Study On Microstructure Characteristics And Absorbability Of Porous Coal-rock Material

This paper, taking the coal as a special kind of porous and adsorption materials, The microstructure of the coal seam and the gas adsorption properties was discussed. The storage characteristics of coal gas, adsorption and desorption characteristics of coal and gas was studied again. It will do good to the safe enhancement of the coal mining and the improving acknowledge of storage characteristics. Also this will help to the development of the theory and technology, which is of great theoretical and practical significance.By combining the previous theory in the coal structure, analyses 33 coal samples from the four coal mines, namely, TC, ZB, CG and XDD in Heshun, Shanxi Province through various means, including polarized light microscopy, scanning electron microscopy , spectrum analysis, infrared analysis and so on. Finally, and it reveals the a double fractured porous media characteristics of coal bed methane from the coal pores, cracks structural characteristics, and so on. It determines the coal's adsorption capacity and storage performance. Cleat in coal is usually orthogonal or nearly vertical at the coal level. The coal has great micro-pores with a very, very specific surface area. The results showed that the diameter of the micropore was at (0.005～1.5mm) through optical microscopic observation. The diameter of some larger pores, such as original pores, foreign pores and mineral pores, were between 1 to 10nm. The larger the scanning electron microscopy is, the smaller the pores could be observed. At this time, The diameter of the pores are about 0.05～3μm. Surface area depends on the size distribution of micropore volume number, and its relationship with the size of the medium hole is not obvious. Subsequently the author analyzes the coal's gap structure and coal bed methane's adsorption characteristics. The larger the average pore diameter, the smaller the surface area, and the smaller the average pore diameter, the larger the surface area.The main peaks of different coal samples in these IR spectrums were the same, but the locations of each peak were a little different from those of others. The results of the IR analysis reveal that the coal contains a lot of organic matter, and coal macromolecular structure has a variety of functional groups which can result in the adsorption of the coal bed methane gas.It results from the mutual attraction between the coal's surface molecules and the coal bed methane gas molecules. The absorption frequency of direction structure, adipose structure and the structure of oxygen-containing functional groups were basically identical. However, the intensities of them are different, which indicated that they have different amount of functional groups and structures.The molecular composition in the coal's macromolecular structure is very complex, and the adsorption of the coal bed methane gas in the inner surface is physical. This article also summarizes the influential factors of the coal's gas-adsorption as special porous adsorbents under special circumstances and analyzes the feasibility and necessity of establishment of experimental model in the laboratory.