PROCESS FOR IMPROVING CHLORINE DIOXIDE BLEACHING OF PULP

摘要

The invention is directed to a method for increasing brightness of pulp, wherein the method includes: contacting a pulp slurry with chlorine dioxide in a final D (ClO2) bleaching stage; and adding a brightening additive to the final D bleaching stage after at least a portion of the chlorine dioxide has been consumed, in an amount sufficient to increase brightness of the pulp; wherein the brightening additive is an inorganic compound chosen from hypochlorous acid, one or more precursor compounds that form hypochlorous acid in said final D bleaching stage, or a mixture thereof.