Calcium carbonate is used to raise the levels of calcium in people who don't get enough calcium in their diets. It is also used for adhesives and as part of construction materials such as concrete, asphalt and plaster. In addition, it is used in glass- and paper-making and in the production of rubber and plastics.
Calcium carbonate is taken orally in capsule, tablet or liquid form. Most patients take it three or four times a day with or right after meals.
Portland cement is a basic ingredient in concrete, and it consists of calcium carbonate, alumina, silica, iron oxide and magnesia. It also contains sulphur trioxide and soda or potash. The calcium carbonate that goes into Portland cement comes from limestone, chalk or marl.
In glass-making, calcium carbonate is used as a stabilizer along with fluxes such as potassium carbonate and formers such as silicon dioxide. It strengthens the glass and allows it to resist degradation from water and humidity. The calcium carbonate also comes in the form of limestone or chalk.
Precipitated or ground calcium carbonate is used as a filling and coating for paper. Some paper manufacturers prefer precipitated calcium carbonate, because they can control its physical and chemical properties. Ground calcium carbonate is mined, and its properties are more random.