Strategies for Implementing Direct Reduction Technologies in an Integrated Steel Plant

Abstract

The rapid increase in the natural gas supply base and subsequent decrease in price has renewed interest in the production of direct reduced iron (DRI) in North America. In late 2013, Nucor started-up a new 2.5 Mt/a ENERGIRON® direct reduction (DR) plant in Louisiana to supply DRI to its US-based electric arc furnace plants. In Texas, voestalpine is constructing a 2.0 Mt/a Midrex® direct reduction plant that will start up in 2016 and deliver hot briquetted iron (HBI) to voestalpine’s blast furnace plants in Austria and sell the balance of the HBI to the marketplace. Other steel companies are considering DRI production to take advantage of low natural gas prices and to provide strategic production and cost advantages.

Hatch assessed the merits of producing direct reduced iron (DRI) in an integrated steel plant using available process gases supplemented by natural gas (NG), and evaluated strategies to consume the resulting DRI. The impacts on steel plant process flows are described, including options to consume the DRI at the blast furnace and/or in the basic oxygen furnaces (BOF), changes to the plant energy balance, the cost impact to produce hot rolled coil, the sale of additional steel and surplus DRI, and the financial return for the DR plant investment. Technical limits to consume DRI in the steel plant are identified and strategies to allow greater DRI consumption discussed.