Study On Microstructure Variation Of Soaked Bitumite On Low Temperature Oxidation Process

Western China as an important strategic energy reserves has rich coal resources, but where coal is about 90% lower rank bituminous coal, and the vast majority of the coal seam spontaneous combustion tendency to self-ignition or spontaneous combustion seam. In the mining process in the lower face, usually adopt water exploration and hydrophobic measures to combat the formation of goaf water damage. This is very easy to form a leakage and oxygen supply channel, and long-term coal left in soaking conditions, leading to changes in the coal. Thereby increasing the float coal goaf spontaneous combustion risk of oxidation that causes goaf area spontaneous combustion of residual coal.In order to grasp the spontaneous combustion of soaked bitumite, in this paper, the typical western bituminous coal mining as the main object of study samples, using experimental and theoretical studies on the method of combining to study the microstructure variation of soaked bitumite on low temperature oxidation process, exploring the microscopic mechanism of spontaneous combustion flooding bituminous coal, which is of great theoretical significance of their resistance and effective control technology research.By industrial analysis experiment, scanning electron microscopy experiments and the specific surface area measurement experiments, analyzed the relationship among the degree of metamorphism and coal surface area, total pore volume, average pore size. studied the microscopic surface physical structure of original bituminous and soaked bitumite. The results showed that: bituminous coal drying after flooding its pore structure and fracture surface increases and the number increased significantly, total pore volume and surface area similar to more primitive bituminous coal are reduced, increasing the average pore diameter, pore and fracture connectivity better, it is conducive to the adsorption of oxygen, increased oxidative bituminous coal spontaneous combustion.By FTIR infrared spectroscopy experiments at different ranks and different experimental conditions of oxidation temperature, analyzed the infrared spectrum characteristics of original bituminous and soaked bitumite. The results show that: the coal molecule content of the largest functional groups are oxygen-containing functional groups, followed by aliphatic hydrocarbons and hydroxyl content of the smallest functional group is aromatic; in the early low-temperature oxidation process, flooding coal coal molecule aromatic nucleus structure is relatively stable basically does not participate in complex reaction, and the reaction, aliphatic hydrocarbons and oxygen-containing functional groups of strong activity, in which a methyl group, methylene group, a carboxyl group, an ether bond and an aromatic ether oxygen bond easily with oxygen complex reaction, these groups may be inducing factors of coal spontaneous combustion oxygen recombination, resulting in spontaneous combustion of coal the main active groups.