| 摘要 |
<p>The removal of lignin from cellulosic pulp is achieved, with reduced cellulose degradation, by partially replacing chlorine with bromine in the acidic chlorination of the pulp. The lignin is removed without appreciable discoloring of the pulp. The present process is adaptable for incorporation into known multi-step processes for treating pulp, such as the halogenation, extraction and oxidation sequence. The bromine-chlorine mixture used comprises between 10 and 70 weight percent bromine, and is used in a concentration of 4 to 14 weight percent, most preferably 6 to 8 weight percent, based on the dry weight of the cellulosic pulp.</p> |
