Research On Lignite Upgrading Process And Dehydration Mechanism

Coal is china's most important fossil energy. With the depleting of oil and gas resources as well as the rising of prices, increasing emphasis has been put on primary energy consumption. Lignite accounts for about 13% of china's total coal resources. In general the seam of lignite is thick, buried shallow and the mining cost is low. It's easy for large-scale mining. However, due to the high moisture of lignite, low calorific value, high transport costs, it is not conductive to long-range transport and storage characteristics, scope of application is limited. At present, the traditional way of lignite quality craft is single, low efficiency and requires large particle size. For the shortcoming of traditional process, this paper uses a process, which provides quality vibration fluidized bed process.This paper explored the vibration fluidized bed method and upgrading process, analysed dry process of lignite and the microwave drying process of physical and chemical properties. With scanning electron microscopy, mercury injection apparatus, fourier transform infrared spectrometer, thermogravimetric analyzer and multifunctional multifunctional analyzer, analysed the structure and morphology of the mass transfer process of coal surface, the aperture of coal, coal and oxygen compound ability, functional group in the molecule of coal and the influence of surface carbon valence state of nature, as well as the relationship between these factors and between coal spontaneous combustion tendency, and to detennine moisture removal effect, spontaneous combustion tendency of low quality lignite optimal process conditions.Research and experimental results illustrate that the low of vibration and fluidization exhibit a mutually reinforcing relationship. Vibration can loose the material, easy the flow; while fluidized role in improving quality at the same time the effects of vibration velocity. Compared with the microwave method, after the mass of brown coal moisture reduced from 1.57% to 0.58%, fixed carbon content from 43.64% to 56.76%, increase heat from 20084 kJ/kg to 26248 kJ/kg. And improving quality of lignite compared this process with a single microwave after the lignite quality, with lower water content, calorfic value of improved features. However, spontaneous combustion tendency to see, lignite quality afte single microwave spontaneous combustion tendency micro vibration fluidized bed than to mention the low quality after spontaneous combustion tendency. Analyzing of the vibration fluidized bed dry lignite under different temperature, temperature at 240? chosen best effect, moisture reduced from 11.51% to 9.14%, increase heat from 12587 kJ/kg to 13628 kJ/kg, and after drying the self-ignition orientation of coal is relatively low.