微生物矿化技术在烧结法赤泥治理中的应用研究
Application of microbial mineralization in the treatment of sintering red mud
刘鹏 1程钰 2陈龙 1邵光辉1
作者信息
- 1. School of Civil Engineering,Nanjing Forestry University,Nanjing 210037,China
- 2. School of Transportation,Shandong University of Science and Technology,Qingdao 266510,China
- 折叠
摘要
本文研究了采用微生物诱导碳酸盐沉积技术(MICP)处理制铝工业的废弃物拜耳法赤泥.通过试验前后试样的无侧限抗压强度、CaCO3含量及分布、金属离子浸出量、pH值以及应力-应变特性的变化,综合评价了处理赤泥的效果.结果表明:MICP技术可以克服赤泥矿物成分复杂、粒度细小、碱性强、多有害物质特性的不良影响,处理拜耳法赤泥是有效、安全、高效的.在此基础上,通过固结排水三轴剪切试验对不同注浆轮数处理的赤泥试样应力-应变特性进行了研究,发现随着碳酸盐含量的增加,拜耳法赤泥的破坏形态由初始的塑性破坏转变为脆性破坏,抗剪强度有明显的增长.利用多种微观测试手段分析了在这一过程中化学成分、矿物组成、微观结构的变化,揭示了微生物固化赤泥的微观机制.
Abstract
Red mud is a highly alkaline solid waste with very fine particles produced in the production of alumina from bauxite,which is difficult to utilize comprehensively.In this paper,microbial mineralization is applied to the treatment of sintering red mud,and the mineralized products with good cementation characteristics generated in the reaction process are used to cement and solidify the red mud,so as to realize the purpose of using red mud to produce building materials and foundation filling materials.The test shows that mineralizing bacteria can overcome the characteristics of strong alkalinity,high salinity,and fine and uniform particles of red mud,the unconfined compressive strength(UCS)of the red mud sample can reach about 3 MPa and the maximum amount of the newly formed carbonate is 27%.Moreover,due to the unique microstructure characteristics of red mud,it is difficult for mineralizing bacteria to adhere to the surface of red mud particles and their aggregates,thus they are suspended in pores.Therefore,most of the formed calcium carbonate crystals form aggregates,showing a stacking state.Based on this,a new microbial mineralization and cementation mechanism is established,which is suitable for fine particulate matter.
关键词
微生物矿化/赤泥/工业固废/方解石/机理分析Key words
microbial mineralization/red mud/solid waste/microbial calcite/mechanism analysis引用本文复制引用
基金项目
National Natural Science Foundation of China(51809139)
出版年
2023
NETL
NSTL
维普
万方数据