Calciumfluorid Chemische Eigenschaften,Einsatz,Produktion Methoden
ERSCHEINUNGSBILD
FARBLOSE KRISTALLEODER WEISSES HYGROSKOPISCHES PULVER.
CHEMISCHE GEFAHREN
Beim Verbrennen Bildung giftiger Fluorid-Rauche. Reagiert mit Mineralsäuren unter Bildungätzender Rauche.
ARBEITSPLATZGRENZWERTE
TLV: (Fluoride als F) 2,5 mg/m?(als TWA); Krebskategorie A4 (nicht klassifizierbar als krebserzeugend für den Menschen); BEI vorhanden; (ACGIH 2005).
MAK: (Fluoride als F) (Einatembare Fraktion) 1 mg/m? Spitzenbegrenzung: überschreitungsfaktor II(4); Hautresorption; Schwangerschaft: Gruppe C; (DFG 2006).
AUFNAHMEWEGE
Aufnahme in den Körper durch Inhalation des Aerosols und durch Verschlucken.
INHALATIONSGEFAHREN
Verdampfung bei 20°C vernachlässigbar; eine gesundheitsschädliche Partikelkonzentration in der Luft kann jedoch beim Versprühen schnell erreicht werden.
LECKAGE
Verschüttetes Material in Behältern sammeln; falls erforderlich durch Anfeuchten Staubentwicklung verhindern. Reste sorgfältig sammeln. An sicheren Ort bringen. Persönliche Schutzausrüstung: Atemschutzgerät, P2-Filter für schädliche Partikel.
R-Sätze Betriebsanweisung:
R36/37/38:Reizt die Augen, die Atmungsorgane und die Haut.
S-Sätze Betriebsanweisung:
S26:Bei Berührung mit den Augen sofort gründlich mit Wasser abspülen und Arzt konsultieren.
S37/39:Bei der Arbeit geeignete Schutzhandschuhe und Schutzbrille/Gesichtsschutz tragen.
S36:DE: Bei der Arbeit geeignete Schutzkleidung tragen.
Chemische Eigenschaften
Calcium fluoride, CaF2, also known as fluorite and feldspar, is a colorless solid composed of cubic crystals. It has a low water solubility, but is readily soluble in ammonium salt solutions. Calcium fluoride is used in the synthesis of hydrofluoric acid and in etching glass.
Calcium Fluoride is not hygroscopic and is relatively inert. It has a sufficiently high resistance to thermal and mechanical shock, and it is easily fabricated into a variety of detector geometries.
Calcium Fluoride has a very low vapor pressure, allowing it to be used in a wide variety of vacuum applications. It is insoluble in water and most organic solvents, permitting radioactive samples in solution to be placed in direct contact with the crystal.
Calcium Fluoride is a transparent material used for detecting γ-rays up to several hundred keV and for detecting charged particles. Because of its low atomic number, the material’s photofraction is relatively small which limits its use in γ-ray spectrometry at higher energies. However, the low atomic number makes Calcium Fluoride an ideal material for the detection of β-particles because of the small amount of backscattering.
Physikalische Eigenschaften
White cubic crystal or powder; refractive index 1.434; density 3.18 g/cm3; hardness 4 Mohs; melts at 1,418°C; vaporizes at 2,533°C; insoluble in water (16 mg/L at 20°C); Ksp 3.9x10-11; slightly soluble in dilute mineral acid; soluble in concentrated acids (with reaction).
Verwenden
Fluorspar is the main primary source of fluorine and its Compounds. 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.
Vorbereitung Methode
The commercial product is obtained from naturally occurring mineral fluorspar, which is purified and powdered. Also, it may be precipitated by mixing a solution of sodium fluoride with a soluble calcium salt:
Ca(NO
3)
2 + 2NaF → CaF
2 + NaNO
3Alternatively, it may be obtained by treating calcium carbonate with hydrofluoric acid：CaCO
3 + 2HF → CaF
2 + CO
2 + H
2O.
Definition
A pure naturally occurring form of calcium fluoride.
Allgemeine Beschreibung
Odorless gray powder or granules. Sinks in water.
Reaktivität anzeigen
Calcium fluoride has weak oxidizing or reducing powers. Redox reactions can however still occur. The majority of compounds in this class are slightly soluble or insoluble in water. If soluble in water, then the solutions are usually neither strongly acidic nor strongly basic. These compounds are not water-reactive.
Hazard
An irritant.
Health Hazard
Little acute toxicity
Industrielle Verwendung
Also called fluorite, fluorspar is a crystalline or massive granular mineral of the composition CaF
2, used as a flux in the making of steel, for making hydrofluoric acid, in opalescent glass, in ceramic enamels, for snaking artificial cryolite, as a binder for vitreous abrasive wheels,and in the production of white cement. It is a better flux for steel than limestone, making a fluid slag, and freeing the iron of sulfur and phosphorus.
Acid spar is a grade used in making hydrofluoric acid. It is also used for making refrigerants, plastics, and chemicals, and for aluminum reduction. Optical fluorspar is the highest grade but is not common. Fluoride crystals for optical lenses are grown artificially from acid-grade fluorspar. Pure calcium fluoride, Ca
2F
6, is a colorless crystalline powder used for etching glass, in enamels, and for reducing friction in machine bearings. It is also used for ceramic parts resistant to hydrofluoric acid and most other acids. Calcium fluorite has silicon in the molecule and is a crystalline powder used for enamels. The clear rhombic fluoride crystals used for transforming electric energy into light are lead fluoride, PbF
2.
Sicherheitsprofil
Moderately toxic by
intraperitoneal route. Mildly toxic by
ingestion. An experimental teratogen. Other
experimental reproductive effects. Mutation
data reported. See also FLUORIDES and
CALCIUM COMPOUNDS. When heated
to decomposition it emits toxic fumes of F-.
mögliche Exposition
Calcium fluoride is used for production of hydrofluoric acid; as a flux in steel manufacture; in
smelting; electric arc welding, making glass and ceramics;
and to fluoridate drinking water.
Versand/Shipping
Calcium fluoride is not specifically covered by
DOT in its Performance-Oriented Packaging Standards.
Inkompatibilitäten
Dust may form explosive mixture with
air. Reacts with water, moist air, and steam, releasing flammable hydrogen gas; and may self-ignite in air. A strong
reducing agent; incompatible with oxidizers (chlorates,
nitrates, peroxides, permanganates, perchlorates, chlorine,
bromine, fluorine, etc.); contact may cause fires or explosions. Keep away from alkaline materials, strong bases,
strong acids, oxoacids, epoxides. Incompatible with metal
halogenates, silver fluoride, and tetrahydrofuran
Calciumfluorid Upstream-Materialien And Downstream Produkte
Upstream-Materialien
Downstream Produkte
