What is sodium silicate
Sodium silicate, also known as water glass, is a water-soluble silicate composed of different proportions of silicon dioxide (SiO₂) and sodium oxide (Na₂O).
The Chemistry and Basic Properties of Sodium Silicate
Chemical formula: Its general chemical formula is usually expressed as Na₂O·nSiO₂, where “n” is called the modulus, which is the molar ratio of SiO₂ to Na₂O. The size of the modulus directly affects the properties, applications, and price of sodium silicate. The common modulus of sodium silicate is between 2.0 and 3.5, and our factory can adjust it to a modulus of 1.0 to 3.5.
Physical forms:
Sodium silicate has two physical forms, one is solid and the other is liquid.
Solid sodium silicate is divided into two types. One is a colorless or slightly colored glassy solid, and the other is a white powder that can dissolve rapidly in water.
The most common form of liquid sodium silicate is a colorless, bluish-gray or slightly red viscous liquid. Our factory can produce high-definition, transparent and colorless liquid sodium silicate according to the specific needs of customers.
Chemical properties:
Alkalinity: Its aqueous solution is strongly alkaline.
Adhesiveness: It has excellent adhesive properties.
Heat resistance & Fire resistance: At high temperatures, it loses water and sintering occurs, forming a glass-like insulating layer, thereby playing a fire-resistant role.
Reaction with acids: It decomposes when encountering acids (even carbon dioxide in the air), generating silicic acid gel.
The main uses of sodium silicate
Sodium silicate is a very important basic chemical raw material with extremely wide applications.
1. Industrial additives
1.1 Detergent industry
It is an efficient additive for laundry powder, soap, and synthetic detergents, capable of softening water, maintaining solution alkalinity, enhancing cleaning power, and preventing dirt redeposition.
1.2 Paper industry
It played an important role in the deinking process of waste paper, providing an alkaline environment, dispersing ink particles, and helping to remove ink.
1.3 Textile auxiliaries
In the textile industry, sodium silicate is used as a bleaching and dyeing auxiliary for fabrics.
1.4 Flotation additives
In the flotation process of mines, especially in fluorite mines, sodium silicate can be used as a flotation inhibitor.
1.5 Water treatment additives
In the wastewater treatment industry, sodium silicate is used as a coagulant aid and corrosion inhibitor.
1.6 Titanium dioxide production additives
In the surface treatment stage of titanium dioxide production, sodium silicate is used as a precipitating agent and coating agent to improve the quality of titanium dioxide.
2. Adhesives
2.1 Corrugated Board and Cartons
Sodium silicate is the main adhesive used in the production of corrugated board and cartons. It is low-cost and has strong adhesive properties.
2.2 Foundry
It is used as an adhesive for foundry molding sand, helping the sand mold to harden quickly and maintain sufficient strength to withstand the impact of high-temperature molten metal, especially suitable for the carbon dioxide hardening foundry process.
2.3 Refractory Materials
It is used as an adhesive for the production of refractory bricks, refractory mortars and other refractory materials.
2.4 Silicate Coatings
It is a key component in the production of silicate mineral coatings, especially inorganic coatings.
3. Construction Industry
3.1 Main Raw Materials for Double-Liquid Grouting
Sodium silicate is suitable for use in tunnel, cave, culvert, foundation pit and other projects that require double-liquid grouting for leakage control, as well as for treating seepage and leakage in basements, water tanks and underground structures.
3.2 Fire Retardant
Sodium silicate can be used to impregnate wood and fabrics or applied to building surfaces. When exposed to fire, it forms an insulating layer that protects the substrate.
3.3 Floor Hardener
Sodium silicate can be used as the main raw material for concrete sealers and hardeners, suitable for all cement-based floors.
4. Chemical Industry
4.1 Main Raw Materials for Sodium Metasilicate
Sodium silicate is the primary raw material for the production of pentahydrate sodium metasilicate and nonahydrate sodium metasilicate.
4.2 Silica Gel Industry
Sodium silicate is the main raw material for the production of silica gel. When sodium silicate reacts with sulfuric acid (or hydrochloric acid), it generates hydrated silicic acid. After aging, washing, and drying, the common desiccant silica gel is obtained.
4.3 Silica White
Sodium silicate is the main raw material for the production of silica white. By adding acid to disrupt the stable silicate ion structure, silicic acid is formed. Silicic acid then polymerizes into hydrated silica. After precipitation, filtration, washing, drying, and grinding, the final silica white product is obtained.

Safety Precautions for Sodium Silicate
Irritation: Sodium silicate solution is alkaline and can irritate and corrode the skin and eyes. Protective equipment (such as gloves and goggles) should be worn during handling.
Solid form: Solid sodium silicate is usually in the form of granules or blocks and should be handled with care to avoid generating dust inhalation.