Borax is the most important compound of boron. When welding metal, people use borax to purify the metal surface. Boric acid is also commonly used as a disinfectant in hospitals. Boron is often listed as a rare element abroad. However, there are abundant borax minerals in our country. Therefore, boron is not a rare element in our country, but an abundant element. The chemical formula of borax should be written as Na2B4O5(OH)4·8H2O. Borax is a colorless crystal that weathers in the air and can be dehydrated into anhydrous sodium tetraborate when heated to 400 to 500°C. It melts into a glassy substance at 878°C. Because the melt contains acidic oxide B2O3, it can dissolve metal oxides. This property can be used to remove oxides on the metal surface when welding metals. Many metal oxides often show characteristic colors after being dissolved in molten borax. For example, cobalt metaborate Co(BO2)2 is blue, and nickel metaborate Ni (BO2)2 is brown, chromium metaborate Cr(BO2)3 is emerald green, etc. Borax has a wide range of uses. It can be used as a filler in washing powder and soap. It is also a raw material for making optical glass, enamel and porcelain glaze. It can also be used to make artificial gemstones, soldering flux, etc. After being refined and refined, it can be used as a heat-clearing and detoxifying medicine. It is cool in nature, sweet and salty in taste, and can treat sore throat, tooth decay, aphtha, and blindness. Borax is also commonly used as a metal rust remover. In agriculture, borax can be used as a boron fertilizer. Borane, a compound of boron, can also be used as high-energy rocket fuel.