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Alteration of allophane and imogolite by alkaline digestion

Published online by Cambridge University Press:  09 July 2018

V. C. Farmer
Affiliation:
The Macaulay Institute for Soil Research, Craigiebuckler, Aberdeen, Scotland
B. F. L. Smith
Affiliation:
The Macaulay Institute for Soil Research, Craigiebuckler, Aberdeen, Scotland
J. M. Tait
Affiliation:
The Macaulay Institute for Soil Research, Craigiebuckler, Aberdeen, Scotland

Abstract

Since digestion of imogolite or allophane in 5% Na2CO3 at 95°C for periods of 2–100 h leads to solid products different in structure and composition from the starting materials, the procedure is unsuitable for selective dissolution of reactive silica-alumina gels from complex clay mixtures. Cold 5% Na2CO3 does not alter these clays, but effects partial solution, the extent of which depends on the degree of dispersion of the clay and the ratio of solids to solution.

Résumé

Résumé

La digestion de l'imogolite ou de l'allophane dans 5% de Na2CO3 à 95°C pendant des périodes de 2–100 heures aboutissant à des produits solides dont la structure et la composition diffèrent des matériaux initiaux, le procédé ne convient pas à la dissolution sélective de gels réactifs de silico-alumine de mélanges complexes d'argile. Le Na2CO3 froid ne modifie pasces argiles, mais effectue leur solution partielle, dont l'importance dépend du degré de dispersion de l'argile et du rapport des solides avec la solution.

Kurzreferat

Kurzreferat

Da das Digerieren von Imogolit oder Allophan in 5% Na2CO3 bei 95°C für Zeiträume von 2–100 Stunden zu Festprodukten führt, die in ihrer Struktur und Zusammensetzung von den Ausgangsmaterialien abweichen, ist das Verfahren für die selektive Auflösung von reaktionsfähigen Silika-Tonerde-Gelen aus komplexen Tonmischung ungeeignet. Kaltes 5% Na2CO3 verändert diese Tone nicht, sondern beeinflusst die teilweise Lösung, deren Ausmass von dem Grad der Dispersion des Tons und dem Verhältnis Festsubstanzen-zu-Lösung abhängt.

Resumen

Resumen

Como la digestión de imogolita o alofano en Na2CO3 al 5%, a 95°C durante periodos de 2–100 h conduce a productos sólidos diferentes en estructura y composición a los materiales iniciales, el procedimiento no es adecuado para la disolución selectiva de geles reactivos de silice-alúmina procedentes de mezclas arcillosas complejas. El Na2CO3 al 5% en frío no altera estas arcillas, aunque produce una solución parcial, cuyo grado depende del de la dispersión de la arcilla y de la proporción de sólidos a solución.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1977

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References

Flanigen, E.M., Khatami, H. & Szymanski, H.A. (1971) Adv. Chem. Ser. 101, 201.CrossRefGoogle Scholar
Follett, E.A.C., Mchardy, W.J., Mitchell, B.D. & Smith, B.F.L. (1965) Clay Miner. 6, 23.CrossRefGoogle Scholar
Hashimoto, I. & Jackson, M.L. (1960) Clays Clay Miner. 7, 102.CrossRefGoogle Scholar
Jackson, M.L. (1956) Soil Chemical Analysis—Advanced Course. Published by the author, Department of Soil Science, University of Wisconsin.Google Scholar
Mitchell, B.D., Bracewell, J.M., De Endredy, A.S., Mchardy, W.J. & Smith, B.F.L. (1968) Trans. 9th Int. Congr. Soil Set 3, 67.Google Scholar
Moenke, H. (1962, 1966) Mineralspektren, I and II. Akademie-Verlag, Berlin.Google Scholar
Wada, K. & Harward, M.E. (1974) Adv. Agron. 26, 211.CrossRefGoogle Scholar