"GCC" is calcite, a "heavy calcium carbonate" for short, the main ingredient is calcium carbonate, calcium carbonate is also referred to as "TSP", usually used as a filler, widely used man-made floor tiles, rubber , plastics, paper, coatings, paints, inks, cables, building supplies, food, pharmaceutical, textile, feed, toothpaste and other household chemical industry, as a filler serve to increase the volume of products, reduce production costs. [Introduction] calcium carbonate (Calcium Carbonate) is an important and widely used inorganic salts. Heavy calcium carbonate (Heavy Calcium Carbonate), also known as ground calcium carbonate (Ground Calcium Carbonate, referred to as the United States, said GCC Kotamite), is directly mechanically crushed natural calcite, limestone, chalk, shells, etc. in the system. Because of its sedimentation volume (1.1-1.9mL / g / g) than the chemically produced precipitated calcium carbonate sedimentation volume (2.4-2.8mL / g) is small, it is called the heavy calcium carbonate. Physical and chemical properties of the chemical formula of calcium carbonate caco3, its crystals are mainly tripartite complex partial three faces of calcite and orthorhombic aragonite crystal class category, at normal temperature and pressure, is stable calcite, aragonite is a quasi-stable, mainly calcite based. Under normal pressure, calcite was heated to 898 ℃, aragonite was heated to 825 ℃, will be decomposed into calcium oxide and carbon dioxide; calcium carbonate react with all the acid occurs, to generate water and the corresponding calcium salts (such as calcium chloride CaCl2), and release of carbon dioxide; at room temperature (25 ℃), the concentration of calcium carbonate in water is the plot 8. 7 × 1029, solubility of 0. 0014, pH value of the aqueous solution of calcium carbonate 9.5 ~ 10 2, air saturated carbonate. pH value of the aqueous solution of calcium 8.0 ~ 8.6. Calcium carbonate, non-toxic, odorless, non-irritating, usually white, the relative density of 2.7 ~ 2.9. Mohs hardness of calcite is 3, aragonite is 3.5 to 4. Calcite has three rhombohedron complete cleavage, aragonite also have cleavage. .. Heavy calcium carbonate sedimentation volume: 1 2 ~ 1 9ml / g, specific surface area of ??1m2 / g or so; heavy calcium carbonate particles due to the large, smooth surface, small specific surface area, and therefore lower oil absorption value for 48ml / 100g or so. Producing heavy calcium carbonate production process in two ways. Dry production process: First, hand-picked from the quarry shipped calcite, limestone, chalk, shells, etc., to remove gangue; then coarse crusher for crushing limestone, then Raymond (tilting) Mill get fine limestone powder, and finally to the mill grading grader meet the size requirements of the powder as a product packaging and storage, otherwise mill flour again. Wet production process: first dry powder made into a suspension of further pulverizing mill, dehydration, after drying to obtain superfine heavy calcium carbonate. Shape The particle shape of calcium carbonate are irregular, quite different particle size, and the particles have a certain angular, rough surface, the particle size distribution is wide, a larger particle size, the average particle diameter is generally 1 ~ 10μm . Heavy calcium carbonate in its original average particle size (d) is divided into: coarse calcium carbonate (> 3μm), finely ground calcium carbonate (1 ~ 3μm), ultra-fine calcium carbonate (0. 5 ~ 1μm heavy calcium carbonate . Powder characteristics: a particle of irregular shape; b wide particle size distribution; c diameter larger field of application of the current, calcium carbonate has been widely used in paper, plastics, plastic film, chemical fiber, rubber, adhesives, sealants... agents, household chemicals, cosmetics, building materials, coatings, paints, inks, putty, sealing wax, putty, carpet layer packaging, pharmaceutical, food (such as chewing gum, chocolate), feed, and its role are: to increase the volume of products, reduce costs , improve the processing properties (such as adjusting the viscosity, rheological properties, curing properties), improved dimensional stability, a reinforcing or semi-reinforcing and improve printing performance, improved physical properties (such as heat resistance, matting properties, abrasion resistance, resistance flammable, whiteness, gloss), etc. whiteness, stable performance.