silikadioxid

Silikadioxid, also known as silicon dioxide or silica, is a chemical compound with the formula SiO2. It is one of the most common compounds in nature and forms a major part of the Earth's crust. Silica occurs in crystalline forms such as quartz, cristobalite, and tridymite, as well as in amorphous forms found in sand, opal, and glass. It consists of a three-dimensional covalent network, which gives it high hardness and a high melting point.

Crystalline silica includes alpha-quartz, which is stable at room temperature, and beta-quartz at higher temperatures. Amorphous silica encompasses glassy silica and silica gel. The material is practically insoluble in water and resistant to most acids, though hydrofluoric acid can dissolve silica.

Industrial production and forms: Silica is produced from high-purity quartz through high-temperature processing to create fused silica or glassy silica. It can also be obtained by precipitation from silicate solutions or by flame hydrolysis to form fumed silica. These forms meet various industrial needs and purity requirements.

Uses: Silica is a key raw material for glass, cement, ceramics, and refractory materials. It serves as an insulating and protective layer in electronics, is used as a desiccant in the form of silica gel, and acts as a food additive (anti-caking agent E551).

Safety and environment: Inhalation of crystalline silica dust is hazardous and can cause silicosis and other lung diseases; proper ventilation and protective equipment are essential in workplaces handling silica. Silica is abundant in the environment and mined worldwide for industrial use.