Effect of metal additions to the reduction of iron oxide composite pellets with hydrogen at moderate temperatures

Il Sohn, S. M. Jung

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

The hydrogen reduction behavior of iron oxide composite pellets containing Ni, Fe, and Mn from 973 K to 1173 K was compared with iron oxide and Al 2O3 containing reference composite pellets to determine the effect of metallic species on the kinetics of iron oxide reduction. The Mn and Ni containing pellets showed slightly faster initial reduction rates compared to the Fe and Al2O3 containing pellets. The effect of the metal phases was found to be more significant at lower temperatures when chemical reaction at the interface is a slower and more controlling factor. From the SEM of partially reduced pellets, a wide intermediate region between an O rich unreacted core and an Fe rich outer shell was observed. Although an initially short topochemical receding interface controlled region exists, the mixed control between the topochemical receding interface and pore diffusion was prevalent. For Fe2O3/Mn composite pellets, the thermodynamic stability of the MnO is higher and Mn can act as a reductant for iron oxide. Thus, the overall metallization of the Fe2O3/Mn composite pellets decreased compared to the other Fe2O3/metal composite pellets. From the temperature dependence of the iron-oxide/metal composite pellets, the apparent activation energy was calculated to be approximately between 15 to 20 kJ/mol, which is typical of a mixed control reduction mechanism of gas diffusion and interface reaction.

Original languageEnglish
Pages (from-to)1345-1354
Number of pages10
JournalSteel Research International
Volume82
Issue number12
DOIs
Publication statusPublished - 2011 Dec 1

Fingerprint

Iron oxides
iron oxides
pellets
Hydrogen
Metals
composite materials
Composite materials
hydrogen
metals
Temperature
temperature
Diffusion in gases
Reducing Agents
Metallizing
ferric oxide
Chemical reactions
Thermodynamic stability
gaseous diffusion
Activation energy
Scanning electron microscopy

All Science Journal Classification (ASJC) codes

  • Condensed Matter Physics
  • Physical and Theoretical Chemistry
  • Metals and Alloys
  • Materials Chemistry

Cite this

@article{c97be53e669b444bb6eea35b499f80fb,
title = "Effect of metal additions to the reduction of iron oxide composite pellets with hydrogen at moderate temperatures",
abstract = "The hydrogen reduction behavior of iron oxide composite pellets containing Ni, Fe, and Mn from 973 K to 1173 K was compared with iron oxide and Al 2O3 containing reference composite pellets to determine the effect of metallic species on the kinetics of iron oxide reduction. The Mn and Ni containing pellets showed slightly faster initial reduction rates compared to the Fe and Al2O3 containing pellets. The effect of the metal phases was found to be more significant at lower temperatures when chemical reaction at the interface is a slower and more controlling factor. From the SEM of partially reduced pellets, a wide intermediate region between an O rich unreacted core and an Fe rich outer shell was observed. Although an initially short topochemical receding interface controlled region exists, the mixed control between the topochemical receding interface and pore diffusion was prevalent. For Fe2O3/Mn composite pellets, the thermodynamic stability of the MnO is higher and Mn can act as a reductant for iron oxide. Thus, the overall metallization of the Fe2O3/Mn composite pellets decreased compared to the other Fe2O3/metal composite pellets. From the temperature dependence of the iron-oxide/metal composite pellets, the apparent activation energy was calculated to be approximately between 15 to 20 kJ/mol, which is typical of a mixed control reduction mechanism of gas diffusion and interface reaction.",
author = "Il Sohn and Jung, {S. M.}",
year = "2011",
month = "12",
day = "1",
doi = "10.1002/srin.201100144",
language = "English",
volume = "82",
pages = "1345--1354",
journal = "Steel Research International",
issn = "1611-3683",
publisher = "Wiley-VCH Verlag",
number = "12",

}

Effect of metal additions to the reduction of iron oxide composite pellets with hydrogen at moderate temperatures. / Sohn, Il; Jung, S. M.

In: Steel Research International, Vol. 82, No. 12, 01.12.2011, p. 1345-1354.

Research output: Contribution to journalArticle

TY - JOUR

T1 - Effect of metal additions to the reduction of iron oxide composite pellets with hydrogen at moderate temperatures

AU - Sohn, Il

AU - Jung, S. M.

PY - 2011/12/1

Y1 - 2011/12/1

N2 - The hydrogen reduction behavior of iron oxide composite pellets containing Ni, Fe, and Mn from 973 K to 1173 K was compared with iron oxide and Al 2O3 containing reference composite pellets to determine the effect of metallic species on the kinetics of iron oxide reduction. The Mn and Ni containing pellets showed slightly faster initial reduction rates compared to the Fe and Al2O3 containing pellets. The effect of the metal phases was found to be more significant at lower temperatures when chemical reaction at the interface is a slower and more controlling factor. From the SEM of partially reduced pellets, a wide intermediate region between an O rich unreacted core and an Fe rich outer shell was observed. Although an initially short topochemical receding interface controlled region exists, the mixed control between the topochemical receding interface and pore diffusion was prevalent. For Fe2O3/Mn composite pellets, the thermodynamic stability of the MnO is higher and Mn can act as a reductant for iron oxide. Thus, the overall metallization of the Fe2O3/Mn composite pellets decreased compared to the other Fe2O3/metal composite pellets. From the temperature dependence of the iron-oxide/metal composite pellets, the apparent activation energy was calculated to be approximately between 15 to 20 kJ/mol, which is typical of a mixed control reduction mechanism of gas diffusion and interface reaction.

AB - The hydrogen reduction behavior of iron oxide composite pellets containing Ni, Fe, and Mn from 973 K to 1173 K was compared with iron oxide and Al 2O3 containing reference composite pellets to determine the effect of metallic species on the kinetics of iron oxide reduction. The Mn and Ni containing pellets showed slightly faster initial reduction rates compared to the Fe and Al2O3 containing pellets. The effect of the metal phases was found to be more significant at lower temperatures when chemical reaction at the interface is a slower and more controlling factor. From the SEM of partially reduced pellets, a wide intermediate region between an O rich unreacted core and an Fe rich outer shell was observed. Although an initially short topochemical receding interface controlled region exists, the mixed control between the topochemical receding interface and pore diffusion was prevalent. For Fe2O3/Mn composite pellets, the thermodynamic stability of the MnO is higher and Mn can act as a reductant for iron oxide. Thus, the overall metallization of the Fe2O3/Mn composite pellets decreased compared to the other Fe2O3/metal composite pellets. From the temperature dependence of the iron-oxide/metal composite pellets, the apparent activation energy was calculated to be approximately between 15 to 20 kJ/mol, which is typical of a mixed control reduction mechanism of gas diffusion and interface reaction.

UR - http://www.scopus.com/inward/record.url?scp=82755181697&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=82755181697&partnerID=8YFLogxK

U2 - 10.1002/srin.201100144

DO - 10.1002/srin.201100144

M3 - Article

VL - 82

SP - 1345

EP - 1354

JO - Steel Research International

JF - Steel Research International

SN - 1611-3683

IS - 12

ER -