Effect of the ultrasonic standing wave frequency on the attractive mineralization for fine coal particle flotation

Yuran Chen; Saeed Chehreh Chelgani; Xiangning Bu; Guangyuan Xie

doi:10.1016/j.ultsonch.2021.105682

Effect of the ultrasonic standing wave frequency on the attractive mineralization for fine coal particle flotation

Ultrason Sonochem. 2021 Sep:77:105682. doi: 10.1016/j.ultsonch.2021.105682. Epub 2021 Jul 23.

Authors

Yuran Chen¹, Saeed Chehreh Chelgani², Xiangning Bu³, Guangyuan Xie⁴

Affiliations

¹ School of Materials Science and Engineering, Zhengzhou University, Zhengzhou 450001, Henan, China; School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou 221116, Jiangsu, China.
² Minerals and Metallurgical Engineering, Dept. of Civil, Environmental and Natural Resources Engineering, Luleå University of Technology, SE-971 87 Luleå, Sweden.
³ School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou 221116, Jiangsu, China. Electronic address: xiangning.bu@foxmail.com.
⁴ School of Chemical Engineering and Technology, China University of Mining and Technology, Xuzhou 221116, Jiangsu, China.

Abstract

Froth flotation for mineral beneficiation is one of the most important separation techniques; however, it has several challenges for processing fine and ultrafine particles. Attractive mineralization between particles and bubbles by ultrasonic standing wave (USW) is a novel and high-efficiency method that could assist fine particle flotation. Frequency is an important ultrasound parameter, whose effectiveness mechanisms on the attractive mineralization did not compressively address. This study explored the effect of the USW field with various frequencies on the fine coal flotation for filling this gap. Herein, a high-speed camera and a focused beam reflectance measurement (FBRM) were used to analyze three sub-processes of the attractive mineralization, including the microbubbles' formation, the conventional flotation bubbles (CFBs)' dispersion, and the particles' movement. It was found that the maximum flotation metallurgical responses were obtained under the highest examined USW frequency (600 kHz). However, the flotation outcomes by a low USW frequency (50 kHz) were even lower than the conventional flotation tests. Observation and theoretical calculation results revealed these results were originated from the influence of frequency on the carrier bubbles' formation and the action of the secondary acoustic force during USW-assisted flotation. These outcomes demonstrated that frequency is a key factor determining the success of attractive mineralization for fine particles' flotation.

Keywords: Attractive mineralization; Fine coal; Flotation; Frequency; Ultrasonic standing wave.