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.