Abstract: 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.