Research On Coal Characteristics And Metamorphic Law

The quality of Longdong coal field is very complex in Xingtai, Hebei province. The characteristics and the metamorphic law of coal in the Longdong coalfield was thorough researched in this paper after numerous experiment analyses such as coal characterization, elemental analysis, industrial analysis, X-ray diffraction analysis, X-ray fluorescence analysis and scanning electron microscope analysis. The metamorphic law was summarized, the genetic mechanism was made comprehensive analysis, and the genetic type was identified. Therefore, it can provide geologic foundation for future exploitationThe Benxi Formation of Middle Carboniferous, The Taiyuan Formation of Upper Carboniferous and the Shanxi Formation of Lower Permian are mainly coal measure strata. Normal faults in NNE～NE direction are the main fractures in this coalfield. 7#upper, 8# and 9# lower coal seams of Taiyuan Formation are stable minable seams. Middle-low ash, middle-high volatile, high calorific value and high Sulfur are main characteristics of the coal in Longdong coalfield. The contents of P, F and Cl is small and the coal belongⅠAs coal.The characteristics of coal quality in Longdong coalfield was studied by using X-ray diffraction method. Combining with the geological background, the XRD structure parameters of the coal were used to illustrate the metamorphic grade and its genetic type.X-ray fluorescence method is one of effective ways in the determination of major elements. The raw data are mass fraction of oxide. Experiment showed that Mid-acidity magmatic intrusiones involve in metamorphsim in this coalfield. By scanning electron microscope, the characteristics of morphology that contained the shape and the size of the pores as well as their paragenetic association was researched, the distribution law of the pores was studied. This experiment showed that the coal had many pores in middle-low rank bitumite.There are numerous types of coal in this coalfield, take lean-meager lean coal, cooking coal, fat coal, gas-fat coal for example, their reserves/resource extent is 14 374 230,11 470 210, 9 370 940,35 731 350 ton in turn. The changes in the various metamorphic coals showed obviously regular distribution.The genetic mechanism of the coal metamorphism in the Longdong coalfield is rather complicated. In this coalfield, there is a middle-small magma intrusion. In consequence, high-rank bituminous coal or anthracite, the high metamorphic grade coal, distributed around the old town, whereas, the low-rank bituminous coal was far away from the town. The metamorphism of main mineable coal seams was affected by the regional metamorphism, as well as, regional magmatic thermal metamorphism.