马尾松化学预热机械浆镁碱过氧化氢漂白

Magnesium-based alkalis for hydrogen peroxide bleaching of masson pine CTMP

研究了用镁碱代替钠碱的马尾松化学预热机械浆(CTMP)浆过氧化氢漂白工艺及其对纸浆性能的影响,分析了镁碱和钠碱过氧化氢漂白废液对环境的影响.试验结果表明,马尾松CTMP浆镁碱漂白过氧化氢的最佳漂白工艺条件为:H2O2体积浓度为4%,Mg(OH)2质量浓度为1.2%,Na2SiO3质量浓度为1.5%、漂白温度为80℃、漂白时间为120 min,其白度可至63.5%(ISO),而经钠碱漂白后纸浆的白度值为61.4%(ISO).镁碱过氧化氢漂白废液化学耗氧量(CODcr)为193.6 g/L,比钠碱过氧化氢漂白废液化学耗氧量(CODcr=312.86 g/L)降低了38.12%.

Magnesium-based alkalis for hydrogen peroxide bleaching of chemithermomechanical pulp from masson pine are investigated. The results show that the optimum conditions for magnesium-based alkalis for hydrogen peroxide bleaching of masson pine CTMP are as follows, hydrogen peroxide concentration 4 %, Mg （OH）2 concentration 1. 2 %, Na2SiO3 concentration 1.5%, time 120 min, temperature 80 ℃. Under the optimum conditions, the brightness of bleached pulp would reach 63. 5% （ISO）, while the brightness of pulp bleached by using the NaOH as alkali is only 61.4M （ISO）. Compared with NaOH-based bleaching, the CODe, of effluent from bleaching process is cut down by 38. 12% in Mg （OH）2-based hydrogen peroxide bleaching.