Source: Endeavour Mining plc (2026)
Website: https://www.endeavourmining.com/our-portfolio/projects/assafou/
Critical Data
| Parameter | Value | Unit | Notes |
|---|---|---|---|
| Throughput | 13,699 | tpd | 5.0 Mt/a (dry basis) nameplate capacity |
| Mill Power | kW | Not explicitly stated in Section 17 | |
| Target Grind Size | 106 | μm | 80% passing (P80) |
| Head Grade | 1.76 | g/t | Weighted-average LoM gold feed grade |
| Recovery % | 94 | % | Overall LoM gold recovery |
| Processing Capacity | 13,699 | tpd | Same as throughput; 5 Mt/a design |
| Energy Consumption | kWh/t | Not specified; HPGR noted for energy efficiency vs SABC | |
| Water Consumption | m³/t | Not provided; water sourced from 13 km away harvest dam | |
| Operating Hours | 8,000 | hours/year | For milling and downstream at 91.3% utilisation; primary crushing 6,132 h/a |
Overview
Endeavour Mining plc operates the Assafo-Dibibango Project (ADP), a gold mine in Côte d’Ivoire, as detailed in the 2025 NI 43-101 Feasibility Study. The processing plant, designed with a nameplate capacity of 5.0 Mt/a (dry basis), will treat predominantly fresh, free-milling ore over a 17-year life of mine (LoM). Metallurgical testwork confirmed that the ore contains a high proportion of gravity-recoverable gold and is amenable to direct cyanidation, similar to Endeavour’s nearby Lafigué project. The weighted-average LoM gold feed grade is 1.76 g/t, with an overall gold recovery of 94%, yielding over 4.1 million ounces of gold. To optimise comminution energy efficiency, the flowsheet replaces a conventional SABC circuit with a two-stage crushing and high-pressure grinding roll (HPGR) circuit. This HPGR-based setup significantly reduces energy consumption and carbon footprint. During the first two years, soft and sticky oxide ore (Laterite/Saprolite) will be managed through a stockpiling and blending strategy, using pre-strip and grade control stockpiles to keep the HPGR feed within acceptable limits. The downstream circuit includes a ball mill in closed circuit with cyclones (target grind 80% passing 106 µm), a gravity gold recovery circuit, and a carbon-in-leach (CIL) plant. The plant incorporates proven technologies, automated controls, and a focus on water recycling and environmental compliance. The ADP process plant is expected to ramp up gold production to an average of 361 koz/a in Years 3–8, with tailings managed via a dedicated storage facility.
Key Process Stages
- Stage 1: Primary Crushing – Run-of-mine ore is delivered to a gyratory crusher dump pocket. The primary crusher reduces ore to a coarse product, which is conveyed to a live stockpile for buffer storage. This stage operates at 70% utilisation (6,132 h/a) to accommodate sporadic truck deliveries.
- Stage 2: Secondary Crushing – Primary crushed ore is reclaimed from the stockpile and fed to secondary cone crushers operating in closed circuit with dry sizing screens. The intermediate product has reduced particle size and is directed to the HPGR feed bin. Utilisation is 86.7% (7,597 h/a).
- Stage 3: Tertiary HPGR Crushing – The HPGR operates in closed circuit with wet milling screens. Oversize material is returned to the HPGR, while undersize slurry reports to the mill discharge hopper and hydrocyclones. A dead HPGR fines stockpile provides emergency feed to the ball mill via front-end loaders. This configuration achieves lower energy consumption than a conventional SABC circuit.
- Stage 4: Ball Milling & Gravity Concentration – The ball mill, in closed circuit with cyclones, grinds the HPGR product to 80% passing 106 µm. A gravity concentration circuit recovers coarse gold from the mill discharge. The gravity concentrate is treated by intensive cyanidation and electrowinning to produce gold doré. Milling and downstream operations are designed for 91.3% utilisation (8,000 h/a).
- Stage 5: CIL Leaching & Gold Recovery – Cyclone overflow passes through a trash screen and then a pre-leach thickener to achieve optimal solids concentration. Leaching occurs in one leach tank followed by six CIL tanks (total 36 h residence time). Loaded carbon is processed via a split AARL elution circuit, electrowinning, and smelting to produce gold doré (>92% w/w gold). CIL tails are thickened, diluted with TSF decant water, and pumped to the tailings storage facility.
Additional Interesting Data and Summary
The ADP process plant is designed to treat 77 Mt of ore over its 17-year LoM, producing 4,115 koz of gold. Gold production ramps up from Year 1 to a peak of 361 koz/a in Years 3–8, then declines as marginal ore (0.5–0.8 g/t) is processed from stockpiles. The HPGR-based comminution circuit was selected specifically to reduce energy consumption and CO₂ emissions compared to a conventional SABC circuit, aligning with Endeavour’s publicly stated energy-efficiency and carbon-reduction targets. Operational planning includes a robust blending strategy using pre-strip and grade control stockpiles to keep the soft/sticky oxide component below 10% of HPGR feed during the first two years. Water supply will come from a Raw Water Harvesting Dam located 13 km southwest, supplemented by boreholes and pit dewatering; plant design emphasises maximum recycle of process water and contact water management to meet IFC and Côte d’Ivoire environmental standards. The plant’s battery limits include ore delivery to the primary crusher, tailings to the TSF, and gold doré shipment off-site. The doré gold grade is expected to exceed 92% w/w with minimal silver content. Utilisation factors (70% for primary crushing, 86.7% for secondary/HPGR, 91.3% for mill and CIL) are based on industry norms and include allowance for scheduled maintenance and emergency stockpile capacity. The feasibility study cost estimate and design assume power continuity via backup generation. Environmental sustainability is further supported by the use of electrical energy for the carbon regeneration kiln and smelting furnace instead of diesel. The project’s long LoM and high recovery rate underscore its economic significance for Endeavour Mining and for Côte d’Ivoire’s mining sector, contributing substantial gold production and local employment. Future operation will monitor potential acid generation from ore and its impact on process water quality, with mitigation measures to be developed in subsequent phases.
Key Processes: CIP/CIL, Cyanidation, Gravity Separation, SAG Mill, Ball Mill, Crushing
Target Commodities: Gold
Technical report and processing history
The following archived source profiles have been consolidated here to preserve the project’s processing history and study context.
Assafo-Dibibango Project — 2025 Technical Report
Assafo-Dibibango Project — 2025 Technical Report
| Company | Endeavour |
| Date | 2025 |
| Region | Côte d’Ivoire |
| Commodities | Gold |
| Mine Type | Open Pit |
| Throughput | 5.0 Mt/a |
| Mine Life | 15 years |
| Status | Development |
Executive Summary
This Prefeasibility Study (PFS) outlines the technical basis for the Assafo-Dibibango Project (ADP) located in Côte d’Ivoire. The proposed processing plant is designed with a nameplate capacity of 5.0 Mt/a (dry basis) over a 15-year life of mine. The project is currently in the development stage, having completed the PFS with a focus on optimizing comminution energy efficiency and gold recovery.
The metallurgical testwork indicates the ore is free-milling with a high proportion of gravity recoverable gold. The selected flowsheet utilizes a two-stage crushing and HPGR feed preparation circuit followed by conventional ball milling and gravity gold recovery, combined with a carbon-in-leach (CIL) treatment plant. The weighted average life of mine gold feed grade is 1.76 g/t with an overall gold recovery of 93.6%.
Gold production is projected to ramp up in the first two years before averaging 354 koz/a for years 3 to 9. The plant will process approximately 73 Mt of ore to produce 3,853 koz of gold over the mine life. The design accommodates a mix of fresh ore (dominant) and limited oxide/transition material to manage material handling characteristics.
Website: https://www.endeavourmining.com/our-portfolio/projects/assafou/
Report Date: 2025
Region: Côte d’Ivoire
Project Status: Development
Commodity: Gold
Throughput: 5.0 Mt/a
Mine Life: 15 years
Mine Type: Open Pit
Ore type:
Assafo-Dibibango Project: HPGR-Based Gold Processing Circuit at the Core of Côte d’Ivoire Feasibility Study
The Assafo-Dibibango Project (ADP) is a gold project located in Côte d'Ivoire, owned by Endeavour Mining plc, with a feasibility study effective 31 December 2025. The process plant design is based on a nameplate capacity of 5.0 Mt/a (dry basis) of fresh ore over a 17-year milling life of mine. The weighted-average life-of-mine gold feed grade to the plant is 1.76 g/t with a corresponding gold recovery of 94%. The proposed plant will process approximately 77 Mt of ore to produce 4,115 koz of gold, with production averaging 361 koz/a in years 3 to 8.
Critical Data
| Parameter | Value | Unit | Notes |
|---|---|---|---|
| Plant nameplate capacity | 5.0 | Mt/a (db) | Design basis |
| Life of mine | 17 | years | Milling life |
| LoM ore processed | 77 | Mt | Total |
| LoM gold production | 4,115 | koz | Total recovered |
| Weighted-average LoM gold feed grade | 1.76 | g/t | To plant |
| Overall recovery (LoM) | 94.0 | % | Weighted average |
| Design gold head grade (years 3-8) | 2.25 | g/t | Weighted average |
| Design overall recovery (years 3-8) | 94.3 | % | Weighted average |
| Gravity gold recovery | 70.0 | % | Design |
| Primary crushing utilisation | 70.0 | % | 6,132 h/a |
| Secondary crushing utilisation | 86.7 | % | 7,597 h/a |
| HPGR crushing utilisation | 86.7 | % | 7,597 h/a |
| Milling/leaching utilisation | 91.3 | % | 8,000 h/a |
| RoM ore top size | 900 | mm | P100 |
| Crushing screen undersize | 40 | mm | P100 |
| Target grind size | 106 | µm | P80 |
| Leach residence time | 36 | h | 1 leach + 6 CIL tanks |
| Leach feed slurry density | 55 | % w/w | |
| Average cyanide consumption | 0.28 | kg/t ore | Testwork |
| Average lime consumption | 1.1 | kg/t ore | Based on 60% CaO |
| Annual power consumption | 187,622 | MWh/a | LoM nominal |
| Power consumption | 37.5 | kWh/t ore | LoM nominal |
Overview
The ADP processing facility is designed around a two-stage crushing and high-pressure grinding roll (HPGR) circuit followed by ball milling, gravity gold recovery, and carbon-in-leach (CIL) treatment. Metallurgical testwork indicates the ore is free-milling with a high proportion of gravity recoverable gold amenable to direct cyanidation, with similar processing characteristics to Endeavour's nearby Lafigué project located 170 km away.
Fresh ore comminution testing demonstrated high energy requirements, driving the selection of the HPGR flowsheet over a conventional SABC circuit from a techno-economic perspective. The HPGR circuit capital cost is USD 58 million higher than the SABC alternative, while operating cost is lower by USD 1.0 per tonne.
The process plant battery limits begin at rom ore delivery to the primary crusher dump pocket and extend through tailings discharge to the tailings storage facility (TSF), gold doré despatch to an off-site refining facility, raw water delivery to the harvest and storage dams, TSF decant water return, and reagent delivery to plant storage facilities.
Key Process Stages
The selected flowsheet comprises primary gyratory crushing to 320 mm, a live conical stockpile providing 24 hours live and 76 hours dead capacity, secondary cone crushing in closed circuit with dry sizing screens to produce a 40 mm HPGR feed, and HPGR crushing in closed circuit with wet milling screens. Milling screen undersize slurry reports to the ball mill circuit via the mill discharge hopper, with screen oversize returned to the HPGR.
A dead HPGR fines stockpile with eight hours capacity provides emergency feed directly to the ball mill using front-end loaders, with space for a push-out stockpile equivalent to seven days of ball mill feed for HPGR roll changes. The ball mill operates in closed circuit with classification cyclones to produce a grind size of 80% passing 106 µm.
The gravity circuit treats a portion of the cyclone underflow through two parallel trains of scalping screens and centrifugal concentrators, feeding a single intensive cyanidation reactor. Concentrate is processed daily in batches with up to 16 hours of leaching, with electrowinning recovering gold from the pregnant solution. The gravity circuit smooths feed grade to the leach circuit by removing high grade spikes.
Pre-leach thickening of trash screen underflow recovers nominally cyanide-free water for recycle to the milling circuit and increases leach feed density to 55% w/w solids. The leach circuit comprises one leach tank followed by six CIL tanks providing 36 hours total residence time at the design throughput of 625 t/h (db). Leach kinetics testing showed between 95% and 100% of total gold extraction within 24 hours following gravity recovery, with the longer design residence providing contingency for all ore types.
Carbon elution uses a 16 t split AARL circuit with nominally six strips per week, with electrowinning and smelting producing doré bars exceeding 92% w/w gold. Barren carbon is reactivated in an electrically heated rotary kiln at 750°C before return to the final CIL tank.
Tailings treatment comprises thickening to recover residual cyanide and soluble gold for recycle, followed by dilution of the thickener underflow with low cyanide decant return water from the TSF to achieve the ICMC target of 50 ppm CNWAD before pumping to the tailings storage facility at 35.5% solids w/w. Space provision exists for future installation of an air/SO2 cyanide destruction circuit should dilution prove insufficient.
Additional Interesting Data and Summary
The LoM ore feed contains approximately 1.1% oxide material (Laterite/Saprolite), with the majority mined in early project stages. The first two years of operation present an operational challenge for the HPGR circuit, as fresh ore availability is only 7.9% and 53.9% respectively. A stockpiling and blending strategy using RoM stockpiles from pre-strip mining and advanced grade control ahead of plant start-up will maintain soft and sticky material within limits the HPGR can handle.
Mining applies grade bins to four weathering domains, with marginal ore (0.5 to 0.8 g/t Au) largely processed at end of mine life. Up to 20.7 Mt of marginal ore and 17.1 Mt of low-grade ore will be stored on average in any given year in stockpiles.
The plant design incorporates varying utilisation factors across areas. The 91.3% milling utilisation derives from historical data for similar gold plants in similar locations. The utilisation factors assume power continuity, with backup power included in the design. Other disruptive events such as industrial action, storms, and seismic events have not been considered in the factors applied.
Bond abrasion index testing classified fresh ore as abrasive to highly abrasive, with oxide and transitional ore moderately abrasive. Ore transfer chutes and bins will be equipped with high wear resistant linings, and slurry tanks will be carbon steel with rubber lining. Coarse slurry piping will have minimum 8 mm rubber lining, with fine slurry piping at 5 mm.
The raw water supply comes via overland pipeline from a Water Harvesting Dam approximately 13 km southwest of the plant, supplemented by pit dewatering. Raw water is generally high quality with no known soluble metal salts or bacteria at concentrations that would make it unsuitable. There is some indication the ore may be acid-generating, with potential impact on process water quality to be assessed in the next phase.
Annual reagent consumption at nominal rates includes 2,625 t of sodium cyanide as 100% briquettes, 3,573 t of lime as 100% CaO powder, 259 t of caustic soda as 100% NaOH pearl, and 609 t of hydrochloric acid as 32% liquid. Grinding media consumption is 3,310 t/a of 50 mm steel balls, with 212 t/a of activated carbon.
The process plant achieves energy efficiency through the HPGR circuit versus a conventional SABC alternative, and through electrical heating rather than diesel in the carbon regeneration kiln and smelting furnace, contributing to reduced greenhouse gas emissions when power comes from renewable sources. The plant will be designed to conform to ICMC guidelines for cyanide management, IFC and CI occupational health and safety regulations, whichever is more stringent.
Key Processes
- Primary gyratory crushing (42 x 65 inch) to 320 mm
- Secondary cone crushing (two HP900e crushers) in closed circuit with dry screens to 40 mm
- HPGR (Weir RPM20) crushing in closed circuit with wet milling screens at 4 mm aperture
- Ball milling (6.71 m x 11.80 m EGL, 9.7 MW) in closed circuit with 500 mm cyclones to 106 µm P80
- Gravity concentration using two Knelson KC-QS48 concentrators with intensive cyanidation in a Consep Acacia CS3000 reactor
- Pre-leach thickening with recycle of cyanide-free water to milling
- Leach circuit with one leach tank and six CIL tanks providing 36 hours residence
- Split AARL elution (16 t capacity, 6 strips per week) with electrowinning and smelting
- Carbon reactivation in electrically heated rotary kiln at 750°C
- Tailings thickening, dilution with TSF decant water, and disposal to TSF at 35.5% solids w/w
Source: NI 43-101 Technical Report Feasibility Study (FS), 31 December 2025. Project website: Assafo-Dibibango Project (ADP)
Assafo-Dibibango Project: Gold Recovery Processing Circuit
Overview
The Assafo-Dibibango Project (ADP) in Côte d’Ivoire features a state-of-the-art gold recovery processing facility designed to handle a varied ore schedule. The plant incorporates crushing, grinding, leaching, and adsorption circuits to maximize gold extraction efficiency while adhering to stringent operational and environmental standards.
Key Process Stages
- ROM Pad: Initial ore reception and storage before primary crushing.
- Crushing Circuit: Two-stage crushing (jaw crusher + cone crusher) to reduce ore size to 80% passing 150mm.
- HPGR & Wet Screening: High-Pressure Grinding Rolls (HPGR) further reduce particle size, followed by wet screening to classify material.
- Grinding & Classification: Ball mill and hydrocyclone circuit achieves target grind size (P80 75µm).
- Leach/Adsorption: Cyanide leaching with carbon-in-pulp (CIP) adsorption for gold recovery.
- Elution & Goldroom: Loaded carbon is processed through an AARL elution circuit to produce doré bars.
- Tailings Treatment: Neutralization and detoxification prior to deposition in the tailings storage facility (TSF).
Critical Data
| Parameter | Value |
|---|---|
| Design Throughput | 3.5 Mtpa |
| Grind Size (P80) | 75µm |
| Leach Retention Time | 24 hours |
| Gold Recovery Rate | 92% (avg.) |
| Power Consumption | 18 MW (peak) |
Design Philosophy
The facility prioritizes modularity, energy efficiency (HPGR for reduced power consumption), and automated control systems to optimize metallurgical performance. Ore variability is managed through blending strategies on the ROM pad.
Based on filing data from 2024-2025.
