碱抽提强化的麦草浆二氧化氯漂白及ECF漂白流程研究

摘要：采用四种不同的碱抽提方式对麦草浆二氧化氯漂白(D0)进行强化，考查了不同碱抽提方式的强化效果，并对不同ECF漂白流程进行了对比研究。结果表明：在D0ED1漂白流程中，不同碱抽提方式对D0木素的修饰效果不同，就后续D1漂段而言，四种不同碱抽提模式下纸浆的可漂性顺序为：D0EOP>D0EP>D0EO>D0E。在D0ED1漂白流程中，D1段ClO2对白度的提升是有限的，达到白度极限后再增加ClO2用量对白度提高不明显。本实验条件下D1段ClO2用量以1.0%~1.2%为佳。从D0ED1与D0EP各漂白流程的对比来看，在终段漂白中以P取代D1效果要好，表明H2O2用于终段漂白其效果要好于ClO2。从其它ECF漂白流程的对比来看，D0EPP和D0EOPP流程漂白效果优于其它流程。本实验条件下采用D0EPP和D0EOPP漂白流程，麦草浆漂后白度可分别达到83.8%和85.7%。

Studies on Chlorine Dioxide Bleaching Reinforced by Caustic Extraction and ECF Bleaching Sequences of Wheat Straw Pulp

Abstract: Applying four kinds of caustic extraction modes to reinforce chlorine dioxide bleaching processes of wheat straw pulp, the impacts of reinforcement were evaluated and various ECF bleaching sequences were investigated comparatively. Results indicated that in D0ED1 bleaching sequences the modification effects of caustic extraction modes on the residue lignin of D0 stage were different. As far as the subsequent D1 stage was concerned, the D1 bleachability order, from easiest to hardest, was D0EOP>D0EP>D0EO>D0E. It was demonstrated that in D0ED1 sequences the enhancement of ClO2 on the brightness of D1 stage was limited, due to approaching the brightness ceiling, which was not advanced significantly with the increasing of ClO2 charges. The optimal charge of ClO2 was 1.0%~1.2% under the conditions of this experimentation. By contrast with various bleaching sequences between D0ED1 and D0EPP, it was found that the improvement of substitute P stage for D1 was significanat, which revealed that the effect of using H2O2 on final bleaching stage was better than that of using ClO2 in D1. By contrast with other ECF bleaching sequences, it was demonstrated that the advancement of D0EPP and D0EOPP sequences were better than those of other sequences. Under the conditions of this experimentation, with D0EPP and D0EOPP bleaching sequences, the final brightness of bleached wheat straw pulp reached 83.8% and 85.7% respectively.