1657. Calcium Carbonate

Nomenclature

CAS number: 471-34-1
Carbonic acid calcium salt (1:1); Cacit (Norwich); Calcichew (Shire); Calcidia (Roche); Caltrate (Wyeth); Citrical (Shire); Fixical (Pharmascience); Maalox Quick Dissolve (Novartis); Maalox Regular Strength (Novartis); Os-Cal (GSK); Tums Smooth Dissolve (GSK).
CCaO3; mol wt 100.09.
C 12.00%, Ca 40.04%, O 47.96%.
CaCO3.

Description and references

Exists in nature as the minerals aragonite, calcite and vaterite. Solubility and scale formation study: J.-Y. Gal et al., Talanta 43, 1497 (1996). Clinical evaluation in protease inhibitor-induced diarrhea in HIV: M. J. Turner et al., HIV Clin. Trials 5, 19 (2004). Review of commercial applications in paints, coatings and adhesives: R. D. Athey, Eur. Coatings J. 5, 256-263 (1994).

Properties

Odorless, tasteless powder or crystals. Two crystal forms are of commercial importance: Aragonite, orthorhombic, mp 825° (dec), d 2.83, formed at temps above 30°; Calcite, hexagonal-rhombohedral, mp 1339° (102.5 atm), d25.2 2.711, formed at temps below 30°. At about 825° is dec into CaO and CO2. Practically insol in water. Sol in dil acids.

Derivative

Precipitated calcium carbonate.

Nomenclature

Precipitated chalk; Aeromatt; Albacar; Purecal (Wyandotte).

Properties

Commercial CaCO3 produced by chemical means. It is 98-99% pure. The byproduct process, the carbonation process, and the calcium chloride process of manuf from limestone are outlined in Kirk-Othmer Encyclopedia of Chemical Technology vol. 4 (Interscience, New York, 2nd ed., 1964) pp 7-11. Review: Woerner in Pigment Handbook vol. 1, T. C. Patton, Ed. (John Wiley, New York, 1973) pp 119-128.

Derivative

Prepared calcium carbonate.

Nomenclature

Drop chalk; prepared chalk; whiting; English white; Paris white.

Properties

Native CaCO3 purified by elutriation.

Caution

Potential symptoms of overexposure are irritation of eyes, skin, respiratory system; cough. See NIOSH Pocket Guide to Chemical Hazards (DHHS/NIOSH 97-140, 1997) p 46.

Use

Manuf of paint, rubber, plastics, paper, dentifrices, ceramics, putty, polishes, insecticides, inks, shoe dressings; as a filler in production of adhesives, matches, pencils; crayons, linoleum, insulating compds, welding rods. In foods, cosmetics, pharmaceuticals, antibiotics; removing acidity of wines. In analytical chemistry for detecting and determining halogens in organic combinations; with NH4Cl for decomposing silicates; preparing CaCl2 soln for standardizing soap solns; for water analyses; as a chelometric standard.

Therapeutic Category

Antacid. Calcium supplement.

Therapeutic Category (Veterinary)

Antacid, calcium supplement, antidiarrheal agent.

Keywords

Antacid; Replenishers/Supplements; Calcium