Fluorwasserstoff Chemische Eigenschaften,Einsatz,Produktion Methoden
ERSCHEINUNGSBILD
FARBLOSES GASODER FARBLOSE RAUCHENDE FLüSSIGKEIT MIT STECHENDEM GERUCH.
CHEMISCHE GEFAHREN
Starke Säure. Reagiert sehr heftig mit Basen. ätzend. Reagiert sehr heftig mit vielen Verbindungen unter Feuer- und Explosionsgefahr. Greift Metall, Glas, einige Kunststoffarten, Gummi und Beschichtungen an.
ARBEITSPLATZGRENZWERTE
TLV: (als F) 0.5 ppm (als TWA), 2 ppm (als STEL, ceiling); BEI vorhanden; (ACGIH 2005).
MAK: 1 ppm, 0.83 mg/m? Spitzenbegrenzung: überschreitungsfaktor I(2); Schwangerschaft: Gruppe C; MAK: BAT 7 mg/g Kreatinin; (DFG 2005).
AUFNAHMEWEGE
Aufnahme in den Körper durch Inhalation, über die Haut und durch Verschlucken.
INHALATIONSGEFAHREN
Eine gesundheitsschädliche Konzentration des Gases in der Luft wird beim Entweichen aus dem Behälter sehr schnell erreicht.
WIRKUNGEN BEI KURZZEITEXPOSITION
WIRKUNGEN BEI KURZZEITEXPOSITION: Die Substanz verätzt die Augen, die Haut und die Atemwege. Inhalation des Gases oder Dampfes kann zu Lungenödem führen (s. Anm.). Die Substanz kann Calciummangel im Blut verursachen. Exposition oberhalb der Arbeitsplatzgrenzwerte kann zum Tod führen. Die Auswirkungen treten u.U. verzögert ein. ärztliche Beobachtung notwendig.
WIRKUNGEN NACH WIEDERHOLTER ODER LANGZEITEXPOSITION
Die Substanz kann zu Fluorose führen.
LECKAGE
Gefahrenbereich verlassen! Fachmann zu Rate ziehen! Belüftung. Dämpfe mit feinem Wassersprühstrahl niederschlagen. Gasdichter Chemikalienschutzanzug mit umgebungsluftunabhängigem Atemschutzgerät.
R-Sätze Betriebsanweisung:
R26/27/28:Sehr giftig beim Einatmen, Verschlucken und Berührung mit der Haut.
R35:Verursacht schwere Verätzungen.
R36/37/38:Reizt die Augen, die Atmungsorgane und die Haut.
R20/21/22:Gesundheitsschädlich beim Einatmen,Verschlucken und Berührung mit der Haut.
S-Sätze Betriebsanweisung:
S26:Bei Berührung mit den Augen sofort gründlich mit Wasser abspülen und Arzt konsultieren.
S36/37/39:Bei der Arbeit geeignete Schutzkleidung,Schutzhandschuhe und Schutzbrille/Gesichtsschutz tragen.
S45:Bei Unfall oder Unwohlsein sofort Arzt zuziehen (wenn möglich, dieses Etikett vorzeigen).
S7/9:Behälter dicht geschlossen an einem gut gelüfteten Ort aufbewahren.
S36/37:Bei der Arbeit geeignete Schutzhandschuhe und Schutzkleidung tragen.
S28:Bei Berührung mit der Haut sofort abwaschen mit viel . . . (vom Hersteller anzugeben).
S36:DE: Bei der Arbeit geeignete Schutzkleidung tragen.
Beschreibung
Hydrofluoric acid is a solution of hydrogen fluoride in water. Hydrofluoric acid is highly corrosive inorganic acid. It is utilized widely in the manufacture of ceramics and graphite, in the electropolishing and pickling of metals, in the etching and frosting of glass, in the semiconductor industry as etchant and cleaning agent, in the chemical and oil-refining industries, and in cleaning solutions, laundry powder and pesticides. Hydrofluoric acid is also widely used in the preparation of many useful fluorine compounds, such as Teflon, Freon, fluorocarbons, and many medications such as fluoxetine (Prozac).
Chemische Eigenschaften
colourless gas with a pungent odour
Verwenden
Hydrofluoric acid is used as a fluorinatingagent, as a catalyst, and in uranium refining.It is also used for etching glass and forpickling stainless steel. Hydrogen fluoridegas is produced when an inorganic fluoride is distilled with concentrated sulfuricacid.
Definition
A colorless liquid produced
by dissolving hydrogen fluoride in water. It
is a weak acid, but will dissolve most silicates
and hence can be used to etch glass.
As the interatomic distance in HF is relatively
small, the H–F bond energy is very
high and hydrogen fluoride is not a good
proton donor. It does, however, form hydrogen
bonds.
Vorbereitung Methode
Anhydrous hydrogen fluoride is manufactured by the action of sulfuric on calcium fluoride. Powdered acid-grade fluorspar (≥97% CaF2) is distilled with concentrated sulfuric acid; the gaseous hydrogen fluoride that leaves the reactor is condensed and purified by distillation.
Anhydrous hydrogen fluoride is manufactured by treating fluorspar (fluorite, CaF2) with concentrated sulfuric acid in heated kilns. The gaseous HF evolved is purified by distillation, condensed as liquid anhydrous HF, and stored in steel tanks and cylinders.
Allgemeine Beschreibung
HF is a colorless inorganic acid. Hydrogen fluoride may be formed by reacting calcium fluoride and sulfuric acid at 200
oC. The fluoride in the acid has very high affinity to silicon, making it useful in etching or removal of silicon.
Air & Water Reaktionen
Fumes in air. Fumes are highly irritating, corrosive, and poisonous. Generates much heat on dissolution [Merck, 11th ed., 1989]. Heat can cause spattering, fuming, etc.
Reaktivität anzeigen
Hydrofluoric acid attacks glass and any other silica containing material. May react with common metals (iron, steel) to generate flammable hydrogen gas if diluted below 65% with water. Reacts exothermically with chemical bases (examples: amines, amides, inorganic hydroxides). Can initiate polymerization in certain alkenes. Reacts with cyanide salts and compounds to release gaseous hydrogen cyanide. May generate flammable and/or toxic gases with dithiocarbamates, isocyanates, mercaptans, nitrides, nitriles, sulfides. Additional gas-generating reactions may occur with sulfites, nitrites, thiosulfates (to give H2S and SO3), dithionites (SO2), and carbonates. Can catalyze (increase the rate of) chemical reactions. Reacts explosively with cyanogen fluoride, methanesulfonic acid or glycerol mixed with nitric acid. Reacts violently with arsenic trioxide, phosphorus pentachloride, acetic anhydride, alkali metals, ammonium hydroxide, chlorosulfonic acid, ethylenediamine, fluorine, potassium permanganate, oleum, propylene oxide, vinyl acetate, mercury(II) oxide. Emits highly corrosive fumes of hydrogen fluoride gas when heated [Sax, 9th ed., 1996, p. 1839]. Contact with many silicon compounds and metal silicides causes violent evolution of gaseous silicon tetrafluoride [Mellor, 1956, Vol. 2, suppl. 1, p. 121].
Hazard
Toxic by ingestion and inhalation, highly
corrosive to skin and mucous membranes.
Health Hazard
Hydrofluoric acid and hydrogen fluoride gasare extremely corrosive to body tissues, causing severe burns. The acid can penetrate theskin and destroy the tissues beneath and evenaffect the bones. Contact with dilute acid cancause burns, which may be perceptible hoursafter the exposure. The healing is slow. Contact with the eyes can result in impairment ofvision.
Prolonged exposure to 10–15 ppm concentrations of the gas may cause redness ofskin and irritation of the nose and eyes inhumans. Inhalation of high concentrations ofHF may produce fluorosis and pulmonaryedema. In animals, repeated exposure toHF gas within the range 20–25 ppm hasproduced injury to the lungs, liver, andkidneys.
LC50 value, inhalation (mice): 342 ppm/h.
Brandgefahr
When heated, Hydrofluoric acid emits highly corrosive fumes of fluorides. Its corrosive action on metals can result in formation of hydrogen in containers and piping to create fire hazard. Toxic and irritating vapors are generated when heated. Will attack glass, concrete, and certain metals, especially those containing silica, such as cast iron. Will attack natural rubber, leather, and many organic materials. May generate flammable hydrogen gas in contact with some metals.
Flammability and Explosibility
Hydrogen fluoride is not a combustible substance
Industrielle Verwendung
Hydrofluoric acid (HF) is a colorless liquid with a characteristic odor. It releases fumes
when in contact with moist air. Hydrofluoric acid is manufactured from fluorite containing
96–97% CaF
2 by reacting it with concentrated sulfuric acid:
CaF
2+H
2SO
4 = 2HF+CaSO
4
The acid is sold as a 40% solution. The hydrofluoric acid is used as an activator and
depressant, mostly during flotation of industrial minerals (i.e. columbite, tantalite,
silica, feldspars).
Materials Uses
Carbon steel (without nonmetallic inclusions) is
acceptable for handling hydrogen fluoride up to
approximately 150°F (65.6°C). Aluminum-
silicon-bronze, stainless steel, or nickel are
suitable for cylinder valves. For higher temperatures,
Monel, Inconel, nickel, or copper
should be used. Cast iron or malleable fittings
should be avoided. Polyethylene, lead, soft copper,
Kel-F, and Teflon are acceptable gasket
materials. Polyethylene, Kel-F, and Teflon are
acceptable packing materials.
Carcinogenicity
NTP conducted two chronic
oral bioassays of fluoride administered as sodium fluoride
(0, 25, 100, or 175 ppm) in drinking water for 103 weeks in
rats and mice.The first study was compromised, so it was
used to determine doses for the second study. NTP concluded
that there was no evidence that fluoride was carcinogenic at
doses up to 4.73 mg/kg/day in female rats or at doses up to
17.8 and 19.9 mg/kg/day in male and female mice,
respectively.
Environmental Fate
Hydrogen fluoride is a colorless, fuming liquid with a strong,
irritating odor. The density is 1.002 at 0 ℃ and the boiling
point is 19.51 ℃. Hydrogen Fluoride is naturally released into
the environment, primarily from volcanoes, ranging from 0.6
to 6 million metric tons per year. The majority of artificial
pollutants come from electrical utilities.
Hydrogen fluoride is removed from air by wet deposition as
fluoride salts with an atmospheric lifetime of 1–5 days.
Lager
All work with
HF should be conducted in a fume hood to prevent exposure by inhalation, and
splash goggles and neoprene gloves should be worn at all times to prevent eye and
skin contact. Containers of HF should be stored in secondary containers made of
polyethylene in areas separate from incompatible materials. Work with anhydrous
HF should be undertaken using special equipment and only by well-trained personnel
familiar with first aid procedures.
läuterung methode
It can be purified by trap-to-trap distillation, followed by drying over CoF2 at room temperature and further distillation. Alternatively, it can be absorbed on NaF to form NaHF2 which is then heated under vacuum at 150o to remove volatile impurities. The HF is regenerated by heating at 300o and is stored with CoF3 in a nickel vessel, being distilled as required. (Water content should be ca 0.01%.) To avoid contact with base metal, use can be made of nickel, polychlorotrifluoroethylene and gold-lined fittings [Hyman et al. J Am Chem Soc 79 3668 1957]. An aqueous solution is hydrofluoric acid (see above). It is HIGHLY TOXIC and attacks glass.
Inkompatibilitäten
HF reacts with glass, ceramics, and some metals. Reactions with metals may
generate potentially explosive hydrogen gas.
Waste disposal
Excess hydrogen fluoride and waste material containing this substance should be
placed in an appropriate container, clearly labeled, and handled according to your
institution's waste disposal guidelines. For more information on disposal procedures,
see Chapter 7 of this volume.
Einzelnachweise
[1] David J. Monk, and David S. Soane, A review of the chemical reaction mechanism and kinetics for hydrofluoric acid etching of silicon dioxide for surface micromachining applications, Thin Solid Films, 1993, vol. 232, 1-12
[2] P. Sanz-Gallen, S. Nogue, P. Munne and A. Faraldo, Hybocalcaemia and hypomagnesaemia due to hydrofluoric acid, Occup Med (Lond), 2001, vol. 51, 294-295
Fluorwasserstoff Upstream-Materialien And Downstream Produkte
Upstream-Materialien
Downstream Produkte
Kupfer(2+)tetrafluoroborat(1-)
6,9-Difluoropregn-4-ene-11,17,21-triol-3,20-dione17,21-diacetate
Zinkbis(tetrafluoroborat)
9-Fluoropregna-1,4-diene-11,17,21-triol-3,20-dione17,21-diacetate
2-Chlor-6-fluortoluol
Ditantalpentaoxid
Lanthanfluorid
Sevoflurane
3-TRIFLUOROMETHYL BENZOTRICHLORIDE
2,4-Dichlor-α,α,α-trifluortoluol
Yttriumtrifluorid
emulsifier acid
Boron trifluoride acetonitrile complex
1,1,1,2,3,3,3-Heptafluorpropan
α,α,α,β,β,β-Hexafluor-m-xylol
Titantetrafluorid
5-(trifluoromethyl)thiazol-2-amine
Sodium trifluoromethanesulfonate
Lithiumfluorid
Bariumfluorid
Chlortrifluormethan
Kaliumtetrafluoroaluminat
1-CHLORO-3-FLUOROISOPROPANOL
Strontiumfluorid
Ethyl-2-methylbutyrat
Neodymtrifluorid
Lithiumhexafluorophosphat(1-)
6α,9-Difluor-11β,17,21-trihydroxypregna-1,4-dien-3,20-dion-17,21-di(acetat)
9-Fluor-11β,21-dihydroxypregna-1,4,16-trien-3,20-dion-21-acetat
1-Chlor-1,1-difluorethan
Chromtrifluorid
Trikaliumhexafluoroaluminat
ZINC TETRAFLUOROBORATE HYDRATE
Doxycyclin
Magnesiumfluorid
Dichlorfluormethan
Trichlortrifluorethan
Chromium(III) fluoride tetrahydrate
Triamcinolone 21-acetate
Kaliumheptadecafluoroctan-1-sulfonat mit 40% anderenPerfluoralkansulfonaten (C4-C7)
