The Montana Department of Environmental Quality (DEQ) has released a positive Record of Decision (ROD) to grant a Mine Operating Permit (MOP) for Sandfire Resources’ Black Butte copper project in Montana. All required permitting is now in place for its 85% owned project, according to Sandfire. Granting of the MOP to Sandfire Resources America’s subsidiary, Tintina Montana, represents the final permitting milestone required to allow development and underground mining of the Johnny Lee deposit at the Black Butte copper project to proceed.

Sandfire Managing Director and CEO Karl Simich said the completion of project permitting at Black Butte represents an exciting milestone on the company’s pathway to develop a new, showcase underground copper mine in North America. “We continue to tick important boxes as part of our long-term strategy to deliver a new, state-of-the-art copper mine at Black Butte, and the receipt of a positive RoD is a major achievement which marks the culmination of many years of patience and hard work,” Simich said.

The Montana DEQ needs to finalize a financial bond calculation within 40 days to issue the MOP.

Tintina concurrently received its preliminary Air Quality Permit and a Montana Pollution Discharge Elimination System (PDES) permit.

The Johnny Lee deposit represents one of the highest copper grade undeveloped projects in the world with a measured and indicated resource of 10.9 million metric tons (mt) at 2.9% copper for 311,000 mt of contained copper, including a Lower Copper Zone with a copper grade of 6.8%, plus an Inferred Resource of 2.7 million mt at 3% copper for 80,000 mt of contained copper, at a 1% copper cut-off, according to the company.

Black Butte’s mine design is for a relatively shallow underground mine to be accessed by a 1,700-meter decline to access the Upper copper zone (60-200 m deep) first, followed by additional development to reach the Lower copper zone (300-500m deep), the company said.