Diatomiitin

Diatomiitin, or diatomite, is a soft, lightweight sedimentary rock primarily composed of the fossilized silica shells of diatoms, a type of microscopic algae. Over geological time, these frustules accumulate in aquatic environments and become consolidated into diatomite. The material is usually white to off-white and varies in purity and texture depending on its source and formation conditions.

The composition of diatomite is dominated by silica (SiO2), often around 80–90%, with varying amounts of impurities such as alumina, iron oxide, and trace minerals. Its structure is highly porous and has a large surface area, which gives it notable absorptive and filtration properties. Diatomite is chemically inert, but fine silica dust can be a respiratory irritant, so handling requires appropriate safety measures in industrial use.

Diatomiitin has a wide range of applications. It is widely used as a filtration medium for liquids such as beer, wine, water, and syrups, as well as a polishing agent and carrier for catalysts and pesticides. It serves as an abrasive in polishes and as a filler in paints, plastics, and cosmetics. In agriculture and pest management, diatomite acts as a mechanical insecticide when ground to a fine powder, damaging the protective waxy layer on insect exoskeletons and causing desiccation. Food- and pharmaceutical-grade grades are produced for specific consumer and industrial uses.

Geology and production: Diatomite deposits are found worldwide, with significant deposits in North America, Europe, and Asia. Deposit quality varies, with higher-purity grades suited to filtration and food uses, and lower-purity grades used for industrial and agricultural purposes. In Finnish, diatomite is called diatomiitin. Safety: inhalation of crystalline silica dust should be avoided; use of dust control and personal protective equipment is advised in industrial settings.