USAC buys flotation plant to up domestic Sb processing

US Antimony

USAC buys flotation plant to up domestic Sb processing as Washington prioritizes secure supply. USAC buys flotation plant to up domestic Sb processing by acquiring Montana’s Radersburg Mill. USAC buys flotation plant to up domestic Sb processing to reduce reliance on foreign antimony concentrates.

The Radersburg Mill is fully operational and sits near USAC’s Thompson Falls smelter in Montana. As a result, the acquisition can shorten logistics and improve feed flexibility. The mill supports ore processing from USAC’s Alaska and Montana mines.

Why Radersburg Mill matters for antimony security

USAC aims to increase domestic antimony ore processing and lower exposure to overseas suppliers. The company still buys ore and concentrate from Chad, Bolivia, Peru, Australia, and Mexico. However, greater in-country processing can stabilize deliveries during trade disruptions.

The mill also expands optionality beyond antimony. It has historically processed gold, silver, copper, lead, and zinc. Meanwhile, the facility can handle tungsten, cobalt, PGMs, and rare earths, depending on feed and flowsheet choices.

DLA contract drives the scale-up

USAC secured a five-year fixed-price contract with the US Defense Logistics Agency for antimony ingots. The contract can reach $245mn and targets up to 6.7mn lb over the term. Therefore, USAC is pushing throughput increases across its network.

Thompson Falls currently produces about 100t per month and targets 500t per month after expansion. The company expects to finish expansion and commissioning in February. Meanwhile, USAC restarted the Madero smelter in Mexico in April to process most international shipments.

The Metalnomist Commentary

This deal strengthens US antimony resilience by linking ore processing with smelting capacity in one region. However, execution risk remains in ramping to 500t per month without bottlenecks in feed quality and logistics. If USAC delivers, it becomes a key Western Sb supply node for defense and strategic alloys.