METHOD FOR RECOVERING METAL ZINC FROM SOLID METALLURGICAL WASTES
The present invention relates to a method for recovering metal zinc from a solid metallurgical waste containing zinc and manganese, comprising the steps of: a. bringing said solid metallurgical waste into contact with an aqueous leaching solution comprising chloride ions and ammonium ions to produce at least one leachate comprising zinc ions and manganese ions and at least one insoluble solid residue; b. cementing said leachate, by adding metal zinc as a precipitating agent, to eliminate at least one metal other than zinc and manganese possibly present in said leachate in form of ions and producing a purified leachate; c. subjecting said purified leachate to electrolysis in an electrolytic cell comprising at least one cathode and at least one anode immersed in said purified leachate to deposit metal zinc on said cathode and producing at least one exhausted leachate; said method comprising, before said electrolysis, a step of precipitating manganese ions by oxidation with permanganate ions and subsequent separation of a precipitate comprising MnO2.