Increasing Efficiency of Initial Grinding Circuit of Share-Babak Copper Complex Concentration Plan

At the grinding circuit of the Share-Babak copper concentration plant two 503 cm ×762 cm ball mills with motors of 2984 kW which are working with 10-cyclone (66. 8 cm diameter) clusters are used. In the initial design of the plant، it was assumed that this circuit could grind a feed rate of 721 t/h with size of 789 μm (80% passing size) to a product size of 90 µm (80% passing size). The study of the circuit during the last year indicated that due to variation of feed characteristics and non-optimized operating conditions P80 of the cyclone overflow (i. e.، flotation feed) was 128 µm with the standard deviation of 12 µm. In order to provide proper operating conditions، the ball mill percent solids was increased from 66 to 70%، and the ball load was also increased from 23 to 35%. On the account of increase in ball load، the mill power draw increased by 28%. To increase the performance of the cyclones، the cyclone feed solids concentration was decreased from 52 increased to 48 %. These changes decreased the P80 of the cyclone by 22. 7% and also lowered its variations by 40%.