IMPROVED BRIGHTENING METHOD

摘要

PROBLEM TO BE SOLVED: To provide a method for the brightening of mechanical pulp at a high pH level in improved efficiency. SOLUTION: The improved method for the brightening of mechanical pulp under neutral or alkaline paper-making condition contains (a) a step of separating the neutral or alkaline pulp dilution water into a flow having high solid content and a neutral or alkaline flow having low solid content and (b) a step of reusing the neutral or alkaline flow having low solid content for the dilution of pulp before bleaching process.