Extraction of AuCl4- from HCl solutions by the chloride salt of the secondary amine Amberlite LA2 and estimation of the interaction coefficient between AuCl4- and H+

The equilibrium distribution of AuCl4- between hydrochloric acid and the chloride salt of the secondary amine Amberlite LA2 in xylene was investigated. The extraction reaction is exothermic (DeltaH degrees = -20.8 kJ/mol). The stoichiometry of the complex formed in the organic phase can be represented by R 'R " NHH+AuCl4- and the extraction equilibrium constant depends on the ionic strength. From this dependency it was found that log K degrees = 3.9 and the interaction coefficient between AuCl4- and H+ is 0.24.