| 摘要 |
2118316 9323607 PCTABScor01 The present invention relates to a process for bleaching pulp which has been digested and oxygen-delignified, using methods which preserve viscosity and strength, to kappa numbers lower than 12, preferably lower than 10, without using chlorine-containing chemicals and employing a bleaching sequence containing at least 3 bleaching stages, whose first three stages are QPZ, preferably containing an additional bleaching stage, appropriately in the form of a P-stage, this chlorine-free process being environmentally optimised, inter alia by keeping the total quantity of filtrate leaving the bleaching plant at a low level.
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