硫酸盐法竹浆无元素氯漂白的研究

研究了硫酸盐法竹浆低二氧化氯用量的DQP漂白中各个漂段的影响因素,并对D段终点pH值、Q段EDTA用量以及P段MgSO4用量进行优化.结果表明:当D段终点pH值为4,Q段EDTA用量为0.2%,P段MgSO4用量为0.02%(以Mg2+计),DQP漂白效果较好.仅用1.5%的有效氯(0.57%的ClO2)和1.5%的H2O2,就可将硫酸盐竹浆漂到83%ISO的白度.还对竹浆DQP和CEH漂白的漂终结果、纸浆强度性质以及废水特性进行了比较.结果表明:与CEH漂白相比,DQP漂白浆的白度稍低,但白度稳定性好,纸浆粘度高,强度性质较好,对环境污染较小.

Study on the Elemental Chlorine Free Bleaching of Bamboo Kraft Pulp

The influential factors of DQP(chlorine dioxide bleaching,chelation and hydrogen peroxide bleaching) of bamboo kraft pulp were studied pH value in D stage,dosage of EDTA in Q stage and charge of MgSO4 in P stage were optimized The results indicated that good results of DQP bleaching were obtained when final pH value in D stage was 4,dosage of EDTA in Q stage was 02%,charge of MgSO4 in P stage was 002% At the optimal conditions,the pulp could be bleached to 83%ISO brightness by DQP seqnence with only 15% active chlorine (or 057% ClO2) and 15% H2O2 A comparison of bleaching results,pulp strength and effluent characteristics of bamboo kraft pulp between DQP and CEH sequences was done The results indicated that,compared with CEH bleached pulp,DQP bleached pulp had slightly lower brightness,much better brightness stability,much higher pulp viscosity,better strength properties and lower pollution loads