A flotation framework for Eulerian multiphase CFD: Integrating bubble-particle aggregates and flotation kinetics

Flotation is a key process for the beneficiation of raw materials in mineral engineering involving complex multiphase flows. The Eulerian multi-fluid approach enables the simulation of such flows up to industrial scales by treating all phases as interpenetrating continua. For flotation, one phase consists of aggregates of a bubble and attached particles. The formation of these aggregates is governed by the kinetics of bubble-particle attachment and detachment. Their buoyancy depends on the attached particles and differs from that of unloaded bubbles. The present work extends a flotation framework to account for these phenomena by considering the aggregates as a multicomponent phase of a floatable particle- and an inert bubble-species. Methods for reactive mass transfer available in major CFD codes can then be adapted to describe the flotation kinetics. Demonstration cases with simplified and realistic attachment models are shown to verify the implementation of the framework in OpenFOAM and illustrate possible uses for flotation.