Sodium aluminosilicate

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| IUPACName = aluminum sodium dioxido(oxo)silane

| OtherNames = {{Unbulleted list|Aluminosilicic acid|aluminum sodium silicate}}

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| CASNo = 1344-00-9

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| UNII = 058TS43PSM

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| PubChem = 19758701

| SMILES = [O-] [Si](=O)[O-].[O-] [Si](=O)[O-].[Na+].[Al+3]

| StdInChI = InChI=1S/Al.Na.2O3Si/c;;2*1-4(2)3/q+3;+1;2*-2

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| StdInChIKey = URGAHOPLAPQHLN-UHFFFAOYSA-N

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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

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.[http://www.chem.unep.ch/irptc/sids/oecdsids/Silicates.pdf United Nations Environment Programme] {{webarchive|url=https://web.archive.org/web/20100331011523/http://www.chem.unep.ch/irptc/sids/oecdsids/Silicates.pdf |date=2010-03-31 }} One supplier quotes a typical analysis for one of their products as 14SiO2·Al2O3·Na2O·3H2O,(Na2Al2Si14O32·3H2O).[http://www.rhodia-silicas.com/markets/datasheets/T17.pdf Solvay link no longer works]

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.{{cite web|title=Sec. 182.2727 Sodium aluminosilicate.|url=https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?fr=182.2727|publisher=U.S. Food and Drug Administration|access-date=10 December 2012|date=1 April 2012}} 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

The formation of sodium aluminosilicate makes the Bayer process uneconomical for bauxites high in silica.{{cn|date=September 2023}}

Minerals sometimes called sodium aluminosilicate

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).{{cn|date=September 2023}}

Synthetic zeolites sometimes called sodium aluminosilicate

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

  • Na12Al12Si12O48·27H2O, zeolite A (Linde type A sodium form, NaA), used in laundry detergentsAlan Dyer, (1994),Encyclopedia of Inorganic Chemistry, ed R. Bruce King, John Wiley & Sons, {{ISBN|0-471-93620-0}}
  • Na16Al16Si32O96·16H2O, Analcime, IUPAC code ANA
  • Na12Al12Si12O48·q H2O, Losod"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
  • Na384Al384Si384O1536·518H2O, Linde type N

References