Study on the transport law of coal loading impact dust and dust suppression technology under airflow disturbance

Coal loading impact is one of the main dust-producing links in open-pit coal mine, especially under the action of natural wind flow, it is easy to cause large-scale dust pollution. Aiming at the problems such as strong meteorological wind, high concentration of loading impact dust and serious dust diffusion pollution in open-pit coal mines in Inner Mongolia, Realizable κ-ε turbulence model and numerical simulation are used to analyze the law of loading impact dust migration under different wind speed disturbances, and to explore the method of dust migration and its effect on preventing and controlling dust pollution. Based on the installation site of Baiyinhua No.3 open-pit mine in Inner Mongolia, the dust suppression technology is optimized and the application and effect analysis are carried out. The results show that the main reason for the migration of dust particles on the downwind side is the vortex wind flow through the loading culvert. With the increase of wind speed, the inhomogeneity of air flow at loading station becomes more and more serious, and the dust particles spread to the downwind area under the entrained action of air flow. The installation of dust suppression net in the dust diffusion pollution path can effectively block the dust migration, and with the increase of the height of the dust suppression net, the wind speed in the downwind area of the loading station decreases significantly, and a low-speed zone with more uniform distribution of wind speed is formed at the exit of the loading culvert, thus reducing the escape velocity of dust particles and effectively controlling the dust diffusion range. In addition, there is a threshold for the influence of the installation height of the dust suppression net on the air flow field and dust migration. Based on the simulation results, the wind and dust suppression net with a net height of 7 m is preferred for field application. The dust concentration measurement results show that the dust reduction efficiency inside and outside the dust suppression net is more than 82.51%, which effectively reduces the dust diffusion range of the loading station, and has great significance for the environmental protection around the mining area.