Evaluation of the performance of surfactants on bituminous coal dust suppression by using microscopic molecular dynamics simulation and macroscopic experimental tests

Abstract The development of mechanization of the coal mining industry has dramatically increased coal production. However, a significant amount of coal dust is generated during production which results in a hazard for the underground miners to overexposure to a high concentration of coal dust. The addition of surfactant into water has been widely used to enhance dust suppression efficiency. However, the performance of the surfactant on the suppression efficiency varies with the different ranks of coal, which is determined by the interaction between surfactant and coal particles. However, this interaction is still unclear, especially at the microscopic level. In this study, the molecular model of a selected type of coal is established. The function mechanism at the microscopic level between suppressant and coal dust molecule is analysed using molecular dynamics simulation based on quantum mechanics theory. The wettability of three functional groups, Benzene-COOH, Benzene-OH and Benzene-CH 3 , of the coal molecule is also evaluated. And Benzene-COOH has the highest adsorption ability to water, while Benzene-CH 3 gives the lowest adsorption ability. Then, the static tests, including surface tension, contact angle, and water retention tests, are conducted to further evaluate the performance of different surfactants. The results show that SDBS compounding with LAD-40 demonstrates the best performance on coal dust wettability. The on-site trial is conducted to further examine the performance of this surfactant compound, and efficiencies of 93.23% and 88.36% are achieved, respectively, for the total dust and respirable dust reduction.