Borax Dm is the sodium salt of boric acid, the basic name of salt tetraborate, which is a boron-containing mineral. According to the amount of crystal water, it can be split right into 3 types: decahydrate borax, pentahydrate borax and also anhydrous borax.
( 1) The chemical name of borax decahydrate is sodium tetraborate decahydrate, the molecular formula is Na2B4O7 · 10H2O, as well as the molecular weight is 381.37. It is colorless translucent crystal or white crystalline powder, odorless, salty, thickness 1.73 g/cm3, melting point 75 ℃. In completely dry air, it can slowly shed water and end up being weather-beaten. When warmed to 300-400 ° C, all crystal water will certainly be shed as well as transformed right into anhydrous sodium tetraborate Na2B4O7. Soluble in water as well as glycerin, insoluble in alcohol. 878 ° C melting right into a glass-like compound.
( 2) The chemical name of borax pentahydrate is salt tetraborate pentahydrate, the molecular formula is Na2B4O7 5H2O, the molecular weight is 291.29, it is a white crystalline powder, the density is 1.815 g/cm3, when heated up to 122 ° C, it loses crystal water as well as becomes anhydrous Salt tetraborate.
( 3) The chemical name of anhydrous borax is sodium tetraborate, the molecular formula is Na2B4O7, the molecular weight is 201.22, it is white crystal or glass body, as well as there are 2 types of α and β: α orthorhombic crystal, melting point 742.5 ℃, thickness 2.28 g/cm3, β Orthorhombic crystal, melting point 664 ° C, density 2.75 g/cm3, solid hygroscopicity, soluble in water, gradually soluble in methanol, as well as can form a remedy with a concentration of 13-16%. Along with heat resistance, water resistance and also acid resistance, borax additionally has solid liquifying power. Borax Dm turns white as well as expands after home heating, as well as ends up being a clear glass round in which metal oxides can be liquified to restore the original color of the metal. This is the well-known borax sphere reaction. Borax can be made use of in the manufacture of capacitors, in numerous glass items, and in the ceramic market as a polish. It is made use of as antifreeze as well as anticoagulant in mining as well as metallurgical market, and also as electrolyte additive and welding representative in nonferrous steel industry. Additionally, it is made use of in the manufacture of preservatives, herbicides, dirt fungicides and also borides.