Optimizing Flotation of Coarse and Composite Particles: A Review of Hydrodynamic Environments, Reagent Systems, and Ore Texture

This review examines current advances in understanding and improving coarse particle flotation (CPF), with a focus on the interplay between hydrodynamic environments, reagent chemistry, and ore texture. The fundamental force balance governing attachment stability is examined, highlighting the increasing dominance of destabilizing gravitational and hydrodynamic forces over stabilizing capillary forces with increasing particle size. Key factors influencing CPF performance are discussed, including turbulence and pulp rheology, alongside emerging flotation technologies such as fluidized-bed systems that provide low-shear environments conducive to aggregate stability. Advances in reagent strategies are reviewed, including the use of stronger collectors, hydrophobicity extenders, nanobubbles, and targeted reagent delivery approaches aimed at enhancing effective hydrophobicity and attachment stability. The role of comminution in controlling surface liberation, particle morphology, and locking texture is also explored as a pathway for improving flotation response at coarse sizes. Despite significant progress, knowledge gaps remain in linking particle size, surface exposure, hydrophobicity, and hydrodynamic conditions to flotation performance. Addressing these challenges requires an integrated framework combining hydrodynamics, surface chemistry, and comminution strategies. Such advances are critical for extending the upper particle size limit of flotation, reducing energy-intensive grinding, and improving the sustainability of mineral processing operations.