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

Abstract

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 O 2 , N 2 , CO 2 , CO, CH 4 , and C 2 H 4 , 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.

Coal dilemma: Is in situ clean power plant a way out?

“…Successful experiments with gas detonation engines have provided valuable insights applicable to harnessing coal dust explosions. 15 A significant body of research has been conducted on the macroscopic explosive properties 16,17 and microstructure 18,19 of pulverized coal, which provides a theoretical foundation for the development and application of pulverized coal explosive engines. A proposed clean power plant, constructed in situ, comprises three functional units: a coal mine system, a detonation power generation system, and a transmission system, as illustrated in Figure 6.…”

Enhancement of Coal Permeability Using Aqueous NaCl with Microwave Irradiation

“…where ω (Hz) corresponds to the angular frequency, f (Hz) is the frequency of the electric field, τ w (s) is the relaxation time of water polarization, ε w0 (F/m) is the dielectric constant of water in an electrostatic field, ε w∞ = 4:9 F/m represents the dielectric constant at high frequency, ε 0 = 8:854 * 10 −12 F/m is the dielectric constant of vacuum, and б (S/m) is the conductivity of water. Equation (5) indicates that the relaxation time τ w of the polarization of water media in the microwave field and the dielectric constant ε w0 of water in the electrostatic field are 7 Geofluids important parameters that affect the dielectric loss of water. They are functions of temperature, as seen in equations ( 6) and ( 7), as shown in Figures 6(a Conductivity б, which is closely related to the ion concentration of the solution, is the most important parameter that affects Joule heat loss.…”

“…In coal underground mineral deposits, the working faces gradually shift to the deeper part of the formation as mining opera-tions progress to deeper levels. Also, coal and gas explosions may cause serious injuries to the personnel [5], events that are especially catastrophic [6]. In coal mines, gas has become an important factor restricting the efficiency of mining activities [7,8].…”

Research on the propagation of pressure and CO gas of methane and coal dust coupled explosion

“…In the experiment of explosion under conditions with different air-fuel ratios, Lin et al [23] suggested that the volume fraction of flammable gas in residual gases of CH 4 /coal dust/air mixture explosions is higher than that of CH 4 /air mixtures. Nie et al [24] investigated the characteristics of gas and solid products of coal dust explosion in a 20 l spherical explosion vessel.…”