Лантан (III) оксид

Химические свойства

Lanthanum oxide is an oxide of lanthanum (III), white orthorhombic or amorphous powder. Soluble in acid, ethanol, ammonium chloride, insoluble in water, ketone. It is mainly used in the manufacture of precision optical glass and optical fiber.

Использование

Lanthanum oxide is used to make high-quality glass, ceramics, carbon-arc electrodes, and fluorescent lamps. Lanthanum (III) oxide was used as an analytical standard in inductively coupled plasma atomic emission spectrometry (ICP-AES) for chemical characterization of ancient pottery.

Подготовка

Lanthanum oxide can be produced by direct combustion of lanthanum in oxygen or air. The oxide also may be prepared by decomposition of an oxo salt of lanthanum, such as nitrate, sulfate, carbonate, hydroxide or oxalate.
La(CO₃)₃•8H₂O → La₂O₃ + 3CO₂ + 8H₂O
2La₂(C₂O₄)₃•9H₂O + 3O₂ → 2La₂O₃ + 12CO₂ + 18H₂O

прикладной

Lanthanum Oxide, also called Lanthana, high purity Lanthanum Oxide (99.99% to 99.999%) is applied in making special optical glasses to improves the alkali resistance of glass, and is used in La-Ce-Tb phosphors for fluorescent lamps and making special optical glasses, such as infrared-absorbing glass, as well as camera and telescope lenses, Low grade of Lanthanum Oxide is widely used in ceramics and FCC catalyst, and also as raw material for Lanthanum Metal production; Lanthanum Oxide is also used as a grain growth additive during the liquid phase sintering of Silicon Nitride and Zirconium Diboride.

Общее описание

Lanthanum (III) oxide is an alkaline earth oxide, and is a diamagnetic, isostructural analog of neodymium oxide. It is also an efficient recyclable catalyst, and can be used in coupling various aryl halides with aromatic/alkyl thiols.

Промышленное использование

Lanthanum oxide (La₂O₃) has a melting pointof 2250°C, is soluble in acids, and very slightlysoluble in water. This oxide of a rare earth elementoccurs in monazite and bastnasite. It ismarketed as the oxide or as other salts such asthe oxalate, nitrate, or hydrate. It quicklyabsorbs water and CO₂ from the atmosphere.Its chief use is as an ingredient in nonsilica,rare element optical glass with oxides of tungsten, tantalum, and thorium. Lanthanumincreases refractive index, decreases dispersion,and is also used in x-ray image intensifyingscreens that speed up x-ray exposure asmuch as two to ten times so that diagnosticdosages may be reduced by as much as 80%with fewer retakes. It is also used in bariumtitanate capacitors.