LITHIUM RESOURCES

Lithium Resources
Today, known global reserves and resources of lithium amount to 35m. tonnes (Evans 2010). Some 61% of this volume is found in high altitude continental brine aquifers of Argentina, Bolivia, Chile, and China and Tibet. About 34% occur in lithium mineral deposits mainly in Australia, Canada, USA, and Zimbabwe of which three quarters are crystalline hard rock deposits and a quarter are soft rock deposits. The 5% balance of this tonnage is contained in oilfield and geothermal brines in the western USA.

The present global distribution of supply and demand is more restricted and unbalanced. Regions of high demand in Asia, Europe, and North America rely almost completely on imported lithium chemicals and minerals from Australia, South America, and Zimbabwe.

The most commercially important brine deposit today, containing 1,600ppm lithium as lithium chloride, is the Salar de Atacama in Chile’s Region Two. It contributes to 50% of the world lithium production mainly in the form of lithium carbonate and is also a major source of potash recovered at an earlier stage in the brine concentration process. The Atacama conditions of high solar evaporation, very low humidity, low concentrations of magnesium and other impurities, and proximity to port are unique.

In contrast lithium-containing mineral deposits are, by far, more evenly distributed around the world.

Today, lithium minerals are mined exclusively from pegmatite hard rocks. Worldwide, numerous deposits, primarily containing spodumene and petalite, are being intensively explored with several at an advanced stage in Canada, Finland and Australia. Beneficiated lithium minerals are used in the mineral form and, today almost exclusively in China, for chemical conversion to lithium carbonate. Spodumene (8.0% Li2O), is the most common commercially exploited lithium mineral. Almost 50% of the spodumene mined in Australia today is converted to lithium carbonate in China. Less commercialised are petalite (4.9% Li2O), lepidolite (4.1% Li2O), and amblygonite (10.0% Li2O). Advanced exploration is proving historically well known and large resources of hectorite (1.2% Li2O) in northwest Nevada, USA. Recently, the new lithium-boron mineral jadarite (7.3% Li2O) was discovered in sedimentary soft rock in Serbia where exploration of a massive resource is ongoing by mining major, Rio Tinto.