| 摘要 |
A method at the bleaching of pulp, comprising bleaching with peracetic acid where the pH value during the bleaching reaction is held within 5-7. In the final phase of the bleaching with peracetic acid, metals released in the pulp are rebound to the fibers in the pulp by increasing the pH value to at least 9, whereafter the pulp is washed. The pH value is increased preferably 1-10 minutes before the washing. It is thereby possible to close the bleaching process in counterflow without risk of accumulation of the metals in the process. |
