Low consistency oxygen delignification process

摘要

The present invention provides for a method for delignifying softwood or hardwood pulp in a fiber line of a pulp and papermaking system having a slurry at low consistency by adding to the pulp slurry oxygen and adding this pulp slurry reaction mixture to a reaction system comprising an efficient mixer and contact tank. The reaction system is preferably physically located after the knotters and before the brown stock washers to make more effective use the residual alkali and heat content in the incoming black liquor.