Chapter 10. Chemical States of Iron in Red Clay Bodies Fired at Low Oxygen Partial Pressures

  1. William M. Carty
  1. H. Takahashi1,
  2. N. Takeuchi1,
  3. S. Ishida1 and
  4. M. Wakamatsu2

Published Online: 26 MAR 2008

DOI: 10.1002/9780470294475.ch10

Materials & Equipment/Whitewares: Ceramic Engineering and Science Proceedings, Volume 19, Issue 2

Materials & Equipment/Whitewares: Ceramic Engineering and Science Proceedings, Volume 19, Issue 2

How to Cite

Takahashi, H., Takeuchi, N., Ishida, S. and Wakamatsu, M. (1998) Chemical States of Iron in Red Clay Bodies Fired at Low Oxygen Partial Pressures, in Materials & Equipment/Whitewares: Ceramic Engineering and Science Proceedings, Volume 19, Issue 2 (ed W. M. Carty), John Wiley & Sons, Inc., Hoboken, NJ, USA. doi: 10.1002/9780470294475.ch10

Author Information

  1. 1

    Kyoto Institute of Technology, Kyoto, Japan

  2. 2

    Taiko Refractory Co. Ltd., Kitakyushu, Japan

Publication History

  1. Published Online: 26 MAR 2008
  2. Published Print: 1 JAN 1998

ISBN Information

Print ISBN: 9780470375570

Online ISBN: 9780470294475

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Keywords:

  • atmospheres;
  • oxygen;
  • temperature;
  • gaseous;
  • colorimetrically

Summary

Red clay bodies containing 7 mass% Fe2O3 were fired at 1000-1250°C in Ar-O2 (oxygen pressure 0.1 kPa) atmospheres. The relationship between color and chemical states of iron in fired bodies was studied by ESR, reflectance spectra, and chemical analysis. The color of the samples changed from red to black with the elevation of the firing temperature, indicating that reduction from Fe2O3 to Fe3O4 or FeO in the samples occurred. The bulk density of the samples fired at temperatures higher than 1150°C was lowered because of the inclusion of gases inside the sample. Since the evolution of oxygen gas was observed at the soaking temperature of 1250°C, it was assumed that the gas enclosed inside the sample was oxygen gas liberated from the Fe2O3.