Idaho Antimony Mining Project Moves A Step Closer To Reality

In what could come to be seen as a landmark development for U.S. efforts to secure domestic supply chains for critical energy minerals, the U.S. Forest Service (USFS) issued a draft record of decision (ROD) Friday authorizing Perpetua Resources to restart operations at the Stibnite Mine in Central Idaho. The draft ROD opens a 45-day comment period required by the Administrative Procedures Act, which would then be followed by a 45-day resolution period. If all goes to schedule, the ROD could become final by the end of 2024.

Friday’s draft decision signals the possible end to a long and complex process of securing local, state, and federal permits required for Perpetua to restart operations at Stibnite, which first began gold and antimony mining operations in 1927. Initial mining operations were shut down in 1958, but a second generation of miners recovered additional resources from 1978 through 1996, when operations were again shut down. The site has remained idle since that time.

In its release, USFS spokesman Kevin Knesek, deputy forest supervisor for the Payette National Forest, said the mine is “ complex, and the impacts were rigorously analyzed over the past seven years,” Knesek continued. “Projects of this scale and type present unique challenges, and that is particularly true as it relates to tribal interests, whether those interests be treaty-related or connected to cultural use and identity. Only through meaningful consultation can the Forest Service seek to understand these concerns and be responsive to them, and I am grateful for the tribal input we’ve received.”

Supporting documentation for the draft ROD estimates the Stibnite mine contains “Proven and Probable Mineral Reserve (the economically mineable part of the measured mineral resource) of 115.3 million tons of ore containing 4.8 million ounces of gold, 6.4 million ounces of silver, and 149 million pounds of antimony.” The overall mining site covers 3,200 acres of land including 3 pit mining sites. Perpetua estimates the Stibnite mine could provide up to 35% of U.S antimony needs in the coming decades.

Perpetua Resources president and CEO Jon Cherry said his company believes “the Stibnite Gold Project is a win-win-win,” adding, “It’s a win for Idaho, it’s a win for the environment, and it’s a win for America’s national security.”

As I noted here in 2021, antimony is a strategic critical mineral that is used in all manner of military applications, including the manufacture of armor piercing bullets, night vision goggles, infrared sensors, precision optics, laser sighting, explosive formulations, hardened lead for bullets and shrapnel, ammunition primers, tracer ammunition, nuclear weapons and production, tritium production, flares, military clothing, and communication equipment. It is the key element in the creation of tungsten steel and the hardening of lead bullets, two of its most crucial applications during WWII. The Stibnite mine provided as much as 90% of U.S. antimony needs throughout World War II.

Today, in addition to the needs of the military, antimony is a critical ingredient in most modern technologies, including those critical to the success of electric vehicles and wind and solar power development. From a national security standpoint, it is problematic that the U.S. is reliant on supply chains dominated by China for the vast majority of its antimony needs.

The Bottom Line

The permitting of any mining operation in the U.S. is an incredibly difficult achievement. The successful restart of the Stibnite mine would ultimately serve to enhance U.S. energy security by lessening the country’s reliance on a country, China, increasingly seen as a potential adversary. If the process does proceed to a final conclusion in the coming months, the reopening of the Stibnite mine would demonstrate that America is still capable of doing big things.