| 摘要 |
With the use of oxygen and alkali for delignification and bleaching of chemical cellulose mass it is not possible to remove more than almost half of that in the cellulose mass after boiling the remaining lignin amount due to the risk of a serious and uncontrollable breakdown of the carbohydrates in the cellulose mass. Through the invention it has become possible to drive the oxygen delignification considerably further and it refers to a process for delignification of alkaline influxed cellulose mass, which is characterized by the combination, that the mass is first impressed with a kappa number of 8-20 by oxygen, on which the mass is activated by means of nitrogen dioxide in order to finally convey a Kappa number lower than 8 by means of oxygen.<IMAGE> |
