US Antimony Estimates Resource for Ontario Tungsten Project

Why It Matters

The deposit offers a domestic source of a critical mineral, reducing reliance on China and strengthening defense supply chains.

Key Takeaways

• Inferred resource: 14.62 Mt @ 0.17% WO₃.
• Contains 53.6 M lbs of tungsten oxide.
• Project valued at $4.6 B before costs.
• US Antimony seeks Defense Production Act funding.
• First North American tungsten mine in a decade.

Pulse Analysis

Tungsten’s unique high‑melting point and density make it indispensable for aerospace, defense, electronics and clean‑energy applications. Over the past year, Fastmarkets reported a near‑tripling of WO₃ prices as China’s export curbs and years of underinvestment tightened global supply. The metal’s concentration in Chinese hands—over 80 % of mining and processing—has turned it into a strategic vulnerability for Western governments, prompting a surge in interest for domestic sources.

The Fostum deposit, located 70 km west of Sudbury, Ontario, now carries an inferred 14.62 million‑tonne resource grading 0.17 % WO₃, equivalent to 53.6 million pounds of tungsten oxide. At current market rates of roughly $1,890 per tonne, the in‑ground metal is valued at about $4.6 billion before extraction costs. US Antimony, already the only fully integrated antimony producer outside China and Russia, plans to leverage its Montana smelter and existing infrastructure to fast‑track an open‑pit operation, with a view to later underground expansion.

Bringing tungsten production back to North America would address a critical gap; the United States and Canada have not shipped a tungsten concentrate since 2016. US Antimony is pursuing Defense Production Act Title III funding to accelerate permitting and development, positioning the project as a strategic asset for the U.S. military’s supply chain. While the stock slipped 9 % on the news, analysts see the long‑term upside of a domestic source that could stabilize prices and reduce geopolitical risk. If successful, Fostum could spark further investment in the region’s critical‑minerals portfolio.