Cerium

Cerium is a component of mischmetal (an alloy of iron and various rare earth metals) used to make the pyrotechnic alloys, i.e., various rare-earth elements, e.g., 50% certium and 40% lanthanum, used for cigarette lighter flints and incandescent gas mantles.  Cerium compounds are used in glass manufacture as a component, decolorizer, and polishing agent.   Cerium is also used in carbon-arc lighting, and as a petroleum refining catalyst.   Cerium oxide is a hydrocarbon catalyst in self-cleaning ovens where it is incorporated into the oven walls to prevent the collection of cooking residues. ^{Lide 4-8}

Cerium was discovered in 1803 by Klaproth and separately by Jöns Jakob Berzelius, a Swedish chemist, and Wilhelm Hisinger, a Swedish mineralogist.   The metal was prepared by Hillebrand and Norton in 1875.   Cerium is found in a number of ores, including allanite (orthite), monazite, bastnasite, cerite, and samarskite.   The element is isolated by metallothermic reduction techniques, such as reducing cerous fluoride with calcium, or by electrolysis of molten cerous chloride or other cerous halides. ^{Lide 4-7}