Cyprus Metallurgical Processes Corporation

Robert K Johnson

Enzo L Coltrinari

Mark A Peters

A process for recovering silver present in cuprous chloride solutions as a soluble silver chloride which comprises saturating the cuprous chloride solution with sodium chloride, subjecting the saturated solution to evaporation to co-crystallize the sodium chloride and silver chloride, separating the solid chlorides from the liquid, recovering silver from the sodium chloride-silver chloride crystals and reclaiming the sodium chloride, adding water to the liquid and cooling it to crystallize cuprous chloride. The procedure is adaptable to processes for recovering copper from its ores in which copper is reduced to cuprous chloride in a leach slurry followed by cooling the leach slurry to crystallize out the cuprous chloride from which copper is recovered by conventional techniques.

Recovery of silver from cuprous chloride solutions by co-crystallization

Copper is recovered from chalcopyrite by means of a pollution-free hydrometallurgical process which entails leaching and converting the chalcopyrite with copper sulfate in order to produce an insoluble copper sulfide, a soluble iron sulfate and sulfuric acid. A secondary leach is then conducted in order to react the copper sulfide with oxygen in the presence of a jarosite-forming cation to produce a soluble copper sulfate and an insoluble iron bearing jarosite. This copper sulfate is separated from the jarosite and sent to a copper recovery process and/or recycled. Alternatively, the copper sulfide from the initial leach may be separated from the iron sulfate solution immediately after the initial leach, and this copper sulfide can be treated with other processes to produce elemental copper and sulfur.

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Robert K Johnson