Diatomites

Diatomites are sedimentary rocks composed primarily of the siliceous skeletons (frustules) of diatoms, a group of microalgae. They form from the accumulation of diatom remains in aquatic environments such as lakes, rivers, and shallow seas. Through burial and diagenesis, the silica persists as a porous, low-density rock with a high silica content, typically around 80–90% SiO2, and impurities such as clay and organic matter.

Diatomite occurs worldwide in sedimentary basins and is often found in historical lakebeds and marine sediments. Its microfossil composition gives the rock a highly porous structure, yielding high porosity and a large surface area that are exploited in various industrial and commercial applications.

Common uses include filtration of liquids and gases, such as beverages, wine, beer, drinking water, and pharmaceuticals, as well as filtration media for municipal and industrial processes. It also serves as an inert filler and carrier in paints, plastics, cosmetics, and pesticides, and as a mild abrasive in polishes and toothpaste. In agriculture and horticulture, diatomite is used as a soil conditioner and as a carrier for pesticides. It is also employed in pest control as diatomaceous earth and in some cases as an additive in cat litter. In building materials, diatomite can be used as an insulating or filler component.

Processing and safety: Many applications use food-grade or filter-grade diatomite that has been processed to remove contaminants. Fine diatomite dust can irritate the respiratory tract, and long-term exposure to crystalline silica poses health risks; therefore, proper dust control and protective equipment are recommended in industrial settings.