Selective recovery of gold on functionalized resins

The functional resins containing guanylthiourea, 1-methylimidazole, 2-mercapto-1-methylimidazole, dipropylamine, 1,2-dimethylimidazole and 1-(3-aminopropyl)imidazole ligands were highly selective for the gold(I) and silver(I) from ammonia solution and they did not sorb ammine complexes of copper(II). The kinetics of gold(I) sorption on these resins was improved by immobilization of N,N-dimethylethanolamine ligands, which were responsible for increasing the hydrophilicity of the polymeric material. 1-Methylimidazole resins retained their capacity towards gold in five consecutive sorption/desorption cycles. All resins in cyanide form displayed high affinity towards gold(I) from ammoniacal solution (100 g/L NH3·H2O, 5.00 g/L (NH4)2SO4). The sorption degrees of gold were 99.5%.