Experimental study on the effect of surfactant on wettability of anthracite

Abstract

The wettability of coal is of great significance to coal seam water injection and dust prevention. In order to study the influence mechanism of surfactant on the wettability of coal dust surface, the coal dust deposition experiment was carried out with the anthracite in Guizhou mining areas as the research object, and the surfactant solution with the best wetting effect was selected. With the help of infrared spectroscopy experiment and Zeta potential measurement experiment, the change law of coal surface wettability under the action of surfactants was explored. The results show that: the four surfactants used in the experiment can greatly improve the wettability of coal dust. Among them, 1% APG has the best wetting effect on coal dust; after modification, the hydrophilic groups and hydrophobic groups of the experimental coal samples increased, but the increase of hydrophilic groups was significantly greater than that of hydrophobic groups. It shows that the effect of surfactant modification on hydrophilic groups is more significant, which is beneficial to improve the hydrophilicity of coal dust surface; after modification, the surface negative charge of the experimental coal sample increased by about 7.68 times, causing the shear surface in the electric double layer to slide to the liquid surface, and strengthening the dipole force between the oxygen-containing functional groups and the water molecules, resulting in the thickening of the hydration layer and the improvement of the surface wettability of the coal sample.

Keywords

• coal seam water injection
• coal dust
• surfactant
• wetting modification
• sedimentation time
• hydrophilic group
• zeta potential