Abstract:Alkaline residue from production of crude cadmium in purification process of zinc hydrometallurgy was treated by high temperature and high acid oxidation leaching. A comparison was made between "electrolytic solution + manganese powder oxidation leaching" and "electrolytic solution direct leaching", the following technological parameters of high temperature and high acid oxidation leaching were as follows: leaching temperature of 85-90 ℃, leaching time of 8 h above, and mass ratio of liquid to solid of about 4 g/g, as a result, leaching rates of zinc and cadmium is 96.88% and 95.35%, respectively. Through industrial practice, the effective treatment of cadmium alkali slag stored in a zinc smelter for a long time can realize recovery of valuable metals such as zinc and cadmium, improve metal recovery rate, and avoid environmental protection risk caused by long-term stockpiling of cadmium-bearing slag, which has good economic and environmental benefits.