CaOt

CaOt is a chemical formula that typically refers to calcium orthosilicate. Orthosilicates are a class of silicate minerals where the silicon atom is bonded to four oxygen atoms, and this [SiO4]4- group is isolated, meaning it is not connected to other silicate tetrahedra. Calcium orthosilicate, with the formula Ca2SiO4, is a significant component of Portland cement.

In cement production, calcium orthosilicate forms during the clinkering process at high temperatures when calcium carbonate and silica react. It is one of the primary hydraulic compounds that contribute to the setting and hardening of cement when mixed with water. This hydration process involves the formation of calcium silicate hydrates (C-S-H gels) and calcium hydroxide, which create the strong, rigid structure of hardened concrete.

There are several polymorphs of calcium orthosilicate, including alpha (α) and beta (β) phases, which differ in their crystal structure and properties. The specific polymorph formed depends on the cooling rate from the clinkering temperatures. Beta-tricalcium silicate (Ca3SiO5) is another important cement mineral, often referred to as alite. While Ca2SiO4 is a distinct compound, it is often discussed in the context of cement chemistry alongside other calcium silicates.