Black Butte Copper Project PFS: $126M NPV, 13.3% IRR
Sandfire Resources America Inc.'s Black Butte Copper Project in Meagher County, south-central Montana, United States has a Pre-Feasibility Study (PFS) outlining an after-tax NPV of $126M, an after-tax IRR of 13.3%, and initial capital of $474M. The mine plan runs 12 years at about 31 kt Cu per year.
Sandfire Resources America Inc.'s Black Butte Copper Project has reported Pre-Feasibility Study (PFS) results for the copper project in Meagher County, south-central Montana, United States. The study headlines an after-tax net present value of $126M at a 8% discount rate. It reflects Sandfire Resources America Inc.'s (SFR.V) latest disclosed economics for the asset.
Economics. The after-tax NPV is $126M using a 8% discount rate. After-tax IRR is 13.3%. Initial capital expenditure is estimated at $474M, with life-of-mine sustaining capital of $180M. The study models a payback period of 4 years. All-in sustaining costs are pegged at 3.04 USD/lb. Economics are based on US$4.70/lb Cu (base case); also US$6.00/lb Cu sensitivity.
Production and mine plan. The project envisions an underground operation. Life of mine is 12 years. Average annual production is approximately 31 kt Cu. Average head grade is 2.6% Cu. Metallurgical recovery averages 88%.
These figures are extracted from Sandfire Resources America Inc.'s technical disclosures and reflect the most recent PFS on file. Compare this project against other developers and producers in our project economics database, and always verify the numbers against the original technical report before making any investment decision.
Reserves & Resources
| Category | Tonnage | Grade | Contained |
|---|---|---|---|
| Probable | 9.5 Mt | 2.9% Cu | 270 kt Cu |
| Probable | 4.7 Mt | 2.1% Cu | 100 kt Cu |
| Probable (Combined) | 14.3 Mt | 2.6% Cu | 370 kt Cu |
| Category | Tonnage | Grade | Contained |
|---|---|---|---|
| Measured & Indicated (Johnny Lee) | 18.9 Mt | 2.4% Cu | 462 kt Cu |
| Inferred (Johnny Lee) | 3.4 Mt | 1.9% Cu | 64 kt Cu |
| Measured & Indicated (Lowry) | 17.9 Mt | 1.4% Cu | 248 kt Cu |
| Inferred (Lowry) | 13.7 Mt | 1.1% Cu | 151 kt Cu |
| Measured (Lowry MCZ) | 2.2 Mt | 1.8% Cu | 39 kt Cu |
| Indicated (Lowry MCZ) | 9.0 Mt | 1.5% Cu | 132 kt Cu |
| Measured (Lowry LCZ) | 0.3 Mt | 1.1% Cu | 4 kt Cu |
| Indicated (Lowry LCZ) | 6.4 Mt | 1.2% Cu | 74 kt Cu |
| Inferred (Lowry UCZ) | 3.5 Mt | 1.1% Cu | 37 kt Cu |
| Inferred (Lowry MCZ) | 3.0 Mt | 1.5% Cu | 45 kt Cu |
| Inferred (Lowry LCZ) | 7.2 Mt | 0.9% Cu | 68 kt Cu |
Our Analysis
The 13.3% after-tax IRR lands in the bottom quartile of our tracked copper projects and sits below the ~15% threshold most developers need for project financing, a gap that is amplified for a single-asset junior. The 8% discount rate is standard for NPV reporting but is not a hurdle; it is low enough to flatter the NPV, which at $126M is only half the company’s market cap. That ratio cuts two ways: it could mean the market has not priced in the project, or that it is skeptical about financing, given the $474M initial capex—376% of NPV—which signals acute dilution risk for a developer of this size.
The base-case copper price of $4.70/lb sits well below the current spot of $6.26/lb, so the returns are not optimistic on price; the sensitivity at $6.00/lb would improve the IRR, but the core financing hurdle remains the capital intensity. The Montana jurisdiction is mining-friendly, but the single most important watch-item is the funding gap: a project with capex nearly four times its NPV and below the market cap will require substantial equity or debt, and at this IRR, debt terms will be punitive.
Our take, benchmarked against the project economics in the Mining Stocks database. Figures are estimates drawn from company technical reports — not investment advice; always verify against the source filing.