Experimental investigation and mechanistic study of coal dust wetting by [BMIM][HSO4]

Enhancing the wettability of coal dust is of considerable importance for effective dust control in coal mines. In this study, the optimal conditions for enhancing the wettability of Huozhou coal dust (CD) using the ionic liquid [BMIM][HSO 4 ] were determined through an orthogonal experimental design. The underlying mechanism by which [BMIM][HSO 4 ] enhances the wettability of CD was systematically elucidated by integrating physicochemical characterization, quantum chemical calculations, and molecular dynamics simulations. The results demonstrated that the optimal treatment conditions consisted of a temperature of 40 ℃, an immersion time of 8 h, and a solid-to-liquid ratio of 1 g:10 mL. Under these conditions, the contact angle of CD decreased markedly from 79.9° to 46.2°, indicating a substantial enhancement in wettability. [BMIM][HSO 4 ] effectively promoted the development of pore and fracture networks within CD, significantly increasing its specific surface area and thereby providing additional pathways for water adsorption and penetration. Meanwhile, [BMIM][HSO 4 ] regulated the surface functional group composition of CD, effectively decreasing the relative abundance of hydrophobic groups while increasing the proportion of hydrophilic groups. Furthermore, [BMIM][HSO 4 ] strengthened the interfacial electronic interactions within the CD-H 2 O system, significantly enhancing the ability of the coal dust surface to adsorb water molecules, increasing the thickness of the interfacial water adsorption layer, and reducing the mobility of interfacial water molecules, thereby promoting the accumulation and stable adsorption of water molecules near the coal dust surface and ultimately improving coal dust wettability.