桉木KP浆筛前和筛后氧脱木素的比较研究

Comparative Study on Oxygen Delignification of Screened and Unscreened Eucalyptus Kraft Pulps

对已筛选与未筛选的桉木KP浆进行了氧脱木素的研究。探讨了已筛浆(A)与未筛浆(B)以及氧脱木素以后两者的性能,并对他们进行了纤维分析和光学显微镜(LM)分析。结果表明,桉木经过硫酸盐蒸煮后,得到了卡伯值和白度分别为20.6、21.1和32.5%、31.5%的浆料A和B。在NaOH用量4.0%、MgSO4用量0.3%、氧压0.5MPa的氧脱木素条件下,浆料A和B的脱木素率分别为50.0%和58.3%。未筛选氧脱木素浆经过筛浆机再次筛选得到的浆(B-1)在白度、黏度和得率上都优于已筛选氧脱木素浆(A-1)。浆料A和B相比在纤维特性、显微镜图片上都有一定的差别,但经过氧脱木素后,浆料A-1和B-1的区别不明显。

Oxygen delignification of screened and unscreened eucalyptus kraft pulps was studied mainly using fiber analyzer and optical microscope（LM） in this paper.The result showed that the brightness and Kappa numbers of the screened and unscreened kraft pulps were 32.5% ISO,31.5% ISO and 20.6,21.1 respectively.The delignification rates of screened and unscreened pulps were 50.0% and 58.3% respectively when oxygen delignification conditions were as follows：alkali dosage 4.0%（on oven dried pulp）,magnesium sulfate dosage 0.3%,and oxygen pressure 0.5 MPa.Compared with delignified screened pulp,the brightness,viscosity and yield of delignified unscreened pulp were better.