改进的深度脱木素的硫酸盐蒸煮──第一部分　用硫化钠预处理的桉树硫酸盐蒸煮

Improved Extended Kraft Cooking──Part 1:Pretreatment of Eucalyptus with Sodium Sulfide Solution

用硫化钠水溶液预处理桉树，接着进行改进的深度脱木素硫酸盐蒸煮。结果表明，在１６０℃预处理后脱木素的选择性较常规硫酸盐蒸煮有显著提高，可得到低Ｋａｐｐａ值（约为１０）的浆而没有明显的强度损失。

The effect of pretreatment of the eucalyptus chips with sodium sulfide solution(concentration 10 and 20g/L) on the modified kraft cooking was studied. The results show that after the pretreatment in 160℃ viscosity of the pulp is much higher than that of the conventional modified kraft pulp at a given Kappa number.This indicates that the improved modified kraft cooking can be extended to an even lower Kappa number without sacrificing pulp strength if the chips are subjected to pretreatment with a sodium sulfide solution.