Overview
Stage | Construction |
Mine Type | Open Pit |
Commodities |
|
Mining Method |
|
On-Site Camp |
156 people |
Production Start | Q3 2023 |
Mine Life | 8.6 years (as of Jan 1, 2021) |
Overall project is 85 percent complete as of November 30, 2022 and first gold pour remains on target for mid-2023. |
Latest News | Séguéla Project on-track for commissioning in the second quarter February 1, 2023 |
Source:
p. 14,15,62
On July 2, 2021, the Fortuna Silver Mines Inc. (Company) acquired all of the issued and outstanding common shares of Roxgold Inc. (“Roxgold”). Through the completion of the acquisition, the Company acquired the Séguéla advanced exploration project.
The non-controlling interest represents a 10% interest in the legal entities that own the Séguéla property, by the Côte d’Ivoire government.
Contractors
Contractor | Contract | Description | Ref. Date | Expiry | Source |
Lycopodium Minerals Canada Ltd.
|
EPC / EPCM
|
Lycopodium Minerals Canada Ltd (“Lycopodium” or the “Company”) has been selected for the design, supply and project delivery of the processing plant and associated plant related services and infrastructure for Roxgold’s Séguéla Gold Project in Côte d’Ivoire.
Lycopodium will be responsible for the design and supply of equipment, manufactured goods and all other materials and the construction management, pre-operational testing and commissioning services, as well as the overarching project man
|
Mar 26, 2021
|
|
|
MOTA-ENGIL S.G.P.S., S.A.
|
Mining
|
Mota-Engil has been awarded the contract for mining services at Séguéla. The agreement has been executed and orders for long lead items placed. Mota-Engil has commenced recruitment for the project and will advance mobilization and establishment of site infrastructure in the third quarter of 2022.
Roxgold will engage a mining contractor for the mining of all the deposits over the first 3.5 years of the mine life, after which mining will transition to a owner operator mining convention.
|
Jun 21, 2022
|
3.5
|
|
Deposit Type
- Vein / narrow vein
- Orogenic
Source:
p.71-83
Summary:
The deposits at the Séguéla Project are considered orogenic lode style systems. The Antenna, Agouti and Boulder deposits are hosted by brittle-ductile quartz albite vein stockworks, often associated with flow banded rhyolite units or porphyritic intrusives. The Ancien and Koula deposits are hosted by rittle-ductile quartz and quartz carbonate vein networks associated with strongly to intensely sheared tholeiitic basalt.
Antenna Deposit
The Antenna deposit occurs within a greenstone package that comprises (west to east) an ultramafic hangingwall, which isin presumed fault contact with an interlayered package of felsic volcaniclastic rocks and flow banded rhyolitic units, which are then in contact with a mafic (basaltic) footwall unit.
The Antenna gold deposit is a brittle-ductile quartz-albite vein stockwork predominantly contained within the flow banded rhyolite units. The stockwork lode varies in width roughly in proportion with the widths of the rhyolitic units which host it (approximately 3–40 m) and extends over a strike length of approximately 1,350 m. Stockwork veins which host mineralisation show two principal orientations; steep east-dipping and steep west-dipping. Veins in the steep west-dipping orientation range from being ptygmatically folded to undeformed, while veins in the east-dipping direction may be variably boudinaged to undeformed. This evidence suggests syn-deformational emplacement of the vein sets during west over east movement along the main fault structures within the region. Mineralisation occurs as free gold, associated with pyrite and pyrrhotite. Alteration assemblages associated with this mineralisation assemblage vary from proximal intense silica – albite ± biotite ± chlorite alteration, through medial silica-albite-sericite ± chlorite assemblages, to more distal sericite-carbonate (ankerite/calcite) and carbonate-magnetite assemblages. Pyrite isthe dominantsulphide associated with higher-grade mineralisation within proximal alteration zones, while sulphide mineralogy is pyrrhotite dominated in medial and distal assemblages and is associated with lower-grade gold mineralisation.
Agouti and Boulder Deposits
The Boulder and Agouti prospects are both located within a distinct northerly-trending litho- structural corridor that extendsfrom Boulder in the south to Gabbro in the north. Regional mapping has defined a broad package of pillow basalts and intercalated basaltic sediments, flanked to the west by a discontinuous gabbro unit and regionally extensive doleritic sequence. The basaltic units are extensively intruded by quartz-feldspar-biotite porphyritic felsic intrusives.
Gold mineralization is associated with strongly foliated or mylonitized, quartz/quartz-carbonate veined basalt and the margins of the felsic intrusives. Generally lower grade mineralization occurs internal to the felsic intrusives where they are brecciated or extensively veined. The highest gold grades generally correlate with the intersection of NNE and NW-trending structures. Mineralization occurs as free gold within a network of milky white quartz veins, and associated with foliation or quartz/quartz-carbonate vein controlled pyrite and minor pyrrhotite.
Ancien Deposit
The high-grade Ancien deposit is located within a thick package of magnetically quiet pillow basalts, tholeiitic basalts and minor mafic sediments that form the westernmost part of the East Domain. The deposit is associated with an interpreted D2 sinistral shear zone, informally labelled the Ancien Shear and comprises (from west to east) a chloritic pillow basalt footwall overlain by a foliated/sheared tholeiitic basalt unit, which is in turn overlain by a second chloritic pillow basalt hangingwall unit. Coarser grained sequences within the pillow basalts are geochemically equivalent to the pillow basalts and are interpreted to be part of the volcanic stratigraphy, rather than later intrusives. Generally narrow quartz-feldspar-biotite rhyolite to dacite porphyry intrusives and calc alkaline lamprophyric dykes are altered and foliated and therefore interpreted to have been emplaced prior to the deformation and mineralizing events.
Significant mineralization is restricted to the more reactive and competent tholeiitic basalt unit and is best developed in zones of strong brittle-ductile brecciation and shearing, with selective sericite+/-silica alteration and intense quartz and quartz-carbonate veining. Mineralization occurs as free gold, predominantly as small grains within microfractured milky- white quartz veins and associated with pyrite and lesser pyrrhotite. Generally lower grade mineralization is also developed at the margins of felsic porphyries that intrude the tholeiitic basalt, and in zones of increased brecciation and veining within these porphyries. Significant mineralization has been intersected over a strike length of greater than 350m and to a vertical depth of greater than 300m and has a moderately to steeply south-plunging core of high-grade mineralization. This high-grade core of the deposit is associated with the most intense deformation and veining and is interpreted to be associated with the hinge zone of the postulated anticline. The deposit remains open down-dip and down-plunge.
Koula Deposit
The high-grade Koula deposit is situated within the same package of mafic rocks as the Ancien deposit located 7km to the south,which is informally labelled the Ancien-Koula corridor. The Koula deposit is hosted within a strongly foliated/sheared tholeiitic basalt unit with a chloritic pillow basalt hangingwall and footwall (Figure 19). Coarser grained sequences within the pillow basalts are geochemically equivalent to the pillow basalts which are interpreted to be part of the volcanic stratigraphy, rather than later intrusives. Felsic intrusives are rare, but geochemically distinct late mafic intrusives of dolerite to gabbro are relatively common in the broader stratigraphic sequence.
Significant mineralization at Koula is restricted to the tholeiitic basalt unit and is best developed in discrete zones of strong shearing, biotite-sericite-(silica) alteration and intense recrystallized quartz and quartz-carbonate veining. Mineralization occurs as free gold, predominantly as small grains within recrystallized and microfractured milky-white quartz veins, and associated with disseminated to blebby, foliation controlled pyrrhotite and lesser pyrite (Figure 20). The predominance of biotite and pyrrhotite at Koula is indicative of higher temperature hydrothermal fluids compared to Ancien, where sericite and pyrite are the more dominant species. This change in mineral species suggests a temperature gradient (increasing) from south to north; which isimportant for ongoing exploration of the Ancien-Koula corridor.
Drilling to date has defined the Koula deposit over a 650m strike length and to a depth of greater than 350m vertically. The deposit remains open at depth and down plunge to the south, presenting a priority target for ongoing exploration.
Source:
Summary:
The Séguéla Gold Project will consist of the simultaneous exploitation of the Antenna deposit and the satellite deposits at Koula, Ancien, Agouti, and Boulder. The overallstrategy isto have production from these satellite deposits complement the production from Antenna.
A conventional open pit mining method will be utilized for the Séguéla Gold Project with no free digging assumed for any of the weathering zones. All material will be mined via drilling and blasting activities, followed by conventional truck and shovel operations within the pits for movements of ore and waste material. Mining of benches is proposed using 5.0 m benches done in two 2.5 m flitches.
Mining operations will occur year-round with Roxgold engaging a mining contractor for initial operations, before switching to an owner mining arrangement after 3.5 years. A common pool of equipment will be used and scheduled across all active pits so that movement between the pits is minimized and consumables and spare parts are shared within the fleet.
A total of fourteen mining stages were designed and scheduled for the Séguéla Gold Project, consisting of individual pits or pit stages within a final pit design. Consideration for pit stages was for planning and scheduling practicality purposes. The schedule utilizes the pit and phase designs and stockpiling strategy to fill the mill at 1.25 million tonnes per annum (“Mtpa”) initially and then increasing to 1.57 Mtpa in year 3.
The mine schedule delivers 12.1 Mt of ore grading 2.8g/t gold to the mill over a nine-year mine life, including three months of pre-production.
Source:

- subscription is required.
Processing
- Smelting
- Centrifugal concentrator
- Intensive Cyanidation Reactor (ICR)
- Carbon re-activation kiln
- Gravity separation
- Concentrate leach
- Agitated tank (VAT) leaching
- Carbon in leach (CIL)
- AARL elution
- Solvent Extraction & Electrowinning
- Cyanide (reagent)
Flow Sheet:
Source:
Summary:
The key project design criteria for the plant are:
• Nominal throughput of 1.25 Mtpa mineralized material
• Crushing plant availability of 75%
• Plant availability of 91.3% for grinding, gravity concentration, leach plant and gold recovery operations.
The proposed process design is comprised of the following circuits:
• Primary crushing of ROM material
• A surge bin with overflow stockpile to provide buffer capacity ahead of the grinding circuit
• Grinding circuit: semi-autogenous grinding (SAG) mill with cyclones
• Gravity recovery of cyclone underflow by a semi-batch centrifugal gravity concentrator, followed by intensive cyanidation of the gravity concentrate and electrowinning of the pregnant leach solution in a dedicated cell located in the gold room.
• Trash screening and thickening of cyclone overflow prior to leaching.
• Gold leaching in a CIL circuit.
• Acid washing of loaded carbon and Split AARL type elution followed by electrowinning and smelting to produce doré. Carbon regeneration by rotary kiln.
• Disposal of tailings to the TSF.
Gravity Recovery Circuit
The gravity circuit comprises of a centrifugal concentrator complete with a feed scalping screen. Feed to the circuit is extracted from the cyclone underflow discharge launder and flows by gravity to the scalping screen. Gravity scalping screen oversize at +2 mm will report by gravity to the mill feed. Scalping screen undersize is fed to the centrifugal concentrator. Gravity tails will gravitate to the mill discharge hopper. Operation of the gravity concentrator will be semi-batch and the gravity concentrate will be collected in the concentrate storage cone and subsequently leached by the intensive cyanidation reactor circuit (ICR).
Intensive Cyanidation Reactor
Concentrate from the gravity concentrator will be sent to the ICR to recover the contained gold by cyanide leaching.The concentrate from the gravity concentrator will be discharged to the ICR gravity concentrate storage cone and de-slimed before transfer to the ICR. ICR leach solution (2% NaCN and 2% NaOH) will be made up within the heated ICR reactor vessel feed tank. Oxygen will be sparged into the reactor vessel. From the feed tank, the leach solution will be circulated though the reaction vessel for approximately 16 hours, then drained back into the feed tank. The leached residue within the reaction vessel will be washed, with wash water recovered to the reaction vessel feed tank, and then the solids will be pumped to the mill discharge hopper. ICR pregnant solution will be pumped to the goldroom for gold recovery as gold sludge using a dedicated electrowinning cell. The sludge will be combined with the sludge from the carbon elution electrowinning cells and smelted or may be smelted separately for metallurgical accounting purposes.
Pre-Leach Thickening
Cyclone overflow will gravitate over the trash screen, to remove foreign material prior to leaching. Trash will report to the trash bin which will be periodically removed for emptying. Screen undersize will gravitate to the pre-leach thickener to increase the solids concentration of the leach feed. Thickener overflow will gravitate to the process water pond and the underflow will be pumped to the CIL circuit.
Leaching and Adsorption Circuit
The leach circuit will consist of one oxidation tank and six CIL tanks. Oxygen will be sparged to each of the tanks to maintain adequate dissolved oxygen levels for leaching.
Cyanide solution will be added into the oxidation tank and the first three CIL tanks as required.
Fresh/regenerated carbon from the carbon regeneration circuit will be returned to the last tank of the CIL circuit, and will be advanced counter-currently to the slurry flow by airlifts. The intertank screen in each CIL tank will retain the carbon whilst allowing the slurry to flow by gravity to the downstream tank. This counter-current process will be repeated until the carbon, by then loaded with gold, reaches the first CIL tank via an air lift system. Recessed impeller pumps will be used to transfer slurry between CIL tanks and from the lead tank to the loaded carbon screen mounted above the acid wash column in the elution circuit.
Slurry from the last CIL tank will gravitate to the vibrating carbon safety screen to recover any carbon leaking from worn screens or overflowing tanks. Screen underflow will gravitate to the tailings hopper before being pumped to the HDPE lined TSF. Screen oversize (recovered carbon) will be collected in a fine carbon bin for potential return to the circuit.
Carbon Acid Wash, Elution and Regeneration Circuit
Prior to carbon stripping (elution), loaded carbon will be treated with a 3% hydrochloric acid solution to remove calcium, magnesium and other salt deposits that would otherwise render the elution less efficient or be ‘baked on’ in the subsequent elution and carbon regeneration steps and ultimately foul the carbon. Loaded carbon from the loaded carbon recovery screen will flow by gravity to the acid wash column. Entrained water will be drained from the column and the column then refilled with a 3% hydrochloric acid solution, from the bottom up. Once the column is filled with the carbon, it will be left to soak in the acid for 30 mins after which the spent acid will be rinsed from the carbon and discarded to the TSF.
Carbon stripping (elution) will utilize the Split AARL process.
Carbon will be reactivated in a diesel fired rotary kiln. Dewatered barren carbon from the stripping circuit will be held in a kiln feed hopper. A screw feeder will meter the carbon into the reactivation kiln, where it will be heated to 700°C – 750°C in an atmosphere of superheated steam to restore the activity of the carbon. Re-activated carbon exiting the kiln will be quenched with water and flow onto the carbon sizing screen. Sizing screen oversize will be transferred to the last CIL tank to replenish the CIL carbon inventory. Sizing screen undersize will report to the carbon safety screen. Fresh carbon, to make up for attrition losses, will be added to the last CIL tanks by opening a new bag and dumping it directly above the tank from the leach area upper level.
Electrowinning and Gold Room
Gold will be recovered from the pregnant eluate by electrowinning and smelted to produce doré bars. The pregnant eluate is pumped through two electrowinning cells with stainless steel mesh cathodes. Gold will be deposited on the cathodes and the resulting barren solution will gravitate back into the strip solution tank for reuse or pumped to the leach circuit. One additional electrowinning cell will be dedicated for processing ICR pregnant solution.
Recoveries & Grades:
Commodity | Parameter | Avg. LOM |
Gold
|
Recovery Rate, %
| 94.5 |
Gold
|
Head Grade, g/t
| 2.8 |
Projected Production:
Commodity | Units | Avg. Annual | LOM |
Gold
|
oz
| 120,000 | 1,028,000 |
All production numbers are expressed as metal in doré.
Operational Metrics:
Metrics | |
Stripping / waste ratio
| 13.9 * |
Annual mining capacity
| 25 Mt * |
Waste tonnes, LOM
| 168.1 Mt * |
Ore tonnes mined, LOM
| 12.1 Mt * |
Total tonnes mined, LOM
| 180,115 kt * |
Daily processing rate
| 3,843 t * |
Tonnes processed, LOM
| 12,064 kt * |
Annual processing capacity
| 1.25 Mt * |
Annual ore mining rate
| 1.57 Mt * |
* According to 2021 study.
Reserves at December 31, 2021:
Mineral Reserves for the Séguéla gold Project are reported at cut-off grade of 0.54 g/t Au for Antenna, 0.55 g/t Au for Agouti, 0.55 g/t Au for Boulder, 0.56 g/t Au for Koula and 0.56 g/t Au for Ancien deposits.
Mineral Resources for the Séguéla gold Project are reported in situ at a cut-off grade of 0.3 g/t Au for Antenna and 0.5 g/t Au for the satellite deposits.
Category | Tonnage | Commodity | Grade | Contained Metal |
Probable
|
12,100 kt
|
Gold
|
2.8 g/t
|
1,088 koz
|
Indicated
|
3,811 kt
|
Gold
|
2 g/t
|
244 koz
|
Inferred
|
4,935 kt
|
Gold
|
2.89 g/t
|
454 koz
|
Commodity Production Costs:
| Commodity | Units | Average |
Cash costs
|
Gold
|
USD
|
567 / oz *
|
Total cash costs
|
Gold
|
USD
|
652 / oz *
|
All-in sustaining costs (AISC)
|
Gold
|
USD
|
832 / oz *
|
All-in costs
|
Gold
|
USD
|
972 / oz *
|
Assumed price
|
Gold
|
USD
|
1,600 / oz *
|
* According to 2021 study / presentation.
Operating Costs:
| Units | 2021 |
OP mining costs ($/t mined)
|
USD
| 2.79 * |
OP mining costs ($/t milled)
|
USD
| 30 * |
Processing costs ($/t milled)
|
USD
| 12.6 * |
G&A ($/t milled)
|
USD
| 5.3 * |
Total operating costs ($/t milled)
|
USD
| 47.8 * |
* According to 2021 study.
2021 Study Costs and Valuation Metrics :
Metrics | Units | LOM Total |
Initial CapEx
|
$M USD
|
142
|
Sustaining CapEx
|
$M USD
|
173
|
Closure costs
|
$M USD
|
11
|
Total CapEx
|
$M USD
|
326
|
OP OpEx
|
$M USD
|
363
|
Processing OpEx
|
$M USD
|
152
|
Refining costs
|
$M USD
|
3
|
G&A costs
|
$M USD
|
64
|
Total OpEx
|
$M USD
|
665
|
Royalty payments
|
$M USD
|
75
|
Gross revenue (LOM)
|
$M USD
|
1,629
|
Pre-tax Cash Flow (LOM)
|
$M USD
|
639
|
After-tax Cash Flow (LOM)
|
$M USD
|
536
|
Pre-tax NPV @ 5%
|
$M USD
|
455
|
After-tax NPV @ 5%
|
$M USD
|
380
|
After-tax NPV @ 10%
|
$M USD
|
271
|
Pre-tax IRR, %
|
|
53
|
After-tax IRR, %
|
|
49
|
Pre-tax payback period, years
|
|
1.6
|
After-tax payback period, years
|
|
1.7
|
Mine Management:
Job Title | Name | Profile | Ref. Date |
Chief Operating Officer
|
David Whittle
|
|
Oct 1, 2022
|
Consultant - Mining & Costs
|
Shane McLeay
|
|
May 26, 2021
|
Consultant - Recovery Methods
|
Niel Morrison
|
|
May 26, 2021
|
Health, Safety & Security Manager
|
Daniel Gouin
|
|
Apr 6, 2022
|
Corporate Filings & Presentations:
News: