Life cycle assessment of copper production: comparison of primary and secondary supply routes
David Anthony Turner, Arthur Haarman, Roland Hischier
Metals play a crucial role in modern society and are found in a multitude of products and infrastructures. Recent global economic and technological development has resulted in an increased demand for a wide array of metals, including various scarce and/or ‘critical’ metals. However, the extraction and processing of metals from the Earth’s crust can lead to potentially substantial environmental impacts on both a global scale (e.g. climate change) and at the local level (e.g. air, water, and soil pollution). The extent of these environmental impacts can be widely variable between geolocations, due to differences in (inter alia) ore grade, environmental governance, and energy mixes. One possible strategy to reducing the environmental impacts of metal production is to increase the supply of secondary metals, which are recovered from end-of-life products and subsequently reprocessed. Whilst the environmental impacts of secondary production are typically much lower, they are heavily influenced by a number of physical and technological factors, such as waste composition and energy and chemical consumption intensity.
To investigate the importance of various geospatial, physical, and technological factors on the environmental impacts of metal production, we apply life cycle assessment (LCA) to compare different primary and secondary supply routes, using copper as a case study. Supply from key primary producing regions and secondary waste streams (e.g. WEEE and electrical cables) are considered. Results show that primary production incurs greater potential environmental impacts than secondary production in all cases. However, large differences exist between different primary and secondary supply routes. Here, we will present the results of the LCA study and analyse the influence of the key factors on the potential impacts of different supply routes. Overall, this study highlights the need for more regionally- and technologically- differentiated data on metal production.