Solvent Extraction of Rhodium from Chloride Media by N,N′‐Dimethyl‐N,N′‐Diphenyltetradecylmalonamide

Abstract

Solvent extraction studies for rhodium (III) in chloride medium have been carried out with N,N′‐dimethyl‐N,N′‐diphenyltetradecylmalonamide (DMDPHTDMA). Rhodium can be effectively extracted by DMDPHTDMA in the presence of tin and can also be successfully stripped by an aqueous mixture of 4 M HCl+0.05 M NaClO₃. The influence of different Sn:Rh feed ratios on the extraction system has been taken into account. Some experimental parameters like equilibration time, extractant concentration and hydrogen and chloride ions concentrations have been investigated in detail. The loading capacity of DMDPHTDMA for rhodium has been determined. An ion‐pair association is proposed to explain rhodium extraction.

Keywords:

• Rhodium
• tin
• malonamide derivative
• hydrochloric acid

Acknowledgments

The financial support kindly offered by “Fundação para a Ciência e Tecnologia” (FCT, Lisbon, Portugal) is gratefully acknowledged.