A solvent extraction study of silver(I), palladium(II) and mercury(II) with 2-tert-dodecylthiopyridine

Abstract

2-tert-Dodecylthiopyridine was synthesized from 2-chloropyridine and tert-dodecanethiol in order to examine its extraction properties for various metals. It was found to have good selectivity for the extraction of palladium(II) and mercury(II) over platinum(II) and -(IV) and base metals from chloride media; silver(I) was found to be almost completely extracted from nitric acid (0.01–5 mol/dm 3 HNO 3). Palladium(II) and mercury(II) were completely extracted from hydrochloric acid over the range 0.01–2 and 0.01–0.5 mol/dm 3 HCl, respectively. The rate of extraction of palladium(II) from hydrochloric acid was much faster than when using dialkylsulfide and triisobutylphosphine sulfide extractants. An aqueous mixture of thiourea and hydrochloric acid was found to be effective as stripping solution for palladium(II). The extent of stripping was dependent on the concentrations of either thiourea or hydrochloric acid.