电加热下褐煤微观结构的演化研究及其工程应用

Microstructure evolution of lignite under electric heating and its engineering application

针对我国低变质煤层开采难度大、成本高的现状,利用电加热法对低变质煤中褐煤的微观结构进行了研究,利用精细显微CT系统分别观察了25℃、300℃、400℃、500℃后褐煤的微观孔隙,利用3D数字岩芯技术建立了三维孔裂隙骨架图,得到高温作用后,试样孔裂隙发育以及孔隙率都得到明显的提升,其中,400℃后,试样热解充分,孔隙发育完全,试样的孔隙率出现陡增,可见,持续高温作用下,有机质热解充分,加快了孔隙的发育。

Aiming at the current situation of difficult and expensive mining in China ’ s low metamorphic coal seams,the microstructure of lignite during electric heating is studied,which is observed at 25℃,300℃,400℃ and 500℃ with microCT. And a three-dimensional pore fissure skeleton diagram of lignite is established using 3 D digital core technology. After treated by high temperature,the pore fissure development and porosity of the sample are significantly improved. After 400℃,the sample pyrolysis is sufficient,and the pore development is complete,the porosity of the sample increases sharply. It can be seen that under continuous high temperature, the organic matter is pyrolyzed sufficiently, which accelerates the pore development.