BOC Gases (Murray Hill, NJ) has completed a new air separation unit (ASU) to provide oxygen to Nucor Steel's Jewett, TX, facility, one of the nation's largest electric furnace-based steel minimills. The completion of the ASU coincided with an 10-year extension of a larger supply agreement under which BOC supplies all industrial gases to the plant.
Under the agreement, BOC supplies Nucor with a variety of industrial gases, especially oxygen, nitrogen and argon critical to production of carbon and alloy steel. BOC has supplied the Jewett plant and surrounding merchant market with gases from two plants since 1985. Four years later, it signed a similar agreement with Nucor's Crawfordsville, IN, facility.
Oxygen finds broad use in the metals industry. Oxygen-enriched atmospheres raise the temperature and productivity of iron blast furnaces, steel electric furnaces, and nonferrous melting systems. Traditional iron blast furnaces, in particular, have grown more oxygen-intensive as producers replace furnace coke with coal and natural gas. Electric steel furnaces, on the other hand, have boosted oxygen use to cut electricity consumption.
BOC adds value to its gases by developing gas-using technologies. For minimills, this often involves ways to reduce energy use. For example, it offers electric arc furnace minimills a process package that incorporates oxy-fuel burners, oxygen lances, process modeling, post-combustion systems, waste-gas analysis, process control systems, and associated hardware.
In 1995, for example, BOC and CoSteel Sheerness developed a post-combustion process that saved 30-40 kwh/m.t.. The process permits the full use of chemical energy immediately after charging of the furnace, as long as scrap is available. BOC uses the process as a starting point for development of post-combustion strategies customized to specific EAFs.
Nucor will produce 10 million tons of finished steel in 1999 by recycling steel scrap. The nation's largest individual recycler, it operates facilities in eight states. Its output ranges from joists, joist girders, decks, and cold finished steel to grinding balls, fasteners, bearings, and metal building systems.
For more information: Tony Palermo, Manager, Iron and Steel Technologies and Business Development, BOC Group, 575 Mountain Ave., Murray Hill, NJ 07974-2082. Phone: 908-771-1215. Fax: 908- 771-1148.
By Alan S. Brown