Potassium hexafluoroaluminate

Potassium hexafluoroaluminate is an inorganic chemical compound with the chemical formula K3AlF6.[1][2][3] It naturally occures as the mineral cryolite.[4]

Potassium hexafluoroaluminate
Names
IUPAC name
tripotassium;hexafluoroaluminum(3-)
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.033.994 Edit this at Wikidata
EC Number
  • 262-553-6
  • InChI=1S/Al.6FH.3K/h;6*1H;;;/q+3;;;;;;;3*+1/p-6
    Key: ZIZQEDPMQXFXTE-UHFFFAOYSA-H
  • F[Al-3](F)(F)(F)(F)F.[K+].[K+].[K+]
Properties
K3AlF6
Appearance powder
Melting point 1035
slightly soluble
Hazards
GHS labelling:
GHS07: Exclamation markGHS08: Health hazard
Warning
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Synthesis

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Potassium hexafluoroaluminate can be obtained by reacting fluoroaluminic acid (obtained by the reaction of anhydrous hydrogen fluoride and aluminum hydroxide) with potassium hydroxide at high temperature, followed by filtering, drying, melting, and crushing.

6HF + Al(OH)3 → AlF3·3HF + 3H2O
AlF3·3HF + 3KOH → K3AlF6 + 3H2O

Physical characteristics

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Potassium hexafluoroaluminate appears as a white to light grey powder, and is slightly soluble in water.

It forms colorless crystals of the tetragonal system, space group I41/a.[5]

Uses

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Potassium hexafluoroaluminate is used as a welding agent.[6]

It is also used in the production of pesticides, manufacture of glassware and enamel industry, in addition to being a solvent for the bauxite in the electrical manufacture of aluminum.

References

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  1. ^ "Potassium Hexafluoroaluminate". American Elements. Retrieved 15 June 2024.
  2. ^ "Potassium hexafluoroaluminate(iii)". NIST. Retrieved 15 June 2024.
  3. ^ Kirk-Othmer Encyclopedia of Chemical Technology, Volume 2. John Wiley & Sons. 27 January 2004. p. 371. ISBN 978-0-471-48521-6. Retrieved 15 June 2024.
  4. ^ Rudawska, Anna (24 October 2018). Abrasive Technology: Characteristics and Applications. BoD – Books on Demand. p. 119. ISBN 978-1-78984-193-0. Retrieved 15 June 2024.
  5. ^ King, Graham; Abakumov, Artem M.; Woodward, Patrick M.; Llobet, Anna; Tsirlin, Alexander A.; Batuk, Dmitry; Antipov, Evgeny V. (15 August 2011). "The High-Temperature Polymorphs of K 3 AlF 6". Inorganic Chemistry. 50 (16): 7792–7801. doi:10.1021/ic200956a. ISSN 0020-1669. PMID 21744814. Retrieved 15 June 2024.
  6. ^ "Potassium hexafluoroaluminate (CAS 13775-52-5)". Santa Cruz Biotechnology. Retrieved 15 June 2024.