Sodium silicate
Description
Sodium silicate (CAS 1344-09-8), also known as water glass, is an inorganic alkali salt used across heavy industry as a binder, sealant, and reactive flocculant. It functions by forming a rigid silica gel network upon drying or acidification.
This mechanism enables bonding, surface hardening, and chemical stabilization across a broad range of substrates. In pulp and paper manufacturing, it stabilizes hydrogen peroxide during bleaching, preventing decomposition and improving whiteness yields.
Adhesive and board manufacturers use it as a structural binder in corrugated packaging. Its fast-set properties and compatibility with cellulose substrates reduce reliance on synthetic resins in high-volume production environments.
Water treatment facilities dose it as a corrosion inhibitor and coagulation aid. It conditions pipe surfaces and supports floc formation in clarification processes to ensure efficient removal of suspended solids from the water stream.
In construction, it penetrates concrete and masonry to densify surfaces. This improves abrasion resistance and reduces permeability without the need for topcoat systems, providing a durable and cost-effective solution for industrial flooring.
Sodium silicate is supplied as a liquid solution, most commonly in SiO2:Na2O ratios ranging from 2.0 to 3.5. Solids content typically falls between 30–50% depending on the specific viscosity requirements of the application.
Solid forms, including powder, granules, and anhydrous glass cullet, are available for applications requiring dry blending. These formats are ideal for extended shelf life and specialized manufacturing processes that avoid liquid handling.
Technical and industrial grades are the standard market offering for most chemical processes. Food-grade and water treatment-certified grades are also available for regulated end uses requiring specific purity and safety compliance.
Physical Properties
| Melting Point | 1410 °C(lit.) |
| Boiling Point | 2355 °C(lit.) |
| Density | 1.4 g/cm³ |
| Appearance | colourless liquid as usually supplied (solution) |
| Color | Colorless |
| Odor | Odorless |
| Form | powder |
| Water Solubility | very slightly soluble cold H2O [MER06] |
| Refractive Index | 1.520 |
| pH | 13.5 (20°C in H2O) |
Safety & Handling (Learn More)
Trade & Regulatory
| HS Code | 28391910 |
| UN Number | 2922 |
| ADR Class | 8 |
| Packing Group | II |
| Storage Class | 10 - Combustible liquids |
| WGK (Germany) | 2 |
Documentation
Other Names
Silicic acid sodium salt|Sodium orthosilicate|Sodium siliconate|Sodium sesquisilicate|Sodium silicate glass|Sodium water glass|Britesil|Carsil
Related Products
Need a chemical? Get a quote within 24 hours.