| Popis: |
The sandstone strata in the Shendong coal field have lots of structural planes, which has a significant influence on the mechanical properties, ultrasonic wave propagation, failure mode and force transfer of the strata. The structural plane in the sandstone strata of the Buertai, Daliuta, Bulianta mine was chosen as the research object, and their microstructure and element characteristics were studied by using FEI-SEM and Energy Dispersive X-ray Fluorescence Spectrometer (EDXRF). Results show that the structural planes in sandstone of the Shendong coal field can be divided into two types (Ⅰ and Ⅱ), with Ⅰ being further divided into three subgroups (Ⅰ1, Ⅰ2, Ⅰ3). TypeⅠ mainly contains coal, whereas typeⅡ mainly contains muscovite. TypesⅠ1 and Ⅱ structural plane particles are not obvious and the particle boundaries are not clear. But the particles of typeⅠ2 and Ⅰ3 structure planes are more obvious with much clearer particle boundaries. The pore diameter and fracture length of typeⅠ1 structure plane are 2.1 μm and 81.8 μm, respectively, whereas those for typeⅠ2 structure plane are 8.9 μm and 38.8 μm, respectively. The pore diameter and fracture length of typeⅠ3 structure plane are 4.5 μm and 143.7 μm, whereas those for typeⅡ structure plane were 3.8 μm and 13.8 μm, respectively. The main elements of typeⅠ1 structure plane are C, O, Si, Al, K, Ti and Fe, whereas the main elements of Ⅰ2 structure plane is C. The main elements of Ⅰ3 structural plane are C, O, Si, Al, K and Mg. The main elements of typeⅡ structural plane are C, O, Si, Al, K and Ti. Therefore, C and O are the main elements of the structural planes in the strata of the Shendong coal field. The microstructures of the two types of structural planes are different. The results are helpful to further reveal the roof dynamic disaster and step subsidence in the Shendong coal field. |
