Life cycle assessment of lithium carbonate production: Comparing sedimentary deposits

Lithium sedimentary deposits which were once considered impractical to extract, have become increasingly attractive for exploiting and producing high-quality lithium compounds, due to the surge in demand for batteries and from other markets. However, potential environmental impacts are yet to be evaluated for this emerging lithium production route. Therefore, this paper presents a comparative Life Cycle Assessment study for three prominent and near-to-opening lithium clay projects globally: Sonora Mexico, Falchani Peru, and Thacker Pass USA. Specifically, this study used literature, statistical data, expert interviews, and technical reports to develop cradle-to-gate models covering the mining to refining processes. The results suggest that lithium carbonate production in the Thacker Pass project has higher impacts than the two other selected sedimentary projects. Additionally, the impact categories of the Sonora project are significantly influenced by the source of electricity. The sensitivity analysis highlights the pivotal role of a transition to clean energy sources for these emerging lithium production routes. Especially, the Thacker Pass project would benefit significantly from on-site sulfuric acid production and power generation to reduce the associated environmental impacts.