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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。
The hydrogen peroxide bleaching process after the AS-AQ pulp oxygen delignification was studied, and the pre-bleaching pretreatment was discussed. The results showed that AS-AQ bleached pulp was pretreated with potassium permanganate before hydrogen peroxide bleaching. The pretreatment conditions were potassium permanganate 0.6%, temperature 25 ℃, time 20 min, sulfuric acid 3% , Pulp concentration of 5%, can effectively improve the pulp whiteness, reduce the kappa number, while the pulp viscosity is not a big decline. It is feasible to use sodium citrate instead of sodium silicate and magnesium sulfate as hydrogen peroxide bleaching stabilizer. The addition of 2% sodium citrate as stabilizer can achieve the effect of adding 3% sodium silicate as stabilizer. The optimum conditions of hydrogen peroxide bleaching were as follows: dosage of hydrogen peroxide 3%, temperature 90 ℃, time 120 min, sodium hydroxide 1.5%, sodium citrate 2% and pulp consistency 10%. Under optimal conditions, the pulp brightness can reach 80.8% ISO.