Separation and purification of palladium from aqueous solution by thiol derivatives

Abstract EN

The extraction of palladium from aqueous nitrate solution was studied with solvents containing 3,4 dithio toluene (H2TDT), bis (2,4,4-trimethylpentyl) phosphinic acid-monothio (CYANEX 302) and dithio (CYNAEX 301) analogues.

The effect of different parameters affecting the extraction of palladium was investigated.

Comparative data are presented to illustrate the effect of composition (sulphur substitution) on the extraction and stripping characteristics of the three reagents.

The selectivity range of the studied extractants was found to be in the order H2TDT > CYNAEX 301 > CYNAEX 302.

The extraction of the Pd (II) complexes with respect to metal-thiol complexes has also been studied.

Experimental data relating to palladium have been analysed numerically to determine the stoichiometry of the extracted species and its equilibrium constant.

It was found that Pd (II) was extracted into the organic phase by the formation of the species RS-Pd (II).