Lithiumfluorid Chemische Eigenschaften,Einsatz,Produktion Methoden
R-Sätze Betriebsanweisung:
R25:Giftig beim Verschlucken.
R32:Entwickelt bei Berührung mit Säure sehr giftige Gase.
R36/37/38:Reizt die Augen, die Atmungsorgane und die Haut.
R23/24/25:Giftig beim Einatmen, Verschlucken und Berührung mit der Haut.
S-Sätze Betriebsanweisung:
S22:Staub nicht einatmen.
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).
Beschreibung
lithium fluoride is a strong irritant to the eyes and skin; potassium bromide is toxic by ingestion and inhalation; sodium chloride is table salt, a medical concern when ingested in excess, but certainly of no significant hazard to emergency responders.
Chemische Eigenschaften
Lithium fluoride is a white crystalline solid. It is not hygroscopic as are the other lithium halides and is not affected by exposure to the air. Lithium fluoride is the least soluble of the alkali metal fluorides. This characteristic likens it to the alkaline earth fluorides. Lithium fluoride is different from the other lithium halides in that it does not form hydrates which can be isolated from solution. Lithium fluoride does show an increase in solubility as hydrofluoric acid is added to an aqueous solution. Under these conditions the fluoride ion is converted to the bifluoride ion, HF-2, allowing further dissolving of the solid lithium fluoride.
Physikalische Eigenschaften
White cubic crystals; refractive index 1.3915; density 2.635 g/cm
3; melts at 845°C; vaporizes at 1,676°C; very slightly soluble in water 0.27 g/100g at 18°C; soluble in hydrofluoric acid; insoluble in alcohol.
Verwenden
The important uses of lithium fluoride are as flux in glasses, vitreous enamels and glazes; in soldering and welding aluminum; and its prisms in infrared spectrophotometers. The compound also is used for storing solar energy.
synthetische
Lithium fluoride is prepared by treating an aqueous solution of lithium hydroxide or lithium carbonate with aqueous hydrofluoric acid: LiOH + HF → LiF + H2O.
Sicherheitsprofil
Poison by ingestion and
subcutaneous routes. When heated to
decomposition it emits toxic fumes of F-.
Used as a flux in enamels, glasses, glazes,
and weldmg. See also FLUORIDES and
LITHIUM COMPOUNDS.
läuterung methode
Possible impurities are LiCO3, H2O and HF. These can be removed by calcining it at red heat, then pulverizing it with a Pt pestle and storing it in a paraffin bottle. Its solubility in H2O is 0.27% at 18o. It volatilises between 1100-1200o. [Kwasnik in Handbook of Preparative Inorganic Chemistry (Ed. Brauer) Academic Press Vol I p 235 1963].
Structure and conformation
The space lattice of LiF belongs to the cubic system, and its rock salt structure has a lattice constant
of a=0.40173 nm and Li-F=0.201 nm. The cleavage plane is (100).
Lithiumfluorid Upstream-Materialien And Downstream Produkte
Upstream-Materialien
Downstream Produkte
