Korea Zinc, the world's largest refined zinc smelter, said on Monday that its $7.4 billion U.S. manufacturing project has cleared an environmental impact assessment. The approval is expected to accelerate the company's plan to build a critical metals refinery in Clarksville, Tennessee, under the project name "Project Crucible," the company said in a press release. The facility is scheduled to begin test operations in 2029 and commercial production of 11 core minerals, 12 nonferrous metals and semiconductor-grade sulfuric acid the following year. Project Crucible is the first "FAST-41" project approved by the Federal Permitting Improvement Steering Council since Korea Zinc signed a memorandum of understanding with the state of Tennessee in May, the company said. "With Project Crucible now designated as a FAST-41 project, we are accelerating critical infrastructure development and improving government efficiency to move this project forward without unnecessary delays," Tennessee Gov. Bill Lee said. In April, Korea Zinc said it had completed the acquisition of a local zinc smelter and other