CFD−PBM Simulation Study on the Optimization of Blade Arrangements to Enhance Mass Transfer Performance in Industrial Leaching Tanks

Industrial leaching tanks are critical equipment in the mineral extraction process, where the gas−liquid mass transfer characteristics inside the tank significantly affect the metal extraction efficiency. To investigate the gas−liquid mass transfer properties within these tanks, a coupled Computational Fluid Dynamics (CFD) and Population Balance Model (PBM) approach was employed to numerically simulate the mass transfer behavior in an industrial−scale leaching tank. The study examined the effects of different impeller combinations on the velocity distribution, gas holdup distribution, bubble size distribution, interfacial area, and volumetric mass transfer coefficient (k_La). The results indicate that the inclined blade impeller (PBT−PBT) combination causes gas accumulation in the axial region, resulting in uneven gas distribution. Compared to the PBT−PBT impeller combination, the hybrid impeller−inclined blade impeller (HBT−PBT) and Rushton impeller−inclined blade impeller (RT−PBT) combinations show better gas dispersion. The RT−PBT impeller combination maintains bubble sizes between 0.005 and 0.017 m, and the number density of bubbles smaller than 0.0048 m is the highest among the three impeller combinations, leading to a 50.3% increase in the global k_La. These findings provide reliable theoretical and simulation−based insights for optimizing mass transfer and structural design in industrial leaching tanks. The optimized RT−PBT impeller combination significantly enhances mass transfer efficiency, contributing to more effective mineral extraction in industrial applications.