METHOD FOR MANUFACTURING CALCIUM CARBONATE

摘要

PROBLEM TO BE SOLVED: To provide a method for manufacturing calcium carbonate having a fine particle diameter and wearing resistance to a plastic wire after pulverization and capable of adding to paper to obtain an excellent quality and efficiently produced in an industrial scale. SOLUTION: The method is composed of a lime slaking process which slakes continuously quicklime containing less calcium carbonate than a specific amount with a white liquid and/or a green liquor under specific lime concentration utilizing a causticizing process in a pulp making process by a sulfate method or a soda method. Milk of lime and/or lime mud from the lime slaking process is mixed continuously with the same amount of the green liquor as the required amount to manufacture the white liquor in a conventional operation in a pre- stage causticizer and then a causticizing reaction is started after the specified residence time of the reacting solution. The causticizing ratio which is same as obtained white liquor in a conventional operation can be obtained by controlling the residence time in a post-stage causticizer.