Environmental assessment of copper production in Europe: an LCA case study from Sweden conducted using two conventional software-database setups

Abstract

This study focuses on the environmental assessment of European copper production. Life cycle assessment is applied to analyse copper cathode production in Sweden, including its mining (an open-pit mine) and refining (pyrometallurgy), and using two combinations of software and databases: SimaPro software with ecoinvent database and GaBi software with GaBi database. The results are compared with results from other case studies from literature. A cradle-to-gate LCA was conducted considering 1 tonne of copper as functional unit. The inventory for the foreground system was elaborated using primary data gathered by the staff from the mine, the concentrator and the smelter. For the background data, LCA databases are used considering datasets for the Swedish market whenever possible. As the smelter has multiple useful outputs, economic allocation was applied at the inventory level. The calculation method CML-IA baseline 3.5 was considered for both combinations of software and database, reporting all the impact categories of the method plus the Cumulative Energy Demand. The inventory of the system and the main environmental hotspots were presented, such as the explosives for blasting (due to their supply chain) or the electricity used in the concentrator. The results obtained with the two combinations of LCA software and databases yield large differences for categories such as abiotic depletion (7.5 times higher for SimaPro and ecoinvent), possibly due to differences in the system boundaries of the databases and the characterisation factors of the method. Although the case study has a relatively high cumulative energy demand (140/168 kMJ/tonne Cu) compared to other mines, its performance in global warming (3.5/4.7 tonne CO2eq/tonne Cu) is much better due to the low greenhouse gas emissions from electricity, which shows that the electricity mix is a key aspect. The environmental performance of mining depends partially on the specific conditions of the deposit, e.g., the ore grade and the mining type. LCA practitioners should consider the potential different results that can be obtained using different combinations of software and database and exert caution when comparing cases, especially for abiotic depletion, human toxicity and ecotoxicity categories. Finally, the use of renewable energies can be key to improve the environmental sustainability of copper production.