Depending on the conditions of precipitation they may be either rosette (scalenohedral), blocky (rhombohedral), or various intermediate types. It is also possible to precipitate the aragonite crystalline form of calcium carbonate, and such particles tend to be needle-like (acicular).
The principal component of calcium carbonate--calcium--is an earth metal comprising 3.64% of the earth's crust. It is always found in combination with other materials, such as carbon or oxygen, and never appears alone naturally. It is polymorphous, meaning it can take on a variety of crystal structures. It is the main component of human teeth and bones in the form of calcium phosphate.
Calcium was isolated by Sir Humphrey Davy in 1808, but it was known long before that in its crystalline forms. Iceland spar was scientifically described in the late 17th century, and was the material that gave R.J. Hauy clues in developing the theory of crystal structure, leading to modern structural crystallography.
When combined as calcium carbonate the element takes the form of limestone, chalk, eggshells, coral, etc. Natural forms of calcium carbonate are generally contaminated with clay and other impurities. White limestone is a relatively pure form of the mineral in nature, while Iceland spar is a tightly crustallized form that has useful optical properties. The limestone form is of course an important building material--especially in U.S. Federal government buildings.
Calcium carbonate is also an important contributor to some geological changes. It is soluble in water that contains carbon dioxide, and thus contributes to the erosion of limestone deposits. It can then be deposited elsewhere. Notable examples of this action are at Carlsbad Caverns in New Mexico and Luray caverns in Virginia. The stalactites and stalagmites are primarily limestone.
Although widely available in various natural forms, modern laboratory, electronic and ceramic applications require the use of synthetically prepared material, for its higher purities and more reliable properties. Principal uses of synthetic calcium carbonate include in medicine, in antacids, and as a dietary supplement (note that Tums contains Calcium Carbonate, not Calcium Phosphate!); food (baking powder) and laboratory purposes.
If you believe you have a use for calcium carbonate, contact us. We will be happy to discuss and help you implement your application.
CaCO 3 , white chemical compound that is the most common nonsiliceous mineral. It occurs in two crystal forms: calcite, which is hexagonal, and aragonite, which is rhombohedral. Calcium carbonate is largely insoluble in water but is quite soluble in water containing dissolved carbon dioxide, combining with it to form the bicarbonate Ca(HCO 3 ) 2 . Such reactions on limestone (which is mainly composed of calcite) account for the formation of stalactites and stalagmites in caves. Iceland spar is a pure form of calcium carbonate and exhibits birefringence, or double refraction
Nanometer calcium carbonate refers to superfine calcium carbonate powder with a particle size between 1nm and 100nm. Owing to its high transparency, dispersiveness and affinity, it has a great reinforcing effect and has been highly acclaimed in rubber, plastic and papermaking sectors.
The rapid development of rubber, plastic, papermaking, coating and ink sectors in the recent years has greatly promoted the consumption of calcium carbonate. The market demand of nanometer superfine calcium carbonate is increasing especially in the production of high-grade cooperplate paper, ...
The world's first nano-grade calcium carbonate commercial production line using the ultragravity process has made a successful running of nearly 10 days.
The commercial production line is jointly developed by Guangdong Guangping Chemical Industrial Co., Ltd. and Beijing University of Chemical Engineering. Guangping Chemical Industrial Co., Ltd. is the only enterprise in China that has introduced foreign technology and equipment to produce nano-grade calcium carbonate. After purchasing the patent of nano-grade calcium carbonate synthesis using the ...