RESUMO
There has been growing concern among the public over the environmental impacts of the copper (Cu) mining and mineral processing industries. As an effective tool enabling interactions of all energy and material flows with the environment, Life Cycle Assessment (LCA) is used in many countries to identify environmental hotspots associated with operations, based on which improvements can be made. However, robust LCA research in this sector is lacking in China. This study aimed to fill this critical gap by investigating two typical Cu mining and mineral processing operations using different mining technologies, based on globally harmonized LCA methodologies. The results of the overall environmental impacts were obtained using a sensitivity analysis. Electricity (38%-74%), diesel (8%-24%) and explosives (4%-22%) were identified as the three main controlling factors. At the same time, the mineral processing stage was found to be the major production stage (60%-79%), followed by the mining stage (17%-39%) and the wastewater treatment (1%-13%). Global Warming Potential (GWP) was prioritized as the most important environmental issue (59%) across the selected impact categories. In addition, it was initially found that underground mining technology has better environmental performance than open-pit technology. Finally, the potential for improvement was estimated and discussed for the three identified controlling factors. Using GWP as an example, using green electricity can effectively reduce CO2 emissions by 47%-67%, whereas replacing diesel and explosives with cleaner fuels and explosives may contribute to lower CO2 emissions by 6% and 9%, respectively.
