Cerium Info: (highest presence in the $SNET samples at 1450 ppm)
Applications
A traditional use of cerium was in the pyrophoric ferrocerium alloy used for lighter flints.
Because of the high affinity of cerium to sulfur and oxygen, cerium itself or as mischmetal is used in various aluminum alloys, and iron alloys. In steels, cerium degasifies and can help reduce sulfides and oxides, and it is a precipitation hardening agent in stainless steel. Adding cerium to cast irons opposes graphitization and produces a malleable iron. Addition of 3–4% of cerium to magnesium alloys, along with 0.2–0.6% zirconium, helps refine the grain and give sound casting of complex shapes. It also adds heat resistance to magnesium castings. Cerium metal is sometimes added to aluminum to improve aluminum's corrosion resistance.
Cerium alloys are used in permanent magnets, and in tungsten electrodes for gas tungsten arc welding. Cerium is used in carbon-arc lighting, especially in the motion picture industry.
CMP
Ceria (CeO2) is the most widely used compound of cerium. The main application of ceria is as a polishing compounds, e.g. chemical-mechanical planarization (CMP). In this application, ceria dioxide has replaced other metal oxides for the production of high quality optical surfaces.
Catalysis
Another important use of cerium oxide is in a hydrocarbon catalyst in self cleaning ovens, incorporated into oven walls and as a petroleum cracking catalyst in petroleum refining.
Major automotive applications for cerium(III) oxide are as a catalytic converter for the oxidation of CO and NOx emissions in the exhaust gases from motor vehicles.
Niche applications
The photostability of pigments can be enhanced by the addition of cerium. It provides pigments with light fastness and prevents clear polymers from darkening in sunlight. Television glass plates are subject to electron bombardment, which tends to darken them by creation of F-center color centers. This effect is suppressed by addition of cerium oxide. Cerium is also an essential component of phosphors used in TV screens and fluorescent lamps. Cerium sulfide forms a red pigment that stays stable up to 350 °C. The pigment is a nontoxic alternative to cadmium sulfide pigments.
Cerium(IV) oxide is used in incandescent gas mantles, such as the Welsbach mantle, where it was combined with thorium, lanthanum, magnesium, or yttrium oxides.
Cerium(IV) sulfate is used as a volumetric oxidizing agent in quantitative analysis. Ceric ammonium nitrate is an oxidant in organic chemistry and in etching electronic components, and as a primary standard for quantitative analysis.
