Experimental study on the influence mechanism of proximate compositions of different coal ranks on cutting dust generation characteristics

Abstract

To investigate the dust generation characteristics of coal with different proximate compositions during the cutting process of a shearer, this paper conducted similarity simulation experiments on seven coal samples with varying degrees of metamorphism using a self-developed coal-rock cutting and crushing dust generation simulation experimental system. The study systematically analyzed the effects of proximate compositions on relative dust generation intensity, respirable dust concentration, particle size distribution, and particle morphology. The experimental results show that fixed carbon positively correlates with relative dust generation intensity and respirable dust concentration. At the same time, volatile matter and moisture exhibit a negative correlation. Ash content has no significant effect on dust generation characteristics. Proximate compositions also influence particle size distribution and particle morphology. Higher fixed carbon content leads to a broader particle size distribution range and particles tending to be more spherical or square-shaped (with reduced aspect ratios). Conversely, higher volatile matter and moisture content result in a narrower particle size distribution range and more irregular particle shapes. The study verified the significance and validity of the model through F-tests and t-tests, providing a theoretical basis for coal mine dust prevention and control as well as occupational health protection for workers.