KalziumkarbonatAblagerungen

Calcium carbonate (Kalziumkarbonat in German) is an inorganic compound with the chemical formula CaCO3. It occurs in several mineral forms, most notably calcite and aragonite, and less commonly vaterite. In nature it is a major constituent of sedimentary rocks such as limestone and chalk, and marble is formed when limestone is subjected to metamorphism. Calcium carbonate also appears in the shells, skeletons, and pearls of many marine organisms, and in cave formations such as stalactites and stalagmites.

Natural formation and occurrence: It precipitates from seawater and freshwater, often biologically produced by organisms to build shells and skeletons. It can also form through geological precipitation during sedimentation and diagenesis.

Properties and reactions: It is a white, relatively soft solid at ambient conditions. It has low solubility in water but dissolves in acids, releasing carbon dioxide: CaCO3 + 2 H+ → Ca2+ + CO2 + H2O. On heating, it decomposes to calcium oxide and carbon dioxide at temperatures around 800–900°C.

Uses: It is a major raw material in the production of cement and lime for construction; used as a filler in paper, plastics, and paints; employed as a dietary supplement and antacid; and used to neutralize acidity in soils and in water treatment.

Occurrence and production: It is one of the most abundant natural minerals, mined from limestone and chalk deposits. Industrial production often involves quarrying and processing to produce ground calcium carbonate and various particle sizes.