Study values Ontario graphite mine restart at $183M

An economic study values restarting Global Battery Materials’ (GBM) past-producing Kearney graphite mine in Ontario at $183 million (C$260 million) – almost four times the project’s initial capital costs.

Based on an 8% discount rate, the preliminary economic assessment (PEA) gives the brownfield investment an after-tax internal rate of return of 67% and a payback period of just 1.3 years, privately held GBM said late Tuesday in a statement. Initial capital costs are estimated at C$65.9 million ($46 million), with sustaining capital pegged at C$30.9 million.

The push to reopen Kearney comes as Canada, which has designated graphite as a critical mineral, works to cut its dependence on China – the home to an estimated 70% of global natural graphite production and more than 90% of downstream battery-grade graphite processing. Canada’s southern neighbour, which imports all its graphite, is pursuing a similar strategy.

Kearney “represents a rare opportunity to establish domestic graphite production quickly and with capital efficiency,” GBM CEO Eric Miller said in the statement. “The mine has a proven history of supplying North American markets, and this study confirms the advantages of our brownfield approach. Combined with our advanced-stage anode material pilot plant in South Korea, GBM is ready to act with urgency to strengthen critical mineral supply chains.”

20-year life

Restarting Kearney, which closed in 1994, would generate about $421 million in after-tax cash flow over a 20-year mine life, according to the PEA. Kearney could initially produce 23,000 tonnes of carbon graphite a year starting in 2028, rising to 50,000 tonnes, Miller told The Northern Miner in May. 

GBM’s plan to restart Kearney would involve refurbishing existing infrastructure instead of building a new operation. The mine’s existing processing facilities, transportation access and previously disturbed site help reduce capital intensity and shorten the development timeline, according to the company.

Project economics assume sales of graphite concentrate, industrial graphite products and upstream battery materials aimed at North American industrial, defence, energy storage and battery markets.

Operating costs are projected at C$31.35 per tonne milled during an initial diesel-powered phase, declining to C$25.50 per tonne after a planned connection to the provincial electricity grid. The study assumes production of about 95% carbon graphite concentrate.

June resource

Located west of Algonquin Provincial Park, about 280 km north of Toronto, Kearney is considered one of the largest flake graphite deposits outside of China.  

Kearney holds about 29.2 million indicated tonnes grading 2.10% graphitic carbon and about 33.8 million inferred tonnes grading 1.90% graphitic carbon, GBM said, citing a June 2026 resource. On that basis, contained graphite would amount to about 613,700 indicated tonnes and about 641,700 inferred tonnes.

The open-pit mine, which opened in 1989 and processed almost 1 million tonnes of ore, was shuttered five years later amid depressed graphite prices. It’s been in care and maintenance since then. 

Ontario Graphite owned the mine until filing for creditor protection in 2020 and subsequently selling the property to G6 Energy. Toronto-based GBM acquired G6 Energy’s assets last year. 

Producing a definitive feasibility study will be the next step in Kearney’s development, GBM said Tuesday. It didn’t provide a timeline for the document.