Black Butte Copper Project
The Black Butte Copper Project is one of the world’s highest-grade undeveloped copper projects. The planned mine development will utilise best-practice technology and modern mining techniques to develop a wholly underground mine with minimal surface footprint and environmental impact.
Sandfire’s interest in the project is held via an 87% equity stake in Canadian listed company Sandfire Resources America Inc. (TSX-V: SFR) (Sandfire America).
The project, located on private ranch land in Meagher County, is close to existing road, power, and rail infrastructure, with the ability to access a residential workforce located nearby and competitive sources of materials and power. The proposed underground mine at Black Butte is designed to provide significant economic opportunity to Central Montana while fully protecting the local watershed.
Project permitting
Project permitting for mining of the Johnny Lee Deposit at Black Butte was completed in April 2020, with the Montana Department of Environmental Quality (MT DEQ) releasing the Final Environmental Impact Statement (EIS) on 13 March 2020 and issuing a positive Record of Decision to grant a Mine Operating Permit (MOP) on 9 April 2020. The MT DEQ issued the final permit on 17 August 2020, and Sandfire initiated Phase I construction.
A legal challenge was filed to the MT DEQ Record of Decision on 4 June 2020, in the 14th Judicial Court in Meagher County, Montana, against the MT DEQ and Sandfire America’s wholly owned subsidiary, Tintina Montana Inc. On April 8, 2022, Montana district court ruling found in favour of the plaintiffs which stopped further construction. Sandfire America and the MT DEQ appealed the ruling to the Montana Supreme Court and Oral Arguments were heard on 21 June 2023. A decision on the case is pending with resolution of the case to inform the next step of the project.
Studies
Mining studies for underground access and mining of the Lowry Deposit (located approximately 2km from the Johnny Lee Deposit) commenced during FY2023. The Lowry Deposit could become a significant addition to the Black Butte underground mining complex and add significant value. Integration of the Lowry Deposit into the mine plan will inform future development options.
Further details can be found on the Sandfire America Resources Inc. website at www.sandfireamerica.com.
Water at Black Butte
Sandfire America is committed to protecting the water resources in the water catchment area. Careful management is critical to maintaining water quality and quantity. To protect the water quality and quantity, the proposed underground mine is designed with:
- All planned openings or entry points to the mine (including air ventilation and escape routes) are located far above the water table to keep water from leaving the mine after closure and mixing with surface water.
- All ground water from the mine and surface run off water from precipitation will be collected, monitored, tested, and treated before being placed back into the ground water system through an underground infiltration system buried 2 metres below the surface. There is zero discharge to surface waters. Water temperature will also be monitored and maintained through this system.
- A Reverse Osmosis (RO) water treatment plant will be constructed onsite for treating all waters discharged to the underground infiltration gallery and will remain operational through the reclamation phase of the mining operation. Sandfire America continues to work closely with the local community and Government agencies to ensure our water management practices are sustainable.