Experimental Investigation of Smoldering Characteristics in Anthracite Coal and Principal Influencing Factors Using Response Surface Methodology

Coal smoldering constitutes a critical safety challenge impeding sustainable development within the global coal sector. This investigation utilizes response surface methodology (RSM) to systematically evaluate critical parameters governing anthracite coal smoldering behavior, specifically analyzing particle size distribution (100–10 mesh), ventilation rate (15.0–25.0 L/min), and moisture content (1–17%). By integrating the entropy method, the study quantifies the contribution of key parameters-smoldering temperature, propagation rate, and activation energy-in the smoldering process, ultimately calculating a comprehensive smoldering hazard index. Experimental results demonstrate that ventilation rate exerts the strongest influence on smoldering temperature, followed by particle size distribution and moisture concentration, based on standardized regression coefficients. Particle coarsening (100–10 mesh) and moisture augmentation (1–17%) elevate activation energy by 9.91–17.63%, while concurrently reducing peak temperature (9.48–10.35%), smoldering propagation rate (30.25–37.37%), and hazard index (62.55–82.16%). Notably, both extremely high and low ventilation rates reduce smoldering temperature, propagation rate, and hazard index. The critical combination of fine particulates (80–100 mesh), moderate ventilation (22.0 L/min), and minimal moisture (1%) yields maximum smoldering propensity, indicating heightened smoldering hazard index. This research provides a theoretical foundation for enhancing fire prevention, reducing energy losses and promoting sustainable coal resource management.