活化温度对赤泥基胶凝材料性能的影响  

Effect of activation temperature on mechanical properties of red mud-based cementitious materials

作　　者：张嘉芮 谭文杰 井敏[1,2] 赵法国 ZHANG Jia-rui;TAN Wen-jie;JING Min;ZHAO Fa-guo

机构地区：[1]山东建筑大学材料科学与工程学院,山东济南250101 [2]山东建科建筑材料有限公司,山东济南250000

出　　处：《砖瓦》2024年第5期40-43,共4页Brick-tile

基　　金：山东省教育厅青年导师访学项目。

摘　　要：在大宗固废利用的背景下,通过对赤泥进行热活化方式提升其胶凝活性,用于制备赤泥基胶凝材料。通过无侧限抗压强度试验机、X射线衍射仪、傅立叶变换红外光谱仪对不同温度活化的赤泥及使用不同温度活化赤泥制备的赤泥基胶凝材料的强度、水化产物的类型进行测试和表征。研究结果表明,不同活化温度赤泥的矿相情况不同,在800℃处于活性最高的亚稳状态,900℃活性降低趋于稳定。使用800℃活化赤泥制备的胶凝材料3d和28d力学性能较未活化赤泥提升了64%和70%,28d抗压强度可达42MPa。分析胶凝材料水化产物的XRD和红外图谱发现,掺加800℃活化赤泥的胶凝材料水化产物的矿相和化学基团与掺加900℃活化赤泥的差别很大,不仅Fe_(2)O_(3)矿相减弱、CaAl_(2)Si_(2)O_(8)·4H_(2)O、Fe_(2)SiO_(4)和KMg_(3)(Si_(3)Al)O_(10)(OH)_(2)矿相增强、赤铁矿参与了水化反应,而且出现了地聚物类凝胶物质和发生最大程度的水化反应,生成致密的结石体,这些都说明800℃是活化赤泥的最佳温度,也是掺加了800℃活化赤泥后赤泥基胶凝材料力学性能最好的原因。In the context of the bulk utilization of solid waste,this paper uses the thermal activation red mud to enhance its gelling activity for preparation red mud-based cementitious materials.The strength of red mudbased cementitious materials and the types of hydration products are characterized and analyzed by uncon⁃fined compressive strength testing machine,X-ray diffractometer and fourier transform infrared spectrometer.The results show that the mineral phase of the red mud experiencing different treatment temperature are vari⁃ous.It is in a metastable state with the high activity after 800℃thermal activation,while in a stable state with the low activity after 900℃thermal activation.The 3d and 28d mechanical properties of the cementitious mate⁃rials prepared with 800℃activated red mud are improved by 64%and 70%compared with that of those with unactivated red mud,and the 28d compressive strength is up to 42MPa.Analysis of the XRD and infrared spectra of the hydration products of cementitious materials show that the mineral phase and chemical groups of the hydration products of cementitious materials doped with 800℃activated red mud are very different from that of those doped 900℃activated red mud.Not only the mineral phase of Fe_(2)O_(3)weakens,the mineral phases of CaAl_(2)Si_(2)O_(8)-4H_(2)O,Fe_(2)SiO_(4),and KMg_(3)(Si_(3)Al)O_(10)(OH)_(2)are enhanced and hematite involves in the hydration re⁃action,but also geopolymer-like gel substances appears and the occurrence of the maximum degree of hydra⁃tion reaction results in the generation of dense crystalline bodies,all of which indicate that 800℃is the opti⁃mal temperature for activated red mud and the why the mechanical properties of the red mud-based cementi⁃tious materials with 800℃activated red mud is the best.

关 键 词：赤泥 胶凝材料 固废利用 活化温度 

分 类 号：X756[环境科学与工程—环境工程]