| 摘要 |
Method of bleaching chemical paper pulp, preferably entirely without using chlorine, in a bleaching sequence which comprises at least one acidic, sulphite-containing, reducing bleaching stage and at least one alkaline, oxidizing bleaching stage in arbitrary order. At least one of the said acidic, sulphite-containing, reducing bleaching stages is carried out under conditions which are in the main sulphonating to a degree of sulphonation exceeding 10 %, preferably exceeding 20 %, and even more preferably to 40-80 %. |
