AN INNOVATIVE APPROACH TO OPTIMIZE THE COMMINUTION CIRCUIT OF MICRONIZED POWDER PRODUCTION PLANT

This research was conducted to investigate and optimize the comminution circuit of the Arak Company in which bentonite micronized powder is produced. The criterion for evaluating was the optimal performance of grinding systems and the efficiency of the devices, and simultaneous optimization was considered in feed and product sizes, capacity, and energy. In addition to the Bond formula, Morrell and Austin relations, as an innovative approach, have also been employed to study the different parameters such as rotation speed and mill filling percent. In this unit, the main grinding operation is performed by a tube ball mill that is located in a closed circuit with two air separators. The size of the final product is finer than 75 microns, and 48 kilowatt-hours of energy are consumed to produce one ton of bentonite. About 59% of the total plant energy consumption was related to the grinding circuit of tube mill. The size of the tube mill feed was 3500 microns (d80), the percentage of charge and accumulation were 21 and 14% respectively, the average diameter of the steel balls was 60 mm and the relative rotation speed of the mill was 79%. The results showed that the efficiency of the grinding circuit is poor, and it was merely about 30%. By increasing the percentage of charge of the tube mill from 21 to 70%, increasing the size of the mill feed by 7000 microns, using balls with diameter of