混合办公废纸精筛渣回收技术的研究

Study on Fiber Recovery Technology from Mix Office Waste Fine Screen Reject

本课题采用高频疏解及浮选对混合办公废纸 (MOW) 精筛渣进行处理研究。结果显示,高频疏解可将精筛渣中大胶黏物从纤维上剥离并碎解,可去除39. 3%的大胶黏物;后续浮选可进一步分离游离的大胶黏物,当排渣率分别为9. 1%、22. 2%及32. 7%时,大胶黏物去除率分别可达88. 5%、89. 5%及98. 2%;高频疏解可以粉碎精筛渣中的大尘埃,可去除49. 3%～50. 6%的大尘埃,后续浮选对尘埃有进一步的去除作用,且对尘埃大小没有明显的选择性,当排渣率分别为9. 1%、22. 2%及32. 7%时,对应的尘埃去除率分别为71. 3%、77. 7%及80. 8%;高频疏解对纸浆亮度的影响不大;高频疏解一定程度上可将油墨粒子从纤维上剥离分散,并在后续的浮选作用下进一步分离,最终的残余油墨去除率可达49. 3%以上。高频疏解结合浮选从MOW精筛渣回收的良浆可以改善纸张抗张强度及耐破度,抗张指数和耐破指数分别提升20. 2%～23. 5%及29. 3%～32. 3%,而对撕裂度的改善效果不明显。

The treatment of fine screen reject of mix office waste(MOW)pulping by high frequency defibering and air floatation was studied in this paper.The results showed that high frequency defibering could remove and break up the macro-stickies from the fine screen reject,and the total removal rate of macro-stickies could reach 39.3%.The floatation could further separate the free macro-stickies from the discharge system.When the flotation reject rates were 9.1%,22.2%and 32.7%,the removal rates of macro-stickies could reach 88.5%,89.5%and 98.2%,respectively further,the large size dirt could be separated from the system by high frequency defibering and the removal rate of large size dirt(≥0.1 mm 2)could reach 36.4%~38.6%.Floatation had further removal effect on dirt,and there was no obvious selectivity to dirt size.When the flotation reject rates were 9.1%,22.2%and 32.7%,the dirt removal rates were 71.3%,77.7%and 80.8%,respectively.The high frequency defibering had little effect on the brightness of the pulp,while the high frequency defibering could separate the ink particles from the fiber and disperse them to a certain extent.The final ERIC removal rate could reach more than 49.3%.High frequency defibering combined with floatation to recover MOW fine screen reject could increase paper tensile strength and bursting strength,by 20.2%~23.5%and 29.3%~32.3%,respectively,but the effect on tearing resistance was not obvious.