Enhanced desulfurizing flotation of high sulfur coal by sonoelectrochemical method

Enhanced desulfurizing flotation of high sulfur coal was investigated using the sonoelectrochemical method. The supporting electrolyte used in this process was calcium hydroxide and the additive was anhydrous ethanol. The effects of treatment conditions on desulfurization were studied by a single-factor method. The conditions include anhydrous ethanol concentration, sonoelectrolytic time, current density, and ultrasound intensity. For the coal sample with a particle size of − 0.076 mm, the optimal experimental conditions achieved for anhydrous ethanol, sonoelectrolytic time, current density, and ultrasound intensity are 2.1 mol/L, 20 min, 15 × 10− 3 A/cm2, and 1.2 W/cm2, respectively. Optimal conditions cause a sulfur reduction of up to 75.4%. The raw and treated coals were analyzed by infrared spectroscopy and a chemical method. Pyritic sulfur, organic sulfur, and ash are partially removed. Compared with enhanced flotation by ultrasound or electrochemistry, desulfurizing flotation of high sulfur coal by sonoelectrochemistry is an effective technology.

► Desulfurizing flotation of high sulfur coal by sonoelectrochemistry. ► The electrolyte was calcium hydroxide and the additlve was anhydrous ethanol. ► The rate of sulfur reduction reaches 75.4%. ► Pyritic sulfur, organic sulfur, and ash are partially removed. ► The combination of high sulfur reduction, high yield, and low sulfur content.