DYNAMIC ANALYSIS AND CONTROL OF CLOSED-CI RCUIT BALL MILL GRINDING SYSTEM

This paper presents a dynamic model for a closed-circuit grinding syst em composed of a ball mill and a separator to represent dynamic behavi or of the system especially taking special account of balances of mass and surface of materials at each point in the system. In this model, the transfer function expressing the transporting characteristics insi de the ball mill and the grinding kinetics by Andreev's formula are ob tained and confirmed with several experiments. The dynamics of the sys tem are analyzed with digital simulation using several parameters whic h have been derived from the experiments. The authors also present a c ontrol method composed of a mill load control loop, product fineness c ontrol loop and non-interactive calculation part for stable operation of the system and improvement of grinding performance. The effectivene ss of this control method is reported with the simulation results and the measurement results of an actual clinker grinding plant.