Experiment Study On Oxidation And Spontaneous Combustion Properties And Parameters Of Coking Coal After Long-term Water Immersion

Coal spontaneous combustion is one of the major natural disasters in coal mine production safety hazards.Due to the complicated geological,China underground coal mine goaf has many water problems,a large number of residual coal in goaf,coal immersion in water for a long time,when due to natural and man-made factors under the influence of coal and water has been removed,often can quickly the formation of a large area of spontaneous combustion in goaf,and the ratio of spontaneous combustion without soaking coal is more intense,the conventional fire extinguishing measures is difficult to control.After long-term water immersion of coal swelling and its physical and chemical properties will have great change,the difference of the characteristics of oxidation compared with raw coal greatly.The long-term water changes of spontaneous combustion characteristics the coal body lack of system research,therefore,is of great significance for the long-term water immersion of coal spontaneous combustion characteristics and microstructure changes.In order to explore the change of long-term water immersion air dry after the coal spontaneous combustion characteristics and parameters,this paperchooses Xiqu Coal 4# as the research object,in the laboratory by programmed temperature,specific surface area and pore analysis,infrared spectroscopy and so on changes of physical and chemical properties of coking coal,and coal spontaneous combustion simulation platform to complete the design of small water coal spontaneous combustion air coal process simulation.The experimental results show that the water dried coal coking coal formed more pores and fissures,hole diameter and the specific surface area increased with immersion time increased,the coal in primary pore and fracture is more dense and uniform,coal and oxygen to increase the contact area,can accelerate the coking coal spontaneous combustion;after long-term immersion,there-OH,the active groups for coal spontaneous combustion in coal molecule-CH₃,-CH₂-increased,coking coal more easily reacts with air;temperature programmed experiments showed that the oxygen consumption rate increases in the oxidation process,on the rise The temperature will produce more CO,CO₂ oxidation products,but the increase rate will gradually decrease,flooding the dry coking coal activation energy decreases with the increase of immersion time,the spontaneous combustion tendency of spontaneous combustion increased,with the increase of immersion time enhanced to a certain extent;through small coal spontaneous combustion simulation platform for coking coal coal and water 30 the day of coking coal low temperature oxidation experiment,analysis of coal low temperature oxidation process of temperature distribution and gas composition showed that long-term water immersion coke more easily oxidizedin the low-temperature oxidation process,the reaction is more intense,the rate of oxygen consumption and oxidation product of CO,CO₂,C₂H₄ and other oxidation products was significantly higher than that of coal coking coal.Overall,after a long time flooding drying the coking coal spontaneous combustion characteristic is enhanced.