摘要
为揭示氧化镁对高炉矿渣的活性激发作用、开发镁质废渣尾矿的资源化回收利用新途径,本文以轻烧氧化镁、高炉矿渣粉和水为原料,在高温饱和水蒸气条件下,获得了具有较高力学性能的硅酸盐建材制品。研究考察了原料配比以及水热反应温度、时间等因素对试样力学强度的影响规律,并通过X射线衍射(XRD)和扫描电镜(SEM)等对产物结构及其发展机制进行了表征。实验结果表明,氧化镁对矿渣粉水化活性的激发作用随环境温度的提高而明显增强,水热固化体力学强度发展的主要源泉是水化硅酸钙CSH(B)及纤蛇纹石质结晶水化硅酸镁的生成与聚集。最佳反应条件建议为:水热反应温度200℃、时间6 h,氧化镁掺量为10%。研究结果有助于新型镁质胶凝材料的研发,还可用于矿渣、低品位镁矿、硼泥等工业废弃物的综合回收利用。
In order to reveal the activating effect of magnesium oxide(MgO) on the hydration of slag and to explore the resourced utilization of magnesia-containing industrial wastes,high-activity MgO,slag powders and water were selected as the starting materials to produce building specimens with a remarkable mechanical strength under the atmosphere of saturated steam at elevated temperatures,namely hydrothermal solidification. Systematic investigations were carried out to reveal the dependence of obtained mechanical strength upon the reaction factors,including mixing ratio of the starting materials,the temperature and time of hydrothermal reaction and so on,while X-ray diffraction(XRD) and scanning electron microscope(SEM) were employed to characterize the structural development during the hydrothermal solidification. The results showed that the activation efficiency of MgO for the hydration of slag improved apparently with the increasing temperature,and the realization of mechanical strength in the hydrothermally solidified specimens should be attributed to the generation and aggregation of calcium silicate hydrate(CSH) and high-crystallity magnesium silicate hydrate,i. e. chrysotile. The optimized conditions were suggested to realize a maximum strength,i. e. the reaction temperature and time was 200 ℃ and 6 h,respectively,while the MgO content was 10% in the starting materials. The results must be helpful to the research and development of new magnesia-based cementitious materials,and to realize the resourced utilizations of industrial wastes such as slag,low-grade magnesite and boron slurry.
出处
《硅酸盐通报》
CAS
CSCD
北大核心
2016年第10期3139-3143,共5页
Bulletin of the Chinese Ceramic Society
基金
住宅与城乡建设部研发项目(2015-K4-003)
关键词
矿渣
氧化镁
水热固化
纤蛇纹石
力学强度
slag
magnesia
hydrothermal solidification
chrysotile
mechanical strength
