Recrystallization of ferric oxyhydroxides consisting of FeO6 octahedral units via aqueous solution

Katsuya Inoue, Sang Koo Kwon, Kozo Shinoda, Shigeru Suzuki, Yoshio Waseda

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Solid particles of ferric oxyhydroxides or iron oxide were recrystallized from ferrous and ferric ions dissolved in aqueous solution. There are different structures of α-FeOOH, β-FeOOH and γ-FeOOH in the ferric oxyhydroxides, of which the formation is influenced by reaction conditions such as oxidation rate of ferrous ions. In this work, a few factors affecting the formation of the ferric oxyhydroxides and iron oxides, which was converted from hydrosulfate green rust, has been studied using different methods. The hydrosulfate green rust (GR2) was synthesized from solutions of ferric sulfate (Fe2(SO4)3), ferrous sulfate (FeSO 4), and sodium hydroxide (NaOH), and they were oxidized by gas containing oxygen. X-ray diffraction measurements and X-ray absorption spectroscopy were used for analyzing the structure and chemical state of solid particles extracted from the suspension during the oxidation. The morphology of the particles was observed by transmission electron microscopy. The results showed that γ-FeOOH or Fe3O4 particles were formed together with α-FeOOH particles during conversion from the green rust, depending on oxidation temperature, oxygen flow rate and addition of manganese. This indicates that the species of ferric oxyhydroxides or iron oxides formed in aqueous solution is sensitively influenced by reaction conditions.

Original languageEnglish
Title of host publicationRecrystallization and Grain Growth III - Proceedings of the Third International Conference on Recrystallization and Grain Growth, ReX and GG III
PublisherTrans Tech Publications Ltd
Number of pages6
EditionPART 2
ISBN (Print)087849443X, 9780878494439
Publication statusPublished - 2007 Jan 1
Event3rd International Conference on Recrystallization and Grain Growth, ReX GG III - Jeju Island, Korea, Republic of
Duration: 2007 Jun 102007 Jun 15

Publication series

NameMaterials Science Forum
NumberPART 2
ISSN (Print)0255-5476
ISSN (Electronic)1662-9752


Other3rd International Conference on Recrystallization and Grain Growth, ReX GG III
CountryKorea, Republic of
CityJeju Island


  • Aqueous solution
  • Ferric oxyhydroxides
  • Magnetite
  • Recrystallization
  • X-ray absorption
  • X-ray diffraction

ASJC Scopus subject areas

  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering

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