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 (300-500 m deep), the company said.