Hydrometallurgical recovery of metals and elemental sulphur from metallic sulphides.

摘要

Oxidative leaching of metal sulphides, for example zinc sulphide concentrate, is carried out in sulphuric acid solution in the presence of an oxidizing agent comprising oxides of nitrogen. Subsequent treatment enables separation of elemental sulphur and valuable metals such as lead, silver, and gold, and reduction of the remaining solution with a metallic reductant in the presence of added acid produces a substantially nitrate-free solution from which metal values such as zinc may be recovered by electrolytic means.