METHOD FOR IMPROVING CHLORINE DIOXIDE BLEACHING EFFICIENCY

摘要

PROBLEM TO BE SOLVED: To provide firstly a technique for enhancing the bleaching efficiency in chlorine dioxide bleaching of chemical pulp, to secondly reduce bleaching cost of the chlorine dioxide and to thirdly obtain higher brightness by the chlorine dioxide bleaching. SOLUTION: A pH buffer agent is preadded before adding the chlorine dioxide in a chlorine dioxide bleaching stage in a multistage bleaching process of the chemical pulp. Thereby, the range of lowered pH of a pulp suspension by the chlorine dioxide bleaching reaction can be reduced. The pH when completing the reaction can be regulated within a suitable range. As a result, the bleaching efficiency of the chlorine dioxide can be raised and the bleaching cost of the chlorine dioxide can be reduced to obtain pulp of higher brightness. COPYRIGHT: (C)2004,JPO