DOC《不同絮凝剂在亚熔盐体系中的沉降性能研究》

不同絮凝剂在亚熔盐体系中的沉降性能研究 公彦兵1,马淑花1,郑诗礼1,李林2,董振新2,刘佳2 (1.

中国科学院 过程工程研究所,北京 100190;

2.中煤金海洋北京化工技术研究院有限公司,北京 100036) 摘要:以亚熔盐法处理拜耳赤泥所得料浆为研究对象,以沉降速度、澄清度、分层效果为评价指标,采用量筒试验法考察了Nalco-

9779、BASF-HP

20、Lcb

8、L1bb和90HS等有机高分子絮凝剂的絮凝性能,最终筛选出最佳絮凝剂为Nalco-9779.重点考察了时间、温度、添加量和碱浓度等因素对Nalco-9779絮凝性能的影响,结果表明,Nalco-9779絮凝沉降的最佳工艺条件为:沉降时间10 min、温度100 ℃、Na2O浓度小于540 g/L、添加量每吨赤泥160 g. 关键词:絮凝剂;

亚熔盐;

赤泥;

沉降性能;

拜耳法 中图分类号:TF821 文献标识码:A 文章编号:1007-7545(2012)09-0000-00 Study on Sedimentation Performance of Different Flocculants in Sub-molten Salt System GONG Yan-bing1, MA Shu-hua1, ZHENG Shi-li1, LI Lin2, DONG Zhen-xin2, LIU Jia2 (1.Institute of Process Engineering, Chinese Academy of Sciences, Beijing 100190, China;

2. Beijing Chemical Technology Research Institute Ltd of Jinhaiyang Company, China National Coal Group Corp, Beijing 100036,China) Abstract: Sedimentation performance of the slurry obtained from the treatment of Bayer red mud through sub-molten salt process was studied by means of cylinder measuring. Sedimentation velocity of slurry, clarity of solution and boundary surface were selected as parameters to evaluate the sedimentation performance with adding of a series of organic polymer flocculants including Nalco-9779, BASF-HP20, Lcb8, L1bb and 90HS, etc. The results show that Nalco-9779 is the optimum one. In addition, the effects of sedimentation time, temperature, dosage of flocculants and concentration of alkaline medium on the sedimentation performance of Nalco-9779 were investigated in detail. The optimum process conditions for slurry treatment mentioned above with use of the flocculants of Nalco-9779 including time of

10 min, temperature of

100 ℃, Na2O concentration of less than 540g/L() and flocculants dosage of

160 g per ton red mud. Key words: flocculants;

sub-molten salt;

red mud;

sedimentation performance;

Bayer process 目前我国90%以上的氧化铝采用拜耳法生产.但当矿石品位铝硅比低于5时,拜耳法能耗和碱耗将大幅度增加,生产成本也会相应提高[1-2].中国科学院过程工程研究所针对低品位一水硬铝石矿物、拜耳法赤泥等处理困难的问题,开发了亚熔盐法氧化铝提取工艺[3-10].新工艺采用了较高的碱浓度,与拜耳法相比体系黏度大、密度大、不易沉降,而沉降分离是氧化铝生产的重要工序[11-16],因此亚熔盐法新工艺对沉降分离所用的絮凝剂提出了更高的要求. 在低碱体系的拜耳法生产工艺中,赤泥沉降分离所使用的絮凝剂主要为阴离子型的聚丙烯酰胺和聚丙烯酸盐类,如国内研制的A-1000[17]、BKN-1[18]以及进口的Nalco和BASF等公司的产品,此类絮凝剂主要特点是阴离子型、高分子量(1 000~2 000万)、溶解速度快、絮凝时间短、分层清晰且上清液清澈等,而在高碱体系的亚熔盐法新工艺中关于絮凝剂沉降性能的研究却未见报道.鉴于此,本文在亚熔盐体系下对多种絮凝剂进行了沉降性能的研究,以期找出适合高碱体系的絮凝剂及其相应的最佳使用条件.

1 试验原料及方法 首先采用亚熔盐法在230 ℃处理河南某氧化铝厂拜耳法赤泥,其化学成分为(%):Al2O3 26.