Overview
The Mount Polley mill is a conventional copper/gold processing facility commissioned in June 1997. The plant features a comprehensive crushing, grinding, flotation, and dewatering circuit capable of processing 17,800 to 22,000 tonnes per day (tpd) of ore. Final concentrate is trucked to Vancouver for overseas shipment to smelters.
Key Process Stages
- Crushing Circuit: Three-stage crushing system producing 16mm feed (42″x65″ gyratory crusher, 7′ standard cone, three short-head cones, four screen decks)
- Grinding Circuit: Rod mill (915 tph capacity) feeding ball mills and pebble mill to achieve 65% passing 200 mesh
- Flotation Circuit: Combination of column and mechanical cells for rougher/scavenger concentration with regrind and cleaning stages
- Dewatering: Thickeners and two pressure filters producing concentrate at 8% moisture content
- Control System: Central PLC with remote I/O stations and on-stream X-ray analyzer for five process streams
Critical Data
| Parameter | Value |
|---|---|
| Design Throughput | 17,800-22,000 tpd |
| Rod Mill Capacity | 915 tph |
| Final Grind Size | 65% passing 200 mesh |
| Concentrate Moisture | 8% |
| Crushed Ore Storage | 15,000 t stockpile |
| Pebble Feed Storage | 2,000 t surge pile |
Process Reagents
| Reagent | Dosage |
|---|---|
| Potassium amyl xanthate | 15 g/t |
| POLYFROTH® W22C | 20 g/t |
| Flocculant | 0.13 g/t |
| Lime | 90 g/t |
Infrastructure
The plant receives power via a dedicated 70km, 69kV line from Soda Creek station. Process water is reclaimed from tailings ponds. Concentrate is transported to Vancouver by truck for overseas shipment.
