Thermodynamic study of the extraction of indium(III) and cadmium(II) by Cyanex 301 from concentrated HCl media

The distribution equilibria of In(III) and Cd(II) between aqueous HCl solutions and kerosene containing Cyanex 301 (bis(2,4,4-trimethylpentyl) dithiophosphinic acid denoted hereafter HL) and 10% (V/V) of n-decanol are investigated; In(III) and Cd(II) are extracted as InL3 and CdL2, respectively and a physico-chemical model is proposed for modelling the distribution data. In the final part of the paper, this model is used to discuss the optimal conditions for separating indium and cadmium, previously co-extracted with Cyanex 301, by stripping in HCl media.