Calcium carbonate is an inorganic compound, is the main component of limestone stone (limestone for short), its molecular formula for CaCO3, relative molecular mass of 100.09. Which calcium oxide (CaO) accounted for 56.03%, carbon dioxide (CO2) accounted for 43.97%. Classification of calcium carbonate 1, according to the production method of classification of calcium carbonate according to the different methods of production of calcium carbonate can be divided into light calcium carbonate, heavy calcium carbonate and activated calcium carbonate. (1) light calcium carbonate: also known as precipitated calcium carbonate, referred to as light calcium, is the limestone and other raw materials section of the burned lime (the main component of calcium oxide) and carbon dioxide, and then add water to digest the lime to generate lime milk (the main component of calcium hydroxide), and then carbon dioxide carbonization of lime milk to generate calcium carbonate precipitate, and finally by dehydration, drying and crushing and made. Or first use carbonate and calcium chloride for complex decomposition reaction to produce calcium carbonate precipitate, and then after dehydration, drying and crushing and produced. Because of the light calcium carbonate sedimentation volume (2.4-2.8mL/g) than the heavy calcium carbonate sedimentation volume (1.1-1.4mL/g) is large, so it is called light calcium carbonate. (2) heavy calcium carbonate abbreviated as heavy calcium, is a mechanical method of direct crushing of natural calcite, limestone, chalk, shells, etc. and produced. Due to the heavy calcium carbonate precipitation volume than the light calcium carbonate precipitation volume is small, so it is called heavy calcium carbonate. (3) active calcium carbonate, also known as modified calcium carbonate, surface treatment of calcium carbonate, gelatinous calcium carbonate or white Yanhua, referred to as active calcium, is the use of surface modifiers on the surface modification of light calcium carbonate or heavy calcium carbonate and produced. As the surface modifier modified calcium carbonate generally have reinforcing effect, the so-called "active", so it is customary to modify the calcium carbonate are known as active calcium carbonate. 2, according to the classification of powder particle size calcium carbonate products is a powder, according to the average particle size of calcium carbonate powder (d) size, can be divided into calcium carbonate particles ( d>5μm), micronized calcium carbonate (1μm .