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Clays and Clay Minerals

, Volume 43, Issue 4, pp 427–432 | Cite as

Decarbonation Behavior of Mg-Al-CO3 Hydrotalcite-like Compounds during Heat Treatment

  • Toshiyuki Hibino
  • Yasumasa Yamashita
  • Katsunori Kosuge
  • Atsumu Tsunashima
Article
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Abstract

Historically, the decarbonation of Mg-Al-CO3 hydrotalcite-like compounds (HTlc) has been thought to occur between 400° and 500°C. The present work demonstrates that when HTlcs having the maximum Al content, Al/(Al + Mg) = 0.33, are heated to 500°C, 20–30% of the carbonates remain. The evolution of the remaining carbonates was observed as two maxima, at 600 and 900°C At these temperatures, Al ions go into MgO, and spinel (MgAl2O4) forms. Therefore, the carbonates are released as the Al ions migrate.

At a lower Al content, Al/(Al + Mg) = 0.25, CO2 evolution is almost complete at 500°C. This HTlc has no maximum of CO2 evolution above 500°C. Lower charge densities, due to lower Al contents, lead to lower amounts of remaining carbonate anions.

Key Words

Decarbonation Heat treatment Hydrotalcite 

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Copyright information

© The Clay Minerals Society 1995

Authors and Affiliations

  • Toshiyuki Hibino
    • 1
  • Yasumasa Yamashita
    • 1
  • Katsunori Kosuge
    • 1
  • Atsumu Tsunashima
    • 1
  1. 1.Materials Processing DepartmentNational Institute for Resources and EnvironmentTsukubaJapan

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