Abstract:

The Heidaigou open-pit coal mine adopts a throwing blasting-dragline stacking process to remove the overlying rock of the coal seam, and the production process has a significant impact on the air quality of the mining pit. In order to effectively control dust, understand the properties and diffusion characteristics of the main atmospheric pollutants in mining pits, and develop effective air quality control measures for mining pits, the method of on-site sampling and testing was used to study the concentration and dispersion of dust generated by loading. On this basis, the numerical simulation method was used to study the dust diffusion process in mining pits. The results show that at a radius of 100 m in the dragline workplace, the highest dust concentration is 12.5 mg/m³, and the respiratory dust concentration is 1.8 mg/m³. The proportion of dust of < 5 μ with the greatest harm to people is 77.2%. Dust first accumulates in the dumping pit and then overflows to the platform where the dragline stands. As the wind speed increases, the maximum diffusion distance of the dust cluster gradually increases, and the position of the maximum dust concentration gradually moves away from the dust production point, moving towards the position where the dragline stands and showing other diffusion characteristics.

Key words: open-pit coal mine, dragline stacking process, dust, diffusion characteristics, numerical simulation