Research On Coal Spontaneous Combustion Dynamics Mechanism And Inhibition Optimization

In order to analyze the occurrence and development process of coal sample spontaneous combustion and the micro-coal oxygen reaction mechanism,Wuyang and Fusheng coal samples with different spontaneous combustion tendencies were selected for research.By comparing and analyzing the distribution characteristics and change laws of functional groups,as well as thermal weight loss parameters such as characteristic temperature,thermal weight loss rate,and stage mass change rate,it is found that the spontaneous combustion of coal samples depends on the stability of the molecular structure of the coal,and the difference in coal-oxygen reaction is mainly reflected in T₃-T₅ and T₆-T₇.Studies have shown that the micro-mechanism of spontaneous combustion of Fusheng coal samples is due to the side chain system?bridge bonds,side chain groups and reactive functional groups?,directly connected to the aromatic ring skeleton,which itself has a higher chemical activity and reducing the stability of coal molecular structure during oxidative decomposition.In order to study the micro-coal oxygen reaction kinetic mechanism,through thermogravimetric-infrared spectroscopy experiments,the characteristic temperatures at different thermal weight loss stages and the molecular structure and decomposition temperature of the coal reacting in the corresponding stages are obtained.Combining the slope of the characteristic group and functional group content with the temperature changes,The common characteristics of the groups that affect the spontaneous combustion of coal are all obtain C-H bond,C-O/C-O-C bond,and O-H bond.Based on the analysis of the above-mentioned chemical bond oxidation mechanism,combined with kinetic theory,the kinetics of different stages in the low-temperature oxidation process is analyzed.It is obtained that different molecular molecular structures react at different stages,resulting in different coal-oxygen reaction mechanisms at different stages.So the mechanism function obtained by the Kinetic analysis is also different.In order to study the inhibitory effect of various inhibitors during low temperature oxidation?T0-T5?,Method for examining thermal resistance that depended on characteristic temperature,thermal weight loss rate,activation energy,and inhibitory rate was developed.Based on the analysis of the oxidation mechanism of C-H bond,C-O/C-O-C bond,and O-H bond,the physical inhibitors of sodium chloride,potassium chloride,magnesium chloride and the chemical inhibitors of ammonium bicarbonate,diammonium hydrogen phosphate,and urea are selected through the the inhibition mechanism analysis.The inhibitory effect ranking of different inhibitors was obtained as magnesium chloride>urea>diammonium hydrogen phosphate>potassium chloride>ammonium bicarbonate>sodium chloride,and 30%was the optimal inhibitory effect concentration of magnesium chloride and urea,Which was investigated the feasibility of the method for thermal resistance inhibition.The paper has 40 pictures,33 tables,and 90 references.