Perpetua Resources Corp. (Nasdaq: PPTA), the U.S. Army, and Idaho National Laboratory opened a modular mineral processing pilot plant in Idaho Falls, Idaho, on July 29, 2026, designed to demonstrate domestic production of antimony trisulfide for military and industrial applications.

The facility, located at Idaho National Laboratory and managed by Battelle Energy Alliance LLC, will process antimony samples from Perpetua's Stibnite Gold Project in central Idaho. Antimony trisulfide is used in more than 300 types of ammunition. China ceased supplying the U.S. with that specialized form of the mineral in 2021. China and Russia currently dominate global antimony production.

The Stibnite Gold Project holds what Perpetua describes as the only identified domestic reserve of antimony. The project received its final federal approvals in 2025 and has entered early works construction.

Since 2022, Perpetua has received over $87 million in U.S. government funding to advance the project and domestic antimony supply. That total includes more than $59 million in Defense Production Act Title III funds and up to $27 million from the U.S. Army through the Ordnance Technology Initiative Agreement, which was originally signed in August 2023. In June 2026, the Army awarded Perpetua an additional $4.7 million under the Defense Ordnance Technology Consortium program.

The ribbon-cutting ceremony was attended by Idaho Governor Brad Little, Lieutenant Governor Scott Bedke, U.S. Representative Mike Simpson, INL Laboratory Director John Wagner, and Perpetua President and CEO Jon Cherry.

"As construction advances at the Stibnite Gold Project, this pilot plant extends that momentum downstream by helping establish the capabilities needed to produce military-grade antimony materials here in America," Cherry said in a statement.

The pilot plant is described as capable of supporting future processing of additional critical minerals beyond antimony.