Process simulation based life cycle assessment of cyanide-free refractory gold concentrate processing – Case study: Cupric chloride leaching

摘要: Abstract The development of cyanide-free gold leaching methods is becoming increasingly important due to the treatment complex ores, where by cyanidation not economically viable. Cupric chloride provides an alternative process replace cyanidation. A detailed simulation refractory concentrate processing cupric presented in this study. with mass and energy balances was built be used as life cycle inventory data evaluate environmental impacts stage process. Three cases, Base Case (125 g/L Cl-), Mild (50 g/L Extremely (20 g/L were investigated two flowsheet options. Loss wash waters observed Flowsheet 1 therefore 2, recirculation water solvent extraction, developed order achieve higher recovery. extraction improved from around 85% 99%. Chemical consumption (NaCl, NaBr, CuCl2) greatly affected conditions, concentrations consuming more initial chemicals. In milder efficient recycling chlorides could obtained process, no addition NaCl required. Case, concentration close sea conditions (20 g/L), provide for effluent disposed after purification. global warming potential estimated 12.5 t CO2-e/kg Au further decreased 10.6 t mildest Cl-). Cl- 50 g/L Cl-) shown decrease acidification potential, eutrophication depletion.