Regionalized Life Cycle Inventories of Global Sulfidic Copper Tailings

Worldwide, an issue of copper production is the generation of mine waste with varying characteristics. This waste can pollute natural environments, and in particular, the heavy metal emissions of the tailings may pose long-term consequences. Currently, life cycle assessments of mine tailings are hampered by both limited data availability in the metal production value chain and lack of appropriate methodologies. We collect data from 431 active copper mine sites using a combination of information available from the market research and technical handbooks to develop site-specific life cycle inventories for disposal of tailings. The approach considers the influences of copper ore composition and local hydrology for dynamically estimating leached metals of tailings at each site. The analysis reveals that together, copper tailings from the large (i.e., porphyry) and medium-size copper deposits (i.e., volcanogenic massive sulfide and sediment-hosted) contribute to more than three quarters of the total global freshwater ecotoxicity impacts of copper tailings. This strongly correlates with hydrological conditions, leading to high infiltration rates. The generated inventories vary locally, even within single countries, showcasing the importance of site-specific models. Our study provides site-specific, dynamic emission models and thus improves the accuracy of tailing's inventories and toxicity-related impacts.

Automated summary

Globally, copper production generates mine waste with varying characteristics, which can pollute natural environments and have long-term consequences. Limited data availability and lack of appropriate methodologies currently hinder the life cycle assessments of mine tailings. To address this issue, data from 431 active copper mine sites were collected to develop site-specific life cycle inventories for tailings disposal. The approach took into account the influence of copper ore composition and local hydrology to dynamically estimate leached metals in tailings. The analysis revealed that large and medium-size copper deposits contribute the most to the global freshwater ecotoxicity impacts of copper tailings, primarily due to hydrological conditions.