HIGH-TEMPERATURE PRESSURIZED HYDROGEN PEROXIDE BLEACHING PROCESS FOR REED KRAFT PULP

摘要

Reinforced oxygen delignification with hydrogen peroxide for reed kraft pulp was studied. The oxygen bleached pulp was treated with sulfuric acid and DTPA before high-temperature pressurized hydrogen peroxide bleaching, and supplement conventional H_2O_2 bleaching for the pulp was also studied. The rule of various affect factors on high-temprature pressurized H_2O_2 bleaching was investigated. It was shown that: because of much more transiton metal ions in the reed kraft pulp, the pretreatment with sulfuric acid and DTPA can effectively increase the bleaching effect of reed kraft pulp, the addition of a small amount of H_2O_2 not only effectively improve the delignification capacity of oxygen bleaching process, but also improve the brightness increase rate of the pulp. Adopting OpPoP bleaching sequence, the brightness can reach to above 80%ISO, and the bleached pulp can still maintained good strength, therefore proved that the OpPoP is suitable short TCF bleaching sequence for reed kraft pulp.