The Separation of Rhodium and Iridium. I. Active Centra and the HCl Effect

Abstract

A study was made of various cationic centra that will be suitable for the efficient separation of IrCl₆ ²⁻ from chlororhodium(III) species both in the form of precipitants and extractants. The double‐charged quaternized ammonium species with the lowest charge density proved to be the best precipitants. The extractant analogues of the most efficient precipitating agents proved to be very efficient as extractants of IrCl₆ ²⁻ but they are not suitable for practical application due to the difficulty to reverse the process in the solvent extraction system.

Keywords:

• Rhodium
• Iridium
• Separation
• HCl effect

Acknowledgments

The authors wish to thank UPE, Impala Platinum, and the FRD for financial support.