Hostname: page-component-586b7cd67f-2plfb Total loading time: 0 Render date: 2024-11-23T02:48:03.598Z Has data issue: false hasContentIssue false
  • English
  • Français

Syntheses of Disordered and Al-Rich Hydrotalcite-Like Compounds

Published online by Cambridge University Press:  02 April 2024

I. Pausch ,
H.-H. Lohse ,
K. Schürmann  and
R. Allmann
I. Pausch
Affiliation:
Fachbereich Geowissenschaften, Lahnberge D-3550 Marburg, Federal Republic of Germany
H.-H. Lohse
Affiliation:
Fachbereich Geowissenschaften, Lahnberge D-3550 Marburg, Federal Republic of Germany
K. Schürmann
Affiliation:
Fachbereich Geowissenschaften, Lahnberge D-3550 Marburg, Federal Republic of Germany
R. Allmann
Affiliation:
Fachbereich Geowissenschaften, Lahnberge D-3550 Marburg, Federal Republic of Germany
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.

Hydrotalcite-like compounds, [Mg1-xAlx(OH)2]x+ [xX−·n H2O], where X− = ½CO32− or OH−, were prepared by hydrothermal syntheses at PH2O=100MPa and T = 100°–350°C. Starting materials were MgO, γ-Al2O3, H2O, and MgC2O4·2H2O. The synthesis depended on temperature, pressure, the Al/(Al + Mg) ratio x, and the CO2 content of the starting material. Previously an Al content of x = 0.33 was thought to be the upper limit in these double-layer compounds, but by using pressure the Al-content was increased to x = 0.44. Up to x = 0.33, a0 decreased linearly to about 3.04 Å, but for x ≥0.33, a0 remained nearly constant at this value. For the synthesized products the layer thickness c’ varied between 7.40 and 7.57 Å in contrast to the natural phases wherein c’ varies from 7.60 to 7.80 Å. At higher temperatures CO2-free syntheses, i.e., those without Mg-oxalate, resulted in a disordered hydrotalcite-like phase. The transition temperature between the ordered and the disordered hydrotalcite-like phase depended on the Al-content, x.

Type
Research Article
Information
Clays and Clay Minerals , Volume 34 , Issue 5 , October 1986 , pp. 507 - 510
Copyright
Copyright © 1986, The Clay Minerals Society

References

Allmann, R., 1970 Doppelschichtstrukturen mit brucitähnlichen Schichtionen [Me(II)1-xMe(III)x(OH)2]x+ Chimie 24 99–108.Google Scholar
Allmann, R. and Jepsen, H. P., 1969 Die Struktur des Hydrotalkits N. Jb. Minéral. Mh. 1969 544–551.Google Scholar
Brindley, G. W. and Kikkawa, S., 1979 A crystal-chemical study of Mg,Al and Ni,Al hydroxy-perchlorates and hydroxycarbonates Amer. Mineral. 64 836–843.Google Scholar
Brindley, G. W., 1980 Lattice parameters and composition limits of mixed Mg,Al hydroxy structures Mineral. Mag. 43 1047.CrossRefGoogle Scholar
Cemÿ, P., 1963 Hydrotalkit z Vezné na zâpadni Morave Acta Musei Moraviae 48 23–30.Google Scholar
Feitknecht, W. and Gerber, M., 1942 Zur Kenntnis der Doppelhydroxyde und der basischen Doppelsalze. III. Über Magnesium-Aluminiumdoppelhydroxyd Helv. Chim. Acta 25 131–137.CrossRefGoogle Scholar
Gastuche, M. C., Brown, G. and Mortland, M. M., 1967 Mixed magnesium-aluminium hydroxides I Clay Miner. 7 177–192.CrossRefGoogle Scholar
Koritnig, S. and Süsse, P., 1975 Meixnerit, Mg6Al2(OH)18-4H20, ein neues Magnesium-Aluminium Hydroxid-Mineral Tschermaks Min. Petr. Mitt. 22 79–87.CrossRefGoogle Scholar
Mascolo, G. and Marino, O., 1980 A new synthesis and characterization of magnesium-aluminium hydroxides Mineral. Mag. 43 619–621.CrossRefGoogle Scholar
Miyata, S., 1980 Physico-chemical properties of synthetic hydrotalcites in relation to composition Clays & Clay Minerals 28 50–56.CrossRefGoogle Scholar
Roy, D. M., Roy, R. and Osborn, E. F., 1953 The system MgO-Al2O3-H2O and influence of carbonate and nitrate ions on the phase equilibria Amer. J. Sci. 251 337–361.CrossRefGoogle Scholar
Serna, C. J., Rendon, J. L. and Iglesias, J. E., 1982 Crystalchemical study of layered [Al2Li(OH)6]+ [X-·n H2O] Clays & Clay Minerals 30 180–184.CrossRefGoogle Scholar
Taylor, H. F. W., 1973 Crystal structures of some double hydroxide minerals Mineral. Mag. 39 377–389.CrossRefGoogle Scholar