Reduction kinetics of iron oxides in molten lunar soil simulant by graphite

Yoshinao Kobayashi, Hiroaki Sonezaki, Rie Endo, Masahiro Susa

Research output: Contribution to journalArticlepeer-review

15 Citations (Scopus)


In space exploration including the utilization of materials and energy outside the earth, construction of a moon base is one of considerable measures to develop the front line. Due to the huge cost of transportation from the earth, structural materials such as iron should be in-situ produced on the moon. Fortunately, the Apollo 14 mission has reported that the lunar soil contains about 10mass% of iron oxides. When considering ironmaking from lunar soils by graphite on the moon, understanding the reduction behaviour should come first but has not yet been attempted for iron resources whose concentration of iron oxides is as low as 10mass%. Thus, the present work has focused on reduction kinetics of iron oxides in molten lunar soil simulant by graphite, and apparent rate constants for reduction reactions have been derived from experiments with systematic variation in reduction conditions for comprehensive discussion about the reaction mechanism. The apparent rate constant derived is 2.0X10 -4cm/s at 1 803 K and the corresponding activation energy estimated is about 360 kJ/mol. The use of a graphite rod rotation mechanism enabled the stirring condition to be changed, resulting in a finding that stronger stirring shifts the rate-determining step from reduction of FeO by CO gas to direct reduction of FeO by graphite. On the basis of all these kinetic findings, it is likely that ironmaking from lunar soils by graphite on the moon is possible in that high vacuum and low gravity conditions would probably promote the removal of CO gas film from the graphite surface.

Original languageEnglish
Pages (from-to)35-43
Number of pages9
JournalISIJ International
Issue number1
Publication statusPublished - 2010
Externally publishedYes


  • Graphite
  • Iron oxide
  • Ironmaking
  • Kinetics
  • Lunar soil
  • Moon
  • Reduction

ASJC Scopus subject areas

  • Mechanics of Materials
  • Mechanical Engineering
  • Metals and Alloys
  • Materials Chemistry


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