Base and precious metals
Copper, nickel, platinum group metals and gold concentrators run long chains of interacting circuits. Closed-loop control works on crushing, grinding and flotation together, because that is where the value between circuits sits.
Circuits we control
Crushing
Holding crushers near their power and load limits without tripping them, and keeping the feed to downstream milling steady rather than letting surges propagate.
Grinding, SAG and ball milling
Balancing mill load, feed rate and water so the mill runs at its constraint rather than safely below it, and so that grind size stays inside the window flotation needs.
Flotation
Coordinating reagent addition, air and levels across banks so the circuit holds a chosen point on the grade and recovery curve as the feed changes.
Thickening and tailings
Keeping thickener behaviour predictable so it stops being the reason feed is reduced, and so water returns to the plant at the rate it is needed.
Results
Two published case studies come from base-metal sulphide concentrators.
- Holding concentrate grade on target: recovery rose 2.5% because the cleaner circuit was held at a chosen point on the grade and recovery curve instead of chasing either number alone.
- Holding the mill in its productive range: throughput rose 2.9% because the mill was held inside its limits: on hard ore it reached its charge limit far less often, and on soft ore it rarely ran underfilled.
Each states the circuit, the control mode, the baseline and assessment periods and the comparison method alongside the result. More are on the case studies page.
See it on your own plant
A desktop review of historian exports. No site visit.