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In pure form, lithium is a very soft, silvery metal that can burn or explode when exposed to water, acid or oxidizing agents. With an atomic number of 3, it is the lightest and least reactive of the alkali metals and the lightest solid element. Lithium occurs in impure trace amounts in many minerals, in most rocks and soils, brine deposits and many natural waters. The most important mineral sources of lithium are spodumene, petalite and lepidolite (a complex lithium mica).
Lithium chemicals, particularly lithium carbonate and lithium hydroxide, are the predominant lithium-containing substances consumed by industry. Major applications for lithium include glass and ceramics, aluminum, synthetic rubber, pharmaceuticals, chemical manufacturing, lubricants, batteries and air conditioning. In the glass industry, lithium minerals can be used directly. More typically, lithium values are recovered in the form of lithium carbonate. Lithium carbonate is usually recovered from brine deposits or spodumene ore. Lithium chloride and organolithium compounds (i.e., butyllithium) are the next leading lithium-containing compounds consumed.
Increased world production of lithium beginning in the past decade (particularly in Australia, Canada, Chile and, most recently, Argentina) has shifted world supply from the traditional U.S. sources to non-U.S. sources. China and Brazil partially meet their demand for lithium products with captive production.
While the end product from both brine and hard rock processes can be lithium carbonate, hard rock typically produces a concentrate for use in more traditional applications such as glass and ceramics, of which the concentrate purified further will produce lithium carbonate. Most producers currently prefer brine deposits. It is a less expensive operation, and does not result in large volumes of bulky inert materials.
The following pie chart shows world reserves of lithium:
China is planning for significant production from brines in the future, but currently its main lithium concentrate production is from hard rock sources in the Altai Mountain region of south central China. Other hard rock production comes from the Henan and Xinjiang Uygur provinces. Other potential areas for production of lithium compounds from hard rock include the Jaijika reserve in the Sichuan Province, and for brines from the Qinghai Province in western China. Although the vast majority of China’s production is currently from hard rock, future production is expected to be from brines, which have a much lower cost structure. It is estimated that hard rock sources of lithium carbonate cannot economically compete with brine sources at less than $2.20 per kilogram. It is not forecast that vast quantities of lithium carbonate will come from China in the next five years, as they learn the intricacies of lithium production and deal with the quality of the brines available. These brines are expected to be difficult and costly to purify since they have a lower lithium content, while having a high boron and magnesium/lithium ratio. |
