In order to solve the problems of insufficient filtration performance of bag dust collector in coal mine and improper selection of filter materials, the performance parameters of seven kinds of filter materials were compared and analyzed. The results showed that with the increase of filtration time, the resistance of different filter materials showed an upward trend, the resistance of ordinary filter material increased rapidly, while the resistance of membrane filter material increased more gently. The time required for ordinary filter material to reach the cleaning cycle is relatively short, the cleaning cycle of polyester filter material is 80s, and the amount of dust accumulated on the surface of membrane filter material is always in a rising state. When the dust particle size is between 6.5 μm and 23 μm, the dust removal efficiency of PTFE filter material increases with the increase of filtering wind speed; The field practice shows that after the LFD-45 horizontal film-coated flat bag precipitator with pre-installed PTFE filter material is installed on the tail guide trough of 106belt conveyor, the dust reduction rates of total dust concentration and respirable dust concentration are 98.57% and 98.95% respectively.

To effectively improve the dust reduction rate of fine dust and prevent the occurrence of secondary dust, surfactant-charged water mist dust reduction technology is proposed. First, the water mist induction-charged atomization mechanism was perfected by an induction-charged spray experiment and the optimal atomization-charged voltage was determined to be 10 kV. Second, by surface tension and spray experiments on AEO-9-charged solutions, the lower the surface tension and viscosity of the solution, the better the atomization effect; the best atomization solution was 10 kV and 0.02% AEO-9. Finally, according to an electrostatic adsorption experiment, it was identified that there was an electrostatic interaction between coal dust and charged droplets. The contact angle experiment showed that the contact angle of the AEO-9 droplets decreased by 68.44% compared with water after 3 s of contact with coal dust. The wetting effect of bituminous coal was significantly improved by adding AEO-9 to water. A molecular simulation was used to study the molecular interaction mechanism among the H₂O, AEO-9, and bituminous coal molecules. The simulation results showed that AEO-9 was more active than water, it easily interacted with bituminous coal, and the hydrophilic group covered the surface of the bituminous coal molecules, which increased the electrostatic interaction between the water molecules and bituminous coal surface molecules. After adding AEO-9 to H₂O, the intermolecular interaction energy of the H₂O/AEO-9/bituminous coal system was enhanced more than that of the H₂O/bituminous coal system. This study provides the basis for the application of surfactant-charged water mist dust reduction technology.

To better solve the problem of dust pollution at the coal transshipment point, the particle tracking calculation method based on the discrete phase model was adopted to study the dynamic three-dimensional flow field of falling dust during coal transshipment. The induced airflow field characteristics and the dust particles migration law at different times and sections were simulated, and the power function relation between the initial falling velocity, falling height, and the induced airflow rate was deduced. The results showed that in the process of coal falling onto the belt, the induced airflow continuously sucked fresh air to form a vortex due to the reduction of vertical static pressure in the vertical direction and self-generated turbulence. The direction of induced airflow at the coal dropping point was different, and the horizontal airflow velocity could reach 1.4 m/s. The spiral migration path of dust particles was formed by the influence of the eddy current. At the same time, under the effect of the negative pressure caused by the induced airflow, the dust particles carried by the coal were emitted from the outlet of the guide trough, and the dust mass concentration was as high as 540 mg/m³. Meanwhile, the induced airflow velocity of falling point increased with the increase of initial falling velocity and coal material falling height, which matched to power function exponents were 1.01 and 0.41 respectively. With the increase of the falling height, more negative pressure air was absorbed into the blanking pipe, which lead to the increase of dust mass concentration in position after the feeding point. The maximum dust mass concentration was 715 mg/m³.