Abstract
Although copper is the principal metal in most electronic scrap, printed circuit boards in mobile phones also contain a significant amount of silver, gold and palladium. A bench-scale extraction study was carried out on the applicability of economically feasible hydrometallurgical processing routes to recover these precious metals. The starting material contained 27.37% copper, 0.52% silver, 0.06% gold and 0.04% palladium. In a first step, the following leaching solutions were applied: an oxidative sulfuric acid leach to dissolve copper and part of the silver; an oxidative chloride leach to dissolve palladium and copper; and cyanidation to recover the gold, silver, palladium and a small amount of the copper. A thiourea leach, as an alternative to cyanidation, was also investigated but did not give a sufficiently high yield. To recover the metals from each leaching solution, the following methods were evaluated: cementation, precipitation, liquid/solid ion exchange and adsorption on activated carbon. Precipitation with NaCl was preferred to recuperate silver from the sulfate medium; palladium was extracted from the chloride solution by cementation on aluminum; and gold, silver and palladium were recovered from the cyanide solution by adsorption on activated carbon. The optimized flowsheet pe united the recovery of 93% of the silver, 95% of the gold and 99% of the palladium.
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Choi, Y.U., Lee, E.C., and Han, K.N., 1991, “The dissolution behaviour of metals from Ag/Cu and Ag/Au alloys in acidic and cyanide solutions,” Metallurgical Transactions B., Vol. 22B, pp. 755–764.
Eisele, J.A., 1989, “Comparative leaching of gold and silver ores with cyanide and thiourea solutions,” Precious Metals, M.C. Jha and S.D. Hill, eds., TMS, Las Vegas, Nevada, pp. 253–254.
Gaita, R., and Al-Bazi S.J., 1995, “An ion-exchange method for selective separation of palladium, platinum and rhodium from solutions obtained by leaching automotive catalytic converters,” Talanta, Vol. 42, pp. 249–255.
Gönen, N., 2003, “Leaching of finely disseminated gold ore with cyanide and thiourea solutions,” Hydrometallurgy, Vol. 69, pp. 169–176.
Jia, Y.F., Steele, C.J., Hayward, I.P., and Thomas, K.M., 1998, “Mechanism of adsorption of gold and silver species on activated carbons,” Carbon, Vol. 36, pp. 1299–1308.
Lacoste-Bouchet, P., Deschênes, G., and Ghali, E., 1998, “Thiourea leaching of a copper-gold ore using statistical design,” Hydrometallurgy, Vol. 47, pp. 189–203.
Mishra, R.K., 1989, “Recovery of platinum group metals from automobile catalytic converters, a review,” Precious Metals, M.C. Jha and S.D. Hill, eds. TMS, Las Vegas, Nevada, pp. 483–501.
Sulka, G.D., and Jaskula, M., 2002, “Study of the kinetics of the cementation of silver ions onto copper in a rotating cylinder system from acidic sulphate solutions,” Hydrometallurgy, Vol. 64, pp. 13–33.
Yapu, W., Segarra, M., Fernández, M., and Espiell, F., 1994, “Adsorption of dicyanoaurate and dicyanoargentate ions in activated carbon”, Metallurgical and Materials Transactions B, Vol. 25B, pp. 185–191.
Zhang, H., Meng, X., and Han, K.N., 1996, “An oxidative chloride leaching of palladium powder,” Proceedings EDP Congress, G.W. Warren, ed., TMS, Warrendale, Pennsylvania.
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Nonmeeting paper number 04-310. Discussion of this peer-reviewed and approved paper is invited and must be submitted to SME Publications Dept. prior to August 31, 2005.
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Quinet, P., Proost, J. & Van Lierde, A. Recovery of precious metals from electronic scrap by hydrometallurgical processing routes. Mining, Metallurgy & Exploration 22, 17–22 (2005). https://doi.org/10.1007/BF03403191
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DOI: https://doi.org/10.1007/BF03403191