The Kansanshi mine, the largest copper mine in Africa, is located in the North western province of Zambia near the bustling town of Solwezi. The operations consist of two open pits, mined using conventional open pit methods and ore treatment facility which allows for variation in ore type either through an oxide circuit, a sulphide circuit and a transitional ore “mixed float” circuit. The operation also has one of the world’s largest copper smelters — with a Plant Wide Control System (PWCS) designed and deployed by Mipac.
- A site based review of process control configuration implemented
- Configuration of the site Siemens PCS7 based DCS and capturing changes in the process control functional descriptions
- Implementation of a ‘flow controller’ based on neutralization tank levels using cascade control, rather than using line pressure to control tailing pumps. A pressure override controller was used for each pump to limit the pump speed and prevent exceeding the pressure rating of the lines
- Implementation of a MOCS (multiple output control system) receives the flow setpoint from the level controller to control the flow of all four pumps. The MOCS controller allows other pumps to ramp up if one or more pumps is limited by upper pressure or is operating at a lower flow as set by the Operator
- Mipac control logic update has allowed operators to run the system in ‘automatic mode’ continuously with minimal manual intervention
- Operations now anticipate cost savings due to all four tailings pump having similar wear rates, a reduction in cavitation damage (due to low tank levels), less human error and an overall increase in pump operating life