Duval Corporation, Tucson

One, the CLEAR process, was investigated by Duval Corporation near Tucson, Arizona (29). It involves leaching copper concentrated with a metal chloride solution, separation of the copper by electrolysis, and regeneration of the leach solution in a continuous process carried out in a closed system. Elemental sulfur is recovered. Not far from the Duval plant, Cypms Mines Corporation operated a process known as Cymet. Sulfide concentrates undergo a two-step chloride solution leaching and are crystallized to obtain cuprous chloride crystals. Elemental sulfur is removed during this stage of the process. 

Elemental sulfur precipitates and is recovered. Copper powder is produced by electrolyzing the resulting solution. Developed by G. E. Atwood and C. H. Curtis of Duval Corporation at Tucson, AZ. See also Cymet. 

The most likely minerals to be processed using hydrometallurgical techniques would probably be sphalerite (ZnS) and chalco-pyrite (CuFeSa). Duval Corporation in Tucson already has a... 

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