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Sodium aluminosilicate

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Sodium aluminosilicate
Names
IUPAC name
aluminum sodium dioxido(oxo)silane
Other names
  • Aluminosilicic acid
  • aluminum sodium silicate
Identifiers
3D model (JSmol)
ECHA InfoCard 100.014.259 Edit this at Wikidata
E number E554 (acidity regulators, ...)
UNII
  • InChI=1S/Al.Na.2O3Si/c;;2*1-4(2)3/q+3;+1;2*-2 checkY
    Key: URGAHOPLAPQHLN-UHFFFAOYSA-N checkY
  • [O-] [Si](=O)[O-].[O-] [Si](=O)[O-].[Na+].[Al+3]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Sodium aluminosilicate refers to compounds which contain sodium, aluminium, silicon and oxygen, and which may also contain water. These include synthetic amorphous sodium aluminosilicate, a few naturally occurring minerals and synthetic zeolites. Synthetic amorphous sodium aluminosilicate is widely used as a food additive, E 554.

Amorphous sodium aluminosilicate

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This substance is produced with a wide range of compositions and has many different applications. It is encountered as an additive E 554 in food where it acts as an anticaking (free flow) agent. As it is manufactured with a range of compositions it is not strictly a chemical compound with a fixed stoichiometry.[1] One supplier quotes a typical analysis for one of their products as 14SiO2·Al2O3·Na2O·3H2O,(Na2Al2Si14O32·3H2O).[2]

The US FDA has as of April 1, 2012 approved sodium aluminosilicate (sodium silicoaluminate) for direct contact with consumable items under 21 CFR 182.2727.[3] Sodium aluminosilicate is used as molecular sieve in medicinal containers to keep contents dry.

Sodium aluminosilicate may also be listed as:

  • aluminium sodium salt
  • sodium silicoaluminate
  • aluminosilicic acid, sodium salt
  • sodium aluminium silicate
  • aluminum sodium silicate
  • sodium silico aluminate
  • sasil

As a problem in industrial processes

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The formation of sodium aluminosilicate makes the Bayer process uneconomical for bauxites high in silica.[citation needed]

Minerals sometimes called sodium aluminosilicate

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Naturally occurring minerals that are sometimes given the chemical name sodium aluminosilicate include albite (NaAlSi3O8, an end-member of the plagioclase series) and jadeite (NaAlSi2O6).[citation needed]

Synthetic zeolites sometimes called sodium aluminosilicate

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Synthetic zeolites have complex structures and examples (with structural formulae) are:

  • Na12Al12Si12O48·27H2O, zeolite A (Linde type A sodium form, NaA), used in laundry detergents[4]
  • Na16Al16Si32O96·16H2O, Analcime, IUPAC code ANA[4]
  • Na12Al12Si12O48·q H2O, Losod[5]
  • Na384Al384Si384O1536·518H2O, Linde type N

References

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  1. ^ United Nations Environment Programme Archived 2010-03-31 at the Wayback Machine
  2. ^ Solvay link no longer works
  3. ^ "Sec. 182.2727 Sodium aluminosilicate". U.S. Food and Drug Administration. 1 April 2012. Retrieved 10 December 2012.
  4. ^ a b Alan Dyer, (1994),Encyclopedia of Inorganic Chemistry, ed R. Bruce King, John Wiley & Sons, ISBN 0-471-93620-0
  5. ^ "Formation and Properties of Losod, a New Sodium Zeolite", Werner Sieber, Walter M. Meie Helvetica Chimica Acta, Volume 57 Issue 6, pp. 1533–1549, 10.1002/hlca.19740570608