Method for bleaching pulp with activated ozone

摘要

An ozone based bleaching method for bleaching lignocellulosic materials comprising a bleaching sequence of at least four sequential stages, said stages including an oxidative treatment stage, an alkaline extraction stage, an activated ozone bleaching stage, and a final bleaching stage to produce a pulp of desired final brightness. The activated ozone bleaching stage comprises the addition of an ethanol/DMSO mixture to the pulp prior to the ozone reaction.