METHOD FOR SEPARATING NICKEL AND COBALT FROM ACTIVE MATERIAL CONTAINED IN SPENT NICKEL-METAL HYDRIDE BATTERY

摘要

A method for separating nickel, cobalt and a rare earth element from a material containing positive and negative electrode active materials of a nickel-metal hydride battery includes mixing a material containing positive and negative electrode active materials with a sulfuric acid solution and dissolving therein, and then separating a leachate from a residue; adding an alkali metal sulfate to the leachate to obtain a mixed precipitate of double sulfate of rare earth elements, and a rare-earth-element-free solution; and adding a sulfurizing agent to the rare-earth-element-free solution to separate a nickel and cobalt sulfide raw material and a residual solution.