Life cycle assessment of ore extraction from a lithium mine

Abstract

Within the scope of a research project, it was intended to adapt the generic methodology of the Life Cycle Assessment (LCA) to the initial phases of the value chain inherent to the production of lithium compounds for electric vehicle batteries. Two main objectives were established: i) measure, characterize and evaluate the potential environmental impacts resulting from the production cycle of lithium carbonate: ii) include in the modelling all stages of the production cycle ranging from the extraction of the ore from the deposit, to the production of lithium carbonate or hydroxide, including the use of the remaining associated minerals aiming at the absence of tailings. In this document, we refer to the mining component that embraces the following unit operations: drilling, blasting, loading, ore and waste haulages, and ancillary operations (e.g., pumping, maintenance, transport of fuel, lubricants and explosives). From the intrinsic characteristics of the mineral deposit (geo-mechanical properties, ore reserves, stripping ratio, mining planning) and also considering some preliminary project decisions (life time, locations of the waste rock disposal and ore processing plant) each one of the main unit operations could be designed, allowing for the selection and number of the required equipment. Next, the corresponding consumption of utilities and emissions could be estimated. The following environmental impact categories were selected: Climate Change, Ozone Layer Depletion, Terrestrial Acidification, Eutrophication of Fresh Water, Human Toxicity, Inhalable Particle Formation, Water Depletion and Depletion of Abiotic Resources. In the methodology used, the potential environmental load for each one of the unit operations that make up the process was evaluated, thus allowing the identification of the hot spots of the production process. Keywords: Life cycle assessment, environmental impact categories, lithium ore.