Light calcium carbonate is also called precipitated calcium carbonate, or light calcium for short. Its molecular formula is CaCO₃, and molecular weight is 100.09. Light calcium carbonate is made by calcining limestone to generate lime and carbon dioxide, then add water to digest lime to generate lime milk, next introduce carbon dioxide to carbonize lime milk to generate calcium carbonate participation, and finally dehydrate, dry and crush it. Because the sedimentation volume of light calcium carbonate (2.4-2.8mL/g) is larger than that of heavy calcium carbonate (1.1-1.4mL/g), it is called light calcium carbonate.
Characteristics of Light Calcium
Light calcium carbonate is white powder, tasteless and odorles. Its specific gravity is about 2.71. It can decompose at 825-896.6℃, with melting point 1339℃. There are two forms of light calcium: amorphous type and crystalline type. The crystalline form can be subdivided into orthorhombic system and hexagonal system, in form of columnar or diamond. Insoluble in water or alcohol but soluble in acid, with heat releasing during action and generating carbon dioxide at the same time. Light calcium is also soluble in ammonium chloride solution.
Application of Light Calcium
Light calcium has a wide range of application. It can be used as fillers in industries of rubber, plastics, paper-making, coating and ink, and it is widely used in production of organic synthesis, metallurgy, glass and asbestos. Additionally it can also be used as neutralizer for industrial wastewater, antacid for gastric and duodenal ulcers, antidote for acidosis, additive for dairy cow feed, and anti-adhesive for oil felt. Besides these application, light calcium can also be used as raw material for tooth powder, toothpaste and cosmetics.
Processing technology
1. Carbonation method
Calcine limestone to generate lime and carbon dioxide, then add water to digest lime to generate lime milk, next introduce carbon dioxide to carbonize lime milk to generate participated calcium carbonate, and finally dehydrate, dry and crush it.
2. Soda ash (Na2CO3) calcium chloride method
Add calcium chloride to soda ash aqueous solution to generate calcium carbonate participation.
3. Caustic soda method
Light calcium carbonate can be obtained as a byproduct during the production of caustic soda (NaOH). Add slaked lime to soda ash aqueous solution can generate calcium carbonate precipitation, and obtain caustic soda aqueous solution at the same time. Finally, after dehydrating, drying and crushing of participated calcium, light calcium is obtained.
4. Calcium-binding method
Soaking slaked lime by hydrochloric acid can react to obtain calcium chloride solution. After absorbing ammonia, the calcium chloride solution is carbonized with carbon dioxide to obtain calcium carbonate precipitation.
5. Solvay method
During the production of soda ash, light calcium carbonate can be obtained as a by-product.
Prospect
With advantages of high purity, high scattering coefficient and good chemical stability, light calcium carbonate has shown wide application prospect in many fields. The market demand is growing and the production methods are becoming increasingly mature. In future, application prospect of light calcium carbonate will be broader. Especially in rubber industry, as a filler, it can significantly reduce production costs and improve products’ performance.
Qingdao Epic Powder Machinery Co., Ltd. is a professional powder equipment manufacturer. Its products include: jet mill, ball mill, vibration mill, broyeur à rouleaux, various classifiers and surface coating modifiers etc. Equipment for grinding, classifying and modifying of light calcium is included. Products from Qingdao Epic are with reliable quality and first-class after-sales service. Customers can also customize with specific demands, “one customer, one design”.
If you have any related needs or questions, please contact L'épopée de Qingdao directly.
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