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Effect of ageing on the nature and interlayering of mixed hydroxy A1-Fe-montmorillonite complexes

Published online by Cambridge University Press:  09 July 2018

C. Colombo
Affiliation:
Dipartimento di Scienze Chimico-Agrarie, Università di Napoli Federico II, 80055 Portici, Italy
A. Violante
Affiliation:
Dipartimento di Scienze Chimico-Agrarie, Università di Napoli Federico II, 80055 Portici, Italy

Abstract

Mixed hydroxy Al-Fe-montmorillonite complexes (5 mmol of Al+Fe per g of clay) were prepared at pH 5.0 by mixing different amounts of Al(NO3)3 and Fe(NO3)3 to give initial Fe/Al molar ratios (R) of 0, 0.1, 0.25, 0.5, 1.0, 4.0, 10.0 or ∞. The effect of ageing on the interlayering, mineralogy, chemical composition, CEC and external surface area of the complexes was studied. The degree of interlayering of freshly prepared and aged complexes (up to 120 days at 50°C) was always greater in the samples with R ranging from 0.5 to 4. Gibbsite and hematite (with traces of goethite) formed in the samples with R ⩽ 1 and R∞, respectively. No crystalline Fe oxide was detected by XRD analyses in the complexes with R ranging from 0.1 to 10, whereas no crystalline Al and Fe oxides were formed in the complexes at R = 4–10. However, some evidence suggests the possible formation of a microcrystalline Fe oxide/oxyhydroxide undetectable by XRD analyses in the complexes richer in Fe. The CEC and the surface area of the freshly prepared mixed hydroxy Al-Fe-montmorillonite complexes increased with increasing R. Large quantities of Al+Fe were solubilized by oxalate in the complexes with R ⩾ 0.5, even after ageing for 120 days at 50°C, indicating that interlayering of Al-Fe species at certain Fe/Al molar ratios was particularly stable.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 1997

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References

Barnhisel, R.I. & Bertsch, P.M. (1989) Chlorites and hydroxy interlayered vermiculite and smectite: Pp. 729–788 in: Minerals in Soil Environments. (Dixon, J. & Weed, S.B., editors), 2nd ed., Soil Science Society of America, Madison, Wisconsin.Google Scholar
Bergaya, F. Hassoun, N., Barrault, J. & Gatineau, L. (1993) Pillaring of synthetic hectorite by mixed [Al13-xFex] pillars. Clay Miner. 28, 109122.Google Scholar
Carstea, D.D. (1968) Formation of hydroxy-Al and -Fe interlayers in montmorillonite and vermiculite: Influence of particle size and temperature. Clays Clay Miner. 16, 231238.Google Scholar
Carstea, D.D., Harward, M.E. & Knox, E.G. (1970) Comparison of iron and aluminum hydroxy interlayers in montmorillonite and vermiculite: I. Formation. Soil Sci. Soc. Am. Proc. 34, 517521.Google Scholar
Colombo, C. & Violante, A. (1996) Effect of time and temperature on the chemical composition and crystallization of mixed iron aluminum species. Clays Clay Miner. 44, 113120.Google Scholar
Frenkel, H. & Shainberg, I. (1980) The effect of hydroxy- A1 and hydroxy-Fe polymers on montmorillonite particle size. Soil Sci Soc. Am. J. 44, 626629.Google Scholar
Goh, T.B., Huang, P.M., Dudas, M.J. & Pawluk, S. (1987) Effect of iron on the nature of precipitation products of aluminum. Can. J. Soil Sci. 67, 135–145.Google Scholar
Jackson, M.L. (1979) Soil Chemical Analysis. Advanced Course. Pp. 799. 2nd ed. Univ. Wisconsin, Madison, Wisconsin.Google Scholar
Krishnamurti, G.S.R., Violante, A. & Huang, P.M. (1995) Influence of Fe on the stabilisation of hydroxy-Al interlayers in montmorillonite. Proc. 10th Int. Clay Conf., Adelaide, 183-186.Google Scholar
Lewis, D.G. & Schwertmann, U. (1979) The influence of aluminum on the formation of iron oxides. IV. The influence of [Al], [OH] and temperature. Clays Clay Miner. 27, 195200.Google Scholar
Loeppert, R.H. (1988) Reaction of iron in calcareous systems. Pp. 689–714 in: Iron in Soils and Clay Minerals. (Stucki, J.W. et al., editors). NATO ASI series. Vol. 217. Reidel Publ. Comp. Dordrecht, Holland.Google Scholar
Mehra, O.P. & Jackson, M.L. (1960) Iron oxides removal from soils and clay by dithionite-citrate systems buffered with sodium bicarbonate. 7th Nat. Conf. Clay Miner. 317-327.Google Scholar
Quirk, J.P. (1955) Significance of surface area calculated from water vapour sorption isotherms by use of the B.E.T. equation. Soil Sci. 80, 423430.Google Scholar
Rich, C.I. (1968) Hydroxy interlayers in expansible layer silicates. Clays Clay Miner. 16, 1530.Google Scholar
Schwertmann, U. (1964) Differenzierung der Eisenoxide des Bodens durch photochemische Extraktion mit saurer AmmoniumoxalatLösung. Z Pflanzenernähr. Bodenk. 105, 194202.Google Scholar
Schwertmann, U., Fitzpatrick, R.W., Taylor, R.M. & Lewis, D.G. (1979) The influence of aluminum on iron oxides. II. Preparation and properties of AIsubstituted hematites. Clays Clay Miner. 27, 105112.Google Scholar
Singleton, P.C. & Harward, M.E. (1971) Iron hydroxy interlayers in soil clay. Soil Sci. Soc. Am. Proc. 35, 838842.Google Scholar
Siss (Societá Italiana Scienza del Suolo) (1985) Metodi Normalizzati di Analisi del Suolo. p. 100. Edagricole, Bologna.Google Scholar
Taylor, R.M. & Schwertmann, U. (1978) The influence of aluminum on iron oxides: Part I. The influence of A1 on Fe oxide formation from Fe(II) system. Clays Clay Miner. 26, 373383.Google Scholar
Tullock, R.J. & Roth, C.B. (1975) Stability of mixed iron and aluminum hydrous oxides on montmorillonite. Clays Clay Miner 23, 2732.Google Scholar
Violante, A., Krishnamurti, G.S.R. & Huang, P.M. (1996) Formation and stability of hydroxy A1-Fe-montmorillonite complexes. Influence of ferrous iron. Clays Clay Miner. (submitted).Google Scholar
Zhao, D.Y., Wang, G., Yang, Y., Guo, X., Wang, Q. & Ren, J. (1993) Preparation and characterization of hydroxy-Fe-Al pillared clays. Clays Clay Miner. 41, 317327.Google Scholar