Synergistic effect of surfactant compounding on improving dust suppression in a coal mine in Erdos, China

Abstract

To effectively improve the ability of water for coal dust suppression using in a coal mine in Erdos, China, surfactant compounding was proposed because of the synergy between surfactants. First, four surfactants with good coal dust wetting ability were selected from a total of 15 surfactants through surface tension, contact angle, and coal dust sedimentation experiments. Next, a compound surfactant was produced by mixing two surfactants in equal volume. The critical micelle concentration (CMC) of surfactants was selected as the concentration of the compound solution. The four surfactants were mixed into six solutions. Then, the wettability of the compound solution was evaluated via surface tension, contact angle, and coal dust sedimentation experiments. The optimal compound solution was selected as an additive to dust suppression by sprinkling in field research in the coal mine. The results revealed that the compound surfactant solution containing 0.025 wt% FMES and 0.025 wt% CDEA was optimal for wetting coal dust, decreasing the surface tension and contact angle by 59.39% (i.e. to 29.23 mN/m) and 83.57% (i.e. to 9.23°), respectively, compared with the respective values of untreated water. Field tests proved that the dust suppression efficiency of the solution containing 0.025 wt% FMES and 0.025 wt% CDEA was >87%, considerably higher than that of water spray, and thus, effective in significantly reducing the dust concentration at the 2104 fully mechanized coal face of a coal mine in Erdos, China.