Sources of Lithium
Lithium is found in economic concentrations in the following sources:
Lithium-bearing, hard-rock pegmatites, such as those at Greenbushes and Dakota’s Lynas Find Project in Western Australia, account for over a third of global production. Although lithium occurs in some 145 minerals, there are three lithium minerals commercially mined today: spodumene, petalite and lepidolite. Spodumene is the most important commercially mined lithium mineral given its higher inherent lithia content. Both open pit and underground mining methods are used to extract lithium minerals. Typically, the mineralised rock contains approximately 1% to 1.5% lithium oxide5.
With production costs falling owing to the value of the Australian dollar versus the US dollar, hard rock lithium from the country has become increasingly competitive in a market that needs quick, new volumes of lithium. Spodumene offers a more rapid route to market by supplying a feedstock to Chinese lithium chemical producers without the need to build complex chemical processing plants at site6.
Lithium is found in commercial quantities in some continental brine deposits of volcanic origin, and in desert areas in playas and saline lakes where lithium has been concentrated by evaporation. These range in concentration from Clayton Valley, USA, at 0.02% Li, to Salar de Atacama in Chile, with 0.14% Li. The process of extracting the lithium from brines involves pumping into a series of evaporation ponds to crystallize other salts, leaving a lithium-rich liquor. After 9-12 months, depending on climate, a concentrate of 1 to 2% lithium is further processed in a chemical plant to yield various end products, such as lithium carbonate and lithium hydroxide. Nearly one half of the world’s lithium supply comes from brine production in Chile and Argentina.
Sedimentary rock deposits account for 8% of known global lithium resources and are found in clay deposits and lacustrine evaporites.
The most commonly-known form of lithium-containing lacustrine deposit is found in the Jadar Valley in Serbia for which the lithium- and boron-bearing element jadarite is named. The project is currently in the exploration stage, but the company believes the deposit “is one of the largest undeveloped lithium sources in the world, with the potential to supply more than 20 per cent of global lithium demand.” It is located on the margins of a Neogene lacustrine basin, with contemporaneous back-arc volcanism and mineralisation associated hydrothermal palaeo-brines – essentially a palaeo version of present-day Chile/Bolivia/Argentina. The extraction of lithium from jadarite has not been commercially proven yet.
5 Benchmark Minerals, 2015
6 Fox Davies, 2013