LAUSR

To know about the reasons leading to variations in dust control efficiency of the surfactant solution spray on coal dust (from the same coal source) with different diameters, the changes of coal dust surface features (specific surface area, pore volume, gas adsorption, and surface potential) with crush degrees and their effects on the wettability were investigated. The experimental results indicated that the surface characteristics of coal dust showed remarkably positive correlations with the crush degree. For example, dust size was reduced from 114.96 to 18.71 μm, the pore volume and gas adsorption of coal dust surface was enhanced by 75%, 104.5%, respectively. It made gas film around dust particles more easily been generated, hindering the contact between dust particles and droplets. The adsorption rate of the surfactant molecules on the coal dust surface was significantly reduced with the dust size decreased, increasing the difficulty of capturing coal dust by surfactant solution. Additionally, based on the linear fitting analysis between surface features and the dust control efficiency, it was indicated that the increased gas adsorption and pore structures on the dust surface was the key factors weakening the dust removal efficiency of the surfactant solution from the perspective of the physical features of coal dust. This study was conducive to optimizing the surfactant-aided dust control technology to better capture coal dust with small size.