【摘要】 运用X射线衍射、红外光谱及固体高分辨核磁共振等手段,研究了苏州高岭石560~1600℃热变产物,结果显示:①高岭石-偏高岭石-莫来石的转变系列存在结构上的连续性,其转变经历了脱羟阶段(约400~600℃),偏高岭石阶段(600~800℃),相分离阶段(800~1100℃),莫来石阶段(1100~1600℃);②莫来石形成过程没有出现Al2O3的大量分凝,但存在SiO2的分凝;③偏高岭石-莫来石转变过程的中间相为Al-Si尖晶石和准莫来石;④引起1000℃放热反应的主要因素是SiO2的大量分凝,其次是准莫来石等过渡相的形成。更多还原

【Abstract】 A combined approach of XRD,IR,DTA and 29 Si and 27 Al magic angle spin nuclear magnetic resonance(MAS NMR) was used to analyze the thermal transformation products of the Suzhou kaolinite at the temperatures from 560～1600 ℃.From the study we can draw the following conclusions:(1) the co-existence of three Al coordinations(Ⅳ,Ⅴ,Ⅵ coordinated Al) were detected in metakaolinite after kaolinite dehydroxylation and AlV became the major coordinated form;(2) the exothermic reaction near 1000 ℃ led to the formation of quasi-mullite;and(3) the mullite occurred at about 1100 ℃.更多还原