BLEACHING OF CELLULOSE PULP IN ONE AND THE SAME STAGE WITH A COMPLEXING AGENT, A MOLYBDENUM CONTAINING SUBSTANCE AND AN OXIDATIVE BLEACHING AGENT

摘要

Bleaching sequences that are based on the use of essentially environmentally friendly bleaching agents often include numerous treatment stages, in which respective pH-values widely vary. From the aspect of liquid closed systems, this has a negative influence on the manufacture of bleached, including fully bleached, cellulose pulp as a whole. The present invention solves this problem and relates to a method of delignifying/bleaching a non-delignified/unbleached or predelignified/prebleached lignin-containing cellulose pulp. The method is characterized in that the cellulose pulp in one and the same stage is treated with a) complexing agent (Q); b) molybdenum-containing substance (Mo); c) chlorine-free oxidative bleaching agent, preferably a peroxide compound (P); and in that this treatment is followed by at least one bleaching stage in which a chlorine-free oxidative bleaching agent, preferably a peroxide compound (P), is used.