粉煤灰基多种工业固废混合耐火材料的制备及性能研究

发布时间：2018-03-17 17:34

  本文选题：粉煤灰　切入点：耐火材料　出处：《昆明理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：耐火材料与高温工业相辅相成,近年来,随着高温工业逐步转型升级,耐火材料行业必须紧跟国家“十三五”规划制度,坚持开发与保护并重,杜绝资源浪费,实现节能环保仍须要技术进步创新;粉煤灰是由火力发电厂所产生的固体污染物,我国堆放大量的粉煤灰不仅侵占了宝贵的土地资源,而且给土壤环境、水体环境和大气环境带来了不同程度的污染;煤矸石、铝灰、尾矿石等工业固废同样对环境构成巨大威胁。粉煤灰中含有大量的有价组元,Al2O3和SiO2二者总质量高达60%以上,也是耐火材料中莫来石组分的主要原料。本研究以粉煤灰为主要原材料,并通过混合多种工业固废制备出性能优良的高附加值耐火材料;并研究了烧结温度、原料成分比例、成型压力等因素对耐火材料的性能影响;利用多元相图结合扫描电镜(SEM)对耐火材料的微观形貌特征进行分析。结果表明,使用粉煤灰、铝灰、煤矸石制备了粘土系耐火材料,粉煤灰添加量为50%、铝灰添加量30%、煤矸石20%,烧结温度在1300℃保温10小时的条件下得到显气孔率26.43%、常温耐压强度46MPa、常温抗折15MPa、耐火度1520℃、加热永久线变化+0.3%的耐火材料,该制品的物理性能和使用性能良好,符合国家耐火材料使用标准(YB/T5106-2009)。通过对相同组分、不同烧结温度耐火材料进行XRD分析研究发现,样品内部主要晶相为莫来石相和刚玉相,其中,莫来石相的含量随着烧结温度的升高而增多。根据均匀试验的结果得知,当烧结温度1300℃、成型压力为20MPa时,耐火材料的力学性能和物理性能最佳;成型压力对耐火材料的显气孔率、体积密度及常温耐压强度、常温抗折强度影响较大,烧结温度则对耐火材料的耐火度及加热永久线变化影响较大。以多元相图所提供的“共晶”理论作为理论依据,结合微观结构图像发现,Al2O3含量直接影响着耐火组分的形态及晶型变化。
[Abstract]:Refractories and high-temperature industries complement each other. In recent years, with the gradual transformation and upgrading of high-temperature industries, the refractory industry must closely follow the national "13th Five-Year Plan" system, attach equal importance to development and protection, and put an end to waste of resources. The realization of energy saving and environmental protection still needs technological progress and innovation. Fly ash is a solid pollutant produced by thermal power plants. A large amount of fly ash in our country not only encroaches on valuable land resources, but also gives soil environment. Industrial solid waste of coal gangue, aluminum ash and tailings also poses a great threat to the environment. Fly ash contains a large number of valuable components, such as Al _ 2O _ 3 and SiO2, which have a total mass of more than 60%. It is also the main material of mullite composition in refractories. In this study, fly ash was used as the main raw material, and high value-added refractories with excellent properties were prepared by mixing various industrial solid wastes, and the sintering temperature and the proportion of raw materials were studied. The influence of molding pressure and other factors on the properties of refractories was analyzed by means of multicomponent phase diagram and scanning electron microscope (SEM). The results showed that clay refractories were prepared by using fly ash, aluminum ash and coal gangue. The amount of fly ash is 50, aluminum ash is 30, coal gangue is 20, sintering temperature is 1 300 鈩，

本文编号：1625768