SEM Image Analysis of Pore and Fracture Characteristics of Lignite Under Temperature Gradient

In order to study the microstructure characteristics of coal surface after different temperature and thermal effects of lignite, the SEM images of lignite after different temperatures were analyzed by means of theoretical analysis and experimental measurement (SEM microscanning electron microscopy) to studied the characteristics of organic matter and inorganic substance, fracture channel and pore structure. The results show that: At 150 degrees C, the volume of lignite expands and the pore size becomes larger, and the water loss fracture will be formed; 200 degrees C is the mutation temperature of the pore structure of lignite; After the temperature reaches 250 degrees C, the coal skeleton gradually becomes empty, the coal body starts to soften, produces colloidal fragments, and the fissure structure is more irregular; When the temperature reaches 350 degrees C, the ablation phenomenon is obvious.