Overview: calcium carbonate is a solid inorganic salt with white color that contains calcium carbon and oxygen, and is one of the most common compounds on Earth, making up about 7 percent of Earth’s crust. It has other names such as: Limestone; chalk; aragonite; calcite. A variety of animal products are also made primarily of calcium carbonate, notably coral, sea shells, egg shells, and pearls.
How it is made: Calcium carbonate can be extracted from nature by mining natural sources, such as chalk, limestone, and marble quarries. It can also be prepared in the laboratory by reacting calcium chloride (CaCl2) with sodium carbonate (Na2CO3).
Applications: Calcium carbonate is nowadays being used in large amounts for a variety of industrial uses, including:
- Medical use: calcium carbonate is well known as an antacid, a substance that neutralizes excess stomach acid (hydrochloric acid; HCl) and relieves the symptoms of acid indigestion, heartburn, upset stomach, and sour stomach. It is also used for a variety of industrial uses, including:
- Agriculture: is used as a cheap method for neutralizing acidic soil, making it suitable for planting and supply calcium needed by growing plants
- Paper-making industry: used to make products with a shiny white color, glossy finish, and firm texture for printing and dyeing;
- Plastic manufacturing: as a filler to reduce the cost of the production
- Paint and coating industry: because of its ability to provide weather resistance, protect the coating against corrosion, reduce drying time, and maintain the proper acidity of the coating material, calcium carbonate is as an extender and as an agent to either reduce or enhance gloss.
- Construction industry: either as a building material, or limestone aggregate for road building, in concrete structures, such as paving-stones, tubes, and sewage tanks, in ready-mixed concrete, and in prefabricated elements…
- Oil industry: calcium carbonate is added to drilling fluids as a formation-bridging and filter cake-sealing agent,
- Food industry: as a food additive it is designated E170 and it has an INS number of 170. Used as an acidity regulator, anticaking agent, stabilizer or color and it is approved for usage in the EU, USA and Australia and New Zealand. It is also used as a raw material in the refining of sugar from sugar beet.