Osisko Metals updates resources at Copper Mountain deposit

Plans are being made to resume mining at the past-producing Gaspé copper open pit. Credit: Osisko Mining

A resource update for Osisko Metals‘ (TSXV: OM) Copper Mountain deposit in Quebec increases the copper-equivalent metal content by 30% over the previous estimate, making it the largest undeveloped copper asset in eastern North America, the company says.

The update puts the deposit at 495 million indicated tonnes grading 0.30% copper, 0.016% molybdenum and 1.75 grams silver per tonne (0.37% copper equivalent), Osisko said in a news release Monday. That resource contains 3.2 billion lb. copper, 180 million lb. molybdenum and 27.9 million oz. silver.

There’s an additional 6.3 million inferred tonnes at 0.30% copper, 0.19% molybdenum and 1.44 grams silver (0.37% copper equivalent).

“We are extremely pleased with the results of the updated mineral resource estimate for the Copper Mountain deposit,” Osisko Metals CEO and chair Robert Wares said.

“Integrating the recently announced positive metallurgical testing results, the Gaspé copper project is showing excellent potential towards becoming a key Canadian copper-molybdenum producer, located in one of the world’s safest mining jurisdictions.”

Metallurgical studies averaged 91.9% recovery from 19 bulk copper-molybdenum flotation tests and 94.2% from three locked-cycle copper-molybdenum separation tests.

“This MRE will provide the basis for a preliminary economic assessment, scheduled to be released in early first quarter 2025 in the context of what we believe is the start of a strong long-term copper market” he continued.

“Furthermore, we strongly believe that this important asset could become a core component of Quebec’s critical mineral development strategy that aims to provide essential metals for global decarbonization initiatives.”

Copper Mountain is part of Osisko’s Gaspé copper project near Murdochville, Quebec. The company acquired 100% of the past-producing Gaspé mine in 2022. Copper was first discovered in 1921, but production did not begin until 1955. Operations ceased in 2002.

Osisko has plans in place to reopen the mine, beginning with the remnant mineralization in the existing pit. The company also believes there is potentially high-grade underground mineralization that was never mined by Noranda subsidiary Gaspé Copper.

Company shares were up 11.1% to C$0.20 on Monday, valuing the company at C$51.3 million. Its shares traded in a 52-week range of C$0.14 and C$0.28.