Hostname: page-component-cd9895bd7-8ctnn Total loading time: 0 Render date: 2024-12-26T05:36:07.613Z Has data issue: false hasContentIssue false

Layer Charge Density of Smectites — Closing the Gap Between the Structural Formula Method and the Alkyl Ammonium Method

Published online by Cambridge University Press:  01 January 2024

Stephan Kaufhold*
Affiliation:
BGR Bundesanstalt für Geowissenschaften und Rohstoffe, Stilleweg 2, D-30655 Hannover, Germany
Reiner Dohrmann
Affiliation:
BGR Bundesanstalt für Geowissenschaften und Rohstoffe, Stilleweg 2, D-30655 Hannover, Germany LBEG Landesamt für Bergbau, Energie und Geologie, Stilleweg 2, D-30655 Hannover, Germany
Joseph W. Stucki
Affiliation:
Department of Natural Resources and Environmental Sciences, University of Illinois, W-321 Turner Hall, 1102 South Goodwin Ave, Urbana, IL 61801, USA
Alexandre S. Anastácio
Affiliation:
Department of Natural Resources and Environmental Sciences, University of Illinois, W-321 Turner Hall, 1102 South Goodwin Ave, Urbana, IL 61801, USA
*
* E-mail address of corresponding author: [email protected]
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.

The layer charge density (LCD) of montmorillonite represents the permanent negative charge, its most important property. The LCD can be determined by two different methods, the structural formula method(SF M) and the alkylammonium method (AAM). Other methods of determining the LCD are calibrated against one or the other of these. The results of the two methods differ systematically: SFM values are larger than AAM values and the difference increases with increasing layer charge density. In the present study, the critical parameters of both methods were considered quantitatively in order to identify the most likely reason for the systematic difference. One particularly important argument against the validity of the SFM is that typical SFM values correspond to unrealistically large CEC values that have never been reported. In addition, SFM does not consider the variable charge which causes cations to be adsorbed to the outer surface (at pH >4). In contrast to minor constituents, which can of course also affect SFM values, the variable charge can explain only part of the systematic difference. The exchange of pure smectite samples with both Cu-trien andalkyla mmonium revealedthe presence of non-exchangeable, nonstructural cations (Na, K, Ca). These cations, together with 10% (or more) variable charge, may explain the differences in LCD values. The non-exchangeable, non-structural cations could stem from undetected traces of feldspar or volcanic glass. The present samples indicated that the systematic difference in LCD values between the two methods is related to the amount of non-exchangeable, non-structural cations only, indicating that the two LCD methods probe different features of smectites. Using the SFM on pure smectite provides a value for the total number of charges (permanent with andwithout fixed (= non-exchangeable, non-structural) cations plus variable charge). The AAM, on the other hand, provides the charge density of the exchangeable cations (without variable charge).

Type
Article
Copyright
Copyright © The Clay Minerals Society 2011

References

Ammann, L. Bergya, F. and Lagaly, G., 2005 Determination of the cation exchange capacity of clays with copper complexes revisited Clay Minerals 40 441453 10.1180/0009855054040182.CrossRefGoogle Scholar
Brindley, G.W. and Pedro, G., 1976 Meeting of the Nomenclature Committee of AIPEA, Mexico City, July 21, 1975 AIPEA Newsletter 12 56.Google Scholar
Čičel, B. Komadel, P., Amonette, J.E. Zelazny, L.W., 1994 Structural formulae of layer silicates Quantitative Methods in Soil Mineralogy Madison, Wisconsin, USA Soil Science Society of America 114136.Google Scholar
Dohrmann, R. and Kaufhold, S., 2009 Three new, quick CEC methods for determining the amounts of exchangeable calcium cations in calcareous clays Clays and Clay Minerals 57 251265 10.1346/CCMN.2009.0570211.CrossRefGoogle Scholar
Emmerich, K. Wolters, F. Kahr, G. and Lagaly, G., 2009 Clay profiling: the classification of montmorillonites Clays and Clay Minerals 57 104114 10.1346/CCMN.2009.0570110.CrossRefGoogle Scholar
Grim, R.E. and Güven, N. (1978) Bentonites–Geology, Mineralogy, Properties and Uses. Developments in Sedimentology, 46, Elsevier, New York, pp. 254.Google Scholar
Janek, M. and Komadel, P., 1999 Acidity of proton saturated and auto transformed montmorillonites characterisedwith proton affinity distribution Geologica Carpathica 50 373378.Google Scholar
Kamil, J. and Shainberg, I., 1968 Hydrolysis of sodium montmorillonite on sodium chloride solutions Soil Science 106 193199 10.1097/00010694-196809000-00007.CrossRefGoogle Scholar
Kaufhold, S., 2005 Influence of layer charge density on the determination of the internal surface area of montmorillonites Berichte der Deutschen Ton- und Tonmineralgruppe 11 2026.Google Scholar
Kaufhold, S., 2006 Comparison of methods for the determination of the layer charge density (LCD) of montmorillonites Applied Clay Science 34 1421 10.1016/j.clay.2006.02.006.CrossRefGoogle Scholar
Kaufhold, S. and Dohrmann, R., 2008 Detachment of colloidal particles from bentonites in water Applied Clay Science 39 5059 10.1016/j.clay.2007.04.008.CrossRefGoogle Scholar
Kaufhold, S. and Dohrmann, R., 2010 Stability of bentonites in salt solutions II Potassium chloride solution–Initial step of illitization? Applied Clay Science 49 98107..Google Scholar
Kaufhold, S. Dohrmann, R. Ufer, K. and Meyer, F.M., 2002 Comparison of methods for the quantification of montmorillonite in bentonites Applied Clay Science 22 145151 10.1016/S0169-1317(02)00131-X.CrossRefGoogle Scholar
Kaufhold, S. Dohrmann, R. Koch, D. and Houben, G., 2008 The pH of aqueous bentonite suspensions Clays and Clay Minerals 56 338343 10.1346/CCMN.2008.0560304.CrossRefGoogle Scholar
Kaufhold, S. Dohrmann, R. Ufer, K. Kleeberg, R. and Stanjek, H., 2011 Termination of swelling capacity of smectites by Cutrien exchange Clay Minerals .CrossRefGoogle Scholar
Komadel, P. and Stucki, J.W., 1988 Quantitative assay of minerals for Fe2+ and Fe3+ using 1,10-phenanthroline: III A rapidphot ochemical method. Clays and Clay Minerals 36 379381 10.1346/CCMN.1988.0360415.CrossRefGoogle Scholar
Köster, H.M., 1977 Die Berechnung kristallchemischer Strukturformeln von 2:1–Schichtsilikaten unter Berücksichtigung der gemessenen Zwischenschichtladungen und Kationenumtauschkapazitäten, sowie die Darstellung der Ladungsverteilung in der Struktur mittels Dreieckskoordinaten Clay Minerals 12 4554 10.1180/claymin.1977.012.1.03.CrossRefGoogle Scholar
Lagaly, G., 1994 Layer charge determination by alkylammonium ions Layer Charge Characteristics of 2:1 Silicate Clay Minerals 6 146.Google Scholar
Lagaly, G. Weiss, A. and Heller, L., 1969 Determination of the layer charge in mica-type layer silicates Proceedings ofthe International Clay Conference, Tokyo Jerusalem Israel University Press 6180.Google Scholar
Laird, D.A., 1994 Evaluation of the structural formula and alkylammonium methods of determining layer charge Layer Charge Characteristics of 2:1 Silicate Clay Minerals 6 79104.Google Scholar
Laird, D.A. Scott, A.D. and Fenton, T.E., 1989 Evaluation of the alkylammonium methodof determining layer charge Clays and Clay Minerals 37 4146 10.1346/CCMN.1989.0370105.CrossRefGoogle Scholar
Maes, A. Stul, M.S. and Cremers, A., 1979 Layer chargecation-exchange capacity relationships in montmorillonite Clays and Clay Minerals 27 387392 10.1346/CCMN.1979.0270510.CrossRefGoogle Scholar
McBride, M.B., 1979 An interpretation of cation selectivity variations in M (super +)–M (super +) exchange on clays Clays and Clay Minerals 27 417422 10.1346/CCMN.1979.0270604.CrossRefGoogle Scholar
Meier, L.P. and Kahr, G., 1999 Determination of the cation exchange capacity (CEC) of clay minerals using the complexes of Copper (II) ion with Triethylenetetramine and Tretraethylenepentamine Clays and Clay Minerals 47 386388 10.1346/CCMN.1999.0470315.CrossRefGoogle Scholar
Mermut, A.R., 1994 Problems associated with layer charge characterisation of 2:1 phyllosilicates Layer Charge Characteristics of 2:1 Silicate Clay Minerals 6 79104.Google Scholar
Newman, A.C.D. and Brown, G., 1987 The chemical constitution of clays Chemistry of Clays and Clay Minerals 6 1128.Google Scholar
Ross, C.S. and Hendricks, S.B., 1945 Minerals of the montmorillonite group U.S. Geological Survey Professional Paper 205-B 2379.Google Scholar
Senkayi, A.D. Dixon, J.B. Hossner, L.R. and Kippenberger, L.A., 1985 Layer charge evaluation of expandable soil clays by an alkylammonium method Soil Science Society of America Journal 49 10541060 10.2136/sssaj1985.03615995004900040052x.CrossRefGoogle Scholar
Stevens, R.E., 1946 A system for calculating analyses of micas and related minerals to end members. Contributions to Geochemistry Geological Survey Bulletin 950 1942–45.Google Scholar
Środoń, J. and McCarty, D.K., 2008 Surface area and layer charge of montmorillonite from CEC and EGM E/H2O retention measurements Clays and Clay Minerals 56 155174 10.1346/CCMN.2008.0560203.CrossRefGoogle Scholar
Tributh, H. and Lagaly, G., 1986 Aufbereitung und Identifizierung von Boden- und Lagerstättentonen. I. Aufbereitung der Proben im Labor GIT-Fachzeitschrift für das Laboratorium 30 524529.Google Scholar
Ufer, K. Stanjek, H. Roth, G. Dohrmann, R. Kleeberg, R. and Kaufhold, S., 2008 Quantitative phase analysis of bentonites by the Rietveldmet hod Clays and Clay Minerals 56 272282 10.1346/CCMN.2008.0560210.CrossRefGoogle Scholar
Verburg, K. Baveye, P. and McBride, M.B., 1995 Cation-exchange hysteresis andd ynamics of formation and breakdown of montmorillonite quasi-crystals Soil Science Society of America Journal 59 12681273 10.2136/sssaj1995.03615995005900050009x.CrossRefGoogle Scholar
Vogt, K. and Köster, H.M., 1978 Zur Mineralogie, Kristallchemie und Geochemie einiger Montmorillonite aus Bentoniten Clay Minerals 13 2543 10.1180/claymin.1978.013.1.03.CrossRefGoogle Scholar
Wolters, F. Lagaly, G. Kahr, G. Nüesch, R. and Emmerich, K., 2009 A comprehensive characterization of dioctahedral smectites Clays and Clay Minerals 57 115133 10.1346/CCMN.2009.0570111.CrossRefGoogle Scholar