Treatment of lead concentrate for mfr. of crude lead - where sulphuric acid converts lead sulphide to lead sulphate, and copper, zinc and cadmium are removed by leaching

摘要

The concentrate is treated with H2SO4 soln. to form an ore pulp consisting mainly of sulphate; and a material(I) contg. an iron salt is added to the ore pulp to convert the residual PbS to PnSO4 and to dissolve Cu, Zn and Cd present in the concentrate. Solid/liq. sepn. processes are then used to obtain separate pptes. of PbSO4, Cu, Zn, and Cd. Material (I) is pref. a by-prod. obtd. in the hydrometallurgical extn. of Zn as a residue; and the H2S evolved by treating the concentrate with H2SO4 is pref. used to ppte. CuS, ZnS, and CdS. Used in the mfr. of Pb by pyrometallurgy, where metals such as Cu, Zn and Cd must be removed as they reduce the yield of Pb.