Recovery and purification of iridium

摘要

A method of recovering iridium from a solution thereof containing rhodium and impurities in the form of base metals comprising; oxidizing the iridium to the Ir(IV) oxidation state in an acid solution in the presence of chloride ions; removing the iridium chlorocomplexes formed using a suitable anion-exchange resin; washing the resin; treating the iridium with an aqueous solution of sulphur dioxide which is substantially free of chloride ions; and thereafter eluting the iridium complex formed from the resin using a suitable eluant.