Fluorspar applications

Fluoride production consists on reacting fluorspar mineral (CaF ) with H SO (cc) to form HF and calcium sulphate. However, reactions do not achieve 100 % yield, so fluorogypsum or anhydrite (CaSO ) obtained contains small amounts of fluoride as CaF in its stmcture. The application of this kind of subproduct is well-known as constmction material, so that the flouride content has to be controlled. 

Calcium fluoride occurs in nature as the mineral fluorspar or fluorite. It is used as a flux in ferrous metallurgy to enhance the fluidity of the slag. An important application of this compound is in the manufacture of fluorine and hydrofluoric acid, starting materials for producing many fluoroorganics. It also is used in glass and ceramics. Pure crystals are used in lasers, optics, and electronics. Other applications are in high temperature, dry-film lubricants ... 

DeCaF treats soil, sludges, solids (e.g., slag), residues, and sediments contaminated with radioactive elements and other hazardous constituents. The technology has potential applications in the treatment of heavy metals. The technology can treat uranium-contaminated calcium fluoride matrices, rare-earth ore residues, and fluorspar contaminated with uranium. The technology can also extract more complex fluoride by-products. 

Copper.—Alloys of copper and vanadium are prepared by firing a mixture of vanadium pentoxide, copper oxide, aluminium shot, lime, soda-ash, and fluorspar with the aid of sodium peroxide in a magnesia-lined crucible.2 Electrolytic methods have also been employed, and are applicable for the preparation of other vanadium alloys.3 An alloy containing 3-38 per cent, of vanadium and 96-52 per cent, of copper was found to be harder than copper and could be drawn into wire. An aluminium-copper-vanadium alloy has been prepared.4... 

Hydrogen fluoride is produced worldwide in 10 ta by reaction of fluorspar with sulfuric acid (equation 1). The reaction is endothermic (AF/298 = 59kJmol ) and is carried out in rotary furnaces that produce up to 45td . The crude HF is scrubbed by H2SO4 and purified further by distillation as required. Silicon tetrafiuoride is a by-product from silicate impurities (equation 2) and is recovered as H2SiFe (equations). Another by-product, CaS04, is used in cement production and other applications. ... 

Fluorspar is utilized, depending upon quality, in the manufacture of aluminum, bricks, cement, glass, glass fibers, enamel and in the metal working industry (foundries). Other applications consume only small quantities. 

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