The recovery of gold from the aqua regia leachate of electronic parts using a core-shell type anion exchange resin

A method of processing Wasted Electric and Electronic Equipment (WEEE), and the separation of gold that it contains, is presented within the present work. Due to the fact that the amount of Au in real-life secondary resources covers a broad range of concentrations, the applied solutions were obtained by digesting in aqua regia WEEE characterized by relatively high (Central Processing Units, CPU) and relatively low (Pin Contact Elements, PIN) amounts of gold. The investigated systems were received after processes of enrichment and leaching, ignoring the usually applied WEEE processing reduction and solvent-extraction processes, keeping the amount of generated wastes to a minimum. The obtained CPU and PIN solutions were then directly contacted with core-shell type anion exchange resins functionalized using ethylenediamine and 1-(2-aminoethyl) piperazine. Application of the designed polymers allowed the process of aqua regia-leaching, omitting the application of other, more harmful agents. The investigated resins revealed great selectivity towards gold. Despite the fact that the obtained solutions contained only 1.5% (CPU) or 0.1% (PIN) of Au, its removal reached 86% and the logarithms of partition coefficients indicate that affinity of the applied resins to gold is almost ten times greater than the very competitive nickel present in the obtained solutions. Finally, the gold-containing core-shell polymers were effectively eluted, recovering 100% of the taken from the solutions gold. (C) 2017 King Saud University. Production and hosting by Elsevier B. V. This is an open access article under the CC BY-NC-ND license.