To provide a method for manufacturing an acicular light calcium carbonate suitable as a pigment for a coated paper which is excellent in pulverizability under an easy and relatively broad synthesis condition needing no complex synthesis condition and operation in manufacture of the acicular light calcium carbonate.
The method for manufacturing an acicular light calcium carbonate for a coated paper comprises a step (A) of firing limestone to obtain quicklime, a step (B) of wet slaking the quicklime to obtain a slaked lime slurry, and a step (C) of injecting a gas containing carbon dioxide to the slurry for the carbonation reaction, wherein the content of carbon dioxide as remains after firing in the quicklime obtained in the step (A) is ≤1.5%; the concentration of the slaked lime slurry obtained in the step (B) is 10 to 20 mass%; the carbon dioxide-containing gas injected in the step (C) is an exhaust gas of a kiln generated in a pulp production process; and the reaction initiation temperature of the carbonation reaction is <20°C.
WATABE TETSUYA
YAEDA TORU
YAMAMOTO MANABU
