Perpetua Resources Opens Modular Mineral Processing Plant With U.S. Army And Idaho National Laboratory To Advance Antimony Trisulfide Supply

The pilot plant is designed to demonstrate and help establish a secure, end-to-end domestic supply chain for antimony, a critical mineral essential to U.S. national security. Idaho Governor Brad Little, Lieutenant Governor Scott Bedke, U.S. Representative Mike Simpson, and INL Laboratory Director John Wagner joined Perpetua President and CEO Jon Cherry for a ribbon-cutting ceremony marking the facility's opening on July 29, 2026.

Located at the INL in Idaho Falls, the modular mineral pilot plant is designed to utilize antimony samples from Perpetua's Stibnite Gold Project in central Idaho with the goal of demonstrating how to process high-quality antimony trisulfide for use in specialized military and industrial applications. Antimony is used in products ranging from defense munitions and battery technologies to solar glass and flame retardants. In recent years, China and Russia have dominated the global production of antimony, leaving the United States heavily reliant on foreign sources of the critical mineral. In 2021, China ceased providing the United States with the specialized form of antimony trisulfide essential for more than 300 types of ammunition. Shortly thereafter, the U.S. Department of War and Perpetua Resources entered into a strategic effort focused on advancing domestic antimony trisulfide production. Perpetua's Stibnite Gold Project contains the only identified domestic reserve of antimony and is in development to provide a large-scale domestic source of the critical mineral alongside significant gold production.

"From the mountains of central Idaho to the national laboratories advancing America's defense and energy capabilities, today's milestone shows what's possible when industry, government, and scientific innovation work together on practical domestic solutions," said Jon Cherry, President & CEO of Perpetua Resources. "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. Together, these investments are laying the foundation for a secure, end-to-end domestic supply chain that strengthens national security while creating long-term economic opportunity."

The pilot plant combines the nation's only identified domestic antimony reserve with INL's advanced materials expertise to further advance innovation, train a skilled workforce, and strengthen the technical capabilities needed to rebuild commercial-scale domestic critical mineral production in America. The pilot plant is the culmination of a multi-year collaboration between the U.S. Army via the Defense Ordnance Technology Consortium (DOTC) and Perpetua Resources to advance a fully domestic, "ground-to-round" antimony supply chain. The facility also has the potential to support future processing of additional critical minerals, creating a scalable platform to strengthen U.S. supply chain resiliency.