A Comparison of the Separation Behavior of Some New Coordinating Resins and Commercial Quaternary Ammonium Resins with Reference to Their Separation of Gold(III) and Palladium(II) in Hydrochloric Acid Media

Abstract

The adsorption and separation of gold(III) and palladium(II) chlorocomplexes by anion‐exchange and synthesized coordinating resins are evaluated and compared in batch and column operations. New coordinating resins with a functional group based on triisobutyl phosphine sulfide with spacer arms containing coordinating O and/or S atoms are used. For both types of resin, the mechanism of the metal adsorption process is characterized. The highest separation factors at equilibrium conditions are obtained with the coordinating resins. However, the adsorption rate is faster with the ion‐exchange resins. A faster kinetics of the adsorption process is obtained with both types of resin when the temperature is increased, but the total adsorption capacity increases at higher temperatures for the coordinating resins and decreases in the case of ion‐exchange resins. In column operations, the highest separation factors are obtained with the coordinating resin containing ethylene oxide chains as a spacer arm. The quantitative elution of both ions is achieved with all the resins, but it is only possible to obtain a 100% pure palladium fraction with the coordinating resins. These resins are also more selective than ion‐exchange resins, allowing the separation of palladium and gold chlorocomplexes from mixtures containing other noble and base metals.