AN INVESTIGATION ON THE EXTRACTION OF RHODIUM FROM AQUEOUS CHLORIDE SOLUTIONS WITH 7-SUBSTITUTED 8-HYDROXYQUINOLINES

Abstract

ABSTRACT The extraction of Rh(III) from chloride solutions with 2 different 7-substituted 8-hydroxyquinoline (R-HQ) reagents was studied. Rh(III) was found to be extracted, to a limited degree, via an ion-pair involving the anionic hexachloro species of Rh(III), RhCl6 3−, and the protonated extractant. Through computer simulation of the extraction equilibria for one extractant, TN 1911, an extraction constant of log Kex= 5.8 was determined. The effect of age, contact time, [HCI], [CI−], [H+], and [SO4 2] on the extraction of Rh(III) with R-HQ reagents is reported.