A theoretical study of SART precipitate

The SART (Sulfidization, Acidification, Recycling and Thickening) process is a cyanide recovery technology currently utilized in gold cyanidation plants worldwide, aimed at reducing operational costs and enhancing income via copper precipitate production. This theoretical study investigates the characterization of the copper precipitate, primarily reported as Cu2S. Recent operational findings, including reagent dosage and copper grades, raise concerns about this characterization and suggest the formation of alternate species. Thermodynamic modeling was utilized to evaluate the potential for CuS formation under varying operational conditions. It was determined that a stoichiometric NaHS addition of 120% based on CuS could yield copper recoveries nearing 90%, although higher NaHS dosages did not lead to increased recoveries and instead heightened NaHS consumption. Furthermore, oxidative reactions prevalent in stored precipitates pose risks of spontaneous combustion under specific conditions. Consequently, it is essential to integrate safety measures in the design and operational protocols of SART plants to mitigate potential hazards associated with the storage of the precipitate.