alkalisilicates

Alkali silicates are a group of inorganic compounds formed by the reaction of an alkali metal oxide or hydroxide with silica. The most common alkali metals involved are sodium (Na) and potassium (K). These compounds are typically water-soluble and form alkaline solutions.

The general formula for alkali silicates can be represented as M2O · nSiO2, where M is an alkali metal cation (like Na+ or K+) and n represents the molar ratio of silica to alkali oxide. This ratio can vary widely, influencing the properties of the resulting silicate. For example, sodium silicate with a high silica content is often a glassy solid, while those with a lower silica content can be viscous liquids.

Alkali silicates are produced industrially by fusing alkali metal carbonates with silica sand at high temperatures in a furnace. Alternatively, they can be produced in aqueous solution via hydrothermal processes.

These compounds have a diverse range of applications due to their adhesive, binding, detergent, and flame-retardant properties. They are used in detergents as builders and corrosion inhibitors, in the production of adhesives for paper and cardboard, as binders in welding rods, and as components in cements and refractories. In the oil and gas industry, they are employed in drilling fluids. Their ability to bind particles and form protective layers also leads to uses in water treatment and as coatings.