Mineralogical of the Jurassic coals in the middle of Ningdong Coalfield

26 samples,including 25 coal-seam samples and one parting,were collected from 7 mines in Ningdong- Coalfield,Ordos Basin,China. Proximate,total sulfur and gross calorific value were analyzed of the 25 coal samples. The composition,chemical composition and micro-topography of samples were studied by low-temperature ashing-X-ray diffraction (LTA-XRD),optical microscopy,scanning electron microscopy (SEM) and energy dispersive spectroscopy ( EDS). The sources of minerals in coal were discussed. The results indicate that Jurassic coal in middle part of Ning- dong Coalfield is a medium volatile bituminous coal,with medium-ash,low-sulfur and low-medium calorific,the miner- al composition (low temperature ashes) is as follows:33. 1% kaolinite,22. 8% illite,21. 5% quartz,13. 2% albite, 6. 6% chamosite,2. 8% calcite. In addition,a trace of pyrite,siderite,ilmenite,chalcopyrite,zircon also found by the scanning electron microscope. Kaolinite,illite,chamosite,quartz,and albite are origin from weathering productions of gneiss,granulite and granite in HelanMoutain.