Physical properties: colorless triclinic crystals. White powder or orthorhombic great six-sided crystals. Density 3.00g / cm3. Melting point 1040 ℃. Boiling Point (sublimation) 1272 ℃. There are several hydrates exist; slightly soluble in water, soluble in hot water. Difficult to dissolve in acid and alkali solution, insoluble in most organic solvents. It can be heated to 300-400 ℃ steam partial decomposition of hydrogen fluoride and alumina. There are three hydrates, namely monohydrate, trihydrate and nine water thereof.
Uses: Optical glass material. Coating materials for the aluminum industry in lowering the melting temperature of the electrolyte and improve the conductivity, is used as a flux of non-ferrous metals, ceramic glazes and enamel component flux and glaze, as well as oil production by-fermentation The inhibitor. Alcohol production for the play deputy fermentation inhibitors.