Desert Gold SMSZ: 1200 tpd Gravity-CIL Gold Recovery Plant
Source: Desert Gold Ventures Inc (2026)
Website: https://desertgold.ca/desert-gold-advances-barani-gravity-plant-installation-and-confirms-july-19th-2026-commissioning-target-at-smsz-project-western-mali-2/
Critical Data
| Parameter | Value | Unit | Notes |
|---|---|---|---|
| Throughput | 1200 | tpd | Nominal plant capacity; 432,000 tpa at steady state |
| Mill Power | 630 (primary) / 400 (secondary) | kW | Primary mill installed power 725 kW; secondary installed 460 kW |
| Target Grind Size | 75 | µm | P90 for secondary mill product; primary mill P80 = 212 µm |
| Head Grade | 0.61 – 1.50 | g/t | Leach feed grade varies: Barani East 0.61, Gourbassi West 0.62, Gourbassi East 1.50 |
| Recovery % | 72 – 90 | % | Gold dissolution in CIL: Barani East 72%, Gourbassi West 90%, Gourbassi East 87% |
| Processing Capacity | 54 | tph | Milling, concentrator, and CIL circuit feed rate (21.9 h/day) |
| Energy Consumption | 10 | kWh/t | Bond Ball Work Index for both primary and secondary milling |
| Water Consumption | m³/t | Not explicitly provided; tailings thickener overflow recycled | |
| Operating Hours | 21.9 | hours/day | Milling and CIL circuit; crushing operates 17.6 h/day |
Overview
Desert Gold Ventures Inc. is developing the SMSZ Project (Barani Project) in Mali, featuring an upgraded modular processing plant designed as a conventional gravity-Carbon-in-Leach (CIL) circuit. The plant has a nominal throughput of 1,200 tonnes per day (tpd), equivalent to 432,000 tonnes per annum at 92% availability. The facility processes oxide and transitional ore from multiple deposits: Barani East, Gourbassi West, Gourbassi West North, and Gourbassi East, with a phased mining approach that optimizes resource utilization. Operations commence at Barani East for the first ~16 months, after which the modular plant is relocated to a central site near Gourbassi West for ~92 months, with Gourbassi East adding another ~18 months to the life-of-mine. The process design integrates crushing, grinding, gravity concentration, CIL leaching, desorption, electrowinning, and smelting to produce Doré gold bars on site. Gravity concentration is included as a pre-leaching step to recover coarse gold, especially from Barani East ore. The plant’s fully skid-mounted modular configuration enables rapid dismantling and relocation within three months, minimizing production downtime. Metallurgical testwork confirms strong amenability to gravity recovery and CIL leaching, with leach residence times of 44 hours at design tonnage. This technical report underpins a Preliminary Economic Assessment (PEA) update, demonstrating both technical and economic feasibility for the life-of-mine across all four ore sources.
Key Process Stages
- Stage 1: Three-Stage Crushing – Run-of-mine ore is reduced to P80 = 13 mm using a primary coarse jaw crusher, a secondary fine jaw crusher, and a tertiary cone crusher in closed circuit with a linear vibrating screen. All crushers and screens are skid-mounted with hydraulic support legs for easy relocation. Feed rate is 67.3 tph over 17.6 hours per day, with dust suppression water sprays.
- Stage 2: Primary Milling and Gravity Concentration – Crushed ore is ground in a primary ball mill (3.2 m x 4.5 m, 630 kW) to P80 = 212 µm in closed circuit with a spiral classifier. Mill discharge feeds two STL-100 centrifugal concentrators (Knelson) that recover coarse gold. Concentrate is upgraded on 6-S shaking tables to produce a high-grade gravity concentrate for direct smelting. Gravity tailings proceed to secondary milling.
- Stage 3: Secondary Regrind Milling – Gravity tailings are further ground in a secondary ball mill (2.4 m x 4.5 m, 400 kW) to a final grind size of P90 = 75 µm, ensuring optimal gold liberation for CIL. The mill operates in closed circuit with cyclones, with a circulating load of 300%. Slurry density is maintained at 50% solids, and the circuit handles 54 tph at 97.3% availability.
- Stage 4: Carbon-in-Leach (CIL) Circuit – Slurry from the thickener (40% solids) is conditioned with cyanide and lime in two 510 m³ tanks, then leached in seven 510 m³ CIL tanks providing 41–44 hours total residence time. Cyanide concentration is 300–400 ppm, pH 10.5–11, with oxygen sparging. Activated carbon (coconut shell, 20 g/L) adsorbs gold counter-currently. Loaded carbon is screened and sent to elution.
- Stage 5: Elution, Electrowinning, and Smelting – Loaded carbon is acid-washed and stripped in a 1-tonne/batch pressure Zadra elution column. Pregnant eluate undergoes electrowinning to produce gold sludge, which is filtered and dried. Gravity concentrate and electrowinning sludge are smelted together in a tilt-pour induction furnace to produce Doré gold bars (>90% Au+Ag) in 50 kg batches. The circuit processes 15 elution batches per month.
Additional Interesting Data and Summary
The gravity-CIL plant is designed with a fully modular skid-mounted configuration, enabling relocation within three months with minimal production loss—a key economic advantage for the phased mining plan. The crushing circuit operates at 67.3 tph over 285 days per year (78.1% availability), while the milling and CIL circuit runs 355 days per year at 97.3% availability. The CIL circuit comprises two conditioning tanks and seven leach tanks, each 510 m³, providing 44 hours total residence time at design tonnage. Cyanide dosing is maintained at 2 kg/t total (0.4 kg/t conditioning, 1.6 kg/t leach) with caustic soda and lime for pH control. Oxygen sparging enhances leach kinetics. Tailings undergo SO₂/air detoxification to reduce weak-acid-dissociable cyanide below 50 ppm before discharge to HDPE-lined tailings storage facilities—one at Barani East and a central facility for the Gourbassi cluster. Gold production estimates from testwork concentrate grades indicate smeltable gold of 67.8 kg/month from Barani East, 16.98 kg/month from Gourbassi West, 35.59 kg/month from Gourbassi West-North, and 63.90 kg/month from Gourbassi East, totaling 184.27 kg/month across all ore sources. The elution circuit processes 15 batches per month (1 tonne per batch) yielding approximately 4 Dore bars per month. Reagent systems are fully bunded with PLC/SCADA control for precise dosing. The plant design incorporates a 5,000-tonne live-capacity crushed ore stockpile with reclaim feeders. Economic impact is underscored by the PEA update, which extends the life-of-mine by ~18 months with Gourbassi East. Sustainability initiatives include water recycling from the thickener overflow and detoxification of cyanide prior to tailings storage. The modular design reduces environmental footprint at each site and allows rapid restoration post-mining. Future outlook includes potential expansion of the gravity circuit based on ore amenability, with the two-stage centrifugal concentrator configuration already providing flexibility for different ore types. The technical feasibility is confirmed through metallurgical testwork and regional operating benchmarks, ensuring robust gold recovery across all proposed feed sources.
Key Processes: Flotation, CIP/CIL, Cyanidation, Gravity Separation, Ball Mill, Crushing
Target Commodities: Gold
