Simulation Study on the Wettability of Solutions and Coal under the Synergistic Effects of Magnetic Fields and Inorganic Salts

This study aims to enhance dust suppression efficiency by investigating the synergistic effects of inorganic salts and the magnetic field on water wettability. Four inorganic salts, sodium carbonate, sodium sulfate, magnesium chloride, and calcium chloride, were selected based on the composition of mine water from the Shigetai Coal Mine to evaluate their effects on the surface tension of aqueous solutions. Additionally, these salts were combined with a magnetic field to further reduce surface tension and improve wettability. Materials Studio simulations were used to investigate the primary ionic mechanisms affecting surface tension and to evaluate the influence of typical coal-dust functional groups on the adsorption energy of salt solutions. Experimental results showed that magnetizing a 0.05 wt % sodium carbonate solution at a flow rate of 1.6 L/min under a 240 mT magnetic field for 20 min significantly reduced surface tension. In addition, the addition of inorganic salts to the solution can reduce the magnetization conditions required to achieve the minimum surface tension. Simulations further revealed that both Na⁺ and CO₃^2- ions reduce hydrogen bond energy, with carbonate ions playing the dominant role. Among the coal-dust functional groups, the carboxyl and methoxy groups exhibited the strongest influence on adsorption energy. These findings offer new insights for improving dust suppression strategies.