to 3:1. Concentration of Cu and Fe in solutions during extraction as well as striping experi-ments was determined by AAS. Stages of studies are illustrated in Figure 1.RESULTS AND DISCUSSION When 5 % LIX 860 N-IC was used, the extraction rate of copper was in the range of 97-98,5 % and iron from 2,5 to 3,8 %. The loaded organic phase came from the solvent extraction was stripped by H 2SO4 solution. The results of stripping experiment are shown in Figure 2. In test the ef fect of varying H 2SO4 concentration on stripping rate of copper and iron were investigated. The stripping rate of copper rises with increasing of H 2SO4 concentration and reached above 92,8 % with respect to sulfuric acid concentration of 150 g/L. Iron stripping rate is constants in all tested range of sulfuric acid con-centration and equaled about 24 %. The infl uence of phase ratio (O:A) on the copper and iron stripping is shown in Figure 3. With the increase of O:A ratio, copper stripping rate increased. When the O:A rose from 0,33 to 1,0 the copper stripping rate in-creased from 67,7 % to 92,8 %. In the highest ratio slightly rise to 98,1 % was observed. The iron striping Figure 1  Diagram of research regarding recovery of copper from solution after bioleaching of PCBsFigure 2  Eff ect of H2SO4 concentration on copper and iron stripping rate, (O:A=1, contact time 5 min.)rate was in comparable equilibrium level during all test. SUMMARYResearch on solvent extraction and stripping test of copper and iron from polymetallic solution after bi-oleaching of e-waste was carried out. It was shown that copper can be separated and recovered by solvent ex-traction using LIX 860 N-IC. Extraction rate of copper was in the range of 97 – 98,5 % and iron from 2,5 to 3,8 %. It is easy to strip copper from loaded organic phase. About 93 % of Cu was stripped by sulfuric acid with concentration of 150 g/L and phase ratio O:A = 1:1. Iron 230  METALURGIJA 53 (2014) 2, 228-230J. WILLNER et al.: EXTRACTION OF COPPER FROM SOLUTION AFTER BIOLEACHING OF PRINTED CIRCUIT...REFERENCES[1] C. Ludwig, S. Hellweg, S. Stucki, Municipal Solid Waste Management: Strategies and technologies for sustainable solutions, Springer, Berlin, 320–322 (2003).[2] S. Panda, P.K. Parhi, N. Prahan, U.B. Mohapatra, L.B. Su-kla, K. H. Park, Hydrometallur gy 121-124 (2012), 1 16-119.[3] J. A. Munoz, D. B. Dreisinger , W.C. Cooper S.K. Young, Hydrometallurgy 88 (2007), 3-18. [4] L. Gotfryd, G. Pietek, Physicochemical Problems of Mine-ral Processing, 49 (2013) 1, 133-143.[5] S. Panada, P. K. Parhi, N. Prahan, U.B. Mohapatra, L. B. Sukla, K. H. Park, Hydrometallurgy (2012) 121-124, 116-119. [6] CH. Zhang, J. Wang, J. Bai, W. Mao, 2010, Production of high purity copper from bio-leaching solutions of waste printed circuit boards, IEEE 1-4. The 4th International Conference on Bioinformatics and Biomedical Enginee-ring, June 18-20, 2010, Chengdu, China.[7] J. Willner, Biological leaching of copper from electronic scraps by pure and mixed cultures of acidithiobacillus, The 4th International Conference on Engineering for Waste and Biomass Valorisation (W asteEng12) Proceedings, 1616-1622.[8] J. Willner, Journal of Achievements in Materials and Ma-nufacturing Engineering, 55 (2012) 2, 860-863. [9] J. Willner, Metalurgia 52 (2013) 2, 189-192.Note: Foks P. is responsible for English language, Katowice, Poland stripping rate was constants in all experiments and equaled about 24 %. AcknowledgementsThe research was conducted within the work: BKM-324/RM1/2012 (Poland). The authors are grateful to BASF (Ireland) for supplying or ganic solvent LIX 860N-IC used in the research. Figure 3  Eff ect of phase ratio (O:A) on stripping rate of copper and iron (H2SO4 concentration 150 g/L, contact time 5 min.)

Extraction of copper from solution after bioleaching of printed circuit boards (PCBs)

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