Solvent extraction of gold (III) by the chloride salt of the tertiary amine Hostarex A327. Estimation of the interaction coefficient between AuCl4− and H+

Abstract

The equilibrium distribution of gold (III) between hydrochloric acid and the chloride salt of the amine Hostarex A327 in n-decane was studied. The extraction reaction is exothermic (ΔH°=−22.9 kJ/mol). Gold (III) is extracted by the reaction:

R3NH+Cl−org+AuCl−4aqright arrow over left arrowR3NH+AuCl−4org+Cl−aqThe extraction equilibrium constant depends on the ionic strength. From this dependency it was estimated that the interaction coefficient (AuCl4−,H+) is 0.26.