Source:
p. 38,146
Hecla Mining Company holds a 100% interest in Casa Berardi through its wholly owned subsidiary Hecla Québec.
Contractors
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Deposit Type
- Sediment-hosted
- Breccia pipe / Stockwork
Summary:
The Casa Berardi gold deposit can be classified as an Archean age, sedimentary-hosted lode gold deposit. Gold deposits of the Archean Abitibi greenstone belt dominantly consist of epigenetic disseminated and vein-hosted deposits, and syngenetic gold-rich massive sulphides (Robert et al., 2005; Monecke et al., 2017).
Three main groups of minerals are found in the mineralized material at the Casa Berardi Mine; silicates (quartz, albite, muscovite), carbonates (siderite, ankerite and dolomite) and sulphides (pyrite and arsenopyrite with traces of chalcopyrite and pyrrhotite). There is also gold mineralization found in a graphitic mud rock formation along the Casa Berardi fault plane. The historical recovery data suggest that material classified as “quartz ore” and is dominantly silicates and carbonates have better recoveries than sulphide dominant material, particularly those that contain arsenopyrite. Carbon in graphitic argillite rock at or near the Casa Berardi Fault can be “preg robbing” and influence gold recovery.
STYLES OF MINERALIZATION
VEINS
Gold mineralization is essentially located in quartz veining, either in the form of plurimetric veins, small-scale veins, or veinlet networks. Veins are heterogeneous and contain a variable percentage of foliated enclaves showing a laminated appearance. Veins are of different color, texture, and structure. Gold grades are generally correlated with increasing complexity. Different quartz phases have b ........

Mining Methods
- Truck & Shovel / Loader
- Longhole stoping
- Transverse stoping
- Longitudinal stoping
Summary:
The ore at Casa Berardi is extracted using a combination of underground and open pit mining methods. The underground mines at Casa Berardi are trackless and are accessed by a combination of ramps and a production shaft. The mining method is longhole stoping using a combination of traverse and longitudinal orientations depending upon the widths of the zone. The combined ore production rate from the underground zones is in the range of 2,000 to 2,200 tons per day.
Open pit mining is used to extract near surface mineralization, both above the existing underground mining horizons and in areas without economic underground resources. At present, one open pit mine is in production and another is being developed. Three additional pits are anticipated. The combined ore production rate from the open pit zones is highly variable depending on the mining sequence and ore release rates. Open pit ore is fed to the plant roughly in equal proportion to the underground ore and any surplus is stockpiled.
Current reserves at the Casa Berardi mine comprise eight zones at the West Mine, spread over a moderate horizontal distance from each other and located at different mine elevations, plus open pit and underground areas at the East Mine. The 113, Lower Inter, 118, 121, 123, 124 (Principal underground and open pit), 134, and the West Mine Crown Pillar ("WMCP") open pit zones in the West Mine, and the 148 Zone (open pit and underground) and the 160 open pit in the East Mine ........

Source:

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Flow Sheet:
Summary:

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Production:
Commodity | Units | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 |
Gold
|
oz
| ...... ^ | ......  | ......  | ......  | ......  | 162,744 | 156,653 |
Silver
|
oz
| | ......  | ......  | ......  | ......  | ......  | ......  |
All production numbers are expressed as metal in doré.
^ Guidance / Forecast.
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Operational Metrics:
Metrics | 2022 | 2021 | 2020 | 2019 | 2018 | 2017 |
Tonnes milled
| ......  | ......  | ......  | 1,378,065 tons | 1,375,718 tons | 1,296,224 tons |
Daily milling rate
| ......  | ......  | ......  | 3,775 tons | 3,769 tons | 3,551 tons |
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Reserves at December 31, 2022:
The average reserve cut-off grades at Casa Berardi are 0.12 oz/ton gold underground and 0.04 oz/ton gold for open pit.
The average resource cut-off grades at Casa Berardi are 0.11 oz/ton gold for underground and 0.034 oz/ton gold for open pit.
Category | OreType | Tonnage | Commodity | Grade | Contained Metal |
Proven
|
In-Situ (OP)
|
4,410 k tons
|
Gold
|
0.09 oz/ton
|
417 koz
|
Proven
|
In-Situ (UG)
|
552 k tons
|
Gold
|
0.17 oz/ton
|
95 koz
|
Probable
|
In-Situ (OP)
|
12,434 k tons
|
Gold
|
0.08 oz/ton
|
936 koz
|
Probable
|
In-Situ (UG)
|
989 k tons
|
Gold
|
0.17 oz/ton
|
166 koz
|
Proven & Probable
|
In-Situ (OP)
|
16,844 k tons
|
Gold
|
0.08 oz/ton
|
1,353 koz
|
Proven & Probable
|
In-Situ (UG)
|
1,541 k tons
|
Gold
|
0.17 oz/ton
|
261 koz
|
Measured
|
In-Situ (OP)
|
483 k tons
|
Gold
|
0.04 oz/ton
|
20 koz
|
Measured
|
In-Situ (UG)
|
2,440 k tons
|
Gold
|
0.22 oz/ton
|
530 koz
|
Indicated
|
In-Situ (OP)
|
1,323 k tons
|
Gold
|
0.04 oz/ton
|
48 koz
|
Indicated
|
In-Situ (UG)
|
3,870 k tons
|
Gold
|
0.17 oz/ton
|
660 koz
|
Measured & Indicated
|
In-Situ (OP)
|
1,806 k tons
|
Gold
|
0.04 oz/ton
|
67 koz
|
Measured & Indicated
|
In-Situ (UG)
|
6,310 k tons
|
Gold
|
0.19 oz/ton
|
1,190 koz
|
Inferred
|
In-Situ (OP)
|
7,828 k tons
|
Gold
|
0.05 oz/ton
|
389 koz
|
Inferred
|
In-Situ (UG)
|
2,221 k tons
|
Gold
|
0.19 oz/t
|
430 koz
|
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