Identification | More | [Name]
Lithium fluoride | [CAS]
7789-24-4 | [Synonyms]
LITHIUM FLUORIDE Fluorolithium Lithium fluoride (Li3F3) Lithium fluoride (LiF) Lithium fluorure Lithium monofluoride Lithiumfluorid lithiumfluoride(lif) lithiumfluorure lithiumfluorure(french) lithiummonofluoride NTL 50 ntl50 TLD 100 TLD 700 tld100 tld700 Trilithium trifluoride Lithium fluoride (99.9% Li) (fused crystals) Lithium Fluoride Anhydrous | [EINECS(EC#)]
232-152-0 | [Molecular Formula]
FLi | [MDL Number]
MFCD00011090 | [Molecular Weight]
25.94 | [MOL File]
7789-24-4.mol |
Chemical Properties | Back Directory | [Appearance]
White powder | [Melting point ]
845 °C (lit.) | [Boiling point ]
1681 °C
| [density ]
2.64 g/mL at 25 °C(lit.)
| [vapor pressure ]
0Pa at 25℃ | [refractive index ]
1.3915 | [Fp ]
1680°C | [storage temp. ]
Store at +5°C to +30°C. | [solubility ]
Soluble in 0.29 g/100 mL (20°C) and hydrogen fluoride. Insoluble in alcohol. | [form ]
random crystals
| [color ]
White to off-white | [Specific Gravity]
2.635 | [PH]
6.0-8.5 (25℃, 0.01M in H2O) | [Stability:]
Stable, but hygroscopic. Hydrolyzes in the presence of water to form hydrofluoric acid, which attacks glass-do not store in glass bottles. Incompatible with aqueous solutions, strong acids, strong oxidizing agents. | [Water Solubility ]
0.29 g/100 mL (20 ºC) | [Sensitive ]
Hygroscopic | [λmax]
λ: 260 nm Amax: ≤0.01 λ: 280 nm Amax: ≤0.01 | [Merck ]
14,5531 | [Solubility Product Constant (Ksp)]
pKsp: 2.74 | [Exposure limits]
ACGIH: TWA 2.5 mg/m3 NIOSH: IDLH 250 mg/m3; TWA 2.5 mg/m3 | [InChIKey]
PQXKHYXIUOZZFA-UHFFFAOYSA-M | [LogP]
0.23 at 25℃ | [CAS DataBase Reference]
7789-24-4(CAS DataBase Reference) | [NIST Chemistry Reference]
Lithium fluoride(7789-24-4) | [EPA Substance Registry System]
7789-24-4(EPA Substance) |
Safety Data | Back Directory | [Hazard Codes ]
T | [Risk Statements ]
R25:Toxic if swallowed. R32:Contact with acids liberates very toxic gas. R36/37/38:Irritating to eyes, respiratory system and skin . R23/24/25:Toxic by inhalation, in contact with skin and if swallowed . | [Safety Statements ]
S22:Do not breathe dust . S26:In case of contact with eyes, rinse immediately with plenty of water and seek medical advice . S36/37/39:Wear suitable protective clothing, gloves and eye/face protection . S45:In case of accident or if you feel unwell, seek medical advice immediately (show label where possible) . | [RIDADR ]
UN 3288 6.1/PG 3
| [WGK Germany ]
2
| [RTECS ]
OJ6125000
| [F ]
10-21 | [Hazard Note ]
Toxic | [TSCA ]
Yes | [HazardClass ]
6.1 | [PackingGroup ]
III | [HS Code ]
28261900 | [Safety Profile]
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. | [Hazardous Substances Data]
7789-24-4(Hazardous Substances Data) | [Toxicity]
LD in guinea pigs (mg/kg): 200 orally, 2000 s.c. (Waldbott) |
Questions And Answer | Back Directory | [Description]
Lithium Fluoride (LiF) has the lowest refractive index of all common infrared materials. It possesses the highest UV transmission of any material, being able to transmit significantly into the VUV region at the hydrogen Lyman-alpha line (121nm). Lithium fluoride can be applied in rechargeable Li batteries, in radiation dosimeter for personnel monitoring as well as radiation research, as an optical material, as a heat sink material, to produce ceramics, and to dissolve fluid fuel for molten salt reactors.
lithium fluoride crystal
| [Uses]
Lithium Fluoride (LiF) is a water insoluble Lithium source for use in oxygen-sensitive applications, such as metal production. It is most widely used as a flux in the production of ceramics, such as enamels, glasses and glazes. Similarly it is also used in brazing and welding fluxes and molten salt chemistry in metallurgy.
Lithium fluoride is also used for:
- X-Ray monochromator plates as an analysis crystal: Lithium fluoride is also used for X-ray monochromator plates where its lattice spacing makes it the most useful analysis crystal.
- Heat sink materials
- UV transmission windows: Lithium fluoride is the material with the most extreme UV transmission of all and is used for special UV optics. Lithium fluoride transmits well into the VUV region at the hydrogen Lyman-alpha line (121nm) and beyond.
| [References]
[1] H. Li, G. Richter, J. Maier, Reversible Formation and Decomposition of LiF Clusters Using Transition Metal Fluorides as Precursors and Their Application in Rechargeable Li Batteries, Advanced Materials, 2003, vol. 15, 736-739
[2] J. R. Cameron, F. Daniels, N. Johnson, G. Kenney, Radiation Dosimeter Utilizing the Thermoluminescence of Lithium Fluoride, Science, 1961, vol. 134, 333-334
[3] E. T. Kvamme, J. C. Earthman, D. B. Leviton, B. J. Frey, Lithium fluoride material properties as applied on the NIRCam instrument, Proc. SPIE 59,4, 2005
[4] Y. Kogure, H. Kaburaki, Y. Hiki, Low-Temperature Thermal Properties of Lithium Fluoride Containing Dislocations, Phonon Scattering in Condensed Matter, 1979, 267-270
[5] H. Naghib-zadeh, C. Glizky, I. D?rfel, T. Rabe, Low temperature sintering of barium titanate ceramics assisted by addition of lithium fluoride-containing sintering additives, Journal of the European Ceramic Society, 2010, vol. 30, 81-86
[6] M. W. Rosenthal, P. R. Kasten, R. B. Briggs, Molten-Salt Reactors – History, Status, and Potential, 1970, vol. 8, 107-117
|
Hazard Information | Back Directory | [Chemical Properties]
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.
| [Physical properties]
White cubic crystals; refractive index 1.3915; density 2.635 g/cm3; 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. | [Flammability and Explosibility]
Nonflammable | [Purification Methods]
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). |
Questions and Answers (Q&A) | Back Directory | [Uses]
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.
| [Preparation]
Lithium fluoride is prepared by treating an aqueous solution of lithium hydroxide or lithium carbonate with aqueous hydrofluoric acid: LiOH + HF → LiF + H2O.
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