Separation of copper and cobalt–nickel sulphide concentrates during processing of manganese deep ocean nodules

Controlled sulphide precipitation was examined in this study for the recovery of copper and nickel–cobalt concentrates from liquors originating from leaching manganese deep ocean nodules in FeSO4–H2SO4–H2O solutions. The metal ions studied include Co2+, Cu2+, Fe2+, Ni2+, Mn2+ and Zn2+. Promising results were obtained when copper and nickel–cobalt concentrates were precipitated with 5.5% solution of (NH4)2S. This was added at optimised flow rate of 0.15 g S2−/min per 1 L of processed solution at the laboratory temperature, pH=1.0 (copper precipitation) and pH=3.0 (nickel–cobalt precipitation).