Separation and selective recovery of platinum and palladium by solvent extraction

摘要

A process for the separation and selective recovery of platinum and palladium values from an acidic aqueous medium which comprises contacting the medium with a mixed organic extraction reagent comprising a water immiscible organic solvent having dissolved therein an organically substituted secondary amine compound capable of forming complexes of platinum and palladium that are preferentially soluble in the organic solvent and whereby the contacting results in creation of an organic extract phase and an aqueous raffinate phase. After phase separation, palladium is selectively recovered by contacting the organic phase with an aqueous solution of an acidified reducing agent. Platinum is separately recovered by contacting the organic phase with an aqueous alkaline solution. The process may be employed as a method for concentrating solutions of platinum or palladium.