Environmental impacts of lithium hydroxide monohydrate production from spodumene concentrate – A simulation-based life cycle assessment

The demand for lithium hydroxide monohydrate (LHM) is likely to increase in the future due its growing use in the manufacturing of high-nickel lithium-ion batteries (LIB), such as NMC811. Conventional production of LHM is largely based on spodumene ore that is refined using sulfuric acid roasting processes, which have been shown to be environmentally straining. Decarbonization of LIB production as part of the green transition requires careful evaluation of all the material production steps. In this work, the environmental impacts of the conventional sulfuric acid roasting process of LHM production were compared to a recently launched soda leaching process using simulation-based life cycle assessment (LCA). This comparison can help in finding the environmentally most competitive process option as well as in identifying the pain points of the processes. The results show that the soda leaching process has lower environmental impacts in all the impact categories observed, notably in global warming, acidification, smog formation, and ozone layer depletion. The global warming potential in the soda leaching process was approximately 33% lower compared to the sulfuric acid roasting process. The other impact categories also showed lower indicator values, the reduction ranging from approximately 16% to 72% when compared to the sulfuric acid roasting process. The largest sources of environmental impacts inside the soda leaching process were the production of heat, soda ash, and quicklime, whereas in the sulfuric acid roasting process, heat, sulfuric acid, and sodium hydroxide were the main contributors in all the impact categories observed.