Qualitative and quantitative characterisation for explosion severity and gaseous–solid residues during methane–coal particle hybrid explosions: An approach to estimating the safety degree for underground coal mines

Abstract

Methane–coal dust explosions can damage coal mining equipment and the working environment by overpressure, particulate release, and gas emissions. In this study, we investigated the influence of fuel concentration and coal particle size on multiple explosion parameters for methane–coal particle mixtures within a 20-L sphere. Next, we analysed the effects of fuel concentration and coal particle size on the oxygen consumption index (OCI). Then, we determined the quantitative and qualitative data pertaining to oxycarbides and hydrocarbons. The surface microstructures, pore structure properties, chemical composition, particle size distribution, and thermal hazard of solid residues and raw samples were systematically evaluated. Results revealed that fuel concentration and particle size exert large influences on the explosibility of methane–coal dust mixtures. Oxycarbides and hydrocarbons were analysed because they are useful for predicting explosions and monitoring air quality. We investigated the effects of microstructure, pore structure, and particle size. We proposed a mechanism by which methane–coal particle hybrid mixtures induce explosions, including the formation pathway of gaseous and solid products. This study aids strategic decision-making pertaining to the prevention of methane–coal dust explosions.