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Taking the fully mechanized mining face of bulianta 12511 as the research object, the distribution law of dust movement in fully mechanized mining face with 8m large mining height was numerically simulated by using CFD software. Through the simulation results of the original dust field, it is found that the dust produced by the collapsed coal seam diffuses to the rear of the shearer under the action of wind flow, the highest point of movement of high-concentration dust mass can reach 4m, and the dust concentration gradually decreases along the roadway. High concentration dust is mainly concentrated in the 10m range before and after the shearer and on the side of the bottom plate close to the coal retaining plate, with a maximum of 3500mg/m3. In order to effectively reduce the dust in the working face, prevent dust accumulation and pollute the underground working environment, this paper innovatively proposes to install an airborne dust collector in the large mining height working face to control the dust spreading to the pedestrian side at the dust source and purify the dust. By studying the influence of dust collector placement position and treatment air volume on the dust movement and distribution rule and dust removal effect of the working face, the optimal dust removal efficiency of the working face with large mining height is obtained by the dust collector placement position and treatment air volume adaptation combination, and the maximum dust removal efficiency can reach 100%.

Dust removal by ventilation is a commonly used dust control strategy. This study analyses the characteristics of airflow transport and dust pollution on a fully mechanised top-coal caving face at different inlet wind velocities by using a numerical simulation experiment, and the best wind velocity for dust suppression is obtained. When the inlet wind velocity fluctuates in the range of 0.5 to 3.0 m/s, the overall dust mass concentration on the working face initially increases and then remains stable, but in the range of 2.5 to 3.0 m/s, the changes in the overall dust mass concentration and dust mass concentration of the respiratory zone on the working face are not significant. The dust pollution in the respiratory zone produced by the hydraulic support lowering pillar and moving frame on the working face is quantitatively analysed at different inlet wind velocities of 2.5 to 3.0 m/s to determine the optimum wind velocity for dust suppression on the working face. The optimum wind speed for dust suppression is 2.6 m/s. This study lays a foundation for the ventilation design and dust control in the early stage of a mine and for the establishment of a clean and green production mine.

A fully mechanized mining face is characterized by serious dust pollution and dust is a major cause of pneumoconiosis that haunts numerous miners. For a fully mechanized face having large mining heights, the main dust source in the pavement area is produced by the moving support frame. To reduce the amount of dust during support's movement, the distribution and dissipation of dust in this process were studied by combining numerical simulations with underground measurements. The results showed that with an increase of the distance from the air inlet, the wind speed of the sidewalk in the fully mechanized face first increased, then decreased, and finally increased again. At the position of the coal cutter, the highest wind speed was 1.78 m/s and the average wind speed of the roadway was about 0.8 m/s. The dust concentration at the dust source was >1000 mg/m3. An area with a high dust concentration and having a length of 15 m was formed on the rooftop, together with a 50 m long dust belt with a dust concentration of 300 to 450 mg/m3 in the pavement area of 10 m from the dust source. Beyond the 45 m radius from the dust source, the dust concentration was stable at about 250 mg/m3. Based on the dust production characteristics of the support frame, an enclosed dust-guiding device was designed and structure-optimized. Based on the on-site field application test results, it was found that the device has a satisfactory dust-guiding effect during support movement and the dust suppression rate near the dust source reached 94.8%.