METHOD FOR OXIDIZING NICKEL SULFIDE IN NICKEL SULFIDE-CONTAINING SLUDGE, AND METHOD FOR RECOVERING NICKEL METAL FROM NICKEL SULFIDE-CONTAINING SLUDGE

摘要

Disclosed is a method for recovering nickel metal from nickel sulfide-containing sludge, wherein: nickel sulfide contained in nickel sulfide-containing sludge is oxidized into nickel sulfite and/or nickel sulfate by supplying air to the sludge, while maintaining the moisture content of the nickel sulfide-containing sludge to 20-60% by mass; a weak acid or water is added into the sludge so that the nickel sulfite and/or nickel sulfate in the sludge obtained by the oxidation is eluted into the weak acid or water; and nickel metal is recovered by electrolytically precipitating the thus-obtained solution of nickel sulfite and/or nickel sulfate.