Extracting valuable metals from zinc sulfide concentrate: A comprehensive simulation-based life cycle assessment study of oxidative pressure leaching

[Display omitted] •The oxidative pressure leaching process for treating ZnS concentrate was modeled.•The process simulation-based life cycle assessment method was used.•The environmental impacts of the oxidative pressure leaching process was studied.•Zn, Cd, Co, Ga, and Ge production exhibited lower environmental impacts.•Recommendations for the process to sustainable zinc production were given. Considering the increasing environmental consciousness and the imperative for sustainable development, conventional zinc smelting operations employing the roast-leaching-electrowinning process face growing environmental pressures. Consequently, the oxidative pressure leaching process has emerged as an alternative processing route. This study focuses on recovery of major metals from ZnS concentrate, building a comprehensive model to simulate the oxidative pressure leaching process. The process model built demonstrated that zinc, sulfur, indium, gallium, cadmium, cobalt, germanium, and copper could be recovered effectively, the main chemical inputs being sulfuric acid, oxygen, and lime, while zinc electrowinning constituting over 90 % of the total electricity consumption. The results were used to compile a life cycle inventory, culminating in a gate-to-gate assessment of the environmental impacts of the process. The global warming potential for the treatment of 1 t of ZnS concentrate is approximately 2,000 kg CO2 eq. The primary environmental impacts in the process are from chemical inputs and electricity consumption. Based on these findings, recommendations for sustainable production practices are proposed. These include systematic recovery and reuse of electrolytic off-gas and roasting heat, greater utilization of renewable energy, enhanced iron removal processes, and exploration of alternative chemicals for Ga and Ge recovery.