This study investigates the optimization of grinding media size (40mm, 50mm, and 60mm diameter) for achieving the target particle size distribution in iron ore pellet feed preparation. Laboratory-scale batch grinding tests were conducted using OBP-2 online pellet slurry with a density of 2.1 g/cm³ in a ball mill (0.097 m³ capacity). The objective was to achieve 30-35% passing 10 microns from an initial value of 5.80%. Results indicate that 40mm diameter grinding media achieved the target specification (32.09% -10µm) in the shortest time of 67 minutes, demonstrating 21% & 16% time reduction compared to 50mm and 60mm media, respectively. This finding has significant implications for industrial grinding mill operations, potentially reducing energy consumption and improving throughput in pellet feed preparation circuits [1].