Hydrodynamics in a three-phase flotation system – Fluid following with a new hydrogel tracer for Positron Emission Particle Tracking (PEPT)

Effect of Retrofit Design Modifications on the Macroturbulence of a Three-Phase Flotation Tank─Flow Characterization Using Positron Emission Particle Tracking (PEPT)

“…The pH was not controlled, as flotation was not optimized in this experiment. For further experimental details, see reports of similar experiments in Mesa et al, Cole et al, and Mesa et al…”

“…The pH was not controlled, as flotation was not optimized in this experiment. For further experimental details, see reports of similar experiments in Mesa et al, 2 Cole et al, 29 and Mesa et al 31 Two retrofits were tested with the rotor impeller to study their effect on turbulence. The retrofits studied were a stator of 20 blades, as designed by Mesa and Brito-Parada, 44 and a honeycomb mesh with a blocked perimeter, as shown by Mackay,49 to increase recovery and decrease entrainment in a laboratory scale flotation tank.…”

“…For our own measurements with PEPT of particle motion in three phase froth flotation, the calculation of TKE experienced by a PEPT tracer particle has become feasible for turbulent structures at macroscale length scales due to several improvements. The application of the Siemens “HR++” PET scanner at PEPT Cape Town with high geometric detection efficiency in combination with careful data treatment , and new tracer techniques , has enabled comparison of the velocity fields of different solid and fluid tracer particles and the resolving of flow structures of several millimeters in size . However, it remains to be determined whether PEPT can track the highest frequency components of the fluctuating path of the tracer particle and resolve the structure of turbulent flow on the microscale due to the inherent sources of noise in a PEPT measurement, such as the finite range of the positron before annihilation, which leads to an uncertainty in the tracer position in each location measurement.…”

On the Ability of Positron Emission Particle Tracking (PEPT) to Track Turbulent Flow Paths with Monte Carlo Simulations in GATE

“…Once the model was validated, two different types of tracer motion were simulated to investigate the tracking ability (in terms of accuracy and precision) of PEPT measurements performed on the HR++ PET scanner. The extended simulations were inspired by the target application of this work, improving the tracking of turbulent flows in mineral froth flotation with PEPT (following [8][9][10]). There do not yet exist sufficiently complex models of the interaction of the three phases in flotation that can produce Lagrangian trajectories of flow carriers of the solid, liquid, and gas phases to use with the HR++ PET scanner simulation (in comparison to recent studies with GATE and DEM simulations of granular flow [28]).…”

“…The time-series location data produced by PEPT can also be used to plot high-resolution, time-averaged, or Eulerian maps of flow behaviour (e.g., [1,2]); additionally, it provides detailed Lagrangian paths of the tracer particle (e.g., [3,4]). For the three-phase mixture of mineral froth flotation, PEPT has revealed the paths and time-averaged flow profiles of particles of different mineral species (e.g., [5][6][7][8][9]) and water [10] inside a flotation vessel. It has also been used to track the interactions between particles and bubbles [11].…”