Centerra rises on Mt Milligan copper-gold mine life boost

Centerra Gold (TSX: CG; NYSE: CGAU) gained the green light to extend operations until 2035 at its Mount Milligan copper-gold mine from British Columbia’s Environmental Assessment Office (EAO).

While Mount Milligan’s mine plan already forecast the open-pit site would produce until 2035, the EAO decision gives it a regulatory stamp of approval, according to the decision published Monday. It authorizes an 11% production boost to 66,500 tonnes of ore per day by deepening the pit and an 80-hectare expansion to the disturbance area for construction materials.

The amendment to the environmental assessment certificate also includes building new infrastructure at the mine 155 km north of Prince George. It also changes the transportation route, raises the tailings storage dam height by 26 metres to 1,121 metres above sea level and updates the reclamation and closure plan.

Centerra shares rose 2% to C$20.85 apiece on Tuesday morning in Toronto, valuing the company at C$4.2 billion ($3 billion). The stock has traded in a 12-month range of C$7.72 to C$21.27.

2045 life possible

The extension comes almost four months after a pre-feasibility study envisioned Mount Milligan could operate until 2045 based on raising gold and copper reserves by 52% and production by 12%.

The EAO decision follows a nine-month review of Centerra subsidiary Thompson Creek Metals’ application to continue mining at the site. That review assessed potential effects on nearby communities and First Nations, water and fish habitats, air quality and noise and considered safety risks.

Economic benefits

If all other authorizations are green lit, the mine expansion will generate more jobs during construction in addition to the 600 people already employed at Mount Milligan, the EAO said. It could also contribute as much as C$450 million in economic benefits to the region.

Mount Milligan, ranked as a mid-tier project by reserve size and grade compared to other mines in BC, had already received a two-year extension through a deal in February 2024, in which Royal Gold (Nasdaq: RGLD) is to pay $125 million in cost support for its share of gold and copper from the mine.

Mount Milligan could produce 150,000 oz. of gold and 69 million lb. of copper annually until 2042, according to the recent pre-feasibility study.

It hosts proven and probable gold reserves of 483.2 million tonnes grading 0.28 gram gold per tonne for 4.4 million oz. of contained gold. Red metal reserves grade at 0.16% copper for 1.7 billion pounds.