Name of the Project
Black Butte copper project.

Location
White Sulphur Springs, in Montana, in the US.

Project Owner/s
Sandfire Resources America, a subsidiary of Sandfire Resources.

Project Description
Sandfire Resources America has announced the results of a feasibility study on the Johnny Lee deposit, the cornerstone of the Black Butte project.

The deposit comprises the upper copper zone and the lower copper zone, both characterised as high grade, and laying at low angles with relatively narrow widths. All deposits have anomalous silver and cobalt mineralisation; however, copper is the only economic product considered in the feasibility study. The study is underpinned by a maiden reserve for the deposit of 8.8-million tonnes at 2.6% copper for 226 100 t of copper.

Further, the Johnny Lee deposit underpins an eight-year mine life and is designed to be mined at 1.2-million tonnes of ore a year. Forecast production, totalling 805 000 dry metric tonnes of copper concentrate containing 189 500 t of copper metal, is forecast over the life-of-mine.

Black Butte's development is centred around the deposit, which has a reserve of 8.8-million tonnes at 2.6% copper for 226 100 t of copper.

Potential Job Creation
Not stated.

Net Present Value/Internal Rate of Return
The project has a pretax net present value, at a 5% discount rate, of $124.9-million and an internal rate of return of 17%, with a payback of three years from the commissioning of the mine.

Capital Expenditure
$247.7-million.

Planned Start/End Date
Not stated.

Latest Developments
Sandfire Resources is continuing to support the Sandfire Americas team to progress the project.

In a critical milestone for project, Sandfire America received a positive ruling from the Montana Supreme Court in March 2024, reinstating the mine operating permit for the project. This removed the last major impediment to the development of the project in its current form.

However, the ultimate decision to proceed will be contingent on project economics. Therefore, Sandfire has been actively conducting targeted exploration drilling to enhance the high-grade resource at the Johnny Lee deposit.

The ongoing 2024 drill programme is focused on upgrading and expanding the Johnny Lee lower copper-zone resource, of which the latest estimate comprised a measured and indicated resource of 1.2-million tonnes grading 6.8% copper and an inferred resource of 500 000 t of 5.9% copper. Since December 2023, the company has drilled about 4 420 m of a planned 20 000 m drill programme. 

Sandfire Resources America announced some high-grade copper intersections from its winter exploration drilling programme in April 2024. Notable highlights include hole SC24-279, which intercepted 5.37 m of 10.2% copper, and hole SC24-284, which intercepted 6.26 m of 10.7% copper. 

Key Contracts, Suppliers and Consultants
None stated.

Contact Details for Project Information
Sandfire Resources America VP of communications Nancy Schlepp, tel +1406547 3466 or email nschlepp@sandfireamerica.com.