Korea Zinc has raised annual capacity for semiconductor-grade sulfuric acid to 320,000 tons from 280,000 tons after completing and starting full operations at Lines 20 and 21 at its Onsan smelter in Ulsan. The 40,000-ton increase, equivalent to approximately 14.3%, is intended to support new fab ramp-ups and equipment investment by South Korean chipmakers amid expanding artificial intelligence infrastructure. The chemical is used to remove organic matter and fine contaminants from wafer surfaces, making ultra-high purity and consistent quality important for semiconductor yields and reliability as circuits become smaller. Korea Zinc produces six nines (6N) acid with purity of at least 99.9999% by recovering sulfur dioxide from zinc and lead smelting, reducing exposure to global sulfur price and supply-chain disruptions. The company is South Korea's largest supplier, covering more than 60% of domestic demand, and supplies approximately 95% of its output to major manufacturers including Samsung Electronics and SK Hynix, while also exporting to Japan, Singapore and other markets. Korea Zinc plans to expand domestic capacity to as much as 500,000 tons a year and is considering a roughly 100,000-ton-a-year line at its Crucible integrated smelter project in Tennessee, with commissioning targeted for 2029 and commercial production for 2030. Carbon Trust granted the product carbon footprint certification to the company's semiconductor-grade sulfuric acid in December 2024. The capacity expansion is expected to support materials stability in South Korea's semiconductor ecosystem and positively affect Korea Zinc's earnings, as new domestic fabs come online.