"Sold Out Before Inventory Builds Up"... The 'Korean Metals' Catching US Attention [Report]

A Visit to Korea Zinc's Onsan Smelter
Antimony and Indium as Strategic Minerals: Key Cards in U.S. Tariff Negotiations
Strategic Mineral Prices Surge Due to China's Export Controls
Korea Zinc: The Only Domestic Producer of Antimony
Recent Antimony Exports to the U.S.: "A First for Korea"
Soaring Strategic Mineral Orders: "No Time for Inventory to Accumulate"

Antimony. Asia Economy DB

On June 11, at the antimony plant of Korea Zinc's Onsan Smelter in Ulsan. This is the only place in South Korea where antimony is produced. On one side of the factory, dust raw material separated from metal plates was piled up like a mountain. At first glance, it looks like nothing more than black rocks, but hidden inside is the high-value-added metal, antimony. It is a by-product generated from zinc and lead smelting processes, and its price has recently exceeded 80 million KRW per ton.

On the 11th, at the Korea Zinc Onsan Smelter's antimony plant, Hwang Yoongeun, head of the Precious Metals 2 Part at the Onsan Smelter, is holding antimony raw material. This raw material is melted and impurities are removed using diaphragm electrolysis technology to increase the antimony purity up to 99.9%. Photo by Shim Sunga

Inside the plant, five to six large induction furnaces were operating simultaneously, melting the ore at high temperatures. The molten metal is then transferred to electrolytic cells and enters the diaphragm electrolysis process. Korea Zinc extracts antimony from by-products of the zinc and lead smelting processes using a hydrometallurgical method based on diaphragm electrolysis technology, without the need for concentrate.

Diaphragm electrolysis technology uses electrical energy to separate and precipitate only metal ions, and through this process, the purity of antimony can be increased up to 99.9%. Unlike conventional metal electrolysis methods, this allows for the production of antimony with ten times higher purity. The impurity removal process alone takes four days.

On the 11th, Hwang Yungeun, head of the Precious Metals 2 Part at the Onsan Smelter of Korea Zinc, explained while pointing to the finished antimony products at the antimony factory. The antimony ingot placed on a single pallet weighs 1 ton, and the price exceeds 80 million won per ton. Photo by Shim Sunga

Each finished antimony ingot weighs 20kg. About 50 rough-surfaced ingots are stacked on each pallet. Hwang Yoongeun, head of the Precious Metals 2 Part at the Onsan Smelter, explained, "Ten sets of 1-ton pallets are produced each day," and added, "The current unit price is just over 80 million KRW per ton, which is six to seven times higher than at the beginning of last year."

According to the industry, about 20 tons of this antimony were recently loaded into containers and shipped to Washington, D.C., United States. This is the first time that antimony, a key material for national defense, has been directly exported from South Korea to the United States. This shipment is scheduled to arrive in the United States next month and will be supplied to more than ten major defense companies.

Antimony is one of the 28 critical minerals designated by the Special Act on National Resource Security. It is an essential strategic material for the production of military supplies such as ammunition, missiles, and shells, and its applications are expanding in heat-resistant materials for vehicle dashboards, tents, and advanced industrial fields.

Previously, in September last year, China, which accounts for more than half of the world's antimony production, restricted exports of domestically produced antimony and related technologies, increasing global supply chain instability. The United States has relied on China for 62% of its total imports, making it urgent to secure alternative suppliers.

In response, Korea Zinc announced that it is formulating specific strategies, including the selection of importers, with the goal of exporting 350 tons of antimony to the United States this year. If the company succeeds in exporting the targeted amount, it will open up a market worth more than 32.2 billion KRW annually. A Korea Zinc representative stated, "After opening the door with this initial shipment this year, we plan to gradually expand export volumes in the future."

About a ten-minute drive from the antimony plant, there is another rare metal facility: the indium plant. Among refining devices as tall as a two-story apartment building, a silvery liquid was gushing out of one line like water from a faucet. An employee was pouring the liquid into molds to form ingots. The process looked very simple, like pouring batter into a fish-shaped pastry mold. Jeon Jongbin, team leader of the Electronic Materials Team at Production Headquarters 3 of the Onsan Smelter, said, "Although it looks simple, casting to a fixed size with precision is a skill that requires experience."

On the 11th, an employee at the Indium plant of Korea Zinc Onsan Smelter was casting liquid indium. Each indium ingot produced this way weighs 5kg and is worth about 2.5 million KRW at the current market price. Photo by Shim Sunga.

The indium here arrives in a liquid, concentrated state from the previous process. The role of the plant is to cast this liquid into solid metal. Since only small quantities are produced, automation is not yet economically viable, so most of the work is done manually.

The warehouse on one side of the plant was almost empty. Only some indium, vacuum-packed, was neatly stacked. Jeon smiled and said, "There was a time when the warehouse was filled with products, but now, since everything is shipped out as soon as it's made, there is no chance for inventory to accumulate." He added, "In the past, we operated 10 to 13 days a month, but recently it's more than 20 days per month," and stated, "Our annual production target is 150 tons."

On the 11th, Jongbin Jeon, a team leader of the Electronic Materials Team at the Production Headquarters 3 of Onsan Smelter, Korea Zinc, is holding vacuum-packed indium in the indium warehouse of the Onsan Smelter. Each indium ingot produced this way weighs 5kg and is worth approximately 2.5 million KRW at market price. Provided by Korea Zinc

Korea Zinc has been supplying about 150 tons of indium annually to the global market, and by exporting a significant amount to the United States, it is establishing an important foundation for the development of global high-tech industries. Indium is a metal widely used in LCD displays, touchscreens, semiconductor substrates, aircraft engines, and solar panels.

A Korea Zinc representative stated, "With China's export controls on critical minerals, Korea Zinc's role in the global supply chain has become even more important, so we will focus even more on stabilizing the production of strategic minerals and cooperating with allied countries." The representative added, "We will do our utmost to prioritize national interests, support the industrial base, and become a key pillar in strengthening resource security."