Champion International Corporation Limited

Other

Raman Ambady

Gerald E Maples

Dewey W Barnes

James R Kidd

George Paulose

Dale E Nutter, Jr

Hector Ferguson

A process for bleaching wood pulp is provided comprising subjecting the wood pulp, after brown stock washing, to an oxygen delignification stage, a washing sequence, a first chlorine dioxide bleaching stage, an oxidative extraction stage, at least one final chlorine dioxide bleaching stage and then recycling the filtrate from the oxidative extraction stage countercurrently through the bleaching plant and brown stock washing. Additionally, and quite beneficially, the filtrate from the first chlorine dioxide bleaching stage is also recycled countercurrently through the brown stock washing thereby significantly reducing the environmental impact associated with the manufacture of bleach wood pulp.

Process for recycling bleach plant filtrate

A process for bleaching wood pulp is provided comprising subjecting the wood pulp, after brown stock washing, to an oxygen delignification stage, a washing sequence, a first chlorine dioxide or ozone bleaching stage, an oxidative extraction stage, an ozone activation stage followed by a chlorine dioxide bleaching stage in the absence of an intermediate washing stage.

Process for manufacturing bleached pulp with reduced chloride production

In the bleaching of wood pulp using the conventional CEH sequence with subsequent oxidation stages, the third stage (H) is replaced by peroxide oxidation (P) to a brightness level of 35-50 GE. Final brightness levels of 70-88 GE are attained using no greater amounts of chemicals in the subsequent stages than are required in the conventional CEHDH process. The temperature in the P stage is between 120.degree. and 170.degree. F.

Process for bleaching wood pulp with hydrogen peroxide

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Pensacola, FL, United States of America

Raman Ambady