Impact of Radial Position on Iron Ore Sinter Reduction and Microstructure at 700-1100 °C

In this research, the reduction of iron ore sinter in a blast furnace (BF) simulator in CO-CO2-N2-reducing gas, simulating conditions at the BF center and wall, is investigated. Measurements from an operating BF guide the study, ensuring realistic reduction parameters. Reduction rate and extent, along with physical properties, are assessed under a temperature range of 700-1100 degrees C. In isothermal reduction experiments, the BF center exhibits superior conditions, particularly at 900 degrees C, achieving an 83.78% reduction degree compared to 27.17% at the wall for the same temperature. In this study, it is highlighted that basic iron ore sinter demonstrates higher reduction efficiency compared to acid iron ore pellets under identical BF center reducing conditions. Specific surface area and porosity measurements unveil a contrasting trend in specific surface area and porosity evolution between the BF wall and center. Surface morphology analysis reveals that the reduction in specific surface area and porosity of sinter samples at the BF center conditions at 1000-1100 degrees C is attributed to the sintering of the formed metallic iron. Carbon analysis confirms no carbon deposition took place during reduction. Mineralogical and physical property analyses provide detailed insights into the evolving phase composition during sinter reduction. In this study, iron ore sinter reduction in a simulated blast furnace environment is investigated. In the results, superior reduction at the blast furnace center, with basic iron ore sinter exhibiting higher efficiency compared to acid pellets, is shown. Temperature variations influence specific surface area and porosity evolution. No carbon deposition occurs during reduction.image (c) 2024 WILEY-VCH GmbH