In this study, modelling and simulation studies to improve the performance of grinding circuit of Madneuli Copper Flotation Plant in Georgia were presented. After detailed sampling surveys, size distribution and solids content of the samples were determined. Then, mass balance of the circuit was calculated using these data. The results showed that the existing performance of the plant was not good and required to be improved. Using the data obtained, the models were developed for the mills and classifiers used in the circuits. Finally, several alternatives for a better performance were evaluated by using computer simulation. The results showed that the performance of the circuit could be improved and energy consumption in the grinding circuit could also be decreased.