烧碱-AQ法麦草浆全无氯漂白的研究

Study on the totally chlorine free bleaching of wheat straw soda-AQ pulp

研究了烧碱-AQ法麦草浆全无氯漂白(0QP)流程中氧脱木素、整合处理和过氧化氢漂白的影响因素.结果表明:氧脱木素段NaOH用量2.5%,MgSO4用量0.5%,浆浓10%,温度105℃,氧压0.7MPa,时间75min时脱木素效果较好,对后续漂白有利.整合处理pH值为3时,浆料的自度最高,卡伯值最低.压力H2O2漂白的最佳工艺条件为:浆浓10%,H2O23.5%,NaOH1.5%,MgSO40.05%,EDTA0.2%,氧压0.6MPa,温度105℃,时间2h.在优化条件下,漂终白度达82.2%IS0.

The influential factors of oxygen delignification,chelation and hydrogen peroxide bleaching on OQP bleaching of wheat straw soda-AQ pulp were studied.The results indicated that good results of oxygen delignification were obtained under the conditions of NaOH 2.5%,MgSO_4 0.5%,consistency 10%,oxygen pfessue 0.7MPa at 105℃ for 75 min,and the highest brightness and the lowest Kappa number were attained when the pH of chelation was 3.The optimal technology of pressured H_2O_2 bleaching were pulp consistency 10%,H_2O_2 charge 3.5%,NaOH charge 1.5%,MgSO_4 0.5%,EDTA 0.2%,O_2 Pressure 0.6MPa,105℃ and time 120 min,the pulp could be bleached to 82.2% ISO with OQP sequence.