Performance improvement of an iron ore sintering bed through the enriched oxygen supply operation

Abstract

Sintering is the process of forming small metals or ceramic particles under the action of thermal energy. In typical iron making process, larger than 5mm sintered ore with appropriate metallurgical properties is manufactured as the burden of the blast furnace. Combustion of solid fuel supplies heat required for the sintering in the conventional operation and it causes imbalance of heat concentration throughout the bed. The unevenly distributed heat is considered to be problematic on the quality aspect of sintered ore. The current issues of sintering technology in the iron and steel making industry are how to increase productivity and to maintain proper quality of end product. Also, the environmental regulations surrounding the sintering process and emission standard are getting tightened. Therefore, in order to maximize the production rate and quality of the products under the environment friendly process, investigation for the improved operating mode is indispensable. In this study, the effect of additional oxygen supply with an adjustment of injection location is primarily discussed. Also, various operating modes such as oxygen supply with the change of coke contents, elongation of bed height, flue gas recirculation and supplementary LNG supply are evaluated. Scale downed pot test is performed for oxygen supply with variation of injection location mode to analyze the effectiveness of oxygen enrichment at the projected area. In addition to the experiment, previously developed unsteady 1-dimenstional sintering bed model is employed for the examination of the other cases. The calculation results predict the tendency of characterized combustion in the bed while various cases are applied. To evaluate the change of operation conditions, quantitative parameters are also employed which ranges from sintering time, maximum temperature of the bed at the given time to combustion and melting zone thickness. The combustion characteristics are systemically analyzed and the ...