| 摘要 |
The present invention relates to a process for bleaching alkaline sulphate pulp which, in a previous step, has been delignified and bleached to a lignin content of below about 1,3 % (kappa value 9,4). The process is performed by adding peroxide to bleach the pulp in a first step, whereupon to the pulp gaseous ozone is added in an amount of less than 0,5 kg/ton pulp in a second step and that the pulp, possibly without any intermediate wash, is alkalized and peroxide added for final bleaching in a third step. |
