Test Research on Two-stages Leaching of Indium From Zinc Oxidation Slag

Leaching of indium from zinc oxidation slag by two-stages leaching process was studied.The effects of sulfuric acid initial concentration,leaching time,the ratio between liquid and solid,temperature,activated time and KMnO4 dosage on leaching of indium were examined.The results show that the indium is enriched in neutral leaching residue after first-stage leaching.Leaching of indium can be enhanced obviously by mechanical activation,but atmospheric oxidation doesn't improve the leaching of indium.The optimum leaching conditions in second-stage leaching process are sulfuric acid initial concentration of 300g/L,leaching time of 3h,the ratio between liquid and solid 3∶1,temperature of 85℃,mechanically activated of 60min.Under the optimum conditions,leaching rate of indium is 90.9%.