The separation of platinum(2), palladium(2) and rhodium(3) by surfactant gel extraction and an abnormal dependence of metal concentrations on the extractability of chloro-complexes into the cationic surfactant phase

and were extracted into止e CPC phase. Rhodium(III)does not form a chloro-complex and was separated丘om platinmm(II)and palladimm(II). CPC and its gel phase play the role of a counter ion and solvent for the anionic complexes. However, an abnormal decrease in extractability was observed for chloro-complexes at low metal. ' concentrations and was explained by the solubility of complexes in the presence of the surfaCtant gel. A kinetic separation of palladimm(II)丘om platinum(II)was performed by a ligand exchange reaction with ammonia. The cationic ammine complex of palladium(II) could not bind with the positively charged CP' and was back extracted into the aqueous phase. The platinum(II) chloro-complexes were stable for at least 3 hours below 50 OC and remained in the CPC phase.