碱法麦草浆黑液碱回收技术的问题与展望

Chemical recovery of black liquor from wheat straw alkaline pulping—problems and prospect

碱法苇浆黑液碱回收在我国已经成功地运行了三十余年。取得了一定的经济与环境效益,成为碱法或硫酸盐法芦苇制浆不可分割的一部分。碱法麦草浆碱回收由于麦草含硅量远远高于芦苇,黑液粘度大,由此而带来一系列的运行障碍,经济与环境效益尚不及前者。却也有若干个这类碱回收车间持续运行了二十余年。当前正从调整原料结构;采用湿法、或干、湿法备料;正在研究向蒸煮液中加脱硅剂等技术措施来降低麦草浆黑液粘度,以改善其运行工况。

For over 30 years, Chinese papermakers have been operating chemical recovery systems for reed-based mills with much success, accumulating quite a bit of experiences in the handling of reed black liquor. Unfortunately, when it comes to wheat straw black liquor, it turns out to be a completely different story. Nevertheless, it has been known that some wheat straw based mills have been persistently trying to keep their chemical recovery systems running during the past 20 years or so. Handling of wheat straw black liquor appears to be greatly handicapped by the high silica content in the black liquor and by the high viscosity of the black liquor. It has been expected that adoption of wet/dry processing of the wheat straw prior to digestion, desilication of the pulping black liquor with chemical aids, and relevant measures taken to reduce the viscosity of the black liquor will help to ease up the problems encountered in wheat straw black liquor chemical recovery.