Fractal Hydrodynamics Engineering: Turbulence-Interface Coupling Mechanism for Enhanced Mass Transfer and Particle Dispersion in Mineral Flotation Systems.

Fractal impellers, with their unique self─similar and complex geometric structures, could generate a wide range of flow velocities and shear forces in the flotation conditioning tank, thereby enhancing reagent mass transfer and mineral particle dispersion. To understand the microscopic mechanisms of fractal impellers in enhancing mass transfer at the solid-liquid interface in the flotation conditioning process, the surface properties characterization (particle size, zeta potential, contact angle analysis), EDLVO theoretical calculation, and atomic force microscopy (AFM) testing were performed to reveal the regulation law of fractal impellers on mineral chemical interactions. The results showed that compared with traditional rectangular impellers (RI exp), fractal impellers (FI exp1/FI exp2) could significantly improve the reagent adsorption efficiency. Under optimized energy input conditions, the systems of fractal impeller FI exp2 exhibited: (1) 11.72% and 2.74% enhancements in surface potential for diaspore and kaolinite, respectively, (2) 2.84% and 16.97% increases in contact angles, and (3) 20.35% and 7.11% growth in effective particle sizes. EDLVO simulations and AFM measurements revealed that fractal impellers enhanced diaspore-diaspore adhesion forces by 8.11% while increasing diaspore-kaolinite repulsion by 9.09%. These findings establish a mechanistic framework linking fractal impeller-induced hydrodynamics to colloidal force modulation, which drives selective mineral separation.