Gold sorption on weak base anion exchangers with aminoguanidyl groups

Two resins with different matrices, both bearing aminoguanidyl ligands, were obtained and used for gold sorption from hydrochloric acidic and from alkali solutions. Resin 1 was a aminoguanidine derivative of poly(acrylonitril-co-vinyl acetat-co-divinyl benzene) terpolymer (AN/VA/DVB), (67:27:10 wt.%), and Resin 2 the same derivative of gel expanded poly(vinylbenzyl chloride-co-divinylbenzene) copolymer (VBC/DVB). The resins sorption capacity and sorption isotherms of both resins were determined for AuCl₄⁻ and Au(CN)₂⁻ anions. Resin 2 revealed the best sorption of gold from acidic and alkali solutions: 68 and 23 mg/g, respectively. The effect of the HCl concentration on AuCl₄⁻ removal from solution was investigated. Gold was recovered quantitatively from both resins using a 5% thiourea solution in 0.1 HCl. Both resins remained ability of multiple gold sorption and desorption under acidic conditions.