Fluorite is also known as fluorspar, its chemical composition is CaF2, and its crystals are equiaxed halide minerals. It emits blue or purple fluorescence under the irradiation of ultraviolet rays, cathode rays or heating, and it gets its name. The crystals are often cubic, octahedral or cubic interpenetrating double crystals, and the aggregates are granular or massive. Light green, light purple or colorless and transparent, sometimes rose red, white streaks, glass luster, transparent to opaque. The octahedral cleavage is complete. Mohs hardness 4, specific gravity 3.18.
Main application
1. Half of the world's fluorspar production is used to produce hydrofluoric acid, and then to develop cryolite for the aluminum smelting industry.
2. Use fluorite as the coolant (Freon) in the refrigerator.
3. In the glass industry, fluorite is added as fluxing agent and sunscreen agent, which can help the melting of glass raw materials. Different glass, the amount of fluorite added is different. For ordinary glass plates, the addition of fluorite is 1% of the charge; for alkaline glass balls, the addition of fluorite is 1% to 2%; for oxidized glass, the addition of fluorite is 3%; white, cream, and colored glass In the production process of fluorspar, in addition to acting as a co-solvent, it also acts as a sunscreen agent, and the amount added is 10% to 20% of the charge. The glass industry has strict requirements on the quality of fluorite, requiring CaF2> 80%; Fe2O3 <0.2%.
4. In cement production, fluorite is added as a mineralizer. Fluorite can reduce the sintering temperature of the charge, reduce fuel consumption, and at the same time increase the liquid phase viscosity of the clinker during sintering and promote the formation of tricalcium silicate. In cement production, the amount of fluorite added is generally 4% to 5% to 0.8% to 1%. The cement industry does not have strict requirements on the quality of fluorite. Generally, the CaF2 content is above 40%, and there is no specific requirement on the content of impurities.
5. In the ceramic industry, fluorite is mainly used as enamel, which can play a role in color and flux in the production of enamel. For example, the addition of fluorite in red enamel can make the color bright and bright, and the amount of fluorite added in ceramic enamel is generally about 10% to 20%.