Calciumcarbonats

Calciumcarbonats, commonly known as calcium carbonate, is a chemical compound with the formula CaCO3. It occurs naturally in several crystalline forms, most notably calcite and aragonite, which are polymorphs of CaCO3, and in vaterite as a less common form. It is one of the most abundant minerals in the Earth's crust and a major component of sedimentary rocks such as limestone, chalk, and marble.

Calcium carbonate forms in nature through both biological and inorganic processes. Biological sources include shells, corals, and other skeletal structures made of CaCO3, while inorganic precipitation also contributes to its accumulation. The mineral commonly contains impurities and substitutions, influencing its hardness and composition. In water, calcium carbonate is only sparingly soluble but dissolves more readily under acidic conditions, releasing carbon dioxide.

Industrial production and forms: The mineral is mined from limestone, chalk, and marble and processed into ground calcium carbonate (GCC) and precipitated calcium carbonate (PCC). PCC is produced under controlled conditions to tailor particle size and shape, while GCC is obtained by milling the natural rock. These materials are used in a wide range of applications due to their whiteness, brightness, and chemical stability.

Uses: Calcium carbonate is used in construction (as a source material for cement and lime), as a filler and whitening agent in paper, plastics, paints, and rubber, and as a soil conditioner and calcium supplement in agriculture. It also serves as a food additive (E170) and appears in various pharmaceutical and cosmetic products.

Safety and environmental notes: Calcium carbonate is relatively inert and of low toxicity, but inhalation of fine dust can irritate the lungs; appropriate handling and dust control are advised. Dissolution of CaCO3 contributes to karst landscapes and affects groundwater chemistry.