METHOD FOR OXYGEN DELIGNIFICATION TREATMENT

摘要

PROBLEM TO BE SOLVED: To provide an efficient method for oxygen delignification treatment of a digested chemical pulp for promoting the delignification of the pulp and decrease the consumption of chemicals in the following bleaching step. SOLUTION: Copper ion or a copper complex is added to digested unbleached chemical pulp in an amount of 0.01-1.0 wt.% in terms of solid component based on absolute dry weight of the pulp or copper ion and a ligand compound capable of forming a complex with copper ion are added in an amount of 0.01-1.0 wt.% each in terms of solid component and the product is subjected to oxygen delignification treatment comprising the addition of pressurized oxygen in an alkaline medium and the heating of the system. COPYRIGHT: (C)2004,JPO&NCIPI