PURPOSE: To provide a method to achieve high delignification selectivity of pulp in a process of high concentration oxygen delignification process.
CONSTITUTION: A method to achieve high delignification selectivity of pulp in a process of high concentration oxygen delignification comprises each following process; applying the first amount of alkaline material to a pulp by washing the pulp with a solution of alkaline material to condense the pulp to high concentration of at least 18 weight % in a wash press, distributing substantially uniformly the first amount of alkaline material through the washed pulp, extracting pressate from the wash press, applying a total amount of alkaline material of at least about 0.8-7 weight % by a measure of weight of oven dry pulp where the total amount contains even the first amount, delignifing oxygen for the alkaline material containing high concentration pulp, and obtaining a high delignification selectivity and oxygen delignification pulp.
SUCHIYUAATO TEI TARETSUTO
SUPENSAA DABURII EIKIYUUZU
BURUUSU EFU GURITSUGUSU
| JPH02289194A | 1990-11-29 |
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