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研究了挪威云杉TMP的高温H_2O_2漂白。以单段H_2O_2漂白浆(温度70℃)作为对比样,利用旋翼式纤维分离机作为混合器,在不同总用碱量下探讨了单段和两段H_2O_2漂白(温度105℃)。实验表明,经过两段高温H_2O_2漂白后的浆料白度高于单段H_2O_2漂白后的浆料白度;两段漂白中应采用低总用碱量(10～15kg/t),第一段H_2O_2漂白的碱与H_2O_2的比值应控制在较小值,以降低COD负荷并得到较高的残余H_2O_2。增加总用碱量并不能提高浆料白度。在漂白温度105℃下,漂白时间可以适当缩短,因为在漂白2.5min后浆料可以达到最高白度。与传统的单段H_2O_2漂白相比,在相同H_2O_2用量及低总用碱量下,两段H_2O_2漂白时碱处理前用H2O2进行预浸渍得到的浆料具有更高的白度和残余H_2O_2,但是COD负荷高于传统的单段H_2O_2漂白。
The H 2 O 2 bleaching of TSP from Norway spruce was studied. Single-stage and two-stage H 2 O 2 bleaching (temperature 105 ℃) was studied under different total alkalinity using single stage H 2 O 2 bleaching pulp (temperature 70 ℃) as a control. The results showed that the bleaching whiteness of H_2O_2 was higher than that of single H_2O_2 bleaching pulp after two periods of high temperature H_2O_2 bleaching. The lower total alkalinity (10 ~ 15kg / t) The ratio of H_2O_2 bleached alkali to H_2O_2 should be controlled to a small value to reduce COD load and obtain higher residual H_2O_2. Increase the total amount of alkali can not increase the whiteness of the slurry. At the bleaching temperature of 105 ℃, the bleaching time can be properly shortened, because 2.5min after bleaching the pulp can reach the highest whiteness. Compared with the traditional single-stage H 2 O 2 bleaching, the pretreatment with H 2 O 2 before bleaching had higher whiteness and residual H 2 O 2 at the same dosage of H 2 O 2 and lower total alkalinity, COD load is higher than the traditional single H_2O_2 bleaching.