Hydrometallurgical process for recovery of Zn, Pb, Ga and Ge from Zn refinery residues

Abstract

Zn, Pb, Ga and Ge were separated and recovered from zinc refinery residues by stepwise leaching. In the first stage, by leaching with H2SO4 media, more than 90% of Zn and 99% of Ga were dissolved, leaving 92% of Ge in the leaching residue. In the second stage, by leaching with HCl media, approximately 99% of Pb and less than 2% of Ge were selectively dissolved. Finally, the remaining 90% of Ge was extracted in 1 mol/L NaOH solution by destroying the correlation between SiO2 and Ge. XRD pattern of the leaching residue demonstrated that ZnSO4·H2O, PbSO4 and SiO2 were removed sequentially through the stepwise leaching. The proposed process achieved high recoveries of Zn, Pb, Ga and Ge, thus presenting a potential industrial application.