Calcium Carbonate Paper Machine Description:

Calcium carbonate provides good optical properties for drawing paper and is relatively inexpensive. As a result, the use of calcium carbonate for paper production has steadily increased. However, the large amounts of calcium carbonate in the paper used for recycling and the closing of waterways have led to high concentrations of calcium ions in the process water of paper mills. The consequence can be undesired precipitation and deposition of calcium carbonate in the machinery and equipment components of the paper mill. To avoid or reduce unwanted precipitation and deposition, an improved understanding of the potential for calcium carbonate precipitation is needed. This potential can be described in terms of the Langelier Saturation Index (LSI). Our investigations show that calcium carbonate deposition occurs only when the LSI value is higher than 0.5. During the treatment of biological wastewater treatment plants, LSI values are usually higher than 0.5. The reasons for such values are the increase in bicarbonate concentration (m-alkalinity) due to the production of carbon dioxide and the increase in pH due to the reduction of fatty acids. With the knowledge about the potential of calcium carbonate precipitation in the process water line, appropriate measures can be implemented.

Calcium Carbonate Paper Machine Instruction:

Calcium carbonate appears as a white, odorless powder or colorless crystals. Calcium carbonate is almost insoluble in water. Calcium carbonate is widely found in rocks around the world. Ground calcium carbonate (CAS: 1317-65-3) comes directly from the mining of limestone. The extraction process brings calcium carbonate very close to its original purity and provides a finely ground product in dry or slurry form. Precipitated calcium carbonate (CAS: 471-34-1) is industrially produced by decomposing limestone into calcium oxide, which is then re-carbonated, or as a by-product of the Solvay process (used to make sodium carbonate). Precipitated calcium carbonate is purer than ground calcium carbonate and has different (and customizable) processing characteristics.

Calcium Carbonate Paper Machine Process：