【摘要】 采用SEM,偏光显微镜和热分析仪等方法研究了鹤壁煤层顶板砂岩在常温至1200℃高温条件下微观结构的变化.结果表明,该砂岩在400℃时出现裂隙,600℃出现颗粒破裂,裂隙增加,900℃时大多数颗粒破裂并有烧结现象.砂岩中含有有机物,其析出温度为400～670℃.砂岩在高温作用下微观结构变化是矿物晶体转化、体积膨胀等产生的热应力和有机物析出与迁移共同作用的结果.更多还原

【Abstract】 The microstructure variety of coal roof sandstone produced from Hebi mining area under the room temperature to 1 200 ℃ high temperature has been studied by SEM, polarizing microscope, TG and DTA. The results indicate that cracks in the sandstone appears when the sandstone is heated up to 400 ℃. A few of mineral crystal particles are split and amount of the cracks increase when the temperature is up to 600 ℃. Most of the crystal particles are split and some of them sintered when the temperature is up to 900 ℃. There is organic matter in the sandstone. The releasing temperature of the organic matter is from 400 ℃ to 670 ℃. The microstructure variety of the sandstone results from thermal stress of crystal form transition and crystal volumetric expansion, and decomposition of the organic matter and migration of the decomposing products during the high temperature.更多还原