Study On Physical And Chemical Characteristics Of Huadian Oil Shale Of Different Densities

This study has been undertaken to provide an insight into the Huadian oil shale, which was divided into six density fractions using the float-sink method. The results of the proximate and ultimate analysis show that with an increase in density of oil shale, there will be an increase of ash content in oil shale, and fixed carbon content, and a decrease of volatile, element hydrogen, organic carbon and nitrogen content.By utilizing XRD, N2 isothermal adsorption/desorption and thermogravimetric analyzer (TGA) etc. analytic methods, the physicochemical properties of oil shale of different densities were studied. The results show that the kind and content of mineral matters in each density fraction of Huadian oil shale were found similar. Quartz is one of the main minerals in all density fractions, the content of which grows with density. Pyrite exists mainly in the highest density fraction in excluded state. The surface features of low-density pulverized oil shale and high-density pulverized oil shale are very similar and both of them all contain micropore porosity. The medium density fractions mainly contain mesoporous pore. The pyrolysis weight loss of low-density pulverized oil shale is the largest, however, due to the content of clay minerals is relatively small, pyrolysis rate of that is not very high.The microwave retorting experiments of oil shale of different densities were peformed on a self-designed microwave retorting installation. The trace elements content in the four-layer oil shale of different densities was tested in different retorting working conditions by inductively coupled plasma analysis. The results show that the heating up rate of high density fraction (>2.0g/cm3) is maximum in the microwave field. The final retorting temperature of low density fraction (<1.6g/cm3) is highest. The yield of shale oil decreased with the increase of the density of oil shale. The most of the elements,enrichment factor in the semi-coke is largest when the microwave power achieved 500W. The inorganic affinity of trace elements As and Cr is very strong, most of which mainly occurs in the high-density pulverized oil shale. The content of them is almost no change during microwave retorting and most of them occur in the semi-coke. The inorganic affinity of Hg is not very obvious, whose distribution is relatively average in oil shale of different densities and the content is almost no change during microwave retorting. Trace elements B and Mo has a certain organic affinity, which leads to the distribution of them, which mainly concentrate in the low-density pulverized oil shale. During microwave retorting, the trace elements Ni and Mn are released about 40% from the semi-coke.