Hydrometallurgical process for the treatment of sulphidized compounds

Abstract

The invention provides a hydrometallurgical process for recovering lead in essentially pure form from a sulphurized compound containing at least lead as a non-ferrous metal. The process involves treating the sulphurized compound with an aqueous lixiviating solution containing at least one chloride of a metal selected from the group consisting of copper, bismuth, antimony, arsenic, and silver, preferably cupric chloride, the quantity of said at least one chloride being less than or equal to that which is stoichiometrically required for the complete dissolution of the lead contained in the sulphurized compound, thereby to obtain a solution containing lead chloride and the chlorides of metals nobler than lead as impurities if originally present in the sulphurized lead compound, and an insoluble residue containing the sulphide of the metal of said at least one chloride, the sulphides of the non-ferrous metals originally present in the sulphurized compound, and free sulphur. The lead chloride solution is separated from the insouble residue, and purified by cementation with metallic lead or a more reducing metal than lead. Thereafter, the lead ions of the purified lead chloride solution are reduced to metallic lead which is recovered. The reduction may be accomplished by cementation with a more reducing metal than lead, preferably iron, or the reduction may be carried out by means of hydrogen.