Hostname: page-component-cd9895bd7-p9bg8 Total loading time: 0 Render date: 2024-12-23T07:17:26.667Z Has data issue: false hasContentIssue false
  • English
  • Français

The Problem of Expressing the Specific Surface Areas of Clay Fractions

Published online by Cambridge University Press:  28 February 2024

E. Padmanabhan  and
A. R. Mermut
E. Padmanabhan
Affiliation:
Department of Soil Science, University of Saskatchewan, Saskatoon, Saskatchewan, Canada S7N OWO
A. R. Mermut
Affiliation:
Department of Soil Science, University of Saskatchewan, Saskatoon, Saskatchewan, Canada S7N OWO
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.

Estimations of the external specific surface areas (S.S.A.) by the N2-BET method of clay separates that were further fractionated by the high gradient magnetic separation technique revealed that the magnetic fractions had consistently lower S.S.A. compared to non-magnetic fractions. This phenomenon has been attributed, in the past, to the intimate association of Fe-oxides with silicate clays. It is the contention of this study that this reasoning is insufficient due to the following reasons. X-ray diffractograms (XRD) confirmed that heavy minerals were abundant in the magnetic fractions of these clays. Total chemical analyses and energy dispersive X-ray analyses showed that these heavy minerals contained Fe and Ti, which were not completely extracted by the dithionite-citrate bicarbonate (DCB) treatments. Crystallinity and quantity of these oxides in the different fractions did not show any relationships with the S.S.A. Lower S.S.A. were found in the magnetic fractions of both coarse and fine clays in the untreated as well as DCB-treated samples. The average particle density of the magnetic fractions was found to be higher than the non-magnetic fractions, resulting in an underestimation of the S.S.A. This underestimation was further proven when clay-sized illmenite (density = 4.79 Mg m−3) was found to have lower S.S.A. than quartz (density = 2.65 Mg m−3) and well-crystallized Georgia kaolinite (density = 2.61 Mg m−3), even though the illmenite particles were smaller in size compared to the kaolinite particles and similar in size compared to the quartz particles. It is, therefore, proposed that the specific surface areas should be expressed either on a volumetric basis or corrected for differences in density to avoid underestimations when heavy minerals are present in the samples.

Keywords

DensityFe and Ti oxidesMagnetic and non-magnetic fractionsSpecific surface area
Type
Research Article
Information
Clays and Clay Minerals , Volume 43 , Issue 2 , April 1995 , pp. 237 - 245
Copyright
Copyright © 1995, The Clay Minerals Society

References

Barberis, E., Marsan, F. Ajmore, Boero, V., and Arduino, E. 1991 . Aggregation of soil particles by iron oxides in various size fractions of soil B horizons. J. Soil Sci. 42: 535–542.CrossRefGoogle Scholar
Bigham, J. M., Golden, D. C., Buol, S. W., Weed, S. B., and Bowen, L. H. 1978 . Iron oxide mineralogy of well-drained Ultisols and Oxisols. II Influence on color, surface area and phosphate retention. Soil Sci. Soc. Am. J. 42: 825–830.CrossRefGoogle Scholar
Borggaard, O. K., 1982. The influence of iron oxides on the surface area of soil. J. Soil Sci. 33: 443–449.CrossRefGoogle Scholar
Buol, S. W., 1985. Mineralogy classes in soil families with Low Activity Clays. In Mineral Classification of Soils. Kittrick, J. A., ed. Soil Sci. Soc. Am. Special Pub. No. 16. Soil Sci. Soc. Am. Inc. Madison, Wisconsin: American Soc. of Agron. Inc., 169–178.Google Scholar
Churchman, G. J., and Burke, C. M. 1991 . Properties of subsoils in relation to various measures of surface area and water content. J. Soil Sci. 42: 463–478.CrossRefGoogle Scholar
Dasog, G. S., Acton, D. F., Mermut, A. R., and Jong, E. De. 1988 . Shrink-swell potential and cracking in clay soils of Saskatchewan. Can. J. Soil Sci. 68: 251–260.CrossRefGoogle Scholar
Deer, W. A., Howie, R. A., and Zussman, J. 1967 . An introduction to the rock-forming minerals. London: Longmans, Green and Co. Ltd. 528 pp.Google Scholar
De Kimpe, C. R., Laverdiere, M. R., and Martel, Y. A. 1979 . Surface area and exchange capacity of clay in relation to the mineralogical composition of gleysolic soils. Can. J. Soil Sci. 59: 341–347.CrossRefGoogle Scholar
Desphande, T. L., Greenland, D. J., and Quirk, J. P. 1968 . Changes in soil properties associated with the removal of iron and aluminium oxides. J. Soil Sci. 19: 108–122.Google Scholar
Feller, C., Schouller, E., Thomas, F., Rouller, J., and Herbillon, A. J. 1992 . N2-BET specific surface areas of some Low Activity Clay soils and their relationships with secondary constituents and organic matter contents. Soil Sci. 153: 293–299.CrossRefGoogle Scholar
Fontes, M. P. F., 1992. Iron oxide-clay mineral association in Brazilian Oxisols: A magnetic separation study. Clays & Clay Miner. 40: 175–179.CrossRefGoogle Scholar
Gallez, A., Juo, A. S. R., and Herbillon, A. J. 1976 . Surface and charge characteristics of selected soils in the tropics. Soil Sci. Soc. Am. J. 40: 601–608.CrossRefGoogle Scholar
Ghabru, S. K., Arnaud, R. J. St., and Mermut, A. R. 1987 . Liquid magnetic separation of iron-bearing minerals from sand fractions of soils. Can. J. Soil Sci. 67: 561–569.CrossRefGoogle Scholar
Greenland, D. J., Oades, J. M., and Sherwin, T. W. 1968 . Electron microscope observations of iron oxides in some red soils. J. Soil Sci. 19: 123–196.CrossRefGoogle Scholar
Harsh, J. B., and Doner, H. E. 1985 . The nature and stability of aluminium hydroxide precipitated on Wyoming Montmorillonite. Geoderma 36: 45–56.CrossRefGoogle Scholar
Hillel, D., 1982. Introduction to soil physics. New York: Academic Press Inc. 364 pp.Google Scholar
Hughes, J. C., 1982. High gradient magnetic separation of some soil clays from Nigeria, Brazil and Colombia. I. The inter relationships of iron and aluminium extracted by acid ammonium oxalate and carbon. J. Soil Sci. 33: 509–519.CrossRefGoogle Scholar
Jackson, M. L., 1969. Soil chemical analysis—Advanced course. 2nd. Edition, 8th. Printing, 1973. Published by M. L. Jackson. Dept of Soil Science, Univ. of Wisconsin, Madison, Wis.Google Scholar
Jones, R. C., Hudnall, W. H., and Sakai, W. S. 1982 . Some highly weathered soils of Puerto Rico 2. Mineralogy. Geoderma 27: 75–137.CrossRefGoogle Scholar
McKeague, J. A. Ed. 1978 . Manual on sampling and methods of analysis. 2nd. Edition. Can. Soc. of Soil Sci., Ottawa. Canada.Google Scholar
McKeague, J. A., and Day, J. H. 1966 . Dithionite- and oxalate-extractable Fe and Al as aids in differentiating various classes of soils. Can. J. Soil Sci. 46: 13–22.CrossRefGoogle Scholar
Mehra, O. P., and Jackson, M. L. 1960 . Iron oxides removal from soils and clays by a dithionite-citrate system buffered with sodium bicarbonate. Clays & Clay Miner. 7: 317–327.CrossRefGoogle Scholar
Newman, A. C. D., 1983. The specific surface of soils determined by water sorption. J. Soil Sci. 34: 23–32.CrossRefGoogle Scholar
Peter, C. J., and Weber, J. B. 1985 . Adsorption, mobility and efficacy of metribuzin as influenced by soil properties. Weed Sci. 33: 868–873.CrossRefGoogle Scholar
Rieke, R. D., Vinson, T. S., and Mageau, D. W. 1983 . The role of specific surface area and related index properties in the frost heave susceptibility of soils. Permafrost: Fourth Int. Conf., Proc. (National Academy of Sciences), Washington, D.C.: National Academy Press, 1066–1071.Google Scholar
Saleh, A. M., and Jones, A. A. 1984 . The crystallinity and surface characteristics of synthetic ferrihydrite and its relationship to kaolinite surface. Clay Miner. 19: 745–755.CrossRefGoogle Scholar
Schulze, D. G., and Schwertmann, U. 1984 . The influence of aluminium on iron oxides: X. Properties of Al-substituted goethites. Clay Miner. 19: 521–539.CrossRefGoogle Scholar
Schwertmann, U., and Kämpf, N. 1985 . Properties of Goethite and hematite in kaolinitic soils of Southern and Central Brazil. Soil Sci. 139: 344–350.CrossRefGoogle Scholar
Smith, C. W., Hadas, A., Dan, J., and Koyumdjisky, H. 1985 . Shrinkage and Atterberg limits in relation to other properties of principal soil types in Israel. Geoderma 35: 47–65.CrossRefGoogle Scholar
Sposito, G., 1984. The surface chemistry of soils. N.Y.: Oxford Univ. Press., Oxford: Clarendon Press. 234 pp.Google Scholar
Tiller, K. G., and Smith, L. H. 1990 . Limitations of EGME retention to estimate the surface area of soils. Aust. 3. Soil Res. 28: 1–26.CrossRefGoogle Scholar
Van Olphen, H., and Fripiat Ed, J. J. 1979 . Data handbook for clay materials and other non-metallic minerals. Oxford, New York, Toronto, Sydney, Paris, Frankfurt: Pergamon Press Inc., 346 pp.Google Scholar
Wann, S. S., and Juang, T. C. 1985 . Grouping soils for management practice. FFTC Book series No. 29: 41–54.Google Scholar