THE EXTRACTION OF RHODIUM FROM AQUEOUS HITRIC ACID BY ORGANOPHOSPHINE SULPHIDES

Abstract

The organophosphine sulphides, tri-phenyl phosphine sulphide (TPPS), tri-n-butyl phosphine sulphide (TBPS) and N,N',N"-tri-n-hexyl phosphorothioic-triamide (THPS) have been investigated for their potential use as extractants for the recovery of fission product rhodium from aqueous nitric acid solutions. The ease with which the extractions proceed can be rationalised in terms of the polarisability of the P=S bond, and in the case of THPS, the extraction is shown to proceed via a solvating type mechanism. Equilibration times for the extraction are of the order of 3-6 hours.