- Title
- Development of a flotation recovery model with CFD predicted collision efficiency
- Creator
- Wang, Ai; Hoque, Mohammad Mainul; Moreno-Atanasio, Roberto; Evans, Geoffrey; Mitra, Subhasish
- Relation
- Minerals Engineering Vol. 159, Issue 1 December 2020, no. 106615
- Publisher Link
- http://dx.doi.org/10.1016/j.mineng.2020.106615
- Publisher
- Elsevier
- Resource Type
- journal article
- Date
- 2020
- Description
- In this study, a novel flotation recovery model based on a first-order kinetics is proposed. The collision efficiency in the recovery model was directly obtained from 3D computational fluid dynamics (CFD) simulations involving a single-bubble-multi-particle aggregate system with typical flotation operating conditions (bubble diameter of 1 mm and particles diameter of 30 µm). The effect of the fluctuating flow field on collision was accounted using a large eddy simulation (LES) turbulence model for two turbulence intensity cases namely 4% and 20%, respectively. It was noted that the collision efficiency decreased in the radial direction away from the symmetry axis of the bubble. The normalized equivalent critical radius K₁ for the overall collision efficiency, was found to be optimum at the lower turbulence intensity of 4%. A maximum bubble surface loading, 0.142 was determined by fitting the model-predicted bubble velocity with available experimental data. With this maximum bubble surface loading constraint, the recovery model predicted two regimes namely a loading regime in the early flotation period and a saturated regime wherein the bubble loading capability was entirely exhausted. Simulation of a batch flotation system suggested that loss in bubble surface loading capacity occurred faster in a dense pulp compared to a dilute pulp system and the predicted recovery decreased with increasing solids concentration for the same gas volume fraction. Similar to the collision efficiency, the optimum recovery was obtained at Ti = 4%. Further, the model predicted recovery was compared to a lab scale coal flotation test and reasonable agreement was obtained.
- Subject
- flotation recovery; bubble-particle collision; collision efficiency; CFD model; turbulence intensity; bubble surface loading
- Identifier
- http://hdl.handle.net/1959.13/1433023
- Identifier
- uon:39151
- Identifier
- ISSN:0892-6875
- Rights
- © 2020. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/.
- Language
- eng
- Full Text
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