| 摘要 |
PROBLEM TO BE SOLVED: To provide a technique to improve a whiteness degree of causticized light calcium carbonate as a byproduct in a causticizing process for regenerating a cooking white liquor in a pulp production process by a sulfate method or a soda method. SOLUTION: In a causticizing process of a pulp production process by a sulfate method or a soda method, the causticized light calcium carbonate as a filler for paper making is produced by mixing calcium oxide containing an iron content of 0.001 to 0.05 wt.% or calcium hydroxide prepared by slaking the calcium oxide with a green liquor produced in the causticizing process, and carrying out the causticizing reaction while stirring or kneading. COPYRIGHT: (C)2011,JPO&INPIT |
