Experimental study on dust reduction via spraying using surfactant solution

Abstract Spraying-based dust reduction is the main technical method to prevent and control the dust coal mines. Surfactants can improve the dust reduction effect via spraying to some extent. In this study, an experimental study was performed to investigate the physical properties of surfactant solutions in the spray and the dust-reduction efficiency of spraying. The experimental results showed that as the mass concentration of the surfactant solution increased, the surface tension decreased. When the surfactant concentration reached CMC, the surface tension of the solution would not have significant decrease any more. The surfactant had no significant effect on the dynamic viscosity of the solution. As the mass concentration of the surfactant increased, the contact angle of the droplet on the tablet surface continuously decreased. The atomization characteristics results revealed that the surfactant can promote the atomization effect and cause a small decrease in the droplet size only under the low pressure. Under the constant pressure of 0.7 MPa, the droplet size in the spraying first decreased and then increased with the increase in the concentration of the surfactant. Overall, the droplet size did not have significant change. Based on the experimental results, as the surfactant concentration increased, the dust-reduction efficiency via spraying showed a trend of first increasing and then decreasing. In addition, although the dust-reduction efficiency was improved for both the total dust and the respirable dust by the surfactant, the promotion effect for the latter was much more significant than for the former. The promotion effect of surfactants on the dust-reduction efficiency of spraying decreased with the increase of pressure.