Toward efficient interactions of bubbles and coal particles induced by stable cavitation bubbles under 600 kHz ultrasonic standing waves

Yuran Chen; Chao Ni; Guangyuan Xie; Qingxia Liu

doi:10.1016/j.ultsonch.2020.105003

Toward efficient interactions of bubbles and coal particles induced by stable cavitation bubbles under 600 kHz ultrasonic standing waves

Ultrason Sonochem. 2020 Jun:64:105003. doi: 10.1016/j.ultsonch.2020.105003. Epub 2020 Feb 5.

Authors

Yuran Chen¹, Chao Ni¹, Guangyuan Xie², Qingxia Liu³

Affiliations

¹ School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou 221116, Jiangsu, China; Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada.
² School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou 221116, Jiangsu, China.
³ Department of Chemical and Materials Engineering, University of Alberta, Edmonton, Alberta T6G 1H9, Canada. Electronic address: qingxia2@ualberta.ca.

PMID: 32062535
DOI: 10.1016/j.ultsonch.2020.105003

Abstract

The interactions of bubbles and coal particles in 600 kHz ultrasonic standing waves (USW) field has been investigated. A high-speed camera was employed to record the phenomena occurred under the USW treatment. The formation and behaviors of cavitation bubbles were analyzed. Under the driving of these cavitation bubbles, whose size is from several microns to dozens of microns, coal particles were aggregated and then attracted by large bubbles due to the acoustic radiation forces. The results of USW-assisted flotation show a significant improvement in recoveries at 600 kHz, which indicates that the interactions of bubbles and particles in the USW field are more efficient than that in the conventional gravitational field. Furthermore, the sound pressure distribution of the USW was measured and predicted by a hydrophone. The analysis of gravity and buoyancy, primary and secondary Bjerknes forces shows that bubble-laden particles can be attracted by the rising bubbles under large acoustic forces. This study highlights the potential for USW technology to achieve efficient bubble-particle interactions in flotation.

Keywords: Acoustic radiation force; Bubble; Interaction; Particle; Ultrasonic standing waves (USW).