Ultrasound-electrochemistry enhanced flotation and desulphurization for fine coal

Abstract

Most studies on coal flotation desulfurization are either focused on the effect of ultrasonic treatment alone or electrochemical method, but there are few studies on the ultrasound-electrochemistry enhanced method. In this paper, ultrasound- electrochemistry enhanced flotation and desulphurization for fine coal is investigated. The effects of ultrasonic power, treatment time, electrolysis current, and the amount of anhydrous ethanol on the desulfurization rate are investigated with Ca(OH)2 as the electrolyte and anhydrous ethanol as an auxiliary agent. The results are compared with the desulfurization effect of electrochemistry and ultrasound-enhanced flotation respectively. Besides, the mechanism of ultrasound-electrochemistry enhanced flotation and desulphurization for fine coal is analyzed. Results show that when anhydrous ethanol dosage, ultrasonic treatment time, electrolysis current, and ultrasonic power are 30 ml, 20 min, 1.5 A, and 250 W respectively, the desulfurization rate and cleaned coal yield of ultrasound-electrochemistry enhanced flotation and desulphurization method reach 75.42% and 72.15% respectively. It is proved that the combination of ultrasound and electrochemistry has a better desulfurization effect on fine coal than ultrasound-enhanced flotation or electrochemistry method.