Life Cycle Inventory Analysis of Copper Production System in Chile

CO2 and SO2 emissions from the copper production system in Chile were quantitatively evaluated using Life Cycle Assessment (LCA) technique. In this study, inventories such as the fuel consumption of the unit processes were based on published papers. The following observations were made based on LCI analysis: (1) CO2 emissions from the pyro- and hydro- metallurgical copper are about 0.88kg and 2.36 kg/kg-Cu, respectively. And, 1.9kWh and 3.0 kWh/kg-Cu were consumed for the electricity, respectively. There is much variance in the CO2 emissions between pyro- and hydro- metallurgical copper, because sulfuric acid originated from the pyro-process is used for the leaching of hydro-process. (2) SO2 emissions from the pyro- and hydro- metallurgical copper are about 0.19kg and 0.23 kg/kg-Cu, respectively. The desulfurization ratio on pyro-metallurgical copper production in Chile is estimated to be 81%, which is lower than that of Japan. (3) Pyro- and hydro-metallurgical coppers have a complementary relationship in the range of self-sufficient sulfuric acid. The environmental burden to soil and water from the copper production system should be evaluated, because it is not covered in this study