METHOD FOR OZONE BLEACHING OF LIGNOCELLULOSIC MATERIAL

摘要

PROBLEM TO BE SOLVED: To provide a method for bleaching with which the bleaching efficiency in an ozone and hydrogen peroxide breaching stage in chlorine-free bleaching of chemical pulp for papermaking is improved and chlorine-free bleached pulp of high brightness is obtained. SOLUTION: The method for bleaching a lignocellulosic material comprises treating the lignocellulosic material with ozone and then chlorine dioxide and subsequently bleaching the material with an alkaline hydrogen peroxide or the alkaline hydrogen peroxide and oxygen. The method is characterized in that the chlorine dioxide is added in an amount of 0.01-0.09 wt.% based on bone-dry pulp and expressed in terms of the chlorine dioxide used. COPYRIGHT: (C)2005,JPO&NCIPI