Korea Zinc launches Crucible Zinc to build US critical metals smelter

Korea Zinc officially launched Crucible Zinc Inc. to build its $7.43 billion critical metals smelter in Clarksville, Tennessee, on April 1, the company said in a statement on April 2.

Along with the new company, affiliates such as Crucible ETN LLC, Crucible MTN LLC and Crucible US Trading Inc. were also launched.

Crucible Zinc and its affiliates were launched after Korea Zinc completed the acquisition of Nyrstar USA's smelter and related companies, according to the South Korean company. Nyrstar had said its Clarksville smelter is the sole primary zinc smelter in the US.

Korea Zinc said it will recycle about 620,000 metric tons of smelting by-products from five ponds at the newly acquired smelter site to recover core minerals such as germanium, gallium and indium. The company will also source raw materials for core minerals from two mines owned by the smelter. Platts, part of S&P Global Energy, previously reported on the metal residue at the Tennessee site.

The company said Project Crucible is proceeding smoothly with various permits and financial arrangements through a strategic partnership with the US government, aiming to start site preparation in 2026, begin construction in 2027, and complete the project in 2029.

"It will sequentially produce zinc, lead, copper and ultimately 13 types of non-ferrous metals, including 11 core minerals designated by the US government, as well as semiconductor sulfuric acid," Korea Zinc said.

Korea Zinc will boost its production of semiconductor-grade sulfuric acid in South Korea by 14.3% to 320,000 metric tons/year in the second half of 2026, the company said March 18, to support the domestic semiconductor industry. The company said it plans to further expand its capacity to 500,000 metric tons/year.

The company said market concerns regarding sulfuric acid supply are growing due to the recent war in the Middle East, as sulfuric acid is produced from sulfur generated during oil refining.

However, Korea Zinc produces semiconductor-grade sulfuric acid through an integrated smelting process instead of oil refining. This enables the company to supply semiconductor-grade sulfuric acid reliably, unaffected by the war or disruptions at the Strait of Hormuz.

The company said the prolonged war in the Middle East and "rising geopolitical risks and economic uncertainty" are increasing the importance of core minerals. "Building a stable supply chain independent of specific countries is emerging as a key issue for economic security," it said.

Korea Zinc also plans to establish a joint venture with Alta Resource Technologies to establish a US plant to recover rare earths from end-of-life permanent magnets, Platts reported earlier.

Platts assessed the CIF China clean copper concentrate treatment charge and refining charge at minus $71/mt and minus 7.10 cents/lb, respectively, on April 1, down $1/mt and 0.10 cent/lb from March 31.