Element And Mineralogical Characteristics Of Jurassic No.4 Coal In Xiaozhuang Mine,Shannxi

This thesis takes No.4 coal from Xiaozhuang Coal Mine in Shaanxi Province as the research object,mainly based on the theories of coal petrology,mineralogy,sedimentology,coal geology,petrology and geochemistry,and carries out X-ray fluorescence spectrum Polarization microscopy observations,inductively coupled plasma mass spectrometer,scanning electron microscopy observations with energy spectra,and X-ray diffraction to analysis on coal and rock samples.The data are processed with the software of CAD,Origin,CorelDRAW,SPSS and so on.The distribution law,occurrence state,correlation and enrichment mechanism of the elements in coal and the mineral form and occurrence characteristics are studied and the characteristics of coal quality and the sedimentary environment of coal measures are discussed.The results show that the minerals in Xiaozhuang No.4 coal mainly consist of clay minerals and carbonate minerals,and contain a small amount of pyrite.Kaolinite has a high content and a wide distribution in clay minerals.The imime mixed layer is found.Carbonate minerals are epigenetic minerals that are usually filled with organic matter,and are not common minerals such as potassium feldspar,gypsum,zircon,rutile and potash.The symbiosis of quartz,Jin Hongshi,kaolinite and pyrite was also discovered.The content of Pb in coal and gangue in No.4 coal of Xiaozhuang is higher than that of Chinese value,Clark value and world value.The elements such as Li,Cu,Tl,Pb and Bi are enriched in coal,and the elements such as Li,Ga,Cu,Rb,Cs,Ba,Rb,Cs are enriched in the gangue,which belong to terrestrial sediments are affected by terrestrial debris.The difference in sedimentary debris in the source area and the flow of water resulted in the trace elements such as Be,Cs,Pb,and U in gangue are slightly higher level than in the bottom plate.The remaining trace elements are relatively high in the coal floor.The type of rare earth elements in Xiaozhuang No.4 coal belongs to light-rich rare earths.The majority of trace elements in Xiaozhuang No.4 coal and ash content are significantly related and the relationship between REY elements and clay minerals is close,most of the elements exist in clay minerals.Mn and carbonate are highly correlated,and it may be exist in calcite.Li and Cs,Be and Ga,Ga and Rb,U,In and Rb,In and Rb were significantly correlated,indicating that they have similar occurrences.Xiaozhuang No.4 coal is low-ash,medium-high calorific value,medium-high volatile,and low-sulfur coal.The coal-forming environment is mainly continental lacustrine deposits,which belong to a terrestrial clastic sedimentary system formed by the lakeshore uplift.