Experimental Study of Mechanism of 1-Ethyl-3-Methylimidazole Bromide Wetting Coal Power

Abstract

Exploring the optimal experimental conditions and mechanism of a novel functionalized ionic liquid 1-ethyl-3-methylimidazolium bromide ([EMIM][Br]) for enhancing the wettability of coal powder is of great significance for reducing the harm of coal dust. This study determined the critical micelle concentration of [EMIM][Br] aqueous solution through ultraviolet(UV) absorption spectroscopy, and analyzed the mechanism of the influence of [EMIM][Br] aqueous solution on the wettability of coal using characterization methods such as contact angle, scanning electron microscope(SEM), automated surface area and porosity analyzer(BET), and fourier transform infrared spectroscopy(FTIR). The results showed that the critical micelle concentration of [EMIM][Br] aqueous solution was 0.005 mol/L, and the optimal experimental conditions were reaction temperature of 40°C, soaking time of 8 hours, and ratio of 1 g to 20 ml. After the action of [EMIM][Br] aqueous solution, the coal dust stomatal layer zone was developed, wedge-shaped stomata and sheet-filled cracks appeared, and the number of mesopores was increased. The content of hydrophilic functional groups such as C–O, carboxyl(–COOH), hydroxyl ether hydrogen bonds(OH…O), and hydroxyl self-consolidating hydrogen bonds(OH…OH) in the pulverized coal was increased, and the content of hydrophobic functional groups such as aryl hydrocarbons –CH₃ and–CH₂ was decreased, which improved the wettability of the pulverized coal.