赤泥基碱激发胶凝材料的制备及机理研究

Preparation technology and mechanism of alkali-activated red mud based cementitious materials

系统总结了国内外对赤泥基胶凝材料的研究成果,分析了赤泥种类、掺合料和激发活化措施对赤泥基碱激发胶凝材料力学性能的影响。研究表明烧结法赤泥活性较高,受热活化和水玻璃激发效果较为显著,抗压强度普遍高于25 MPa;拜尔法赤泥较则难以被激发,而目前90%的铝业公司使用拜耳法生产Al2O3。结合已有研究,利用工业固体废弃物脱硫石油焦渣激发拜耳法赤泥,确定了赤泥基激发胶凝材料的基本配合比,经标准养护28 d抗压强度达到25.6 MPa。利用XRD进行的微观分析发现,赤泥中的铝硅酸盐矿物可以在碱性激发剂的作用下发生反应,经过溶解-聚合反应生成聚合物凝胶是赤泥受激发产生强度的主要原因。研究将赤泥用于制备胶凝材料,可以实现赤泥大规模、高附加值的资源化再生利用。

It systematically summarizes the research results of red mud-based cementitious materials at home and abroad.The effects of red mud type,admixture and excitation activation measures on the mechanical properties of red mud base activated cementitious materials were analyzed.Studies have shown that the red mud activity of the sintering method is higher,and the activation effect by heat activation and water glass is more significant.It indicates that the compressive strength of the red mud after sintering is generally higher than 25 MPa.The Bayer process is harder to be excited.However,90%of aluminum companies currently use the Bayer process to produce Al2O3.Combined with existing research,this paper uses industrial solid waste desulfurization petroleum coke to stimulate Bayer red mud.The basic mixing ratio of the red mud-based activated cementitious material was determined,and the compressive strength of the standard curing 28 d reached 25.6 MPa.Microscopic analysis by XRD found that the aluminosilicate mineral in red mud can react under the action of alkaline activator.The polymer gel produced by dissolution-polymerization is the main reason for the red mud to be excited.The research uses red mud to prepare cementitious materials,which can realize large-scale and high value-added resource recycling of red mud.