EXTRACTION EQUILIBRIA OF MERCURY(II) FROM ACIDIC CHLORIDE SOLUTIONS WITH TRIOCTYLAMINE

Abstract

Distribution equilibria of mercury(II) between trioctylamine-hydrochloric acid salt in xylene and acidic solution containing high or low chloride ion concentrations were measured at 298 K.
Mercury(II) is extracted as the complexes (RH)₃HgCl₅ ⋅H₂O and (RH)HgCl₃, which are formed respectively by the reactions of HgCl₄^2- and HgCl₃^- with the amine salt, from aqueous solution with high chloride ion concentration. In the extraction from O.1 mol/dm³ hydrochloric acid solution, it is considered that HgCl₂ also reacts with the amine salt and then forms the complex (RH)₂HgCl₄⋅H₂O. The formation constants for their respective reactions were determined.