Chemistry:Sodium aluminosilicate

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
PubChem CID	19758701
UNII	058TS43PSM Y
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

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. One supplier quotes a typical analysis for one of their products as 14SiO₂·Al₂O₃·Na₂O·3H₂O,(Na₂Al₂Si₁₄O₃₂·3H₂O).

The United States FDA has as of April 1, 2012 approved sodium aluminosilicate (sodium silicoaluminate) for direct contact with consumable items under 21 CFR 182.2727. 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.

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).

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
• Na₁₆Al₁₆Si₃₂O₉₆·16H₂O, Analcime, IUPAC code ANA
• Na₁₂Al₁₂Si₁₂O₄₈·q H₂O, Losod
• Na₃₈₄Al₃₈₄Si₃₈₄O₁₅₃₆·518H₂O, Linde type N