Study on distribution law of coal dust concentration-particle size in fully mechanized mining face of Shoushan No.1 Mine

In order to solve the problems of serious dust pollution and difficult dust removal in fully mechanized coal mining face, we conduct research on the concentration and particle size field of dust in the fully mechanized mining face of Shoushan No.1 Mine, propose the dust source multi-level and multi-dimensional closed atomization control dust removal technology. The results show that the air flow occurs around and across the shearer drum, and the wind speed is up to 2.5 m/s, the wind speed tends to be stable at about 10 m away from the shearer; a high-speed wind flow zone was formed in 9 m area downwind of the center of the front drum, with the average wind speed exceeding 2.0 m/s. The high concentration dust belt with a length of 38 m is formed in the goaf of the unmoved frame area within 10 m away from it, and the concentration is between 1 629 mg/m3 and 2 257 mg/m3. The length of the high concentration dust belt near the center height of the front roller reaches 40 m, and the dust concentration in this range is between 1 590 mg/m3 and 2 845 mg/m3. In the pavement area, the particle size ranges from 0.25 μm to 10 μm, causing great disturbance to the breathing of the downhole workers. After the application of dust source multi-stage and multi-dimensional closed atomization control dust removal technology, the average dust reduction rate of on-site exhaled dust was 84.68%, and the average dust reduction rate of total dust was 88.52%.