Method for oxidizing nickel sulfide in nickel sulfide-containing sludge, and method for recovering metallic nickel from nickel sulfide-containing sludge

摘要

A method for recovering metallic nickel from nickel sulfide-containing sludge, wherein the nickel sulfide contained in the sludge is supplied by supplying air to the sludge while maintaining the moisture content of the nickel sulfide-containing sludge at 20 to 60% by mass. Nickel sulfite and / or nickel sulfate is oxidized, weak acid or water is added to sludge, oxidized nickel sulfite and / or nickel sulfate in sludge is eluted into weak acid or water, and the resulting nickel sulfite and / or sulfuric acid A nickel solution is electrolytically deposited to recover metallic nickel.