A novel method for the measurement of flotation recovery by means of 4D particle tracking velocimetry

This work focuses on the analysis of the collection process in flotation by a simultaneous time-resolved measurement of particle and bubble trajectories. We introduced a new method that determined the probability of collision and attachment by a 3D particle tracking method with high temporal (1000 fps) and spatial (0.03 mm/pixel) resolution in the dense particle flow (5000 particles/ml). A tomographic particle image velocimetry device with three high-speed cameras recorded the three-phase flow in a rectangular bubble column (bubble chain). Particles made of fluorescent polystyrene were employed so that particles appeared bright and bubbles dark on the captured images. An attachment occurred if the trajectory of a particle coincided with that of a bubble. The recovery was calculated based on the number of particles attached to a bubble compared to the total particles density. With this method, the true flotation depending on the particle diameter (30 µm - 100 µm) was investigated and compared the results with an existing model of the bubble-particle collection microprocess.