The effects of dust on gas explosion characteristics induced by high-temperature heat source

Abstract Gas outbursts in coal mine goafs can entrain coal dust from the surface of spontaneously combusting coal, significantly increasing the risk of methane/coal dust explosions that often result in catastrophic accidents. However, few studies have investigated the explosion characteristics of methane/combustible dust mixtures ignited by high-temperature heat source. To address this, a self‑developed gas explosion setup was employed to examine the effects of coal dust on methane/air explosions under high‑temperature ignition conditions. Specifically, experiments were conducted to clarify the relationship between coal dust concentration and ignition temperature. The results demonstrate that the explosion process of methane/coal dust mixtures induced by high-temperature heat source follows a pattern similar to that of conventional methane/air explosions. Notably, the addition of coal dust significantly affects key explosion parameters ( P , d P /d t , T ). Based on these findings, a comprehensive method for assessing the explosion risk of methane/coal dust mixtures is proposed, which identifies the most hazardous concentration for the tested coal dust and reveals the underlying explosion reaction mechanism. Furthermore, the coal dust ignition temperature experiments proposed by Palmer and Tonkin were validated, their prediction formula modified, and an improved prediction formula for coal dust ignition temperature was derived. These findings provide experimental and theoretical support for enhancing safety in coal mine goafs and improving industrial explosion prevention.