Effect of ultrasonic standing waves on flotation bubbles

Ultrasonics Sonochemistry

Kanghui Zhang¹  Yanan Tu²  Weidong Wang³  Ziqi Lv⁴  Lizhang Jin⁴ 

[1] School of Chemical and Environmental Engineering, China University of Mining&Technology (Beijing), Beijing 100083, China;Technology (Beijing), D11, Xueyuan Road, Haidian District, Beijing 100083, China.;;Corresponding author at: Yifu 217, China University of Mining &School of Chemical and Environmental Engineering, China University of Mining&Technology (Beijing), Beijing 100083, China;

关键词: Bubble aggregation;    Entrapment and entrainment;    Standing waves;    Standing waves ultrasonic flotation;   

DOI  :  

来源: DOAJ

【 摘 要 】

Ultrasonic flotation was an effective method to float fine coal. In this study, the effects of the standing waves with different frequencies on ultrasonic flotation were investigated. The dynamic processes of bubble and coal-bubble were revealed by a high-speed camera. The results showed that under the action of Bjerknes force, bubble aggregates were formed within 450 ms and coal bubble aggregates were formed within 20 ms. The bubble aggregates were statistically analyzed by image processing method. The number of aggregates and small bubbles in the ultrasonic field at 100 kHz was greater than those at 80 and 120 kHz. Besides, 100 kHz ultrasonic flotation achieved the highest yields of clean coal (35.89%) and combustible recovery (45.77%). The cavitation bubbles acted as either a “medium” or an “inclusion”, entrapping and entraining the coal particles in the flotation pulp. It promoted the aggregation of bubbles with coal particles, so the flotation efficiency was effectively improved in the presence of ultrasonic standing waves.

【 授权许可】

Unknown