The effect of cutting speed on the generation of bituminous coal dust: Experimental and theoretical discussion

To address the issue of an unclear mechanism for dust generation, an experiment was conducted to investigate the dust generation and migration under varying cutting speeds of a single cutting tooth. The findings indicate that coal dust production involves a rapid physical transformation process comprising four stages: coal body deformation, formation of the crushing zone, stress release, and collapse of fractured material. Increasing the cutting speed results in a continuous rise in both the total dust production rate and the respiratory dust rate. At a cutting speed of 10 mm/s, the RF coal sample exhibited a total dust production rate of 32.41 g/t, while the HP coal sample had a total dust production rate of 93.10 g/t. The moisture content of the coal samples exhibited a negative correlation with the total dust production rate, whereas the fixed carbon content and porosity showed a positive correlation with this rate. However, the size of the porosity had no significant impact on the production rates of respirable dust and PM2.5 dust. These research findings enhance the understanding of the dust production mechanism during coal and rock cutting, providing guidance for dust control at the origin.