拜耳法赤泥粒径分级预处理的研究  

Study on particle-size separation pretreatment of Bayer red mud

作　　者：刘万超[1] 张校申[1] 江文琛[1] 朱新锋[1] 杨家宽[1] 

机构地区：[1]华中科技大学环境科学与工程学院,武汉430074

出　　处：《环境工程学报》2011年第4期921-924,共4页Chinese Journal of Environmental Engineering

摘　　要：赤泥是从铝土矿中提取氧化铝的过程中产生的工业废渣。分析了拜耳法赤泥的粒径分布,以及主要化学组成和矿物组成在不同粒径赤泥中的变化规律。在此基础上,提出先将赤泥粒径分级预处理,然后根据粗细粒径赤泥的差异分别进行回收利用的思路。研究结果表明,赤泥中粒径大于0.075 mm的粗颗粒以铁、硅、钙为主,实践证明可以通过磁选或重选工艺直接从中回收铁矿;赤泥中粒径小于0.075 mm的细颗粒占赤泥总质量的74.31%,其铝硅比(A/S)由原来的0.81提高到1.08,初步实验证明可以利用还原焙烧-溶出-磁选工艺联合回收铁铝元素。分析认为,该预处理过程具有较好的环境效益。Red mud is the solid waste generated in alumina extracting process from bauxite.The different chemical compositions and mineral phases in Bayer red mud with different size range were investigated.A size separation pretreatment process followed by recovery of value elements from red mud with different size range was proposed.The results show that iron,silicon and calcium are the three dominating compositions in the large particles（≥0.075 mm） from raw red mud.Iron ore can be directly enriched from the bulk particles by magnetic separation or gravitational separation.The content of small particles（〈0.075 mm） in raw red mud is 74.31% by weight.The massive ratio of Al2O3 to SiO2（A/S） in small particle is improved to 1.08 from 0.81 of raw red mud.Primary experiments show that it is possible to recover Fe and Al from fine red mud by reducing roast-dissolution-magnetic separation technique.And it is believed that the pretreatment process is positive to environment protection.

关 键 词：拜耳法赤泥 粒径分级 材料表征 固废处理 

分 类 号：X758[环境科学与工程—环境工程]