Selective extraction of zinc, gallium, and germanium from zinc refinery residue using two stage acid and alkaline leaching

Abstract

In this research, zinc, gallium, and germanium were selectively dissolved from zinc refinery residue by stepwise leaching. The thermodynamic study demonstrated that Zn, Ga, and Ge could be selectively leached by controlling a suitable pH condition. In the first stage of leaching with sulfuric acid media, >93% of the Zn content, approximately 100% of the Ga content, and <8% of the Ge content were leached using 2 Mol/L H2SO4 with a liquid-solid ratio of 10 mL/g at 80 °C for 4 h. in the second stage of leaching with sodium hydroxide media, about 90% of the Ge content and 33% of the lead content were extracted using 1 Mol/L NaOH with a liquid-solid ratio of 20 mL/g at 80 °C for 4 h.