| 摘要 |
PROBLEM TO BE SOLVED: To provide a kraft cooking method which can notably improve a pulp yield without requiring large-scale equipment changes, and a pulp yield improver used for the method.SOLUTION: In a kraft cooking method where pulp material is cooked in black liquor including sodium hydroxide and sodium sulfide, a cationic polymer compound is added into the black liquor. Preferably, the cationic polymer compound includes at least one of a cross-linked cationic polymer, a straight-chain cationic polymer and a cationized starch. |
