Overview
Stage | Construction |
Mine Type | Underground |
Commodities |
|
Mining Method |
- Drift & Fill
- Cut & Fill
- Paste backfill
|
Mine Life | 9 years (as of Jan 1, 2020) |
Black Butte Copper is one of the highest-grade copper deposits being developed in the world.
In the June Quarter 2022, Sandfire Resources America Inc., announced the results of the state District Court Legal Challenge related to its Mine Operating Permit (MOP). The District Court Judge issued an order aligned with the joint motion and that will allow Phase I Construction of the Black Butte Copper Project to be completed under the existing Permit.
Sandfire America is working on strategies to complete additional test work, analysis and reporting for additional authorisations from the MT DEQ with the objective of moving the project past Phase 1 of the Permit. |
Source:
p. 15
Sandfire holds an 87% interest, via Canadian listed company Sandfire Resources America Inc. , in the high grade Black Butte Copper Project.
Contractors
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Summary:
The majority of the Project area is underlain by gentle to moderately southward-dipping rocks of the Belt Supergroup. The Belt Supergroup lithofacies are juxtaposed against gently south-dipping Cambrian sedimentary rocks along the VVFZ. To the north of the Project area, Belt Supergroup rocks are also exposed, below the basal Cambrian unconformity. Intermediate to mafic, Early Tertiary intrusive dykes and sills occur within the Belt Supergroup. Late Tertiary sedimentary lithofacies unconformably overlie all other units in the area.
Potentially economic Cu mineralization has been identified in the Newland Formation at the UCZ and the LCZ. The mineralization in both of these deposits is largely hosted by massive sulphide units referred to as the USZ and LSZ, respectively. Although not included in the MOP application, Cu mineralization also occurs at Lowry situated 3 km SE of the Johnny Lee deposit (Figure 7.2). Mineralization at Lowry is hosted by the LSZ and the MSZ. In order to discriminate between Johnny Lee and Lowry, the MSZ and LSZ at Lowry are herein referred to as Lowry Middle Sulphide Zone (LMSZ) and Lowry Lower Sulphide Zone (LLSZ). Mineralization at Lowry that occurs in these zones is referred to as the Lowry Middle Copper Zone (LMCZ) and Lowry Lower Copper Zone (LLCZ).
Johnny Lee Lower Copper Zone
The LCZ occurs at depths of 340 to 520 m below surface, strikes approximately EW and dips at 15° to 30° to the south. Mineralization in the LCZ i ........

Mining Methods
- Drift & Fill
- Cut & Fill
- Paste backfill
Summary:
Upper Copper Zone Mining Methods
The UCZ is a flat dipping deposit with multiple parallel lenses. It will be entirely extracted using DF mining methods.
The DF panels will be setup with two parallel access drifts spaced 60 - 90 m apart where possible. Primary ore drifts spaced 15 m apart will be developed from one access drift to within 5 m of the second access drift. Once the drift has completed mining, all the services will be stripped from the drift and a barricade will be built at the access. Paste and breather holes will then be drilled from the second access drift through the pillar and paste fill will be placed in the drift.
Once two adjacent primary drifts have cured, a secondary ore drift will be driven to the end of the panel in the middle of the two cured drifts. This drift will be 5 m wide with two 2.5 m wide pillars on either side. These pillars will then be extracted by drilling unsupported slashes up against the paste and mucking out on remote control. Once the secondary drift has been mined out, a barricade will be built, and the secondary drift will be filled using the same process as the primary drifts.
Once an entire panel has been mined out and both access drifts are paste filled, the pillar is mined out and then paste filled.
In areas where there is no second access to fill from, the same general sequence will be followed. However, the primary drifts will be located 10 m apart and the secondary drifts will ........

Source:

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Flow Sheet:
Summary:

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Reserves at October 19, 2020:
Mineral Reserves were estimated using a NSR cut-off value of $70/t.
Mineral Resources are reported using a cut-off grade of 1.00% recoverable Cu.
Category | Tonnage | Commodity | Grade | Contained Metal |
Proven
|
1,998,000 t
|
Copper
|
3 %
|
60,700 t
|
Probable
|
6,804,000 t
|
Copper
|
2.4 %
|
165,400 t
|
Proven & Probable
|
8,802,000 t
|
Copper
|
2.6 %
|
226,100 t
|
Measured
|
2 Mt
|
Copper
|
3.5 %
|
69.1 kt
|
Indicated
|
8.9 Mt
|
Copper
|
2.7 %
|
241.8 kt
|
Measured & Indicated
|
10.9 Mt
|
Copper
|
2.9 %
|
310.9 kt
|
Inferred
|
2.7 Mt
|
Copper
|
3 %
|
79.7 kt
|
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