United States Antimony Corporation officially commissioned a new critical mineral flotation mill and laboratory in Radersburg, Montana, on Tuesday, marking what company leadership called the final piece in building the only fully integrated antimony production operation outside of Russia and China.
A New Facility With Strategic Significance
USAC acquired the Radersburg property in January for $4.75 million and has since invested roughly $2 million more — approximately $1 million each on a new laboratory and additional capital improvements. The mill will concentrate antimony ore for shipment to the company’s Thompson Falls smelter, the only antimony smelter operating in the United States.
The facility is expected to create around 20 jobs in the area and is capable of concentrating a range of critical and precious minerals beyond antimony, including palladium, platinum, cobalt, and tungsten, as well as recovering gold, silver, copper, lead, and zinc. USAC has indicated it intends to pursue partnerships with other Montana mining operations to expand the mill’s throughput.
Governor Greg Gianforte attended Tuesday’s opening celebration in Radersburg, underscoring the state’s interest in growing Montana’s role in domestic critical mineral production.
Closing the Loop on Domestic Antimony
USAC Chairman and CEO Gary Evans framed the commissioning as a turning point for the company’s vertical integration strategy. “Radersburg was our missing link,” Evans said. “Now we can proudly beat our chest and say we are a fully integrated antimony mining company. The only one in the world outside of Russia and China.”
The concentrated antimony produced at Radersburg will be directed to the Thompson Falls smelter, which expanded last year and now carries a production capacity of 15 million pounds of antimony oxide and 5 million pounds of antimony metal annually. Output from Thompson Falls is slated for sale to the U.S. Departments of Energy and Defense — federal customers with a growing appetite for domestically sourced critical minerals.
The strategic backdrop is significant. China currently controls roughly 85 percent of global antimony production, a concentration that has drawn increasing concern from defense planners and policymakers. Antimony is used in flame retardants, ammunition, and semiconductors, among other defense and industrial applications. A fully domestic supply chain — from Montana mining to Montana smelting — addresses a vulnerability that federal agencies have identified as a national security concern.
Montana’s Growing Role in Critical Minerals
The Radersburg opening is part of a broader effort to position Montana as a key supplier in the national push to reduce dependence on foreign sources for strategically important materials. USAC’s Thompson Falls operation has already been expanding as federal demand for domestic antimony has grown, and the addition of the Radersburg concentrating mill gives the company control over each step of the production process within the state.
Governor Gianforte has made resource development and critical mineral production a priority of his administration, and his presence at Tuesday’s commissioning reflected the state’s interest in attracting and retaining companies that can connect Montana’s mineral wealth to federal supply chains. The state’s workforce and regulatory agencies have also been working to support industrial expansion across Montana’s resource sectors.
USAC’s stated goal of partnering with other Montana mining operations could extend the Radersburg mill’s impact beyond the company’s own properties, potentially offering concentration services to smaller producers who lack downstream infrastructure. If those partnerships materialize, the facility could serve as a regional hub for critical mineral processing rather than a single-company operation.
For a small community like Radersburg, the roughly 20 jobs tied to the facility represent a notable economic addition. More broadly, the project illustrates how federal defense and energy priorities are beginning to translate into tangible investment in Montana’s mining sector, connecting longstanding resource extraction traditions with the demands of a supply chain that Washington has identified as a matter of national security.
