| 摘要 |
Bleaching process consists of chlorination, extn., bleaching with hypochlorite and bleaching with peroxide (C-E-H-P continuous process), sufficient amount of soln. from the chlorination process is mixed into pulp slurry from the hypochlorite bleaching process and pH of the pulp slurry is controlled to less than 7, pref. 2 to and esp. 5 before the pulp slurry is fed into peroxide bleaching process. The pulp slurry from the hypochlorite bleaching process should pref. be controlled to a concn. of 1 to 10%. The peroxide bleaching process employs hydrogen peroxide in 0.2 to 1% based on dry weight of pulp and the pulp is kept in the concn. of 4 to 20% and at a pH of about 10 to 11.5.
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