This technical report details the processing facilities, design criteria, and operational performance for the Séguéla gold mine in Côte d’Ivoire.
Report context
This technical report is dated December 31, 2025, and addresses the Séguéla Gold Mine project in Côte d’Ivoire. The report describes the process plant design, which is based on a metallurgical flowsheet envisioned to produce gold doré while minimizing initial capital expenditure and operating costs. The flowsheet consists of crushing, milling, gravity recovery, a CIL circuit, carbon elution, and a gold recovery circuit, with CIL tails disposed in a high-density polyethylene (HDPE)-lined tailings storage facility.
Processing route
Crushing and Materials Handling
The crushing circuit is designed for 75% availability. Run-of-mine material is trucked from the pit to the ROM pad and reclaimed by a front-end loader into the ROM bin. Ore is drawn via an apron feeder and scalped over a vibrating grizzly, with undersize reporting directly to the discharge conveyor and oversize reporting to a primary jaw crusher. All crushed and scalped material is conveyed to a surge bin providing approximately 30 minutes of surge capacity. The excess capacity allows for routine crusher maintenance without interrupting mill feed.
Grinding and Classification
The grinding circuit uses a single stage semi-autogenous grinding (SS SAG) mill in closed circuit with a classifying cyclone pack. SAG mill trommel oversize is directed to a scats bunker and returned to mill feed via a front-end loader, while undersize gravitates to the cyclone feed pump box. Cyclone overflow gravitates to a trash screen before reporting to the pre-leach thickener, and cyclone underflow returns to the SAG mill feed chute. A portion of the cyclone underflow is directed to the gravity concentration circuit.
Provision was made for expansion to convert the SS SAG circuit into a SAG and ball milling circuit (SABC). Alternatively, throughput could be increased to 1.57 Mtpa by maintaining the SS SAG circuit but coarsening the grind to 106 µm.
Gravity Recovery and Intensive Cyanidation
The gravity circuit comprises a centrifugal concentrator with a feed scalping screen. Feed is extracted from the cyclone underflow discharge launder and flows by gravity to the scalping screen. Oversized material at +2 mm reports to mill feed. The gravity concentrator operates on a semi-batch basis, with concentrate collected in a storage cone and subsequently leached in an intensive cyanidation reactor circuit (ICR). ICR leach solution (2% w/v NaCN and 2% w/v NaOH) is made up in a heated vessel feed tank, with oxygen sparged into the reactor. Gold is recovered from the ICR pregnant solution using a dedicated electrowinning cell.
Pre-Leach Thickening and Leaching
Cyclone overflow passes over a trash screen to remove foreign material, then gravitates to the pre-leach thickener where solids concentration is increased prior to leaching. The leach circuit consists of one pre-leach tank and six CIL tanks. Oxygen can be sparged to each tank. Cyanide solution is added to the pre-leach tank and the first three CIL tanks. Fresh or regenerated carbon is returned to the last CIL tank and advanced counter-currently by airlifts. Slurry from the last CIL tank passes over a vibrating carbon safety screen before reporting to the tailings hopper and being pumped to the HDPE-lined TSF.
Carbon Elution, Regeneration, and Gold Recovery
Loaded carbon is treated with a 3% w/v hydrochloric acid solution to remove deposits prior to stripping. Carbon stripping uses the split Anglo American Research Laboratories (AARL) process. The elution sequence commences with pre-soaking at 95°C using a 2% w/v NaOH and 2% w/v NaCN solution, followed by elution under pressure at 125°C. Carbon is reactivated in a diesel-fired rotary kiln at 700–750°C in an atmosphere of superheated steam.
Gold is recovered from pregnant eluate by electrowinning using stainless steel mesh cathodes. Gold sludge is washed off, dried, mixed with fluxes, and smelted in a diesel-fired furnace to produce gold doré.
Reagent Handling and Control Systems
Reagent preparation and storage facilities are located within containment areas designed for 110% of the largest storage tank volume. Reagent systems installed include quicklime, sodium cyanide, sodium hydroxide, hydrochloric acid, flocculant, activated carbon, anti-scalant, and smelting fluxes.
The plant control system comprises programmable logic controllers beneath a supervisory control and data acquisition network layer. Communication is via a plant-wide Ethernet network using single-mode fiber optic cables.
Key reported parameters
| Parameter | Units | Design | Actual | Testwork |
|---|---|---|---|---|
| Plant throughput | Mtpa | 1.25 | , | , |
| Gold head grade (LOMP) | g/t Au | 2.8 | 2.87 | , |
| Crushing plant availability | % | 75 | , | , |
| Leach and refinery availability | % | 91.3 | , | , |
| SAG mill availability | % | , | 96.2 | , |
| Mill feed rate | t/h | , | 216 | , |
| Overall gold recovery | % | 95.0 | 93.5 | , |
| Cyclone overflow size, P80 | µm | 75 | , | , |
| Leach time, target | h | 24 | , | , |
| Leach tails solution grade | g/m³ Au | 0.01 | , | , |
| NaCN addition | kg/t ore | 0.22 | , | , |
| Lime addition (at 93% CaO purity) | kg/t ore | 0.33 | , | , |
| Bond Crusher Work Index (CWi), design | kWh/t | 19.3 | , | , |
| SMC Axb | , | 30.6 | , | , |
| Ore specific gravity | t/m³ | 2.82 | , | , |
| Feed size, F100 | mm | 800 | , | , |
| Crushing plant product size, P80 | mm | 150 | , | , |
Project website: https://www.denvergold.org/corporate-member/roxgold-inc/
Project website: https://fortunamining.com/
Project website: https://www.northernminer.com/news/site-visit-fortunas-seguela-gold-mine-poised-for-growth/1003885271/
Project website: https://appiancapitaladvisory.com/roxgold-receives-mining-permit-and-breaks-ground-at-seguela-ahead-of-initial-gold-production-in-2022/
Project website: https://www.mining-technology.com/projects/seguela-gold-project-woroba/
Note: Actual gold recovery of 93.5% is from operational data collected prior to the data cut-off date at an average mill feed rate of 216 t/h and head grade of 2.87 g/t Au.
Technical qualifications
The qualified person considers process requirements to be well understood, with commissioning and ramp-up operating data confirming design assumptions. The report notes there is no indication that the characteristics of the material being mined will change, and therefore the processing and recovery assumptions applied for future mining, including from other deposits, are considered reasonable for the life-of-mine plan. The plant is described as being of conventional design using readily available consumables.
*Source: Séguéla Gold Mine, Côte d’Ivoire , Technical Report, December 31, 2025, Sections 17.1–17.9.*
Consolidated report summaries
The following former standalone pages about this operation were consolidated here on October 25, 2026. They are retained for source traceability; dates and figures reflect each report’s own effective date and may be superseded by the current information above.
Gold Recovery Methods at Séguéla: Crushing, CIL & Gravity Circuit
Gold Recovery Methods at Séguéla: Crushing, CIL & Gravity Circuit
Source: Fortuna Mining Corp (2026)
Website: https://fortunamining.com/mine/seguela-mine-cote-divoire/
Critical Data
| Parameter | Value | Unit | Notes |
|---|---|---|---|
| Throughput | 216 | t/h | Average mill feed rate achieved (actual operational data) |
| Mill Power | kW | Not reported | |
| Target Grind Size | 75 | µm | Cyclone overflow P80, design target |
| Head Grade | 2.87 | g/t Au | Average head grade (actual operational data) |
| Recovery % | 93.5 | % | Average overall gold recovery (actual operational data) |
| Processing Capacity | 1.25 | Mtpa | Nominal design throughput |
| Energy Consumption | kWh/t | Not reported | |
| Water Consumption | m³/t | Not reported | |
| Operating Hours | hours/day | Not specified; availability 91.3% for leach and refinery |
Overview
The Séguéla Gold Mine, operated by Fortuna Mining Corp. in Côte d’Ivoire, employs a proven and efficient process plant to produce gold doré. Located in the Worodougou region, the facility commenced commissioning in late April 2023 and rapidly ramped up to achieve regular throughputs of 180 dry tonnes per hour by September 2023. The plant is designed for a nominal throughput of 1.25 Mtpa, with a metallurgical recovery of 93.5% and a target grind size of 75 µm. The significance of the Séguéla processing plant lies in its conventional yet robust flowsheet that integrates crushing, single-stage semi-autogenous grinding (SS SAG), gravity concentration, carbon-in-leach (CIL) leaching, and carbon elution with electrowinning. Operational data through late 2023 demonstrates consistently strong performance, averaging 93.5% gold recovery at a mill feed rate of 216 t/h and head grade of 2.87 g/t Au. The plant was designed with expansion in mind; future throughput increases to 1.57 Mtpa are possible by converting the SS SAG circuit to a SAG-ball mill configuration or by coarsening the grind to 106 µm. The tailings are disposed of in a high-density polyethylene (HDPE)-lined tailings storage facility. This integrated recovery method ensures maximum gold extraction while maintaining operational reliability and environmental stewardship, making Séguéla a significant contributor to Fortuna Mining’s gold production portfolio.
Key Process Stages
- Stage 1: Primary Crushing and Materials Handling – ROM ore is dumped at the pad, reclaimed by a front-end loader, and fed into a ROM bin. A mobile rock breaker handles oversize. Material passes over a vibrating grizzly; oversize reports to a primary jaw crusher, reducing to a product size P80 of 150 mm. Crushed ore is conveyed to a surge bin with 30 minutes capacity, providing buffer for the mill feed apron feeder.
- Stage 2: Grinding and Classification – The SAG mill (SS SAG, with future potential for SABC conversion) operates in closed circuit with classifying cyclones. Cyclone overflow (P80 of 75 µm) goes to pre-leach thickening; underflow returns to the mill for further grinding. A portion of underflow is directed to the gravity circuit. SAG mill availability reached 96.2% during performance testing.
- Stage 3: Gravity Recovery and Intensive Cyanidation – Cyclone underflow feeds a centrifugal concentrator via a scalping screen (+2 mm returned to mill). Semi-batch gravity concentrate is collected in a storage cone and then leached in the intensive cyanidation reactor (ICR) using 2% NaCN and 2% NaOH at elevated temperature with oxygen sparging for ~16 hours. Pregnant solution is processed in a dedicated electrowinning cell to recover gold sludge. Designed gravity recovery is 40%.
- Stage 4: Pre-Leach Thickening and CIL Leaching – Cyclone overflow passes through a trash screen to remove foreign material, then to a pre-leach thickener for solids concentration. Thickener underflow feeds one pre-leach tank and six CIL tanks. Oxygen and cyanide (0.22 kg/t NaCN) are added to maintain leaching conditions. Gold is adsorbed onto activated carbon moving counter-currently via airlifts. Leach time target is 24 hours, achieving tails solution grade of 0.01 g/m³ Au.
- Stage 5: Carbon Elution, Electrowinning, and Gold Room – Loaded carbon from the first CIL tank is acid washed (3% HCl) before elution using the split AARL process at 125°C with 2% NaCN and NaOH. Pregnant eluate is electrowon onto stainless steel cathodes. Gold sludge is dried, mixed with fluxes, and smelted in a diesel-fired furnace to produce doré bars. Carbon is regenerated in a rotary kiln at 700–750°C. The gold room includes comprehensive security systems.
Additional Interesting Data and Summary
The Séguéla processing plant incorporates several auxiliary systems critical to its performance and sustainability. Reagent handling facilities for quicklime, sodium cyanide, sodium hydroxide, hydrochloric acid, flocculant, and activated carbon are designed with 110% containment to prevent spills. Lime addition is 0.33 kg/t ore (93% CaO purity) and sodium cyanide addition is 0.22 kg/t ore. The plant is controlled by a PLC/SCADA system with fiber optic communication, and a site-wide emergency power plant has been installed. Electrical reticulation uses 11 kV and 415 V three-phase, 50 Hz power, with underground cables within the plant and overhead lines for remote areas (TSF and water storage dam). Services include high-pressure air (700 kPa) for plant and instrument air, low-pressure blowers for leach tanks, and a pressure swing adsorption oxygen plant for CIL and ICR circuits. Raw water from storage is used for fire water, filtration, and reagent make-up; potable water from treated bore water is supplied to camp and plant. Filtered water serves elution and gland water needs. Tailings are deposited in an HDPE-lined TSF with decant return water providing most process water, supplemented by raw water. The Qualified Person confirms that process requirements are well-understood, with commissioned ramp-up data validating design assumptions. The plant uses conventional technology and readily available consumables, with no anticipated changes in ore characteristics. Future expansion potential exists to increase throughput to 1.57 Mtpa via SABC conversion or grind coarsening. Environmental considerations are addressed through containment systems and lined tailings storage. The facility’s strong operational performance—exceeding crusher and mill throughput KPIs and meeting gold recovery targets—demonstrates its economic viability and sustainability. For the life-of-mine plan, processing assumptions are considered reasonable, positioning Séguéla as a reliable gold producer in Côte d’Ivoire.
Key Processes: CIP/CIL, Cyanidation, Gravity Separation, SAG Mill, Ball Mill, Crushing
Target Commodities: Gold
