Sustainable Mining and Metallurgy

The purification process of zinc hydrometallurgy in a smelter has the problems of high content of zinc and codmium and low grade of lead. The main reasons are that the particle size of alloy zinc powder used for purification is coarse, the efficiency of cadmium removal in the first stage purification is low, cobalt is enriched in the system, and the leaching rate of cobalt and nickel slag is low. In view of the above problems, the purification process was optimized : the screening process of alloy zinc powder was increased, the original one-stage purification process of copper and cadmium was changed to the two-stage copper and cadmium removal processes, the high cobalt slag and electrolytic zinc anode slime were combined for multiple high temperature and high acid oxidation leaching, and the lead slag washing process was increased. After the process optimization, the amount of lead slag produced by the comprehensive recovery of cobalt-nickel slag decreased by more than 60%, the lead grade reached more than 35%, the zinc content decreased to about 10%, and the zinc recovery rate reached more than 91%. This technology comprehensively recovers valuable metals with remarkable benefits, and achieves the goal of energy conservation, emission reduction and environmental friendliness.