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1、摘要本文对芦苇浆经过处理后再漂白,与常规CEH三段漂进行比较,探讨少氯漂白的研究的可能性。实验结果表明:常规三段漂的适宜条件是:C段浆浓3%、时间60min,温度25℃、pH<2,E段浆浓10%、时间90min、温度60℃、pH值>10,H段浆浓6%、时间120min、温度40℃、pH值7.5-8.0(终了),8g绝干浆,用氯量在8.0%,C:H=6.5:3.5时白度最高。先进行NaNO3预处理后CEH三段漂,能达到更好的漂白效果,NaNO3预处理的最佳工艺条件为:浆浓9.0%、0.16mol/kg水NaNO3处理量2
2、6ml,0.2M的H2SO4用量0.9%,温度90℃,时间120min,卡伯值由原来的17.506下降到7.128,经处理后白度在用氯量4%升至最高为85.3%ISO,增加了10%ISO。NaNO3预处理后EH二段漂的白度达到81.3%ISO,粘度为700.8。氧碱漂前预处理最佳条件:酸性H2O2的用量0.2%,浆浓5%,温度60℃,时间30min,pH值3。氧碱漂的最佳条件:用碱量3%,最高温度115℃,保温60min,氧压1.0Mpa,MgSO4用量0.5%,H2O2用量0.8%,浆样20g,浓度1%,漂后的粘度下
3、降为682.8,卡伯值5.113,经氧碱漂后再CEH三段漂的白度在用氯量4.0%时增加了10.6%ISO,粘度浆至474.6ml/g。CEpH漂白的最佳条件为:C段,E段和H段的条件与前面的常规三段漂的条件是一样的,E段中p段H2O2的用量0.8%,Na2SiO2的用量2%,MgSO4的用量0.05%,用氯量在8%时的白度比常规漂多2%ISO,粘度降低到618ml/g。结果表明,经处理后在漂白的白度都有所增加,其中氧碱后处理的白度增加最多,但粘度下降的也最多,而过氧化氢的白度虽然增加的不是最多,但粘度下降的最少。关键词
4、:芦苇硫酸盐法浆,NaNO3,氧碱漂白,过氧化氢,少氯漂白ABSTRACTBleachingafterreedpluphasbeendealwith,andcomparewithconventionalityCEHthreesequencebleaching,thepossibilityofbleachingforlowchlorinehasbeendiscusscd.Theresultsshowthat:theconventionalityCEHthreesequencebleachingwiththeoptimum
5、conditionsofCsequenceconsistencyofpulp3%,time60min,temperature25℃,pHlessthen2.Esequenceconsistencyofpulp10%,time90min,temperature60℃,pHmorethen10.Hsequenceconsistencyofpulp6%,time120min,temperature40℃,pHabout7.5to8.0(ending).absolutelydryofpulp8g,usechlorine8%,C
6、:H=6.5:3.5thebrightnesswasthebestofall.IfuseNaNO3dealwiththeCEHthreesequencebleachinginadvance,theresultwillbeobtainhigherbrightness.withtheoptimumconditionsofNaNO3dealwithinadvance:consistencyofpulp9%,the0.16mol/lNaNO3ofdosage26ml,the0.2MH2SO4ofdosage0.9%,tempe
7、rature90℃,time120min,kappavaluefallto7.128comparewithformerly17.506,thebrightnessofusechlorine4%hasbeendealwithattintopof85.3%ISO,addto10%ISO.EHtwosequencebleachingafterNaNO3dealwith.,thebrightnessreach81.2%ISO,viscosity700.8ml/g.withtheoptimumconditionsofoxygen
8、bleachingdealwithinadvance:acidityofH2O20.2%,consistencyofpulp5%,time30min,temperature60℃,Phvalue3.withtheoptimumconditionsofoxygenbleaching.alkali3%,toptemperature11