Critical minerals: US DoD backs plan to revive antimony mine

Perpetua Resources wants to revive this abandoned mine in the US state of Idaho. (Perpetua Resources)

US-based Perpetua Resources Corporation is trying to revive an abandoned mine in the state of Idaho that it says could eliminate the US military's reliance on foreign – and potentially unreliable – sources for antimony, a critical mineral used to make ammunition and missiles.

China and Russia produce most of the world's antimony, which has commercial and military applications. While most of the antimony from the Idaho mine would go towards commercial uses, such as batteries that store solar- and wind-generated energy, the site could provide enough antimony to meet the US Department of Defense's (DoD's) needs for “decades”, helping the DoD meet its goal of bolstering domestic production of critical minerals, Mckinsey Lyon, Perpetua vice-president of external affairs, told Janes in December 2022.

Minerals may be deemed ‘critical' if they are essential to economic or national security and are vulnerable to supply chain disruptions for political or other reasons. US lawmakers have expressed concern that many of the critical minerals the DoD uses to build advanced weaponry come solely or mostly from China and Russia.

The Idaho mine was busy during the Second World War and the Korean War, producing antimony for the US ammunition industry. However, antimony activity at the site ended in the 1950s amid declining demand, leaving the US with no domestic source of the mineral, Lyon explained. “Gold mining picked up at the site in the 1980s, but all mining activity ceased in the 1990s,” she said.