Solution circulation for green and sustainable gold extraction with an integrated low potential thiosulfate leaching-resin adsorption recovery process

A systematic research of solution circulation for gold extraction from a gold ore with an integrated low potential thiosulfate leaching-resin adsorption recovery process was performed by using the analysis and detection methods of ICP-OES, SEM-EDS, HPLC, XPS, etc. The pulp potential was controlled at about 200 mV under low reagent concentration and closed condition where the gold leaching percentage achieved 89.02 % while the thiosulfate consumption was only 19.22 kg/t. 100 % of the gold and 32.61 % of the copper in the leaching solution were adsorbed by the resin, and their desorption percentages separately reached 98.59 % and 98.86 % after selective two-stage desorption. The leaching and adsorption percentages of gold first decreased and separately kept at about 91 % and 96 % after 10 solution circulations while the gold desorption percentage and thiosulfate consumption were basically unchanged with solution circulation. The sulfur-oxygen anions in the solution including S2O32–, S3O62–, S4O62–, SO32– and SO42–, and only SO42– was gradually accumulated with solution circulation. SO42–, S2O32– and S3O62– were the main sulfur-oxygen anions adsorbed on the resin, and they did not accumulate obviously on the resin with solution circulation. The novelty of this study is that gold was recovered as elemental gold product based on the the proposed process, and the effect of solution circulation on gold extraction and the accumulation and conversion rules of sulfur-oxygen ions during solution circulation were revealed for the first time.