Ultrasonic flotation of chalcopyrite in a piezoelectric tube: Particle size effects and energy dissipation

This paper explores the enhancement of flotation kinetics for chalcopyrite (CuFeS 2 ) particles through the application of ultrasound at a relatively high frequency (1.08 MHz). A novel laboratory-scale flow tubing system incorporating an ultrasonic piezoelectric tube, was designed and utilized for batch-mode flotation tests with external aeration and tailings recycling. The flotation performance was evaluated across a range of particle size fractions: < 38 μm, 38–45 μm, 45–53 μm, 53–75 μm, 75–106 μm, 106–150 μm, and 150–250 μm. The employment of ultrasound resulted in statistically significant improvements in flotation performance for finer particles (< 38 µm and 38–53 µm), with increases of up to 16 percentage points in final recovery ( R max ), 55 % in the flotation rate constant ( k ) and 58 % in the modified flotation rate constant ( R max · k ). Energy dissipation tests indicated that approximately one-quarter of the total energy input to the piezoelectric tube was dissipated as heat. These results demonstrate the potential of high-frequency ultrasound to selectively enhance the flotation of fine chalcopyrite particles.