U.S. Army drafts Perpetua for antimony refining

The U.S. Army is backing a new generation of small, mobile refineries to secure critical minerals for weapons production, beginning with antimony sourced from Perpetua Resources’ (Nasdaq: PPTA; TSX: PPTA) $1.3-billion Stibnite project in Idaho.

The Army has spent about $30 million developing a refinery that fits into four shipping containers and can produce 7–10 tonnes per year of antimony trisulphide. Meantime, Idaho National Laboratory is preparing to host a separate pilot plant for Perpetua aimed at processing ore from the company’s Stibnite gold-antimony project about 150 km northeast of Boise. 

“While the volumes are not likely to be large, the small-scale approach will nonetheless contribute to refining intellectual property development in the U.S.,” BMO Capital Markets wrote in a note this week. “We flagged antimony as one of the U.S.’s “most critical” minerals in our recent critical minerals report.” 

The combined initiatives mark a significant shift in U.S. defence strategy as the military moves to secure antimony — a unique munitions hardener that is almost totally imported — through modular refining technology and closer collaboration with industry. They also expand Perpetua’s partnership with the Army through the Defense Ordnance Technology Consortium, which has awarded the company up to $22.4 million to advance domestic processing.

‘Resilience’

“The successful demonstration of this plant will contribute to sustained growth in American mineral independence and resilience,” Perpetua Resources CEO Jon Cherry said in a release. 

Shares in Perpetua Resources gained 14% on Thursday to close at C$40.21 apiece in Toronto, valuing the company at C$4.9 billion ($3.56 billion). 

In defence applications, antimony is combined with lead to harden bullets and shell casings, and antimony trisulphide is used in primers, detonators and other ignition systems. It is considered critical because there is no viable substitute for several of these functions, and the U.S. relies almost entirely on foreign supply.

Construction

Perpetua began early-works construction in October at Stibnite in central Idaho. The Trump administration fast-tracked the development as part of the U.S. Army’s objective of establishing a fully domestic “ground-to-round” antimony trisulphide supply chain.

Perpetua’s agreement with Idaho National Laboratory, via Battelle Energy Alliance, will see the lab host, commission and operate a modular pilot plant capable of recovering critical and defence-related minerals from Stibnite ore. It will conduct pilot-scale testing to produce antimony trisulphide concentrate for munitions and advanced systems used by the U.S. military.

U.S. Representative Mike Simpson (R-Idaho) said the initiative shows the state “has the potential to provide our country with a domestic source of critical minerals that are essential to our national security needs.”

With files from Colin McClelland.