Overview
The Carlin Complex features an integrated network of processing facilities designed to handle diverse gold ore types from multiple open pit and underground sources. The complex utilizes specialized circuits including roasting, pressure oxidation, and heap leaching to maximize recovery based on ore characteristics such as gold grade, oxidation level, and refractory nature.
Key Process Stages
- Gold Quarry Roaster: 4.3 Mtpa capacity facility processing double refractory ores through dry grinding and single-stage roasting (515-538°C) with P80 of 74 µm grind size. Recent upgrades include airslide improvements and new SO2 converter.
- Goldstrike Autoclave: 5.0 Mtpa pressure oxidation plant with parallel CIL trains, converted from thiosulphate to conventional cyanide leaching in 2023. Processes both refractory (acid/alkaline POX) and oxide ores.
- Goldstrike Roaster: 6.6 Mtpa dual-stage fluidized bed roaster (524-593°C) for carbonaceous ores, featuring complete off-gas cleaning and mercury recovery systems.
- Heap Leaching: North and South Area facilities processing low-grade oxide ores (0.25-1 g/t Au) through run-of-mine or crushed ore stacking with CIC recovery.
Critical Data
| Parameter | Gold Quarry Roaster | Goldstrike Autoclave | Goldstrike Roaster |
|---|---|---|---|
| Throughput (Mtpa) | 3.9 (LOM avg) | 3.8 (LOM avg) | 5.1 (LOM avg) |
| Recovery (%) | 83.6 (71-89 range) | 80.8 (74-85 range) | 85.1 (84-90 range) |
| Annual Production (Moz) | 0.6 | 0.2 | 0.8 |
| Power Consumption | 115.74 kWh/t | 248.72 GWh/yr avg | 303.00 GWh/yr avg |
| Key Reagents | Sulphur (2.64 kg/t), Lime (12.21 kg/t) | Sulphuric Acid (5.07 kg/t) | Oxygen (high purity) |
Process Highlights
The Goldstrike Roaster features two parallel dry grinding circuits feeding dual-stage fluidized bed roasters using 99.5% O2 for carbon/sulphide oxidation. The off-gas system includes mercury recovery via chlorine sparging and SO2 neutralization with lime.
The Goldstrike Autoclave operates three parallel vessels (524-561°C) with flexible acid/alkaline POX modes. The 2023 circuit conversion to cyanide CIL from thiosulphate RIL improved recoveries by 5-7% for single refractory ores.
Heap leaching operations utilize sophisticated solution management with CIC recovery, tracking pad inventory through monthly metallurgical balances and kriged grade reconciliation.
