Properties - Sodium Silicate
December 19, 2001

Introduction General Physical Data Stability Toxicology Transport Information Personal Protection

Associated Links Fluoride Removal

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Introduction

The term sodium silicate refers to any one of several compounds containing sodium oxide, Na₂O, and silica, Si₂O, or a mixture of sodium silicates. Sodium orthosilicate is Na₄SiO₄ (or 2Na₂O·SiO₂); sodium metasilicate is Na₂SiO₃ (or Na₂O·SiO₂); sodium disilicate is Na₂Si₂O₅ (or Na₂O·2SiO₂); sodium tetrasilicate is Na₂Si₄O₉ (or Na₂O·4SiO₂). All these compounds are transparent, glassy or crystalline solids that have high melting points (above 800°C) and are water soluble. They are produced chiefly by fusing sand and sodium carbonate in various proportions. The product is commonly known as water glass. The greatest single use of sodium silicates is as a raw material for making silica gel.

General

Synonyms: water glass, soluble glass, silicate of soda, sodium orthosilicate, sodium silicate glass
Molecular formula: Na₄O₄Si
CAS No: 2344-09-8
EC No: 239-981-7

Physical Data

Appearance: colourless liquid
Boiling point: ca 102°C for a 40% aqueous solution 
Specific gravity: 1.3 for a ca. 40% solution

Stability

Stable. Incompatible with acids, most metals, many organic materials.

Toxicology

Harmful by ingestion. Corrosive - may cause burns through skin or eye contact. Very destructive of mucous membranes.

Transport Information

Non-hazardous for air, sea and road freight.

Personal Protection

Safety glasses, gloves.