Sodium silicate

Sodium silicate (CAS 1344-09-8), also known as water glass, is an inorganic alkali salt used as a binder, sealant, and reactive flocculant.

Where is Sodium silicate used?

• Pulp and paper: stabilizes hydrogen peroxide during bleaching, preventing decomposition and improving whiteness yields
• Adhesives and board: structural binder in corrugated packaging
• Water treatment: corrosion inhibitor and coagulation aid
• Construction: penetrates concrete and masonry to densify surfaces
• It forms a rigid silica gel network upon drying or acidification.
• Used in garment dyeing.
• Used as a raw material for silica gels.
• Used in the chemical industry for the production of silica, zeolite molecular sieves, precipitated silica, and various silicates, and as a raw material for detergents and cleaning agents.
• In drilling, mixed with a catalyst such as an ester to form a polymerized gel that stabilizes soil and increases its strength and stiffness.

Formulation notes

• Liquid sodium silicate (water glass) is suitable for direct use in processes, while solid sodium silicate is supplied as powder or granules and requires preparation of a solution before use.
• Modulus is the key specification that determines alkalinity, binding behavior, and cure characteristics, so different applications require different ratios.
• Should not be brought into uncontrolled contact with acids.

Typical specification

• Offered in liquid form.
• Commercial sodium silicates have molar ratios between 1.5 and 4.0.
• Higher silica ratio increases binding strength and heat resistance, while lower ratios increase alkalinity and solubility.
• Generally marketed as a solution with a concentration between 25% and 50%.

Regulatory status

• Sodium silicate has REACH registration number 01-2119448725-31.
• Liquid sodium silicate is non-hazardous for all modes of transport.

Storage, packaging and handling

• Powder sodium silicate products should be kept in a dry environment.
• Should be stored in corrosion-resistant tanks.
• Liquid sodium silicate products should be protected from freezing.

Frequently asked questions about Sodium silicate

What is the difference between sodium silicate and sodium metasilicate?

The anhydrous form of sodium silicate is known as sodium metasilicate with CAS number 6834-92-0.

What are the typical specifications for liquid sodium silicate?

Liquid sodium silicate has a Baumé range of 32.5–51.0 °Bé at 20 °C.

What modulus ratio is available for instant powder grade?

Instant powder grade LGS-20 has a modulus ratio of 1.9–2.1.

Technical content is compiled and updated by the SoleChem product team from public technical sources; the certificate of analysis (COA) governs product-specific specifications.