Study on pollution evolution law of coal and rock mixed dust in coal–oil shale fully mechanized mining face: a study case

To better understand the dust dispersion and pollution laws in coal–oil shale fully mechanized mining faces, the airflow distribution and coal and oil shale mixed dust emission law was simulated, and the simulation results are analyzed and verified in combination with the field measured data. The research results showed that in the area 0–10 m on the leeward side of the front drum, most of the coal dust particles with a large particle size stay near the roof of the hydraulic support and the height of the breathing zone, while most of the oil shale dust particles with a large particle size stay in the area below the height of the breathing zone. In the height of the breathing belt, oil shale and coal dust particles seriously polluted the 0–6-m and 0–13-m areas on the leeward side of the front drum of the shearer, respectively. According to the different distribution of coal dust and oil shale dust, a wet dust collector and multi-nozzle atomization set are designed to remove dust. The field test results show that the dust removal rates of the two kinds of dust reach 83.4% and 87.5% respectively after the dust removal device is opened.