Hostname: page-component-78c5997874-8bhkd Total loading time: 0 Render date: 2024-11-14T21:27:41.474Z Has data issue: false hasContentIssue false

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

Published online by Cambridge University Press:  28 February 2024

Toshiyuki Hibino
Affiliation:
Materials Processing Department, National Institute for Resources and Environment, 16-3 Onogawa, Tsukuba, 305 Japan
Yasumasa Yamashita
Affiliation:
Materials Processing Department, National Institute for Resources and Environment, 16-3 Onogawa, Tsukuba, 305 Japan
Katsunori Kosuge
Affiliation:
Materials Processing Department, National Institute for Resources and Environment, 16-3 Onogawa, Tsukuba, 305 Japan
Atsumu Tsunashima
Affiliation:
Materials Processing Department, National Institute for Resources and Environment, 16-3 Onogawa, Tsukuba, 305 Japan
Rights & Permissions [Opens in a new window]

Abstract

Core share and HTML view are not available for this content. However, as you have access to this content, a full PDF is available via the ‘Save PDF’ action button.

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.

Type
Research Article
Copyright
Copyright © 1995, The Clay Minerals Society

References

Allmann, R., 1968. The crystal structure of Pyroaurite. Acta Crystallogr. B24: 972977.CrossRefGoogle Scholar
Bish, D. L., and Brindley, G. W. 1977. A reinvestigation of takovite, a nickel aluminum hydroxy-carbonate of the pyroaurite group. Amer. Mineral. 62: 458464.Google Scholar
Chibwe, K., and Jones, W. 1989a. Intercalation of organic and inorganic anions into layered double hydroxides. J. Chem. Soc. Chem. Commun. 926927.Google Scholar
Chibwe, K., and Jones, W. 1989b. Synthesis of polyoxometalate-pillared layered double hydroxides via calcined precursors. Chem. Mater. 1: 489490.Google Scholar
Ingram, L., and Taylor, H. F. W. 1967. The crystal structures of sögrenite and pyroaurite. Mineral. Mag. 36: 465479.Google Scholar
Miyata, S., 1975. The syntheses of hydrotalcite-like compounds and their structures and physico-chemical properties–I. The systems Mg2+-Al3+-NO3, Mg2+-Al3+-Cl, Mg2+-Al3+-ClO4, Ni2+-Al3+-Cl and Zn2+-Al3+-Cl. Clays & Clay Miner. 23: 369375.Google Scholar
Miyata, S., 1980. Physico-chemical properties of synthetic hydrotalcites in relation to composition. Clays & Clay Miner. 28: 5056.Google Scholar
Narita, E., Kaviratna, P., and Pinnavaia, J. 1991. Synthesis of heteropolyoxometalate pillared layered double hydroxides via calcined zinc-aluminium oxide precursors. Chem. Lett. 805808.Google Scholar
Ross, G. J., and Kodama, H. 1967. Properties of a synthetic magnesium-aluminum carbonate hydroxide and its relationship to magnesium-aluminum double hydroxide, manasseite and hydrotalcite. Amer. Mineral. 52: 10361047.Google Scholar
Sato, T., Kato, K., Endo, T., and Shimada, M. 1986a. Preparation and chemical properties of magnesium aluminum oxide solid solutions. React. Solids 2: 253260.Google Scholar
Sato, T., Wakabayashi, T., and Shimada, M. 1986b. Adsorption of various anions by magnesium aluminum oxide (Mg0.7Al0.3O1.15). Ind. Eng. Chem. Prod. Res. Dev. 25: 8992.Google Scholar