Abstract
The separation of the secondary PGM (Rh, Ir, Ru, Os) complexes in chloride media is very difficult due to the existence of the metal ions in various chemical complexes forms. The formation of the stronger thiocyanate complexes allows a much more consistent extraction behaviour. The extraction of the PGM thiocyanate complexes by π-donor solvating ligands and polymers, such as MIBK, TEP, R3N and Amberlite XAD-7 (a methacrylate type polymeric absorbent) vas studied. The scheme presented is based on the separation of Ru/Os by selective distillation from thiourea solution, followed by formation of the thiocyanate complexes of the residual elements. The PGM thiocyanates are passed on XAD-7, which removes Pd, Pt, and then Rh is separated from Ir by extraction with [Alamine-336] HSCN. The metals are recovered from the thiocyanste solutions by precipitation as sulfides.

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