造纸黑液酸析法回收木质素

Recovery or lignin from black liquor of paper-making by acidulation method

研究了加酸沉淀回收碱法草浆黑液中木质素的工艺，探讨了酸浓度、温度、ｐＨ值及加酸速度对木质素回收量的影响，得出的最佳条件是：硫酸浓度为５０％，温度为４０℃～５０℃，ｐＨ值为３． ０左右，加酸速度以控制不使产生大量泡沫为准。在上述条件下，本质素的回收效果最佳。

The process of recovering lignin from the alkaline straw pulp effluent black liquor by acidulationprecipitation was studied. The effects of acid concentration (c), pH. temperature (t) and acid now rate on lignin recovery were discussed in detail, while the optimum conditions were obtained : c = 50%, pH=3. 0, t= 40C ~ 50'C and the acid flow rate was controlled not to form a lot of froth. Under the above conditions, the lignin recovery was the best.