【作者】 张杜杜；

【导师】 杨家宽；

【作者基本信息】 华中科技大学 ， 环境工程， 2006， 硕士

【摘要】 微晶玻璃是由玻璃控制晶化制得的多晶固体,矿渣微晶玻璃即利用矿渣为原料制备微晶玻璃。在环境问题日益严重的今天,能够把矿渣固废转换成有用的多晶材料应该是一项很有意义的课题研究。本论文就是利用高掺量的赤泥和粉煤灰两种工业固废制备微晶玻璃,然后利用差热分析(DTA)来确定微晶玻璃的最佳核化温度和晶化温度,并进行晶体形成动力学研究,再在此基础上,利用X射线衍射分析(XRD)和扫描显微镜(SEM)研究不同晶化条件下热处理方式对微晶玻璃结构和机械性能的影响,同时还探讨了赤泥微晶玻璃显微组织和机械性能之间的关系、不同晶核剂对赤泥微晶玻璃的影响、熔融法和烧结两种方法制备赤泥-粉煤灰微晶玻璃的区别。研究结果表明:本实验赤泥、粉煤灰的最大掺量可达到90%以上,赤泥-粉煤灰微晶玻璃的最佳热处理工艺为核化温度697℃,保温2h,晶化温度约为950℃,保温2h。以5%TiO2赤泥-粉煤灰微晶玻璃为例,研究得其析晶活化能为306.37 kJ / mol,n为0.7,接近1,证明了赤泥-粉煤灰微晶具有表面析晶的倾向,同时,核化温度对晶体的成核和生长方式影响较大,晶化温度对晶体的生长状态影响较大,另外还研究得出赤泥微晶玻璃显微组织和机械性能之间的关系是不同的晶相和微观结构导致了不同的机械性能,选择机械强度高的晶相和高致密性的微观结构有利于形成高强度的赤泥微晶玻璃。研究赤泥微晶玻璃晶核剂时得出结论:添加1%TiO2的玻璃核化能力小于5%TiO2,也小于5%ZnO,而且随着TiO2添加量的增加,赤泥微晶玻璃的主晶相发生了变化,不同的晶核剂对赤泥微晶玻璃的晶相和微观结构都产生影响。研究熔融法和烧结两种方法制备赤泥-粉煤灰微晶玻璃时得出结论:熔融法的显微结构致密,气孔少,其主晶相是钙铝黄长石(Ca2Al2SiO7),次晶相为钙铁透辉石(Ca(Mg,Fe)Si2O6),随着晶化温度的提高,主晶相和次晶相不发生变化,只是相对比例发生了变化,而烧结法的微观组织均匀,其微晶玻璃更倾向于高温晶化,在晶化温度逐渐提高的过程中,主晶相发生了变化,由钙铝黄长石(Ca2Al2SiO7)变为斜硅钙石(Ca2SiO4)。更多还原

【Abstract】 Glass-ceramic is prepared from the original glass via controlled crystallization, and slag glass-ceramic is made from slags. Because of worsing environment situation, it becomes significative to transform slag and some solid wastes into useful materials. This paper reports the glass-ceramics using the most amounts of fly ash and red mud, two kinds of solid wastes. The best nucleation and crystallization temperatures are determined and the kinetics of glass-ceramics are studied by using DTA, then the influences of heat treatments on the crystal phase, the microstructure and the mechanical properties of glass-ceramics are investigated according to the results of the x-ray diffraction and the SEM. Meantime, another three aspects are investigated, which contain the relationship of the micro texture and mechanical property, the influence of different crystal nucleus on red-mud glass-ceramic and the distinctness of red-mud glass-ceramic in melt method and agglomeration method.The results show: the most amounts of red-mud and fly ash are above 90%, and the best heat treatment technics is 697℃, nucleation temperature, for 2h and crystallization temperature 950℃for 2h. For example, taking 5%TiO2 as crystal nucleus, the active energy of glass-ceramics made from fly ash and red mud is 306.37 kJ / mol. n equals 0.7 and nears 1, which shows that the red-mud glass-ceramic is apt to surface crystallization. At the same time, nucleation temperature has a great influence on the crystal-growing mode, but crystallization temperature has a great influence on the crystal state. On the other hand, different crystal phases and different microstructures result in different mechanical properties, so the crystal phase of higher strength and the denser micro texture is beneficial to shaping high strength red-mud glass-ceramics.The results obtained from the investigation of crystal nucleus of red-mud glass-ceramic show: the crystal capability of 5%TiO2 and 5%ZnO is greater than 1%TiO2, and with the increase of TiO2, the main crystal phase change, so crystal nucleus has a influence on the crystal phase and micro structure of red-mud glass-ceramic. In addition, the results obtained from that the red-mud glass-ceramic is made in melt method and agglomeration method show: the micro structure of glass-ceramic made in melt method is denser, and the air hole in it is less than that in agglomeration glass-ceramic, but the micro texture of agglomeration glass-ceramic is evener than melt glass-ceramic. In melt method, the glass-ceramics contain main crystal phase Ca2Al2SiO7 and minor crystal phase Ca(Mg,Fe)Si2O6, and with the increase of crystallization temperature, the main crystal phase and the minor crystal phase has no change, but their proportion changes. However, in agglomeration method, the red-mud glass-ceramic is apt to higher temperature crystallization, when the crystallization temperature increases, the crystal phase changes from Ca2Al2SiO7 to Ca2SiO4.更多还原