Overview
Stage | Feasibility |
Mine Type | Underground |
Commodities |
|
Mining Method |
|
Mine Life | 9 years (as of Jan 1, 2023) |
Perseus Mining poured first gold at the Yaouré Gold Mine in December 2020, becoming its third operation. Since 2020, ore at Yaouré has primarily been mined from the CMA open pit, with some contributions from minor satellite pits. CMA open pit stage 2 and stage 3 cutbacks are due to be completed during FY24 and FY25 financial years respectively, whereafter mining will move on to satellite pits and the recently expanded Yaouré open pit.
Yaouré’s updated LOMP incorporates for the first time an UG mining operation below the CMA Open Pit, as well as the existing CMA Open Pit and an expanded Yaouré Open Pit.
Perseus recently completed a CMA UG feasibility study, proving the technical and economic viability of underground mining of the CMA orebody, down dip and down plunge of the stage 3 CMA open pit. Underground mining of the CMA orebody is expected to begin in early FY26, once all related approvals have been received. |
Source:
p. 15,147
Company | Interest | Ownership |
Government of Côte d’Ivoire
|
10 %
|
Indirect
|
Perseus Mining Ltd.
|
90 %
|
Indirect
|
Perseus Yaouré SARL
(operator)
|
100 %
|
Direct
|
Perseus has a 90% interest and the Government of Côte d’Ivoire a 10% free carried interest Perseus Mining Yaouré SA. Perseus owns a 90% interest in Perseus Yaouré SARL, owner of Yaouré Gold Mine.
Contractors
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Deposit Type
- Orogenic
- Vein / narrow vein
Summary:
Yaouré may be described as orogenic lode-style gold mineralisation. The Yaouré project comprises several neighbouring gold deposits, including Yaouré and CMA, that occur near the south-eastern flank of the Bouaflé greenstone belt in central Côte d’Ivoire. Mineralisation is hosted by Paleoproterozoic-aged metabasalts and granodiorites of the Birimian Supergroup. The rocks are metamorphosed to lower greenschist facies and only locally feature penetrative deformation fabrics. Timing of the gold mineralisation event at Yaouré is dated to have occurred circa 2,105+4 Ma associated with crustal shortening.
Gold mineralisation is predominantly associated with quartz-albite-carbonate veining in reverse fault (Y) structures, forming a series of interconnected lodes with the best developed structures typically dipping at 25 to 30 degrees to the east. Gold mineralisation is also associated with extensional sub-vertical strike-slip fault (S) structures commonly orientated in a general east-west strike, in addition to the reverse fault structures. Gold is associated with disseminated pyrite within veins and altered wall-rocks. Arsenopyrite and molybdenite occur in trace quantities. No significant concentrations of other economic metals or deleterious elements are known to occur with the mineralisation.
The CMA Underground Mineral Resource comprises fifteen discrete lodes with typical thicknesses ranging from 2-3 metres up to 15-20 metres. Eighty-nine percent of the ........
Summary:
Perseus recently completed a CMA UG feasibility study, proving the technical and economic viability of underground mining of the CMA orebody, down dip and down plunge of the stage 3 CMA open pit. Underground mining of the CMA orebody is expected to begin in early FY26, once all related approvals have been received.
The CMA underground will be mined by a combination of flat longhole open stoping and conventional longhole open stoping mining methods. These methods have been selected as the most cost-effective and productive mining methods for the flat-dipping CMA orebody. The mining method is dependent upon the dip of the orebody which ranges from 5 degrees to 20 degrees for the majority of flat longhole stoping, and from 50 degrees up to 62 degrees for conventional longhole stoping. The mine design encompasses significant variability in plunge and dip across the deposit, for which a flexible mining method is required. Flat longhole stoping accounts for the majority of ore tonnes (98%), while conventional stoping applies only to the CMA northwest area of the mine (2% of ore tonnes).
Mining equipment will be mechanised, and equipment is planned to include electric-hydraulic drills for development and production, and rubber tyred loaders and trucks for load and haul activities. Production loading will incorporate tele-remote loading for non-entry mining stopes.
The CMA underground is based on a “no backfill” case for mining the CMA deposit. At thi ........
Flow Sheet:
Source:
Crushing and Grinding Circuit
ROM ore will be drawn from the ROM bin at a controlled rate by an apron feeder and discharged onto a vibrating grizzly. The grizzly oversize will report to the jaw crusher for primary crushing. The jaw crusher product together with grizzly undersize will report to the primary crusher discharge conveyor feeding directly to the coarse ore stockpile.
Ore will be withdrawn from the coarse ore stockpile and fed via the mill feed conveyor to the SAG mill. Lime and SAG mill grinding media will be added to the mill feed conveyor as required.
The grinding circuit will consist of a SAG mill in open circuit, a pebble crusher and a ball mill in closed circuit with hydrocyclones.
The optimum recovery is achieved at a grind size P80 of 53 µm, slightly finer than the grind size P80 of 75 µm for the open pit ore. Cost vs benefit studies have been undertaken to determine whether a batch treatment or blending option will be most beneficial for the CMA underground ore, with batch processing currently the preferred option. The underground ore will therefore be batch treated utilising more of the available installed ball mill power to achieve a finer grind.
The SAG mill will discharge via a pebble dewatering screen, and oversize consisting of pebbles and worn steel grinding media, will discharge onto the pebble transfer conveyor. Worn media will be removed by a magnet and pebbles will be crushed in the pebble crusher and will report back to the SAG mill conveyor. The screen undersize will gravitate to the mill discharge hopper and will be pumped to the hydrocyclone cluster for size classification.
The cyclone underflow (coarse material) will report to the ball mill feed chute for further grinding. The cyclone overflow (product size material) will gravitate to the trash screens prior to leaching.
Flow Sheet:
Summary:
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Combined production numbers are reported under
Yaoure
Operational Metrics:
Metrics | |
Annual ore mining capacity
| ...... |
Waste tonnes, LOM
| ...... |
Ore tonnes mined, LOM
| ...... |
Total tonnes mined, LOM
| ...... |
* According to 2023 study.
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Reserves at June 30, 2023:
Cut-off grades for the CMA underground Ore Reserve range from 0.5 g/t for development ore to 2.5 g/t for production (stoping) ore.
CMA underground Mineral Resources are reported below the CMA Stage 3 pit design at a 1.5 g/t gold cut-off grade.
Mineral Resources are reported inclusive of Mineral Reserves.
Category | Tonnage | Commodity | Grade | Contained Metal |
Probable
|
4.9 Mt
|
Gold
|
3.51 g/t
|
559 koz
|
Indicated
|
7.3 Mt
|
Gold
|
4.17 g/t
|
976 koz
|
Inferred
|
4.4 Mt
|
Gold
|
3.4 g/t
|
485 koz
|
Commodity Production Costs:
| Commodity | Units | Average |
All-in sustaining costs (AISC)
|
Gold
|
USD
|
......
|
Assumed price
|
Gold
|
USD
|
......
|
* According to 2023 study / presentation.
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Operating Costs:
| Units | 2023 |
UG mining costs ($/t mined)
|
USD
| 55.1 * |
Processing costs ($/t milled)
|
USD
| ...... |
G&A ($/t milled)
|
USD
| ...... |
* According to 2023 study.
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2023 Study Costs and Valuation Metrics :
Metrics | Units | LOM Total |
Expansion CapEx
|
$M USD
|
......
|
Sustaining CapEx
|
$M USD
|
......
|
- Subscription is required.
- Subscription is required.