Chemists Berzelius, Hisinger, and Klaproth independently of each other, discovered cerium in 1803 in rock samples from Bastnas, Sweden -- the town that lent its name to the Light Rare Earth-bearing mineral, Bastnaesite. Cerium was named after the asteroid Ceres, which itself was discovered in 1801. Cerium is a soft, silvery white, malleable and ductile metal, which oxidizes readily in air. In pure form, cerium can ignite if scratched, a property which is known as pyromorphism and is utilized in lighter flints. Cerium can be safely used when combined with other materials, lanthanum, praseodymium, with neodymium excepted; these metals being combined to make misch metal, which is in and of itself pyrophoric.
Cerium is primarily obtained through solvent extraction processes of light rare earth minerals such as bastnaesite, and most of it is produced in China. Minor quantities of cerium are now being produced from stockpiled bastnaesite ores in California.
APPLICATIONS OF CERIUM
Glass and Ceramics: Cerium oxide is used to polish glass surfaces, having largely replaced jeweler's rouge in the glass industry. Cerium compounds are also used in the manufacture of glass and enamels, both as a component and as a decolorizer. Cerium in combination with titanium gives glass a golden yellow color. Cerium oxide (Ce2O3 and CeO2) is also a component of the walls of self-cleaning ovens
In LEDs, cerium combined with yttrium turns blue light into white light. Cerium oxide, in combination with tin oxide (SnO) is used for UV absorption for solar panels. Cerium is also used to stabilize zirconia and for alumina ceramics in catalytic converters. It is also utilized in dental ceramics.
Alloys and Metals: Cerium is alloyed with iron to make nodular iron to improve machineability of automotive power-train components.
Cerium is added to magnesium alloys as a grain boundary modifier in magnesium, which improves thermal resistance and give sound casting of complex shapes. In steels, cerium degasifies and can help reduce sulfides and oxides, and it is used in stainless steels as a precipitation hardening agent. Cerium is also used in making aluminum alloys and as an alloying element in tungsten electrodes for Tungsten Inert Gas (TIG) welding. It is sometimes used in alloys that are used to make permanent magnets.
Energy: Cerium oxide, doped with other rare earth oxides, has been investigated as a solid electrolyte in intermediate temperature solid oxide fuel cells
Medicine: Cerium is used as an additive to some anti-emetic pharmaceuticals.
Catalysts: Cerium oxide is used as a catalytic converter to reduce carbon monoxide emissions in the exhaust gases from motor vehicles. Cerium additives to diesel fuel enable the fuel to burn more cleanly, with less resulting air-pollution.
Cerium sulfate (Ce(So4)2) is used in some chemical analysis procedures, and in production of styrene. Cerium oxide is also used as a petroleum cracking catalyst in petroleum refining. Cerium and cerium compounds such as cerium chloride have uses as catalyts in organic synthesis
Other Uses: Cerium is one of the rare earth elements used to make carbon arc lights, which are used in the motion picture industry for studio lighting and projector lights. Cerium is a major component of ferrocerium, also known as ‘lighter flint". Although modern alloys of this type generally use Mischmetal rather than purified cerium, it is a prevalent constituent. Cerium oxide is used in incandescent gas mantles, such as the welsbach mantle, where it was combined with thorium, lanthanum, magnesium or yttrium oxides.
LINKS: For chemical and physical properties: www.webelements.com or http://education.jlab.org/itselemental/ele058.html
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