Process for the delignification or brightening of cellulosic pulp using oxidized white liquor

摘要

Oxidized white liquor is used as an alkali source in the delignification or bleaching of primary and secondary pulps by oxygen delignification, alkali extraction (E), oxygen alkali extraction (Eo), peroxide-enhanced alkali extraction (Ep), peroxide-enhanced oxidative extraction (Eop), peroxide bleaching (P), hypochlorite bleaching (H), ozone bleaching (Z), chlorine dioxide bleaching (D), or FAS bleaching. Oxidized white liquor is a replacement for sodium hydroxide as an alkali source in these processes, and the use of oxidized white liquor gives improved bleaching and delignification compared with the use of sodium hydroxide.