Low CO2 emission technologies for iron and steelmaking as well as titania slag production

Abstract The world wide discussion on climate change caused by CO 2 and other greenhouse gases (GHGs) attributable to human activities has put the focus on the energy intensive production technologies for iron and steelmaking. Taking into account the enormous production increase for these versatile materials in the last years, modern technologies with lower CO 2 and GHGs emissions are imperative to keep at least today’s status, though a decrease is challenged. Outokumpu Technology has developed direct reduction technologies that allow in combination with smelting reduction processes or electric arc furnaces a substantial lowering of CO 2 emissions. In the presented contribution to MMME 06 three examples will be given: The Circofer ® process, already demonstrated in pilot plant scale, uses coal as reductant in a two stage CFB (circulating fluidized bed)/FB (fluidized bed) reactor configuration to obtain a highly metallized product suitable for charging into smelting processes. One possible application of Circofer is, in a single stage configuration, as prereduction unit in combination with HIsmelt ® , a smelting reduction technology to produce hot metal using iron ore and coal fines. Using Circofer as prereduction step, the capacity of a given HIsmelt installation can be increased by the factor three to four compared to cold feed and CO 2 emission can be lowered to values about 20% below the standard of a modern blast furnace, as this combination of technologies requires no agglomeration plant or coke ovens. A second application of Circofer is the combination with an electric arc furnace (EAF) to produce steel directly from direct reduced iron (DRI). The direct charging of metallic fines into an EAF was successfully tested, observing no increased dust emission from the furnace. Charging hot DRI into an EAF decreases drastically electric power consumption and thus further lowers CO 2 emission. Applying Circosmelt, the combination of a single stage Circofer system with an electric reduction furnace for ilmenite processing, only half of the electric power consumption required today for titania slag production using cold, unreduced feed material is required. A common additional advantage of all Circofer based routes is that a 99% pure CO 2 stream is removed for process reasons from the process gas and can be used for enhanced crude oil production or sequestration methods. The paper will report on the status of the different developments and its market introduction. Outokumpu Technology GmbH (formerly Lurgi Metallurgie) has been involved in the development, design and supply of plants for processing iron bearing ores in fluidized bed reactor systems for more than 30 years.