Adhesives & Binders

Sodium silicate is mainly used in cartons, corrugated paper, and paper products adhesives. It has extremely low cost, fast drying speed, sufficient initial adhesion, and is suitable for high-speed assembly lines. In construction adhesion, including artificial quartz stone, terrazzo adhesion, insulation board bonding, wall repair, thin tile bonding, and cement curing accessories. Sodium silicate can also be used in wood, plywood, and bamboo products inorganic adhesives, combined with starch or bentonite for use. Sodium silicate can also be used in metal, glass, and ceramic bonding and sealing.
The advantages of sodium silicate adhesives include:

The aqueous solution is easy to dilute and clean, and the production equipment is simple to clean.

1.Raw materials are cheap and readily available, with production costs much lower than epoxy resins, polyurethanes, and white latexes.

2.Inorganic and environmentally friendly, without formaldehyde, benzene, etc. organic volatile substances, and fire-resistant A grade.

3.Broad range of bonding substrates: paper, wood, cement, metal, glass, and refractory materials.

4.After curing, it is resistant to high temperatures, oil, and organic solvents, with stable dimensions and no shrinkage.

Ceramics

Sodium silicate plays several key roles in ceramics, including acting as a desiccant (water reducer), binder, and reinforcing agent. These functions are crucial throughout the various stages of ceramic production.

During the preparation of ceramic slurry, sodium silicate is one of the most commonly used desiccants, reducing the viscosity of the slurry. Sodium silicate can improve the fluidity of the ceramic slurry, reduce the frictional resistance between particles, and lower the moisture content: while maintaining fluidity, it can significantly reduce the moisture content of the slurry, thereby reducing energy consumption in the spray drying process and improving the suspension property: it enhances the stability of the slurry and prevents particle settling.

During the ceramic molding and sintering processes, sodium silicate can enhance the bonding force of the ceramic body, increase its flexural and compressive strength, and a small amount of sodium silicate can promote the sintering of the ceramic body during the firing process, lower the firing temperature, and shorten the firing time.

Concrete Densifiers

Sodium silicate is the earliest and most fundamental core component used in concrete sealing curing agents, and it is the core raw material of the first generation of curing agents.

The fundamental role of sodium silicate in concrete sealing curing agents is to fill and compact the concrete structure through chemical reactions. The reaction mechanism is: sodium silicate + calcium hydroxide → hydrated silicate calcium (C-S-H).

Sodium silicate penetrates into the interior of the concrete, forming C-S-H gel to fill the pores, significantly improving the surface hardness, compressive strength and wear resistance of the floor. The Mohs hardness of the concrete surface can be significantly increased from approximately 3.5. After reacting with calcium hydroxide, the loose surface layer is solidified into a dense whole, effectively solving the problems of dusting and sanding on the floor. The generated C-S-H gel blocks the capillary channels of the concrete, reducing the permeability of the floor to water, oil and other liquids, and providing certain anti-seepage effect.

As a first-generation product, although sodium-based curing agents have limitations such as efflorescence and poor water resistance in performance, they still have wide applications in ordinary floor scenarios where performance requirements are not high due to their low cost advantage.

Detergents & Cleaning

As an important inorganic auxiliary agent for synthetic detergents, liquid sodium silicate and powdered instant sodium silicate are widely used in the production of laundry detergent, washing powder, industrial degreasing agents, and bleach stabilizers. Sodium silicate has excellent alkaline buffering performance, which can maintain the stable pH value of detergent solutions, avoid equipment corrosion caused by excessive acidity and alkalinity, and protect metal washing equipment.

In detergent formulations, sodium silicate can chelate metal ions in water, soften hard water, reduce the impact of calcium and magnesium ions on the decontamination effect of detergents, and significantly improve the decontamination, emulsification and dispersion capabilities of detergents. At the same time, water glass can form a protective film on the surface of fabrics and metal utensils to prevent secondary pollution and wear during the washing process. In industrial cleaning agents, sodium silicate enhances the degreasing and rust removal effect, and is suitable for surface cleaning of mechanical equipment, metal parts, and industrial pipelines.

Foundry & Casting

The foundry industry is a key application field of high-modulus industrial sodium silicate. Solid sodium silicate and high-viscosity liquid sodium silicate are used as high-efficiency binders for casting sand molds and core making, replacing traditional organic binders. Sodium silicate casting technology has the advantages of low cost, high molding speed, good casting surface quality, and no harmful gas volatilization during use, which is in line with green casting production standards.

In the foundry process, sodium silicate is mixed with quartz sand and curing agent, and after molding and curing, a high-strength sand mold is formed. The water glass sand mold has high hardness, strong dimensional stability, and good high-temperature resistance, which can effectively avoid casting deformation, sand sticking and porosity defects. After casting cooling, the sand mold has good collapsibility, which is convenient for subsequent cleaning and processing, greatly improving casting production efficiency and product qualification rate.

Mining

Sodium silicate is used as an inhibitor and dispersant in the mineral flotation field to enhance the separation efficiency of the target minerals from the gangue minerals.

The essence lies in: through hydrolysis, silicate ions are generated and adsorbed on the surface of the gangue minerals, increasing their hydrophilicity and surface negative charge, thereby preventing the gangue from floating with the bubbles; at the same time, it disperses fine mineral slimes and improves the flotation environment.

As one of the most cost-effective flotation agents, sodium silicate is widely used in the flotation separation of various ores such as tungsten ore, phosphate ore, titanium-iron ore, and copper ore.

Paper Making

Sodium silicate, with its core characteristics of alkaline buffering, metal ion chelation, colloid dispersion, and inorganic bonding, runs through six processes in papermaking: pulping and cooking, waste paper deinking, hydrogen peroxide bleaching, wet end papermaking, surface sizing, and special functional paper. It is a low-cost, multi-functional inorganic additive for papermaking. The industry’s preferred standard modulus for liquid sodium silicate ranges from 2.2 to 2.8.

During deinking, sodium silicate provides the strong alkaline environment needed for deinking, saponifies ink oils, softens ink coatings, and allows ink to be stripped from the fibers; it has buffering capacity, resisting interference from acidic impurities, and has a small pH fluctuation.

At the same time, sodium silicate complexes iron, manganese, and copper heavy metals in the pulp, avoiding ineffective decomposition of hydrogen peroxide by metal catalysis, and simultaneously protecting the bleaching system. The sodium silicate colloid carries a negative charge, encapsulates ink particles to form a stable suspension, preventing ink from re-adhering to the fibers; during flotation, ink is easier to separate with foam, resulting in a 15% increase in deinking rate and an 8-10 degree increase in the whiteness of recycled paper.

During bleaching, sodium silicate can provide a stable alkaline environment, maintain the effective bleaching activity of hydrogen peroxide, reduce fiber oxidation and degradation, and result in higher pulp whiteness and slower yellowing.

Sodium silicate has extremely low cost, much lower than organic chelating agents, organic sizing agents, and special deinking additives. It can cover multiple processes such as deinking, bleaching, sizing, and enhancement, while improving paper’s flame retardancy, high-temperature resistance, and solvent resistance. It is widely used in papermaking processes.

Refractory Materials

Sodium silicate (water glass) is a low-cost, versatile inorganic binder widely used in medium-temperature refractory materials. It effectively improves the green strength, structural stability and acid corrosion resistance of refractory products, serving as a key auxiliary for industrial furnace refractory linings.

Its performance is mainly governed by the silica-to-sodium oxide modulus ratio. High-modulus sodium silicate (3.2–3.5) forms dense, high-strength bonding structures, while low-modulus grades deliver better fluidity for on-site construction. The hardening process involves physical dehydration at low temperatures and chemical curing via accelerators or atmospheric carbon dioxide. The generated silica gel sinters at high temperatures, forming a continuous ceramic bonding phase that tightly integrates refractory aggregates.

As a non-hydraulic binder, sodium silicate boosts the molding efficiency and structural integrity of refractories. Its compact bonding structure reduces material porosity, enhancing wear resistance and medium-temperature thermal stability. Notably, it exhibits excellent acid resistance but poor tolerance to strong alkali and alkaline slag erosion.

It is extensively applied in refractory bricks, monolithic castables, gunning mixes and lightweight thermal insulation refractories for furnaces operating below 1350°C. Featuring fast room-temperature curing, low cost and great process adaptability, it suits both factory production and on-site rapid construction.

Nevertheless, it has obvious limitations. The sodium-containing silicate phase softens at ultra-high temperatures, causing strength loss above 1350°C. Free sodium ion migration and high thermal expansion may lead to spalling and thermal cracking. Proper modulus selection, sodium fluorosilicate addition and standardized high-temperature drying can optimize its performance. Overall, sodium silicate remains a dominant cost-effective binder for medium-temperature refractory engineering in multiple industrial fields.

Textile Processing

Sodium silicate is used in dyeing as a fixative for reactive dyes, a stabilizer for hydrogen peroxide, a treatment agent for dyeing wastewater, and a functional finishing aid. The core application lies in the alkaline characteristics of sodium silicate, the chemical activity of silicate ions, and its physical and chemical properties such as film formation and adsorption.

In the dyeing process, sodium silicate serves as a fixative for reactive dyes. This application is mainly based on the cold rolling pile dyeing process. When reactive dyes are dyed, an alkaline environment is required to ionize the hydroxyl (-OH) or amino (-NH₂) ions in cellulose fibers (cotton, linen, viscose, etc.) or protein fibers (silk, wool, etc.), thereby forming a covalent bond with the active groups in the dye molecule. The aqueous solution of sodium silicate is strongly alkaline and can provide an alkaline environment, buffer the pH value, and promote the formation of covalent bonds between the dye and the fiber.

In the fabric bleaching process, sodium silicate functions as a stabilizer for hydrogen peroxide, which can control the decomposition rate of hydrogen peroxide and improve the bleaching effect.
At the same time, sodium silicate is also used as a dyeing wastewater treatment agent for the decolorization and purification treatment of dyeing wastewater.

Waterproofing

Sodium silicate waterproofing and leak-stopping projects are widely used and it is one of the core materials in the grouting leak-stopping technology. The principle of its leak-stopping is as follows: After the sodium silicate solution is injected into the leakage area, it reacts chemically with a specific curing agent (such as cement slurry, calcium chloride solution, etc.) to rapidly form insoluble silica-gel or C-S-H gel, filling the cracks and blocking the water leakage channels, thereby achieving the purpose of stopping water.

Double liquid grouting is a leak-stopping process where the sodium silicate solution and the curing agent solution are separately transported by a double liquid grouting pump, mixed in the hole or crack, and then rapidly react and solidify. This is the most commonly used and most reliable method in waterproofing and leak-stopping. Cement-water glass double liquid slurry is the most widely used leak-stopping material in engineering practice, which combines the strength of cement slurry and the rapid setting characteristics of sodium silicate. This reaction has the characteristics of rapid setting, high strength, and micro-expansion.

Sodium silicate is one of the core active components of cement-based penetrating crystalline waterproofing agent (CCCW). After sodium silicate dissolves in water, it generates silicate ions, which react with the free calcium ions in cement to form insoluble calcium silicate crystals. The crystals grow and aggregate in the capillary pores, forming a dense waterproof layer.

Sodium silicate products can be applied to the waterproof treatment of brick masonry surfaces, and the paper surface sizing agent improves the waterproof performance of the paper. Sodium silicate can also be used for the waterproof protection and reinforcement of site soil.

Strong adhesion

Sodium silicate forms a rigid silica gel structure after dehydration and chemical reaction. It provides strong and stable adhesion on paper wood, metal, glass and refractory materials. The adhesive force is durable and not easyto peel off under normal conditions.

Excellent binding performance

With good colloidal bonding and filling properties, sodium silicate can tightly combine fibers, powder materials and granular fillers. It effectively improves the overall compactness, surface strength and structural stability of finished products, widely used in paper sizing, adhesive formulation and casting industry.

Fire resistance

Sodium silicate is an inorganic non-combustible material. After curing, it forms a high-temperature resistant silicon-oxygen network film. It does not burn, does not release smoke or toxic gas, and maintains stable performance under high temperature. It is an ideal raw material for fireproof paper, fireproof board and refractory binder.

Corrosion resistance

The cured sodium silicate layer is dense and inert. It can resist oxidation, oil erosion and most chemical corrosion. It effectively protects the base material from aging and damage, improving the service life of products.

Environmentally friendly

As a pure inorganic water-soluble material, sodium silicate contains no formaldehyde, no VOC and no harmful substances. It is non-toxic, odorless, biodegradable and meets international environmental protection standards for paper making, adhesives and industrial applications.

What is sodium silicate used for?

Sodium silicate (water glass) is a multi-functional industrial chemical with extremely wide application fields. Industrial sodium silicate is mainly used in construction waterproofing and concrete modification, detergent industry auxiliary agent production, foundry sand mold bonding, refractory material manufacturing, chemical adhesive production, water treatment, textile sizing, and ceramic processing.

Different types of sodium silicate correspond to different scenarios:

liquid sodium silicate is suitable for ready-to-use industrial production and construction on-site operation;

solid sodium silicate is suitable for long-term storage and large-scale deployment;

instant sodium silicate is suitable for rapid preparation and small-batch production.

As a core industrial auxiliary material, sodium silicate covers almost all basic industrial processing fields.

Is sodium silicate waterproof?

Yes, sodium silicate has excellent waterproof and impermeable performance, which is one of its core advantages.

After the sodium silicate solution reacts with carbon dioxide and cement hydration products in the air, it will form a dense and insoluble silica gel layer on the surface of the matrix.

This layer can effectively block water molecules penetration, significantly improving the waterproof and anti-seepage capacity of concrete, walls, and building foundations.

Waterproof-grade industrial sodium silicate provided by professional sodium silicate supplier is widely used in basement waterproofing, tunnel anti-seepage, roof waterproof coating and other projects, with stable and long-lasting waterproof effect.

What is the difference between sodium silicate and potassium silicate?

Both sodium silicate and potassium silicate belong to alkali silicate compounds, but they have obvious differences in raw materials, performance and application.

First, the raw material of sodium silicate is sodium oxide and silica, with low production cost and high cost performance; potassium silicate takes potassium oxide as the raw material, with higher cost.

Second,industrial sodium silicate has stronger bonding performance and better waterproof effect, suitable for construction, foundry, detergent and large-scale industrial scenarios; potassium silicate has better weather resistance and is mostly used for high-grade coatings and precision chemical industry.

Third, sodium silicate products includingliquid sodium silicate and solid sodium silicate have more complete specifications and wider market applications, making them the mainstream choice of industrial silicate products.

Is water glass soluble in water?

Yes, water glass (sodium silicate) is easily soluble in water, which is its basic physical property.

Liquid sodium silicate is itself an aqueous solution with good water miscibility and can be mixed with water in any proportion.

Solid sodium silicate can be completely dissolved in hot water to form a uniform sodium silicate solution; instant sodium silicate can be quickly dissolved in normal temperature water without heating, with no residue and high dissolution efficiency.

Only high-modulus sodium silicate has slightly reduced solubility, but it can still be completely dissolved in hot water, fully meeting industrial deployment and use needs.

What modulus of sodium silicate is used in construction?

The construction industry mainly adopts sodium silicate with a modulus of 2.2–2.8, which is the most balanced modulus grade for construction scenarios.

Low-modulus sodium silicate (1.6–2.2) has fast curing speed and is mostly used for concrete quick-setting and emergency repair;

medium-modulus sodium silicate (2.2–2.8) has moderate curing speed, excellent waterproof and bonding performance, and is suitable for building waterproof mortar, foundation reinforcement and anti-corrosion engineering;

high-modulus sodium silicate above 2.8 is mainly used for refractory materials, not conventional construction waterproofing. Professionalsodium silicate manufacturer can provide construction-specific modulus sodium silicate products according to engineering needs.

Can sodium silicate be used in detergent formulations?

Absolutely yes. Sodium silicate is an essential core auxiliary agent for detergent formulations.

Low-modulus liquid sodium silicate and instant sodium silicate are widely added in washing powder, laundry detergent, industrial degreasing agents and bleach stabilizers.

It can buffer solution alkalinity, soften hard water, chelate metal ions, improve detergent decontamination and emulsification ability, and protect fabrics and metal equipment from corrosion.

Industrial sodium silicate for detergents has low impurity content and stable performance, which can effectively improve the comprehensive quality of detergent products and reduce production costs, and is favored by daily chemical enterprises.