Lithium has become a hot topic in mining and environmental circles as it leads the charge in the mineral battle against climate change. Edge Exploration has compiled this definitive article about the oft-sought after metal.
Lithium is a chemical element with the symbol Li and atomic number 3. Lithium is the first of the alkalis in the periodic table. The name derives from the Latin lithos for “stone” because lithium was thought to exist only in minerals at that time. In nature it’s found like a mixture of the isotopes Li6 and Li7.
It is a soft, silvery-white alkali metal. Under standard conditions, it is the least dense metal and the least dense solid element. Like all alkali metals, lithium is highly reactive and flammable, and must be stored in vacuum, inert atmosphere, or inert liquid such as purified kerosene or mineral oil.
When cut, it exhibits a metallic luster, but moist air corrodes it quickly to a dull silvery gray, then black tarnish. It never occurs freely in nature, but only in (usually ionic) compounds, such as pegmatitic minerals, which were once the main source of lithium. Due to its solubility as an ion, it is present in ocean water and is commonly obtained from brines. Lithium metal is isolated electrolytically from a mixture of lithium chloride and potassium chloride.
In many of its properties, lithium exhibits the same characteristics as do the more common alkali metals sodium and potassium. Thus, lithium, which floats on water, is highly reactive with it and forms strong hydroxide solutions, yielding lithium hydroxide (LiOH) and hydrogen gas. Lithium is the only alkali metal that does not form the anion, Li−, in solution or in the solid state.
Lithium is chemically active, readily losing one of its three electrons to form compounds containing the Li+ cation. Many of these differ markedly in solubility from the corresponding compounds of the other alkali metals. Lithium carbonate (Li2CO3) exhibits the remarkable property of retrograde solubility; it is less soluble in hot water than in cold.
The nucleus of the lithium atom verges on instability, since the two stable lithium isotopes found in nature have among the lowest binding energies per nucleon of all stable nuclides. Because of its relative nuclear instability, lithium is less common in the solar system than 25 of the first 32 chemical elements even though its nuclei are very light: it is an exception to the trend that heavier nuclei are less common.
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Lithium does not occur as the metal in nature, but is found combined in small amounts in nearly all igneous rocks and in the waters of many mineral springs. Spodumene, petalite, lepidolite, and amblygonite are the more important minerals containing lithium.
Most lithium is currently produced in Chile, from brines that yield lithium carbonate when treated with sodium carbonate. The metal is produced by the electrolysis of molten lithium chloride and potassium chloride.
Uses For Lithium
Many uses have been found for lithium and its compounds. Lithium has the highest specific heat of any solid element and is used in heat transfer applications. The most important use of lithium is in rechargeable batteries for mobile phones, laptops, digital cameras and electric vehicles. Lithium is also used in some non-rechargeable batteries for things like heart pacemakers, toys and clocks.
Lithium metal is made into alloys with aluminium and magnesium, improving their strength and making them lighter. A magnesium-lithium alloy is used for armour plating. Aluminium-lithium alloys are used in aircraft, bicycle frames and high-speed trains.
Lithium is needed to produce virtually all traction batteries currently used in EVs as well as consumer electronics. Lithium-ion (Li-ion) batteries are widely used in many other applications as well, from energy storage to air mobility. As battery content varies based on its active materials mix, and with new battery technologies entering the market, there are many uncertainties around how the battery market will affect future lithium demand.
Battery manufacturing process
Lithium and its compounds have several industrial applications, including heat-resistant glass and ceramics, lithium grease lubricants, flux additives for iron, steel and aluminium production.
Another important compound of lithium is lithium stearate. Lithium stearate is added to petroleum to make a thick lubricating grease. The grease is used in many industrial applications because it does not break down at high temperatures, it does not become hard when cooled, and it does not react with water or oxygen in the air. Lithium greases are used in military, industrial, automotive, aircraft, and marine applications. Lithium stearate is also used as an additive in cosmetics and plastics.
Lithium chloride is one of the most hygroscopic materials known, and is used in air conditioning and industrial drying systems (as is lithium bromide). Lithium carbonate is used in drugs to treat manic depression, although its action on the brain is still not fully understood. Lithium hydride is used as a means of storing hydrogen for use as a fuel.
Lithium is present in biological systems in trace amounts; its functions are uncertain. Lithium salts have proven to be useful as a mood stabilizer and antidepressant in the treatment of mental illness such as bipolar disorder.
History of Lithium
The first clues to the existence of lithium surfaced in 1800. De Andrada was a Brazilian scientist and statesman visiting in Scandinavia. During one of his trips to the countryside, he came across a mineral that he did not recognize. He called the mineral petalite.
Some scientists were not convinced that petalite was a new mineral. In 1817, Johan August Arfwedson of Stockholm analyzed it and deduced it contained a previously unknown metal, which he called lithium. He realized this was a new alkali metal and a lighter version of sodium. However, unlike sodium he was not able to separate it by electrolysis.
In 1818, Christian Gmelin was the first to observe that lithium salts give a bright red color to flame. However, both Arfwedson and Gmelin tried and failed to isolate the pure element from its salts. It was not isolated until 1821, when William Thomas Brande obtained it by electrolysis of lithium oxide, a process that had previously been employed by the chemist Sir Humphry Davy to isolate the alkali metals potassium and sodium.
Brande also described some pure salts of lithium, such as the chloride, and, estimating that lithia (lithium oxide) contained about 55% metal, estimated the atomic weight of lithium to be around 9.8 g/mol (modern value ~6.94 g/mol). In 1855, larger quantities of lithium were produced through the electrolysis of lithium chloride by Robert Bunsen and Augustus Matthiessen. The discovery of this procedure led to commercial production of lithium in 1923 by the German company Metallgesellschaft AG, which performed an electrolysis of a liquid mixture of lithium chloride and potassium chloride.
Australian psychiatrist John Cade is credited with reintroducing and popularizing the use of lithium to treat mania in 1949. Shortly after, throughout the mid 20th century, lithium’s mood stabilizing applicability for mania and depression took off in Europe and the United States.
Occurrence and Production
Recent NASA research suggests that most of the lithium present on earth originated in distant stars. More specifically, from a stellar event known as a classical novae, or when a small star collapses under the gravity of a larger star. Funded by a grant from NASA, researchers at Arizona State University showed that most of the lithium in the universe originated via the nuclear reactions which power these novae. It is estimated that approximately 97% of the lithium on earth trace back to these massive interstellar explosions!
Despite expectations that lithium demand will rise from approximately 500,000 metric tons of lithium carbonate equivalent (LCE) in 2021 to some three million to four million metric tons in 2030, we believe that the lithium industry will be able to provide enough product to supply the burgeoning lithium-ion battery industry. Alongside increasing the conventional lithium supply, which is expected to expand by over 300 percent between 2021 and 2030, direct lithium extraction (DLE) and direct lithium to product (DLP) can be the driving forces behind the industry’s ability to respond more swiftly to soaring demand.
Like all alkali metals, lithium reacts easily in water and does not occur freely in nature due to its activity, Lithium is a moderately abundant element and its present in The Earth’s crust in 65 ppm (parts per million). This situates lithium below nickel, copper, and tungsten and over cerium and tin, referring to abundance. It is found in small units in nearly all igneous rocks and in many mineral springs. Lepidolite, spodumene, petalite, and amblygonite are the more important minerals containing it.
Until the 1990s the lithium chemical and metal market was dominated by American production from mineral deposits, but by the turn of the 21st century most production was derived from non-U.S. sources; Australia, Chile, and Portugal were the world’s largest suppliers. (Bolivia has half the world’s lithium deposits but is not a major producer of lithium.)
The major commercial form is lithium carbonate, Li2CO3, produced from ores or brines by a number of different processes. Addition of hydrochloric acid (HCl) produces lithium chloride, which is the compound used to produce lithium metal by electrolysis.
Lithium metal is produced by electrolysis of a fused mixture of lithium and potassium chlorides. The lower melting point of the mixture (400–420 °C, or 750–790 °F) compared with that of pure lithium chloride (610 °C, or 1,130 °F) permits lower-temperature operation of the electrolysis. Since the voltage at which decomposition of lithium chloride takes place is lower than that of potassium chloride, lithium is deposited at a purity level greater than 97 percent.
Graphite anodes are used in the electrolytic production of lithium, while the cathodes are made of steel. The pure lithium formed at the cathode coalesces at the surface of the electrolyte to form a molten pool, which is protected from reaction with air by a thin film of the electrolyte. The lithium is ladled from the cell and cast by pouring it into a mold at a temperature only slightly above the melting point, leaving the solidified electrolyte behind.
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The solidified lithium is then remelted, and materials insoluble in the melt either float to the surface or sink to the bottom of the melt pot. The remelting step reduces the potassium content to less than 100 parts per million. Lithium metal, which can be drawn into wire and rolled into sheets, is softer than lead but harder than the other alkali metals and has the body-centred cubic crystal structure.
As the world turns away from fossil fuels to embrace clean energy sources and combat climate change, lithium battery technology is becoming increasingly important to the competitiveness of the U.S. and other countries around the globe.
In the U.S., Lithium is presently being recovered from brines of Searles Lake, in California, and from those in Nevada. Large deposits of quadramene are found in North Carolina.
Major Producers of Lithium Worldwide
|country||mine production 2006 (metric tons)*||% of world known mine production||demonstrated reserves 2006 (metric tons)*||% of world demonstrated reserves|
Source: U.S. Department of the Interior, Mineral Commodity Summaries 2007.