calciumsilicate

Calcium silicate refers to compounds composed of calcium, silicon, and oxygen with the approximate formula CaSiO3, including both natural minerals and synthetic materials. The term is often used for the mineral wollastonite, CaSiO3, as well as for calcium silicate-based products used in construction and industry.

Natural wollastonite occurs in various geological environments, particularly as a metamorphic silicate mineral in skarns and contact metamorphic rocks. It appears as a glassy to fibrous solid and is mined as a source of calcium and silica for ceramics, plastics, and fillers. Industrial calcium silicate materials are prepared by high-temperature reactions of calcium oxides with silica, or by hydrating cement clinker enriched in calcium silicate phases.

In cement chemistry, the calcium silicate system includes the phases dicalcium silicate (C2S) and tricalcium silicate (C3S). Hydration of these phases yields calcium silicate hydrates (C-S-H) and calcium hydroxide, which contribute to the set and strength of cement and concrete.

Common uses include calcium silicate boards for fire-rated wall panels and insulation, refractories and kiln linings, and various filler or insulating products. Natural wollastonite is used as a mineral commodity in ceramics and as a filler in plastics and paints.

Safety and handling considerations focus on dust: fine calcium silicate powder can irritate the lungs and eyes, so standard industrial hygiene practices are advised. Under normal conditions it is chemically stable, though it can react with strong acids to form calcium salts and silica.