Korea Zinc is accelerating investment in the expansion of its oxygen plant at the Onsan Smelter in Ulju County, Ulsan.
About 10 months after announcing the project last December, the company has placed orders covering 87% of its planned investment, moving the expansion closer to completion.
ETNews learned on Oct. 19 that Korea Zinc had placed orders worth KRW117 billion for the expansion by the end of September, equivalent to about 87% of the total investment budget. The expanded plant is scheduled to undergo commissioning in the first half of 2027 and begin commercial operations in the second half.
Korea Zinc announced last December that it would invest approximately KRW134.5 billion to expand the oxygen plant by 2027. Once the project is complete, oxygen production capacity will rise from 80,000 to 130,000 normal cubic meters per hour (Nm³/h), a measure of gas volume under standardized temperature and pressure conditions. Nitrogen production capacity will increase from 120,000 to 150,000 Nm³/h.
The expansion will boost oxygen capacity by approximately 62.5% and nitrogen capacity by 25%. Both are industrial gases used in smelting: oxygen supports processes such as the oxidation and melting of metal-bearing raw materials, while nitrogen helps maintain controlled conditions in equipment and processing environments. The additional capacity is expected to strengthen the smelter's ability to meet its gas requirements.
The oxygen plant supplies oxygen for smelting, nitrogen for various processes and essential support for stable operations across the site. Its functions include supporting fuel combustion, helping control oxidation and fire risks, and delivering industrial gases to multiple production processes.
Smelting involves a series of interconnected stages, from raw material processing to metal production. Reliable supporting infrastructure is therefore just as important as the equipment used at each stage. Because disruptions to industrial gas supplies can affect related processes, the expansion will provide infrastructure that supports both increased production capacity and reliable smelter operations.
“The oxygen plant expansion is essential to increasing and stabilizing production capacity at the Onsan Smelter as it develops into a global critical minerals hub,” a Korea Zinc official said. “We will carry out the planned investment through next year and complete the expansion as scheduled.”
