Lanthanum metal is a silver-white metal, soft and easy to cut. The fresh section is silver-gray and easily oxidized in the air. Avoid contact with acids, oxides, halogens, sulfur. Contact with heat, open flame, oxidant and other substances may cause a fire hazard. Generally sealed in solid paraffin or immersed in kerosene, it is easily eroded by inorganic acids.
The chemical properties of metal lanthanum are lively and easily soluble in dilute acid. It is easy to oxidize in the air, and the fresh surface quickly darkens when it encounters the air; it can burn when heated to generate oxides and nitrides. Heating in hydrogen generates hydride, which reacts strongly in hot water and emits hydrogen. Lanthanum is present in monazite sand and bastnasite. Lanthanum can react directly with carbon, nitrogen, boron, selenium, silicon, phosphorus, sulfur, halogen, etc. The compound of lanthanum is diamagnetic. High-purity lanthanum oxide can be used to manufacture precision lenses; lanthanum-nickel alloys can be used as hydrogen storage materials, and lanthanum hexaboride is widely used as a high-power electron emission cathode.

Application field
1. The metal lanthanum shell is used to produce nickel-metal hydride batteries, which is one of the most important applications of lanthanum.
2. It is mainly used for the manufacture of special alloy precision optical glass, high-refractive optical fiber board, suitable for cameras, cameras, microscope lenses and prisms of advanced optical instruments. Also used in the manufacture of ceramic capacitors, piezoelectric ceramic doping agents and X-ray luminescent materials such as lanthanum oxybromide powder. It is extracted from lanthanum lanthanum ore or obtained by burning lanthanum carbonate or lanthanum nitrate. It can also be obtained by thermal decomposition of lanthanum oxalate.
3. Used as a catalyst for various reactions, such as catalyzing the oxidation reaction of carbon monoxide when doped with cadmium oxide, and catalyzing the hydrogenation of carbon monoxide to form methane when doped with palladium. Lanthanum oxide impregnated with lithium oxide or zirconium oxide (1%) can be used to make ferrite magnets. It is a very efficient selective catalyst for the oxidative coupling of methane to ethane and ethylene. It is used to improve the temperature dependence and dielectric properties of barium titanate (BaTiO3) and strontium titanate (SrTiO3) ferroelectrics, and to manufacture fiber optics and optical glass.