Stibnite Gold Antimony Mine Approved by US Forest Service

According to Mining.com, Perpetua Resources' $1.3 billion Stibnite gold-antimony project in Idaho has received approval from the US Forest Service (USFS).

The company was informed of the decision record for the project in January, obtained final federal approval in May, and Friday's notice is the final step before construction, allowing work to begin once financing is in place.

The company expects to finalise bond financing within the next few weeks, and construction could start by October.

The Stibnite project is expected to commence official production in 2028, supplying over 100 million pounds of antimony over its 15-year mine life, meeting more than 35% of annual US demand.

Antimony is critical for the defense industry, including munitions, as well as renewable energy technologies such as solar panels. Currently, the US has no domestic antimony production and relies heavily on imports for its consumption.

"This is a milestone," said Jon Cherry, CEO of Perpetua Resources, in a press release. "After eight years of evaluation and over $400 million in investment, the Stibnite gold-antimony project is ready to supply the US. Stibnite will be revitalized as a strategic national mineral deposit."

The project is also expected to produce nearly 450,000 ounces of gold annually, increasing project revenue. The mine has proven and probable reserves of 148 million pounds of antimony and over 6 million ounces of gold.

Last year, the US Export-Import Bank (Exim) offered the company a letter of interest for $1.8 billion in funding, which is still under evaluation.

The project has gained support from investment tycoon John Paulson and has also attracted attention from the US government.

Perpetua Resources emphasizes both mining production and environmental restoration. The final mine plan reduces the ecological footprint by 13%, improves stream and wetland conditions, and restores fish habitats.

However, the project faces opposition from the Nez Perce Tribe in Idaho, who are concerned it could endanger salmon populations in the area.

The mine is located in the Stibnite-Yellow Pine area of Idaho, 222 kilometers northeast of Boise, and was a key supplier of antimony during World War II.

A feasibility study indicates proven and probable ore reserves of 104.6 million mt, with a gold grade of 1.43 g/mt and antimony grade of 0.064%, equivalent to gold reserves of 4.8 million ounces and antimony reserves of 148 million pounds.