Abstract:To improve the prevention of spontaneous coal combustion, reduced iron powder and other ingredients should be added together to form an iron-based deoxidizing inhibitor, with the dual effect of oxygen consumption and inhibition. The oxygen consumption rate of the inhibitor was studied through experiments. According to the theory of coordination resistance, the coordination resistance of Fe 3+ was studied via the density functional method. Subsequently, a comparative experiment of the effects on spontaneous coal combustion was conducted. The research shows that several kinds of common resistance agents that are added to the reduced iron powder can consume oxygen. However, the rate of oxygen consumption varies. Fe 3+ produced by the reduced iron powder indicates a strong coordination resistance. When compared with traditional inhibitors of Mg 2+ , Fe 3+ has a stronger inhibition effect on the N, P, and S reactive groups in coal. The overall inhibitory effect is better than that of traditional inhibitors, because of the increased oxygen consumption and the coordination resistance of Fe 3+ on the basis of traditional inhibitors.

According to the influence of the combination of short-distance coal seam group on mining roadway, using numerical simulation software FLAC 2D to draw the abutment pressure distribution ahead the working face and the area of influence in fully-mechanized mining conditions, the variation rules of surrounding rock supporting pressure of floor roadway and the deformation rules were summarized. GYS-300 anchor dynamometer was used to measure the roadway surface displacement, and the conclusions of numerical simulation were verified.

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In view of the stress concentration problem left by the joint coal seams mining since the reservation of the coal pillar, it was proposed that non-pillar mining technology be used in Dongrong No.2 coal mine. The numerical simulation software FLAC 2D was used to draw the relationship between surrounding rock deformation of roadway driving along next goaf and the size of the coal pillar, so the safety and suitable position of roadway was determined. The distribution of lateral abutment pressure was measured by using the ZYJ-30 drilling stress gauge in the coal wall. The conclusions of the numerical simulation were verified.

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