Binders
Silicates are used to bind particles together in applications such as briquetting, pelletizing, agglomeration, and coatings. The particles can range from very fine powders, such as flyash, to much larger gravel-sized aggregates.
As in paper adhesives, the dehydration of a liquid silicate results in a strong bond, hardening as it dries. Setting agents that react with the liquid silicates may also be used to obtain binders that set faster and are water-resistant. Applied heat will also increase water resistance by driving off excess moisture.
Powdered silicates are also used, although they must be dissolved before they can provide binding power. The powdered silicate can be pre-mixed with a dry setting agent and hydrated to start the reaction. This feature allows the use of a fast-acting setting agent such as calcium chloride without the problems associated with a premature set.
How It Works
Silicate is a water-based polymer of silica. As the silicate binder is dehydrated, the silicate thickens and forms a sticky glue to coat and bind surfaces and particles in briquetting, pelletizing, agglomeration, and coating applications. Liquid silicates may also be mixed with setting agents for fast-setting and water-resistant bonding. Powdered silicates are useful for formulating and for product transfer prior to dissolving to prepare the liquid silicate binder.
Applications
Agglomeration
Briquetting
Pelletizing
Fibrous Acoustical Materials
Abrasive Grit
Cathode Ray Tube Phosphors
Foundry Molds and Cores
Refractory Cements
Roofing Shingle Granules
Welding Rod Coatings
Detergents