Characterisation of metalfix-chelamine and its application in precious metal adsorption

The physical and chemical characteristics of the chelating resin Chelamine, which contains a pentamine ligand, are investigated in order tb consider its application in the separation of precious metals. Adsorption isotherm experiments for Pt, Pd and Au and kinetic experiments were carried out under batch procedures. The resin presents a high level of adsorption selectivity for Pt(IV), Au(III) and Pd(II) giving a capacity of 2.8 mmol/g, 3.1 mmol/g and 2.0 mmol/g respectively. Acidic solutions, complexing agents, lipophilic anions and ammonia were used for metal elution. NaClO4 solutions are the most effective eluting agents for Pt(IV) while thiourea is the best slipping agent for both Pd(II) and Au(III). Selective separation of the three metals can be achieved by sequential elution from the resin with NaClO4 solutions in different HCl concentrations and thiourea 0.5 M.