(225ag) Gold Recovery from Simulant Mine Tailings Using Chelating Ion Exchange Resins with Thiosulfate-Thiourea Lixiviant.

Recovery of gold from mining tailings is an important process economically and environmentally in the mining industry. With a limited amount of mineable gold remaining, the process of recovering gold from mine tailings needs development. This paper will specifically investigate the recovery of gold using ion-exchange resins in a thiosulfate-thiourea lixiviant solution. A range of resins of different functionalities: Purolite® A200, Lewatit® MonoPlus TP 214, Dowex™ M-4195, Puromet MTS9140 and Lewatit® VPOC 1026 were assessed for their gold uptake capabilities via dynamic column experiments. A mixed-metal solution was used to accurately simulate the spent lixiviant from thiosulfate/thiourea leaching of mine tailings. All resins showed selectivity towards gold over the numerous other metals in solution, which was believed to be due to the stability of aqueous gold thiourea complexes. MTS9140 had the highest gold capacity, with a calculated uptake capacity of 41.6 mg/L. Modified-Dose Response (MDR), Bohart-Adams and Yoon-Nelson models were used to describe the data; the MDR model was the most successful.