Oxidation of Flash Reduced Iron Particles in Various Gas Mixtures Under the Conditions of a Novel Flash Ironmaking Process

  • Zhixue Yuan
  • Hong Yong Sohn
  • Miguel Olivas-Martinez


A novel flash ironmaking process that directly reduces iron oxide concentrate particles by gas is under development. The goal of this work was to study the possibility of reoxidation of iron particles in various gas mixtures. As the product iron cools down in the lower part of the flash reactor, conditions may become favorable for reoxidation because of equilibrium and high reactivity of iron particles. The effects of temperature (823 – 973 K) and H2O partial pressure (40 – 100 pct., Ptotal = 86.1 kPa) on the reoxidation rate were examined. The pressure dependence was first order with respect to water vapor, and the activation energy was 146 kJ/mol. A complete rate equation that adequately represents the experimental data was developed. For oxidation in O2-N2 mixtures, the effects of temperature (673 – 873 K) and O2 partial pressure (5–21 pct., Ptotal = 86.1 kPa) were determined. Reoxidation in pure CO2 was also investigated at 873 – 1073 K for comparison.


Oxidation kinetics of iron particles Flash ironmaking Reduction of iron oxide 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    H.Y. Sohn, M.E. Choi, Y. Zhang, and J.E. Ramos, “Suspension Reduction Technology for Ironmaking with Low CO2 Emission and Energy Requirement,” AIST Iron & Steel Technology, 6 (6) (2009), 158–165.Google Scholar
  2. 2.
    M.E. Choi, “Suspension Hydrogen Reduction of Iron Ore Concentrate” (Ph.D. dissertation, University of Utah, 2010).Google Scholar
  3. 3.
    H.Y. Sohn, “Suspension Ironmaking Technology with Greatly Reduced Energy Requirement and CO2 Emissions”, Steel Times Int., 31 (4) (2007), 68–72.Google Scholar
  4. 4.
    R.L. Stephenson, Direct Reduced Iron: Technology and Economics of Production and Use (Warrendale, PA: The Iron and Steel Society of AIME, 1980) 64–99.Google Scholar
  5. 5.
    M.E. Choi and H.Y. Sohn, “Development of Green Suspension Ironmaking Technology Based on Hydrogen Reduction of Iron Oxide Concentrate: Rate Measurements,” Ironmaking Steelmaking, 37 (2) (2010), 81–88.CrossRefGoogle Scholar
  6. 6.
    H. Wang and H.Y. Sohn, “Hydrogen Reduction Kinetics of Magnetite Concentrate Particles Relevant to a Novel Flash Ironmaking Process,” Metall. Mater. Trans. B, 44(1) (2013) 133–145.CrossRefGoogle Scholar
  7. 7.
    H. Wang, “Reduction Kinetics of Iron Ore Concentrate Particles Relevant to a Novel Green Ironmaking Process” (Ph.D. dissertation, University of Utah, 2011).Google Scholar
  8. 8.
    M.E. Choi, H.Y. Sohn, Y.M.Z. Ahmed, F.M. Mohamed, G. Han, and M.E.H. Shalabi, “Effect of CaSO4 Pelletization Conditions on a Novel Process for Converting SO2 to Elemental Sulfur by Reaction Cycles involving CaSO4/CaS: Part I. CaSO4 Pellet Strength and Reducibility by Hydrogen,” Chem. Eng. Technol., 30 (5) (2007), 628–634.CrossRefGoogle Scholar
  9. 9.
    W.E. Boggs, R.H. Kachik and G.E. Pellissier, “The Effect of Oxygen Pressure on the Oxidation of Zone-Refined Iron,” J. Electrochem. Soc, 112 (6) (1965), 539–546.CrossRefGoogle Scholar
  10. 10.
    W.A. Johnson and R.F. Mehl, “Reaction Kinetics in Processes of Nucleation and Growth,” TMS-AIME, 135 (1939), 416–458.Google Scholar
  11. 11.
    P.W.M. Jacobs and F.C. Tompkins, “Classification and Theory of Solid Reactions,” Chemistry of the Solid State, W. E. Garner, Ed., (London: Butterworths, 1955), 184–212.Google Scholar
  12. 12.
    B.-S. Kim and H.Y. Sohn, “A Novel Cyclic Process Using CaSO4/CaS Pellets for Converting Sulfur Dioxide to Elemental Sulfur without Generating Secondary Pollutants: Part II. Hydrogen Reduction of Calcium Sulfate Pellets to Calcium Sulfide,” Metall. Mater. Trans. B, 33 (2002), 717–721.CrossRefGoogle Scholar

Copyright information

© TMS (The Minerals, Metals & Materials Society) 2014

Authors and Affiliations

  • Zhixue Yuan
    • 1
  • Hong Yong Sohn
    • 1
  • Miguel Olivas-Martinez
    • 1
  1. 1.Department of Metallurgical EngineeringUniversity of UtahSalt Lake CityUSA

Personalised recommendations