Fluorspar CaF

Fluorine comes from the minerals fluorspar, CaF, cryolite, Na3AlF6 and the fluorapatites, Ca,F(P04)3. The free element is prepared from HF and KF by electrolysis, but the HF and KF needed for the electrolysis are prepared in the laboratory. Chlorine primarily comes from the mineral rock salt, NaCl. The pure element is obtained by electrolysis of liquid NaCl. Bromine is found in seawater and brine wells as the Br ion it ts also found as a component of saline deposits the pure element is obtained by oxidation of Br (aq) by Cl,(g). Iodine is found in seawater, seaweed, and brine wells as the I" ion the pure element is obtained by oxidation of I (aq) by Cl,(g). 

Scheele made a number of other extremely valuable contributions to chemistry. He added oil of vitriol to fluorspar (CaF ) and distilled it. He found extensive corrosion of the retort containing the reaction mixture all the luting used to seal the apparatus was now brittle and friable, and a white deposit was formed on all interior surfaces of the apparatus. Scheele had formed hydrofluoric acid (HE), which attacked the glass vessel (silicon dioxide) and formed gaseous SiF. When he duplicated the experiment but added water to the receiver, he was surprised to find a layer of gelatinous silica on top of the water. 

CF = CF, CAS number 116-14-3) from decomposition of tetrafluoromethane in an electric arc. TFE was obtained by bromination and separation of the dibromide (CF Br-CF Br) from the other reactive products. Dehiogenation with zinc was the next step for obtaining pure TFE. Commercially significant techniques for TEE preparation list fluorspar (CaF ), hydrofluoric acid, and chloroform as the starting ingredients [7-13]. The reaction sequence is shown in Fig. 3.2. 

Anhydrite is formed as a result of tire HF produetion proeess, when fluorspar mineral (CaF,) reaets with H SO (ee). However, before using tliis subproduet, anhydrite must be neutralized with CaO resulting in a maximum amount of 1.5 % CaO. The neutralization reaetion generates water, and then a part of CaO is hydrated. 

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. 

Chemical Designations - Synonyms Fluospar, Fluorspar Chemical Formula CaF. ... 

A mixture of calcium fluoride ("fluorspar" 0.08 mol), potassium chloride (0.1 mol) and phosgene (0.14 mol), maintained at 500 C and about 3.4 MPa over a period of 63 h, gave a mixture consisting of COCIF, COFj and unconverted COCl. The solid residue consisted of a CaClj.KCl phase no CaFj.CaCl was detected, and 79% of the CaF was converted. Under similar conditions, maintained over 24 h, 67% of the CaF was converted and, after 4 h. 

Gaseous hydiofluoric acid is generally made by the reaction of acid-grade fluorspar [14542-23-5], CaF, with sulfuric acid (see Fluorine compounds, inorganic)... 

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