Interaction of applying stable micro-nano bubbles and ultrasonic irradiation in coal flotation

• Published in: International journal of coal preparation and utilization Vol. 42; no. 5; pp. 1548 - 1562
• Main Authors: Ebrahimi, Hossein, Karamoozian, Mohammad, Saghravani, Seyed Fazlolah
• Format: Journal Article
• Language: English
• Published: Abingdon Taylor & Francis 04-05-2022; Taylor & Francis Ltd
• Subjects: Ashes; Bubbles; Cavitation; coal; Flotation; Irradiation; micro-nano bubble; Mineral processing; Radiation; Selectivity; Sustainable use; ultrasonic irradiation
• ISSN: 1939-2699; 1939-2702
• DOI: 10.1080/19392699.2020.1732947

Due to the short life of nanobubbles in the pulp, their use in mineral processing, especially in fine grains, is rare. Hence, the use of sustainable nanobubbles with a long lifetime can lead to new results. In addition to the presence of micro-nano bubbles, the ultrasonic emission factor can also have a positive effect on flotation performance. The simultaneous effect of these two factors has not been considered in previous studies. In this study, the stable micro-nano bubbles produced by the hydrodynamic cavitation mechanism were used in the pulp and simultaneously the ultrasonic waves were irradiated. Under these conditions, a wide range of bubbles ranging from 80 nm to 1 mm was generated which caused the flotation of the fine to coarse size particles. Simultaneous use of these two factors showed that the yield of coarse (−850 + 420 µm), medium (−420 + 105 µm) and fine (−105 µm) particles improved by more than 10%, 10%, and 30%, respectively. Combustibles recovery in variable feed ash along with the ash selectivity index were enhanced. In addition, consumption of the collector was reduced up to 90%, while the concentration required for the frother agent was reduced to approximately a quarter.