| BuLianGou coal mine exploited a extremely thick seam called 6#, which has spontaneous combustion tendency, depth is 200m. The shortest spontaneous combustion period is 12 days. In order to master it is spontaneous combustion characteristics of coal, law of spontaneous combustion in gob, and their relationship, by means with laboratory experiment, field measurement, theoretical analysis and numerical simulation, the main results are obtained as follows.Using strap tube technology to monitor gas distribution in gob, use of software called Fluent to simulation air leakage and oxygen concentration condition, then divided gob into three zones of the spontaneous combustion, determined the distribution of spontaneous combustion danger zone, which is oxidation zone close to working face in it's central section while far away in it's both ends, and confirmed a security advance speed which can restrain easy self-ignition. Through field measurement, grasp the strata behavior regularity of first weighting and periodic weighting, obtain the conclusion the roof form "step rock beam" or "short masonry beam" after roof breakage by using of key strata theory and explain why large pressure intensity, small roof weighting step and surface step subsidence. Using RFPA2D to simulate the abutment pressure of surrounding rock caving, based on support pressure of gob floor, Based on characteristics of the roof sliding instability to analysis flow characteristics and permeability with airflow in porous media. Calculated expansion coefficient and permeability coefficient of gob broken rock. Comparative analysis the distributions of spontaneous combustion three zones under a condition of different roof characteristics in initial mining and normal recovery level, and obtained their correspondence. Established a model that broken of key layer collapse gob, then analysis the relationship between CO emission and pressure in working faces. |
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