Overview
Status | Care and Maintenance |
Mine Type | Underground |
Commodities |
|
Mining Method |
- Longhole stoping
- Longitudinal stoping
- Transverse stoping
- Cemented (undefined) backfill
- Undefined backfill
|
Production Start | ... |
All operations have been suspended as a result of the flooding event at the Perkoa mine on April 16, 2022.
Trevali Mining Corporation announced that its 90%-owned subsidiary Nantou Mining Burkina Faso S.A. has filed an application for liquidation with the Judicial Tribunal of Commerce in Burkina Faso. A liquidator has been appointed by the Judicial Tribunal. The liquidator has assumed responsibility for the management of the affairs of Nantou Mining and Trevali no longer exercises operational control over Nantou Mining or the Perkoa mine.
On June 30, 2023, Trevali Mining Corporation announced that the Supreme Court granted an order in the Company's ongoing CCAA proceedings pursuant to which FTI Consulting Canada Inc., the Court appointed "Monitor", has been granted enhanced powers in the CCAA Proceedings with respect to the Company's business and affairs.
The Monitor's powers to manage the Company, the remaining employees have ceased their employment with the Company. |
Source:
p. 2
Company | Interest | Ownership |
Government of Burkina Faso
|
10 %
|
Indirect
|
Trevali Mining Corp.
|
90 %
|
Indirect
|
Trevali is the indirect owner of 90% of the shares in the capital of Nantou Mining Burkina Faso S.A. (“Nantou Mining”), the entity that owns the Perkoa Mine. The remaining 10% of Nantou Mining is owned by the Government of Burkina Faso, in accordance with the Burkina Faso Mining Law.
On November 14, 2022, Trevali Mining Corporation ("Trevali" or the "Company") announced that further to the October 6, 2022 press release of the Company, the Judicial Tribunal of Commerce in Burkina Faso has granted an order providing for the liquidation of the Company's 90%-owned subsidiary Nantou Mining Burkina Faso S.A. ("Nantou Mining"). A liquidator has been appointed by the Judicial Tribunal. The liquidator has assumed responsibility for the management of the affairs of Nantou Mining and Trevali no longer exercises operational control over Nantou Mining or the Perkoa mine.
Contractors
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Summary:
The Perkoa deposit lies in a felsic to intermediary series of volcanic and volcaniclastic rocks, within the Paleoproterozoic Birimian Supergroup of West Africa. The prospective Birimian-aged rocks in Burkina Faso are the same sequences that host major gold deposits in Burkina Faso and in the neighbouring countries of Ghana and Mali. The Birimian Supergroup of West Africa is renowned for their gold mineralization; however, known occurrences of base metals are scarce. The Perkoa deposit represents the only significant zinc-silver massive sulphide mineralization discovered in the Birimian to date and it is also the first zincsilver massive sulphide mineralization discovered in this region. Only zinc is being recovered at the Perkoa Mine.
The Perkoa deposit has been classified as a volcanogenic massive sulphide (“VMS”) deposit. VMS deposits are lenses and sheets of massive sulphide that form from seafloor hydrothermal systems where metal rich fluids precipitate on (exhalative) or near the seafloor (sub-seafloor replacement.). The Perkoa mineralization occurs as a series of stacked, northeast-southwest striking tabular VMS lenses hosted, and separated by, tuffaceous material that has been overturned with an average dip of approximately 70°. The deposit is unusual for its high concentrations of zinc and barium mineralization, and relatively low levels of lead and copper. Mineralization occurs within two continuous VMS lenses, the main Perkoa lens and the Hanging Wall len ........
Mining Methods
- Longhole stoping
- Longitudinal stoping
- Transverse stoping
- Cemented (undefined) backfill
- Undefined backfill
Summary:
The Perkoa mine is an underground operation, however, a small open pit was mined to reach near surface material during initial start-up to increase plant throughput as the underground mine ramped up production. The pit is now complete. Underground mining with contractors carrying out all aspects of the mining process commenced in February 2013.
The mine is accessed via an 85 m long decline in the box cut prior to entering the portal.
The decline and associated cross cuts are excavated in the competent quartz diorite of the footwall. The 5.3 m wide x 5.5 m high decline is a spiral and the level spacing is set at 30 m. Each level is identical with a footwall drive, sumps, and services cubbies.
A ventilation shaft connects all levels of the mine and acts as an emergency egress via the inking bucket (kibble). A further secondary ventilation ramp egress exists into the completed open pit to allow personnel to escape on foot in an emergency situation. A 35 m crown pillar has been maintained between the open pit and underground production workings.
Longhole stoping is being used as the primary extraction method. There are several variations on this mining method employed such as longitudinal and transverse, with both bottom-up and top-down mining sequences. The exact method chosen is dependent on the orebody geometry. Stopes are backfilled with either cemented rock fill (CRF) or waste.
Longitudinal bottom-up stoping has been u ........
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Flow Sheet:
Summary:
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Pipelines and Water Supply
Source:
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Production:
All production and cost data for 2022, are given for the first two quarters of the year, following the Perkoa flooding event on April 16, 2022 that resulted in the suspension of all operations to date.
Commodity | Product | Units | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 | 2016 |
Zinc
|
Payable metal
|
M lbs
| ...... | ...... | ...... | ...... | 184 | | |
Zinc
|
Concentrate
|
kt
| | | | | 197 | 171 | 154 |
Zinc
|
Metal in concentrate
|
M lbs
| | | | | | 204 | 180 |
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Operational Metrics:
Metrics | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 |
Ore tonnes mined
| ...... | ...... | ...... | 751,681 t | 708,263 t | 721,503 t |
Tonnes milled
| ...... | ...... | ...... | 739,849 t | 724,995 t | 657,933 t |
Daily milling capacity
| ...... | ...... | ...... | 2,000 t | 2,000 t | 2,000 t |
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Reserves at December 31, 2021:
The Perkoa Underground Mine Mineral Reserve estimate is reported based on planned stopes with a net smelter return cutoff value of $90/tonne, with an average zinc price of $1.39 per pound.
The Perkoa Underground Mine Mineral Resource estimate is reported based on a cut-off grade of 5% zinc equivalent.
Mineral Resources are reported inclusive of Mineral Reserves.
Category | Tonnage | Commodity | Grade | Contained Metal |
Proven
|
0.73 Mt
|
Zinc
|
11.31 %
|
181 M lbs
|
Probable
|
0.23 Mt
|
Zinc
|
9.45 %
|
48 M lbs
|
Proven & Probable
|
0.96 Mt
|
Zinc
|
10.86 %
|
229 M lbs
|
Measured
|
1.51 Mt
|
Zinc
|
12.72 %
|
424 M lbs
|
Indicated
|
1.2 Mt
|
Zinc
|
9.48 %
|
251 M lbs
|
Measured & Indicated
|
2.71 Mt
|
Zinc
|
11.29 %
|
675 M lbs
|
Inferred
|
0.47 Mt
|
Zinc
|
8.51 %
|
88 M lbs
|
Corporate Filings & Presentations:
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