Experimental Analysis on Gas and Solid Residues of Pre- and Post-explosion Coal Dust

The gas and solid residues after coal explosion contain abundant information that can reflect the reaction mechanism and hazardous effects of coal dust explosion. To investigate the characteristics of gas and solid products of coal dust explosion, experiments were conducted in a 20 L spherical explosion vessel. The micromorphology characteristics and chemical functional groups of solid residues were observed by scanning electron microscopy and Fourier-transform infrared (FTIR) spectroscopy analysis. Moreover, the composition and concentration of gas residues were tested by gas chromatography. The results indicated that the coal with low metamorphism after the explosion showed a significant decrease in the volatile content, and more holes and finer particles appeared on the surface of the coal dust particles. In the coal dust explosion process, oxygen-containing functional groups with FTIR bands at 1800–1000 cm–1 and aromatic structures with bands at 900–700 cm–1 are largely consumed, while the aliphatic structures with bands at 3000–2800 cm–1 disappeared. Furthermore, the main gas components after coal dust explosion were O2, N2, CO2, CO, CH4, and C2H4, and the presence of hazardous gas and lack of oxygen pose a threat to people’s lives and safety. The characteristics of gas and solid residues after coal dust explosion can be applied to identify and analyze coal dust explosion accidents and provide a reference for determining the degree of coal dust participating in explosions and the essential causes of explosion accidents.