Nomenclature
CAS number: 7789-75-5
CaF
2; mol wt 78.07.
Ca 51.34%, F 48.67%.
Description and references
Occurs in nature as the mineral fluorite or fluorspar. Prepd from CaCO3 + HF: O. Ruff, Die Chemie des Fluors (Berlin, 1920) p 89;
Emeleus in Fluorine Chemistry vol. I, J. H. Simons, Ed. (Academic Press, 1950) p 36; Kwasnik
in Handbook of Preparative Inorganic Chemistry Vol. 1, G. Brauer, Ed. (Academic Press, New York, 2nd
ed., 1963) p 233. Toxicity study: K.-R. Stratmann, Dtsch. Zahnaerztl. Z. 34, 484
(1979).
Properties
White powder or cubic crystals. When F ions are
pptd with Ca 2+ in the absence of CO3 ions,
a gel is obtained. For the crystals: d 3.18; mp 1403°; bp 2500°; Mohs' hardness: 4. Becomes luminous when heated. Practically
insol in water (soly at 18°: 0.0015 g/100 ml). Slightly sol in dil
mineral acids; dissolved by concd mineral acids with liberation of
HF. LD50 i.p. in mice: 2638.27 mg/kg (Stratmann).Use
Fluorspar is the main primary source of fluorine
and its compds. In ferrous metallurgy it is used as a flux to increase
the fluidity of the slag. The steel industry is the largest consumer;
the chemical industry, second and glass and ceramics, third. Synthetic
fluorspar is used in the optical industry (transmits u.v. rays), and
pure calcium fluoride is used as catalyst in dehydration and dehydrogenations.
Used to fluoridate drinking water.