| 摘要 |
The invention concerns a delignification and bleaching method for chemical paper pulp comprising an acid treatment step for reducing by at least 10 % the amount of hexenuronic acids present in the pulp; a step for adjusting the pulp pH designed to deposit or redeposit alkaline-earth metal ions on the pulp fibres; adding a chelating agent to the pulp before and/or during the acid treatment and/or before, during or after the pH adjustment step; a pulp washing step and a step which consists in treating the pulp with an oxidant. The duration of the acid treatment step is less than 120 minutes, the temperature and the pH being adapted so as to obtain the desired degree of whiteness. |
