Overview
The Tucano Gold Mine features a sophisticated mineral processing circuit designed to handle 3.4-3.6 Mt/a of predominantly sulphide ore (90%). The plant utilizes a SAG/ball mill grinding circuit feeding a hybrid carbon-in-leach (CIL) system with enhanced oxygen injection, followed by cyanide detoxification of tailings. The 2018 expansion project added critical infrastructure including a new ball mill, pre-leach thickener, and oxygen plant to improve processing efficiency.
Key Process Stages
- Crushing: METSO C-150 jaw crusher (1400mm x 1200mm) with 125mm CSS, feeding through a vibrating grizzly for ore classification
- Grinding: 7MW Outotec SAG mill (7.32m diameter x 7.95m EGL) in open circuit followed by 6MW ball mill in closed circuit with 10 hydrocyclones (80% < 75μm product)
- Pre-Leach Thickening: 28m diameter Outotec thickener with 24-hour residence time at design capacity
- Hybrid CIL: 1x2650m³ pre-leach tank (>15ppm DO) + 6x2650m³ CIL tanks with mechanical agitators and inter-tank screens
- Elution: Zadra pressure system (135°C) with 720kW heater processing 4.8t carbon/day
- Tailings: Cyanide detoxification using SMBS/lime/copper sulphate (60min residence) before deposition in TSF
- Gold Recovery: Electrowinning cells, drying oven, and two gas-fired furnaces producing doré bars
Critical Data
| Parameter | Value |
|---|---|
| Design Throughput | 3.6 Mt/a (450 t/hr) |
| Power Consumption | 17 MW (fresh rock) |
| Grinding P80 | <75μm |
| Leach Residence Time | 24 hours |
| Oxygen Levels | >15ppm in pre-leach |
| Carbon Regeneration | 700°C kiln temperature |
| Cyanide Destruction | Reduces to ~10ppm in TSF |
Process Consumables
- Quicklime (pH control)
- Sodium cyanide (gold dissolution)
- Lead nitrate (leach enhancement)
- Hydrochloric acid (carbon washing)
- SMBS + copper sulphate (cyanide destruction)
- Oxygen (leach optimization)
