Method for treating sulfide

A method for recovering a valuable metal from a waste lithium-ion battery,

• the method comprising obtaining a leachate by leaching a sulfide comprising copper and nickel and/or cobalt with an acid, the sulfide being generated by sulfurizing a molten body obtained by reducing, heating, and melting the waste lithium-ion battery,
• wherein the sulfide is subjected to a pulverizing treatment so as to have a particle size of 800 μm or less and the pulverized sulfide is subjected to a leaching treatment with an acid under a condition in which a sulfurizing agent being sulfur is present,
• wherein the sulfurizing agent is added to the pulverized sulfide in an amount of 1 equivalent or more with respect to total amount of copper contained in the pulverized sulfide to create conditions where the pulverized sulfide and the sulfurizing agent coexist, and
• by subjecting the pulverized sulfide to the leaching treatment, non-sulfidized copper metal contained in the pulverized sulfide is converted to copper sulfide, and copper sulfide contained in the pulverized sulfide is maintained as solid copper sulfide precipitated in the leachate.

A method for recovering a valuable metal from a waste lithium-ion battery,

• the method comprising a pyrometallurgical treatment, in which the waste lithium-ion battery is reduced, heated, and melted to obtain a molten body, and sulfurizing the molten body to obtain a sulfide containing copper and nickel and/or cobalt, and
• a hydrometallurgical treatment, in which the sulfide is leached with an acid,
• wherein, in the hydrometallurgical treatment,
• the sulfide is pulverized so as to have a particle size of 800 μm or less, and
• the pulverized sulfide is subjected to a leaching treatment with an acid under a condition in which a sulfurizing agent being sulfur is present,
• wherein the sulfurizing agent is added to the pulverized sulfide in an amount of 1 equivalent or more with respect to total amount of copper contained in the pulverized sulfide to create conditions where the pulverized sulfide and the sulfurizing agent coexist, and
• by subjecting the pulverized sulfide to the leaching treatment, non-sulfidized copper metal contained in the pulverized sulfide is converted to copper sulfide, and copper sulfide contained in the pulverized sulfide is maintained as solid copper sulfide precipitated in the leachate.