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Abstract

A process is described for recovering metal values from a zinc-containing complex sulphide material comprising leaching the material in a first leaching stage under non-oxidative conditions with a controlled amount of an aqueous chloride lixiviant solution containing cupric chloride in an amount which is selected so as to solubilize at least a part of the zinc in the material and to precipitate a quantity of cupric sulphide substantially equivalent on a molar basis to the zinc leached from the material, the lixiviant solution further containing sufficient of a source of chloride ions other than cupric chloride to ensure solubilization of metal chlorides present, recovering from the first leaching stage a zinc chloride-containing leach liquor, recovering metal values from said leach liquor in a metal recovery section, treating solids from the first leaching stage under oxidizing conditions in a second leaching stage with a liquor containing hydrochloric acid and metal chlorides thereby to solubilize further metal values from the solids, to precipitate iron values and to regenerate cupric chloride-containing lixiviant solution for use in the first leaching stage, and recovering from the second leaching stage (a) a solids residue consisting essentially of (i) iron values in the form of ferric hydroxide and jarosite and (ii) sulphur and that is substantially free from non-ferrous metal values and (b) a cupric chloride-containing lixiviant solution for recycle to the first leaching stage.

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First Claim