calciumsilfaat

Calciumsilfaat, or calcium silicate, is a family of inorganic compounds composed of calcium, silicon, and oxygen. The simplest member is wollastonite (CaSiO3), a naturally occurring mineral. In cement chemistry, the term also designates calcium silicate phases such as dicalcium silicate (Ca2SiO4) and tricalcium silicate (Ca3SiO5), which are major clinker components that hydrate to form strength-giving calcium silicate hydrates (C-S-H).

Natural sources and production: Wollastonite occurs in certain metamorphic rocks and is mined for industrial use. Industrial calcium silicates are produced by high-temperature reactions of lime or calcium carbonate with silica, processes central to Portland cement manufacture and to calcium silicate boards and refractories.

Properties: Calcium silicates exhibit high thermal stability and a high melting point. They are relatively insoluble in water, but hydration with water yields calcium silicate hydrates that contribute to strength in cementitious systems. They can be formulated into dense blocks or lightweight insulating boards and are widely used for fire resistance and insulation.

Applications: In construction, C2S and C3S constitute the cement matrix, while calcium silicate boards and blocks provide noncombustible, fire-rated building components. Calcium silicate insulation boards are used for thermal insulation and fireproofing; refractories rely on calcium silicate compositions for high-temperature service.

Safety: Handling of calcium silicate powders or crystalline silica dust requires appropriate dust control and respiratory protection, as inhalation can pose health risks.