To provide a method of producing calcium carbonate having high whiteness which can be used as a pigment for coated paper and in which impurity is not contained, from lime sludge formed when unslaked lime or slaked liquid produced by making unslaked lime react with a sodium hydroxide containing liquid is added to a green liquor produced by a pulp manufacturing process by a kraft process to be causticized.
The method of manufacturing calcium carbonate from lime sludge formed by causticizing a green liquor produced by a pulp manufacturing process by a kraft process by unslaked lime or slaked liquid prepared by making unslaked lime react with a sodium hydroxide containing liquid is characterized in that lime sludge is passed through a white liquor recovery process, thereafter the lime sludge is dried by being passed through a flash dryer using an elevated temperature hot blast, and is dry ground.
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KITATANI JUNJI
KAJI HIROO
