Calcium carbonate ground natural

It is also made by precipitation from dissolved calcium hydroxide and carbon dioxide. The natural ground calcium carbonate and the precipitated material compete industrially based primarily on particle size and the characteristics imparted to a product. 

Natural ground calcium carbonate has been used for years as the primary constituent of putty. Since 1945, the processing of natural calcium carbonate has seen the introduction of beneficiation by flotation (qv) to remove impurities and the development of grinding processes to manufacture finer products. Precipitated calcium carbonate was first introduced in England in 1850 commercial production started in the United States in about 1913. 

M. D. Stmtz and C. T. Sweeney, Natural Ground Calcium Carbonate, Proceedings Tappi Neutral jMlkaline Short Course October 1990, Tappi Press, Adanta, Ga., 1990. 

CALCIUM CARBONATE. [CAS I3I7-65-3I- Calcium carbonate, [CAS. 471-34-11- CaCOi, mol wi 100.09. occurs naturally as the principal constituent of limestone, marble, and chalk. Powdered calcium carbonate is produced by two methods on the industrial scale. It is quarried and ground from naturally occurring deposits and in some cases beneftciated. It is also made by precipitation from dissolved calcium hydroxide and carbon dioxide. The natural ground calcium carbonate and the precipitated material compete industrially based primarily on particle size and the characteristics imparted to a product. 

Huggenberger L, Neubold H B. Pigments for Paper. Natural Ground Calcium Carbonate as Coating Pigment and Filler. 

The sedimentary rocks consisting mainly of calcite crystals are processed by standard mining procedures and then subjected to grinding and classification. In addition to natural ground calcium carbonate (GCC), there also exists a chemically produced form known as precipitated calcium carbonate (PCC), which may be finer and of higher purity, but also more expensive than the natural one. 

Fig. 2.14 Scanning electron micrograph pictures of natural ground calcium carbonate filler and chemical pulp fibers in a paper sheet (source OMYA).

Calcium carbonate - Natural ground calcium carbonate (GCC) is produced in a wide range of particle sizes and is available either as powder or slurry. High brightness and low cost make GCC very popular with alkaline papermakers. There are, however, problems associated with its use, especially in the area of deposit formation on the papermachine. Most pitch deposits found on an alkaline papermachine are composed mainly of calcium carbonate that has deposited along with other sticky components in the fiimish. 

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