Sodium aluminosilicate

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.

Sodium aluminosilicate

Names
IUPAC name aluminum sodium dioxido(oxo)silane
Other names Aluminosilicic acid aluminum sodium silicate
Identifiers
CAS Number	1344-00-9 Y
3D model (JSmol)	Interactive image
ECHA InfoCard	100.014.259
E number	E554 (acidity regulators, ...)
PubChem CID	19758701
UNII	058TS43PSM Y
CompTox Dashboard (EPA)	DTXSID7026021
InChI InChI=1S/Al.Na.2O3Si/c;;2*1-4(2)3/q+3;+1;2*-2 Y Key: URGAHOPLAPQHLN-UHFFFAOYSA-N Y
SMILES [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). Infobox references

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.^[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

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

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).^{[citation needed]}

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 detergents^[4]
• Na₁₆Al₁₆Si₃₂O₉₆·16H₂O, Analcime, IUPAC code ANA^[4]
• Na₁₂Al₁₂Si₁₂O₄₈·q H₂O, Losod^[5]
• Na₃₈₄Al₃₈₄Si₃₈₄O₁₅₃₆·518H₂O, Linde type N

References

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. 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