Ball Mill ACE is designed to manage the primary control functions of the Ball Mill cyclone circuit. The objective of the Ball Mill ACE system is to maintain cyclone feed pressure and density at specified targets while keeping the Ball Mill sump level in an acceptable range. Consistent cyclone feed pressure and density is critical to achieving constant P80 grind performance for improved downstream recovery and to avoid recirculating excess solids to the Ball Mill, which allows the circuit to achieve maximum production rate.

Ball Mill ACE uses BrainWave® Model Predictive Controllers (MPCs) for closed-loop control of the Ball Mill sump level, cyclone pressure and density, and for control of sump dilution water addition and SAG feed rate during override and constraint situations. Cyclone open and close operations are included in the controllers as feed-forward variables to minimize disturbances to process flow. Total feed rate to the SAG mill is monitored so that Ball Mill sump level controls can anticipate disturbances and adjust cyclone pressure and density setpoints and operate cyclones proactively to avoid sump level upsets.

The system manages four integrated control functions. Ball Mill Sump Level Control adjusts cyclone pressure and density setpoints over a defined range to achieve mass balance in the circuit, opens or closes cyclones as required when setpoint adjustment range is insufficient, and overrides SAG feed rate or sump water addition to protect the circuit during extreme process transients. Cyclone Pressure Control uses BrainWave MPC to adjust cyclone feed pump speed, with cyclone open and close events included as feed-forward disturbance variables to minimize pressure disruption. Cyclone Feed Density Control uses BrainWave MPC to adjust dilution water addition to the Ball Mill sump or cyclone feed pump discharge, with SAG mill feed rate monitored as a feed-forward variable; pressure and density setpoints are managed together to preserve mass balance and prevent recirculating load escalation. Cyclone P80 Control monitors SAG production rate and automatically adjusts nominal pressure and density setpoints to configure the circuit for lower P80 during reduced production periods, maximizing recovery opportunity, while returning to nominal setpoints at full production rate.

In addition to process optimization, Ball Mill ACE includes automatic rotation of cyclones in service to prevent premature wear and protection of cyclone feed pumps from overload conditions.