Study On The Influence Of CO₂ On The Microstructrue Of Coal Oxidation Based On The Characteristic Temperature Point

The combination of coal and oxygen leads to spontaneous combustion of coal.Coal spontaneous combustion is the main cause of coal mine fire in China.The technology of carbon dioxide prevention is an important technology in coal fire prevention.In order to study the microscopic effect of carbon dioxide on the auto ignition process of coal.In this paper,the change of characteristic temperature point in coal spontaneous combustion temperature is compared under different atmosphere.The critical temperature and dry crack temperature in different atmosphere are obtained.Peroxidation of coal samples under the same conditions.Then the coal samples were studied by infrared and XRD experiments to study the changes of the functional groups and crystal structures.Experiment with coal.The characteristic temperature change of coal under different conditions is analyzed.The characteristic temperature of coal rises with the increase of carbon dioxide concentration.The atmosphere of carbon dioxide is higher than that of coal under nitrogen atmosphere.The oxygen consumption rate of coal samples under the atmosphere of carbon dioxide is lower than that of nitrogen.Through the infrared spectrum experiment and the XRD experiment.It is concluded that with the increase of oxygen concentration,the c-o and hydroxyl groups of the critical temperature and dry crack temperature have increased.As the oxygen concentration decline-COO,decrease the content of C = O,reasons for prevented the occurrence of coal oxidation,carbon dioxide in the coal sample represented by-C-OH-C-O-key more difficult to be oxidized to carboxylic acid of C = O bond;The high and low levels of benzene content in coal are mainly affected by the temperature of the coal,and the aromatics and aromatic rings are mainly affected by the temperature.The content of fatty hydrocarbon in coal increases with the increase of carbon dioxide concentration.The chemical properties of fatty hydrocarbons are unstable.When the concentration of carbon dioxide increases,the carbon dioxide gas molecules impede the oxygen uptake,and more fatty hydrocarbons cannot react with oxygen.There was no significant change in the type and oxygen concentration of the gas in the high Lc and the effective stacked aromatic films.Dryness temperature crystal stack height Lc and effective number of pile aromatic piece Mc each crystal parameters are less than the critical temperature point,this shows that the temperature mainly affects crystal stack height,ductility and crystal parameters such as effective stack aromatic piece number.