A FACTORIAL STUDY OF GOLD LEACHING IN TEMPERATURE CONTROLLED THIOSULFATE SOLUTIONS CONTAINING COPPER AND MESO-2,3- DIMERCAPTOSUCCINIC ACID

摘要

A factorial study was performed to investigate the relative effects of temperature, copper concentration and meso-2,3-dimercaptosuccmic acid (DMSA) concentration on the performance of thiosulfate leaching of gold. A total of 24 leaching experiments were performed representing eight unique combinations of high-low levels of the three factors performed in triplicate. All investigations were performed in an electrochemical cell with an electrolyte composed of 0.1 M sodium thiosulfate with a combination of copper (either 0 mM or 1 mM) and DMSA (either 0μM or lμM). All leaching investigations were conducted under open circuit while the electrolyte, which was open to the atmosphere and mechanically stirred, was maintained at either 25°C or 50°C. After 1.5h of leaching the amount of gold in solution was quantified using ICP-MS analysis from an aliquot of the electrolyte. Results indicate that DMSA addition improved gold leachmg performance, most notably at 50°C and with addition of copper. Under this unique condition, the quantity of gold in solution was reproducibly and significantly above the average response of all other factors studied.