以硫酸盐桉木浆为原料研究了氧脱木素工艺条件对草酸根形成的影响,分别进行了不同时间、温度、氧压和用碱量(NaOH质量分数)下的单因素试验.在此基础上,利用响应面分析法中的Box-Benhnken实验设计对氧脱木素的主要工艺条件进行了优化.实验结果表明,在硫酸镁用量为0.2%(质量分数)、浆浓为10%的情况下,控制氧脱木素过程中草酸根形成的最佳工艺条件如下:温度100℃、用碱量1.5%、反应时间60 min、氧压0.5 MPa.在上述工艺条件下,草酸根含量为0.25 g/L,卡伯值差值和黏度差值的比值为0.045.
The oxalate formation of the kraft pulp with different influence factors(namely time,temperature,oxygen pressure and alkali charge(NaOH mass fraction) during an oxygen delignification process was investigated by single-factor experiments. On this basis,the Box-Benhnken experiment of the response surface methodology was conducted to optimize the main factors influencing oxygen delignification. The results show that,under the condition of 0. 2% MgSO4 and 10% pulp consistency,optimal oxalate formation conditions during the oxygen delignification are a temperature of 100 ℃,an alkali charge of 1. 5%,a reaction time of 60 min and an oxygen pressure of 0. 5 MPa. Under the optimal conditions,the oxalate content is 0. 25 g/L and the ratio of the Kappa number difference to the viscosity difference is 0. 045.