粗皮桉AS-AQ浆氧脱木素后的过氧化氢漂白

Hydrogen Peroxide Bleaching of AS-AQ Eucalyptuspellita Pulp after Oxygen Delignification

研究粗皮桉AS-AQ浆氧脱木素后的过氧化氢漂白工艺,并对漂前预处理进行了探讨。结果表明:粗皮桉AS-AQ氧漂浆在进行过氧化氢漂白前采用高锰酸钾进行预处理,预处理条件为高锰酸钾用量0.6%,温度25℃,时间20 min,硫酸3%,浆浓5%,可以有效地提高纸浆的白度,降低卡伯值,同时纸浆黏度下降比例不大。使用柠檬酸钠取代硅酸钠和硫酸镁作为过氧化氢漂白的稳定剂是可行的,添加2%的柠檬酸钠作稳定剂可以达到添加3%的硅酸钠作稳定剂的效果。过氧化氢漂白的最佳工艺条件为:过氧化氢用量3%,温度90℃,时间120 min,氢氧化钠用量1.5%,柠檬酸钠2%,浆浓10%。在最优条件下,纸浆白度可以达到80.8%ISO。

A research was conducted on H202 bleaching process of AS-AQEucalyptuspellita pulp after oxygen delignification and the pretreatment before bleaching was also investigated. The results showed that when pretreatment agent KMnO4 was used for pulp pretreating before H202 bleaching, the optimal conditions of pretreatment were KMnO40.6%, H2SO43%, pulp consistency 5% and 20 minutes at 25°C. Sodium citrate in two percent can be used as a H202 bleaching stabilizer substituting for Na2SiO3. The optimal conditions of H202 bleaching were pulp consistency 10%, H202 3%, NaOH 1.5%, sodium citrate 2% and 120 minutes at 90~C. The final whiteness of the pulp could be 80.8%ISO under the optimum condition.