Overview
The McIlvenna Bay Project features a conventional copper-zinc processing plant designed to treat 4,900 tonnes per day (1.789 million tonnes annually) of blended ore from the CS and MS mineralization zones. The plant incorporates crushing, grinding, sequential copper-zinc flotation with concentrate regrind, and comprehensive dewatering circuits to produce saleable copper and zinc concentrates while managing tailings through pyrite flotation and paste backfill systems.
Key Process Stages
- Primary Crushing: ROM ore crushed to 100% passing 245 mm (80% passing 125 mm) using FJ 1000 jaw crusher
- Grinding Circuit: SAG mill (7.32m × 3.38m EGL, 3,500 kW) with pebble crusher in closed circuit with ball mill (5.03m × 7.85m EGL, 3,500 kW) producing P80 of 75 µm
- Copper Flotation: Four 50 m³ rougher cells followed by regrind (M1000 IsaMill to P80 25 µm) and three-stage cleaning
- Zinc Flotation: Four 50 m³ rougher cells with regrind (dual M1000 IsaMills to P80 20 µm) and three-stage cleaning
- Pyrite Flotation: Jameson cell followed by three 50 m³ conventional cells for tailings desulphurization
- Concentrate Dewatering: High-rate thickeners (6m for copper, 7m for zinc) producing 55% solids underflow filtered to 9% moisture cake
- Tailings Management: Thickened to 55% solids, filtered to 15% moisture for dry stacking; pyrite concentrate used for paste backfill
Critical Data
| Parameter | Value |
|---|---|
| Nominal Throughput | 4,900 tpd (1.789 Mtpa) |
| Crushing Availability | 60% |
| Grinding Availability | 92% |
| Bond Work Index (Blended) | 14.7 kWh/t (Rod Mill), 16.5 kWh/t (Ball Mill) |
| Plant Feed Grades | 1.27% Cu, 3.64% Zn, 0.56 g/t Au, 18.45 g/t Ag |
| Energy Consumption | 18.4 MW average demand |
| Water Requirement | 42 m³/h raw water |
| Grinding Media Consumption | 0.53 kg/t (SAG), 0.66 kg/t (Ball Mill) |
| Major Reagent Consumption | 93 g/t MIBC, 2,229 g/t Quicklime, 350 g/t Na₂S₂O₅ |
Special Features
The plant incorporates several advanced features including horizontal IsaMills for concentrate regrinding, automated reagent dosing systems, comprehensive water recycling (with 60% solids tailings thickener underflow), and integrated paste backfill production from pyrite concentrate. The metallurgical accounting system includes online stream analyzers (OSA) for real-time process control.
