Patents

An improved extraction process for the separation of pure zinc and cobalt from secondary zinc raw-materials containing a mixture of both. The zinc and cobalt containing solution is contacted with a water-immiscible organic solution containing a tertiary amine. The process is particularly useful for aqueous solutions containing high total metals content and elevated cobalt concentrations, while avoiding the formation and precipitation of ammonium sulphate containing double salts during the solvent extraction of the cobalt. The process involves the leaching of Co-Zn containing secondaries in chloride medium and contacting the leach liquor with a water-immiscible organic solution to separate zinc from cobalt selectively and produce a zinc loaded organic phase leaving all the cobalt in the raffinate. The zinc-loaded organic phase is then contacted with pure water to strip out 100% of the loaded zinc to the aqueous phase which could directly be used for the synthesis of any value added product of zinc.