Combustion kinetics characteristics of fixed carbon in coal series kaolinite

Coal series kaolinite is a kind of rock and a paragenetic mineral of coal. This mineral paragenesis increases the complexity of combustion of coal in kaolinite. Therefore, it is necessary to study its combustion characteristics, which is of positive significance to make good use of coal gangue resource. Taking the combustion mechanism of coke in FCC catalyst as reference, an unreaction shrinking core model for fixed carbon combustion reaction in kaolinite particle was established based on a series of hypothesis. The combustion of fixed carbon in coal series kaolinite was conducted by using an isothermal thermogravimetric method in air atmosphere. Results clearly show that the control step of fixed carbon combustion process below 700℃ is the interface combustion reaction. By means of the unreaction shrinking core model analysis and calculation of unhomogeneous particle system, the combustion kinetics parameters for fixed carbon combustion in coal series kaolinite are obtained, the value of activation energy (E) is 100.12kJ/mol, and the frequency factor (A) is 2.27×10⁶s^-1.