Extraction and Purification of Lithium from Minerals

Abstract Demand for lithium‐ion batteries for use in electric vehicles is driving lithium demand. A large increase in demand between now and 2040 is expected due to increasing electrification of the transport and energy sectors of the economy. This is in part due to an interest in improving air quality in cities and in the reduction of greenhouse gas emissions when electricity is generated without fossil fuel combustion. Currently, the two major natural sources of lithium for use in lithium‐ion batteries are brines and hard‐rock minerals. Lithium‐bearing clays have also been investigated as a potential source of lithium. Battery recycling is another potential source. Lithium in hard‐rock minerals is predominantly found in pegmatites. Lithium‐bearing minerals that may occur in pegmatites include petalite, lepidolite, and spodumene. The latter is currently the predominant hard‐rock lithium source. Following comminution, a number of treatments or combinations of treatments can be used to produce materials suitable for the final stage of purification of lithium products. Most involve high‐ or very‐high‐temperature treatments with various reagents followed by water leaching, although a few treat lithium‐bearing feed directly with acid leaching. Other elements are co‐leached and must be separated from lithium to allow the production of high‐purity lithium carbonate or lithium hydroxide, which are then used to manufacture lithium‐ion battery cathodes.