Study On Ignition Character And Kinetic Of Coal

With the reduction of high-quality resource day by day, low-quality fuel will gradually be utilized in cement industry. Confined to production technological level of present cement, the range of coal adapted is relatively narrow. The large and medium-sized cement enterprises in our country generally use high-quality bituminous coal and low quality coal can not been used. In order to widen selective range of coals in cement kiln, in this thesis , the research of ignition characteristics , kinetics and microstructure to different quality coal is carried on, which offer the foundation theoretical for the low quality coal used in New Dry Process kiln craft.Coal ignition temperature measurement method by homemade coal combustion comprehensive measurement instrument was studied. Some main influence factors were discussed such as temperature speed , preparing testsample etc.The research show that ignition temperature of steady and reproducible is attained at 10℃/min and pole testsample.Kinetic parameters of different quality coal in cement calciner were studied. Kinetic parameters of twelve coals were attained.The research show that from anthracite, lean coal to bituminous, reaction rate become more and more large and ignition activation energy become more and more small; ignition activation energy falls and reaction rate increases as the volatile content increases;With the carbon content of dry ash-free basis increasing, ignition activation energy increases and reaction rate falls.The relationship of carbon microstructure and ignition character, kinetic parameters of coal by X-ray diffraction was analysied. The research show that the content of disordered carbon is a good index of the reactivity of coal and coal char, correlates with ignition characters very well. Ignition characters of coal is referred as the content of disordered carbon of char before ignition.With the content of disordered carbon declining, the reactivity fall , ignition temperature and ignition activation energy increase.