Electrostatically Dominated Interfacial Interactions Between Surfactants and Rank-Diverse Coals: A Multiscale Simulation and Experimental Validation

The dust generated during coal mining poses a significant threat to miners’ health and safety. Surfactants, as effective agents for improving coal wettability, require a deeper exploration of their microscopic action mechanisms. This study systematically investigates the micro-interaction behaviors and wetting regulation mechanisms of four types of surfactants—anionic (SDBS), cationic (CTAB), zwitterionic (BS-12), and nonionic (AEO-9)—with lignite, bituminous coal, and anthracite through molecular simulations and dynamic contact angle experiments. To correlate the wettability differences with the physical and chemical properties of different coal ranks, XRD and SEM observations were employed to analyze the mineral composition and surface microstructure. The results demonstrate that SDBS has the strongest adsorption capacity on coal, with the wettability capacity ranked as follows: SDBS > CTAB > BS-12 >AEO-9. This research reveals the regulation mechanism of surfactants on coal wettability, providing a theoretical basis for optimizing dust prevention technologies and fostering the development of green mining.