Copper, lead, and zinc are recovered from complex sulfides, e.g., ores or smelter flue dusts, by leaching with calcium or barium chloride in the presence of oxygen at 80 deg-150 deg c. Thus, a sulfide ore containing cu 0.6, PB 2.6, Zn 4.6, Fe 35, s 37 pct, and 7 oz/ton ag, was reacted with a 20-pct solution of cacl2 in an autoclave at 100 deg c and 60 psi o2 for 20 h. The solubilization was cu 75, pb 71, ag 67, and zn 96 pct. Approximately 90 pct of the fe and sulfates remained in the residue.
U.S. Patent Number 4,410,496, October 18, 1983; Chem. Abstr. 99:216,507N