Table of Contents

    • 50

    • Modeling the Impacts of Nuisance Elements on Blast Furnace Operations

      Computational modeling techniques for blast furnace simulation have been developed by Purdue University Northwest researchers to study blast furnaces operated by member companies of the Steel Manufacturing Simulation and Visualization Consortium. Presently, further understanding of the impacts of nuisance elements such as zinc, potassium and sodium on the furnace is desired. These elements can react with reducing gases, reducing the efficiency of operation, and their circulation within the furnace under certain conditions can also result in material buildup. This research will discuss modifications to existing computational fluid dynamics models to track nuisance element chemical reactions and concentrations to better quantify their impacts.

    • 58

    • Melting Behavior of Hydrogen-Reduced DRI in a Simulated EAF Steel Bath

      The melting behavior of carbon-free direct reduced iron (DRI) produced by hydrogen reduction has been investigated in a simulated electric arc furnace (EAF) melting environment. A testing apparatus was created to document the melting rates under various bath conditions in slag and steel. This investigation is specific to pellets melted in a steel bath. A model was developed to simulate the shell growth and melting rate of a non-reactive DRI pellet in molten steel. Data acquired from preliminary experiments are utilized to validate the model. This investigation sheds light on the potential effects of melting hydrogen-reduced DRI in the EAF.

    • 64

    • Structural Analysis and Failure Prediction of Direct Reduced Iron

      The use of direct reduced iron (DRI) to produce high-quality iron units for steelmaking has increased in recent decades due to increasing pressure to reduce emissions in the steelmaking industry, especially CO2. The disintegration of cold DRI, especially during shipping and handling, has remained a consistent issue and a significant source of lost revenue if not recovered. Therefore, characterization of aspects of DRI that influence its ultimate compressive strength is warranted. Limited compressive testing was utilized to predict compressive strengths of samples without causing catastrophic failure of DRI produced from several origins. Furthermore, central cross-sectional image analysis of selected samples was performed to correlate large, identified porosity and defects with predicted strength, with limited success. More comprehensive porosity and defect analysis is required to establish a link between these two measures.

    • 70

    • Porosity in Iron Ore Sinter Analogues

      Iron ore sinter properties such as strength, reducibility and mineralogy are crucial for blast furnace operations. New evidence suggests that porosity might be the main factor controlling reducibility, not mineralogy. To investigate porosity of simple sinter systems, hematite and magnetite were mixed with lime and silica and fired at controlled conditions. The influence of maximum temperature, holding time and chemistry on porosity were verified by image analysis techniques using optical microscopy and scanning electron microscopy images. The results demonstrated a stronger influence of chemistry on porosity rather than temperature and time. The hematite-lime-silica-containing samples presented the highest porosity (close to 30%), while the pure hematite samples had the lowest porosity (less than 5%).