Metal values separation from residue generated in alkali fusion-leaching of copper anode slime

Most Cu, Te, Sb and precious metals in copper anode slime were enriched in residue using an alkali fusion-leaching process. In this paper, Cu and Te were extracted from the residue by acid leaching and Sb was separated by sulfide leaching. It was found that 96.2% Cu and 83.5% Te were extracted into leaching solution under the optimum conditions: 1 mol/L of H2SO4 concentration, 6% of NaCl addition, 20 °C of leaching temperature and 20 min of leaching time. 86.8% Sb was extracted when Na2S concentration, leaching temperature and leaching time were determined at 90 g/L, 80 °C and 40 min, respectively. Chemical analysis indicated that Ag, Pb and Au were enriched in the sulfide leaching residue, which could be processed to recover precious metals.