Simulation Of Product Specifications Of A Samarco’s Secondary Grinding Stage For Different Ball Sizes

This work studied the effect of different ball sizes in the secondary grinding stage of Samarco. The Moly-Cop Tools 3.01 spreadsheet was used for models calibration and simulations, considering grinding balls topsize of 15, 20, 25, 30 and 35mm diameters. A normal specific selection function up to the largest fed ore particle size (840μm) was obtained. The higher generation of fines and compliance with particle size specifications (+ 74μm and -44μm) proved to be more favorable for smaller ball sizes. The specific energy consumption was lower for the 15mm ball (10.7kWh/t), increasing up to the 35mm ball (13.0kWh/t). Although smaller diameter balls seem to be the best option for the size specifications, some factors may limit their use, such as: the higher generation of specific surface area; and the amount of ball purge in the discharge of the mills.