Research On Spontaneous Combustion Control Techniques Of 065-2 Fully Mechanized Caving At Inflammable And Large Inclined Angle Seam In Gushan Coal Mine

The number of spontaneous combustion accounts for more than 90% of the total number of fires. In China big dip coal reserves account for 14.05% of total coal reserves. The issue of big dip thick seam spontaneous combustion prevention becomes more serious. The coal seam of Gushan Mine is prone to spontaneous combustion,065-2 caving mining area is a big dip thick seam caving mining area which is liable to likely spontaneous combustion, high natural tendency, short period of combustion, and difficult prevention. Combined with the actual site, the use of on-site testing, laboratory experiments, theoretical analysis (simulation), and the method of combining engineering applications, the work carried out and the main results are as follows:(1) Through on-site sampling, indoor TGA experiments, the spectral characteristics experiments, the thesis studies the spontaneous combustion characteristics and the combustion period of the Gushan Mine.(2) By 065-2 big dip caving mining mined-out area gases, temperature field monitoring and numerical simulation studies, the thesis indicates that there are significant differences between big dip caving mining mined-out area and nearly horizontal and gently inclined caving mining mined-out area in oxygen concentration distribution, temperature distribution, air flow velocity distribution, oxidation zone distribution and other aspects. The thesis gets the spontaneous combustion danger zone distribution characteristics of the big dip caving mining mined-out area.(3) By using COMSOL Multiphysics 4.3b?D numerical simulation software, by numerical simulation, the thesis concludes the nonlinear relationships among the amount of nitrogen injection, the location of nitrogen injection, the time of nitrogen injection and the oxidation width.(4) By using numerical solution method, the thesis makes comparative research on the effectiveness of the regulation of mined-out area air flow structure by building masonry wall in the two aspects of wall length and the number of channels, and obtains the quantitative relationship between technical parameters of different air flow structure regulation and mined-out area oxidation width, and effective protection range of building masonry wall; Based on the principle of least squares and after data center processing, using a four-step regression analysis, the thesis gets the quantitative relationships between wall parameters and oxidation width:Lmax=37.318-0.752(xi-10) +0.643(x2-6)+0.267(x2-6)2-0.052(x1-10)2 (R2=0.970), the length of the wall and the number of channels can be increased by reducing oxidation width.By implementing comprehensive control measures of spontaneous combustion, the gas and CO in air flow is safe during the period of recovery, which effectively predicts and prevents the spontaneous combustion of floating coal in mined-out area, and ensures the safety of the period and the efficiency of recovery.