Korea Zinc's (KRX:010130) $7.4 billion U.S. smelter project has cleared a key environmental review after federal authorities found it would have no significant environmental impact, according to U.S. Department of War documents.

The finding advances Project Crucible, an integrated smelting and refining facility planned in Clarksville, Tennessee.

The project is targeting trial operations in 2029, with all processes expected to reach full operation in 2030.

The facility is designed to produce 12 nonferrous metals, including 11 minerals designated as critical by the U.S. government, as well as semiconductor-grade sulfuric acid.