Process simulation and gate-to-gate life cycle assessment of hydrometallurgical refractory gold concentrate processing

摘要: Currently, almost all cyanide-free gold leaching processes are still in the development stage. Proactively investigating their environmental impacts prior to commercialization is of utmost importance. In this study, a detailed refractory concentrate process simulation with mass and energy balance was built for state-of-the-art technology (i) pressure oxidation followed by cyanidation and, compared alternative technology, (ii) halogen leaching. Subsequently, simulated used as life cycle inventory data order evaluate predominant alternative. The indicators each scenario based on produced HSC Sim steady-state simulation. balances were evaluated identify challenges technologies. software compatible GaBi LCA software, where LCI from HSC-Sim directly exported to. produces consistent (LCI). global warming potential (GWP), acidification (AP), terrestrial eutrophication (EP), water depletion (Water) estimated. assessment revealed that GWP 10.1 t CO2-e/kg Au, whereas indicated slightly higher 12.6 t Au. difference partially explained fact footprint calculated against units Au; total recovery route only 87.3%, could extract much 98.5% gold. addition second unit also washing increased up 98.5%, decreasing 11.5 t However, both processing scenarios when dominating technology. estimated predict development-stage has some cyanidation; investigated scenarios, generally Further improvements, example form decreased moisture feed halide leaching, adaptation situ practices chloride may give options competitive edge.