High Yield Bleaching Upgrade at Boise Cascade, Steilacoom, 1994 Pulping Conference Proceedings

David Munroe, Om Bhatia, Jan Westling, Mark McCrary, Anthony Casassa, Steve Masse

As part of a Total Quality Process at Boise Cascade, a Brightness Improvement Task Force was assembled to identify and implement improvements in the bleaching system at the recycled newsprint mill at Steilacoom. The task force was made up of representatives from both Boise Cascade and Morton. One of the major process changes undertaken was the upgrade of the sodium hydrosulfite bleach generation system. The upgrade included the installation of newly developed high yield technology as well as a change in the generation chemistry. The technology improved the efficiency of the Borol bleach generating unit, lowering the amount of raw materials needed to generate the hydrosulfite bleach. The efficiency of the system was improved 4-5%, significantly lowering the bleaching costs for the mill. This was done in combination with the new generation chemistry which offered further advantages to the mill. The successful start-up of this high yield bleaching system was a milestone, being the first in the world using this chemistry.