Po Bleaching of Magnesium-Based Sulfite Pulp

This paper mainly studies on the Po bleaching of magnesium-based sulfite bamboo/bagasse pulp, which is pretreated with sulfuric acid. The experimental results indicate that the optimal conditions are as follows: temperature 80°C, time 70min, the dosage of Na₂SiO₃ 4.0% and the charge of NaOH 2.5%. Under these optimized conditions, the brightness of the bleached pulp is up to 81.96%ISO while the Kappa number is 6.8. Evidently, the Po process is an effective bleaching process with non-pollution, which is suitable for this kind of pulp.