Potassium silicate, also known as potassium water‑glass with the CAS number 1312‑76‑1 and the general chemical formula K₂O·nSiO₂·xH₂O, is a non‑toxic, low‑VOC and eco‑friendly inorganic compound. Its core performance depends on the modulus, the molar ratio of silica to potassium oxide, and the modulus of commercial‑grade products varies from 1.5 to above 4.5. Low‑modulus potassium silicate carries strong alkalinity and dries rapidly, whereas high‑modulus versions deliver outstanding bonding strength and water‑resistance. It can be obtained in forms of transparent viscous liquid, glass‑like solid chunks, flakes or spray‑dried powder. Industrial liquid potassium silicate is colourless, light‑green or pale‑yellow. Its alkaline solution dissolves well in water yet cannot dissolve in ethyl alcohol, and gelatinous silicic acid will precipitate after acid reaction. Superior to sodium silicate, its cured coating hardly generates white efflorescence under humid conditions and boasts favourable ultraviolet‑resistant property. Manufacturers fuse quartz sand together with potassium carbonate under high‑temperature furnaces, dissolve the melted glass in hot‑water for liquid goods and adopt spray‑drying to produce powdered potassium silicate.

Potassium silicate covers broad‑ranging uses across industry, daily‑life sectors and agriculture. It works as the inorganic binder for anti‑rust primers of metal constructions, bridges and offshore installations, and constitutes essential ingredients of fire‑retardant coatings for steelwork and timber. It is also adopted for welding‑rod coatings, electronic part adhesives, refractory binders and foundry sand binders. Within the detergent industry, it adjusts alkalinity and prevents metal corrosion during cleaning procedures. As soluble silicon‑potassium fertiliser, it strengthens plant cell walls and helps crops defend against pests, fungal disease, drought and heat stress. Other applications contain paper surface sizing, fabric flame‑resistant finishing, mould‑proof wood treatment, silica‑gel synthesis, concrete curing additives and water‑treatment corrosion inhibitors. Since its aqueous solution features strong alkalinity, operators ought to wear protective gear and prevent direct contact with skin, eyes and mucosal tissue.