Hostname: page-component-cd9895bd7-q99xh Total loading time: 0 Render date: 2024-12-23T19:14:21.035Z Has data issue: false hasContentIssue false

Simultaneous thermal analysis of different bentonite–sodium carbonate systems: an attempt to distinguish alkali-activated bentonites from raw materials

Published online by Cambridge University Press:  09 July 2018

A. Steudel*
Affiliation:
Competence Center for Material Moisture (CMM), Karlsruhe Institute of Technology, Hermann-v-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany Institute for Functional Interfaces (IFG), Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany
D. Mehl
Affiliation:
Institute for Functional Interfaces (IFG), Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany
K. Emmerich
Affiliation:
Competence Center for Material Moisture (CMM), Karlsruhe Institute of Technology, Hermann-v-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany Institute for Functional Interfaces (IFG), Karlsruhe Institute of Technology, Hermann-von-Helmholtz-Platz 1, D-76344 Eggenstein-Leopoldshafen, Germany
*

Abstract

Alkali activation with sodium carbonates is a traditional method to improve bentonite properties for a variety of applications. In some applications, natural sodium-rich bentonites are preferred, and custom regulations require proper declaration of Na-rich bentonites, with respect to activation. Consequently, there is need for a method that can unambiguously distinguish between natural and activated Na-rich bentonites.

The paper deals with the preparation of several alkali-activated sets, specifically (a) anhydrous Na2CO3 with trace amounts of thermonatrite (Na2CO3.H2O) and trona (Na3(CO3)(HCO3).2H2O), hereafter called ASC, (b) mixtures of ASC with CaCO3, and (c) mixtures of ASC with CaCO3 and a Ca2+-rich bentonite at different moisture contents, to distinguish natural and alkali-activated bentonites by simultaneous thermal analysis (STA) linked with a mass spectrometer for the analysis of evolved gases. STA linked with MS revealed alkali activation of bentonites, even in the presence of CaCO3. The moisture content during activation and storage of activated samples, however, has a strong influence on the detection of activated samples by STA-MS. Uncertainties remain with respect to unknown foreign phase contents of technical ASC used for alkali activation in practice and the influence of carbonates like dolomite or siderite, which are often present in natural bentonites.

Type
Research Article
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2013

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Abend, S. & Lagaly, G. (2000) Sol-gel transitions of sodium montmorillonite dispersions. Applied Clay Science, 16, 201–227.Google Scholar
Alther, G.R. (1986) The effect of the exchangeable cations on the physico-chemical properties of Wyoming bentonites. Applied Clay Science, 1, 273–284.CrossRefGoogle Scholar
Boylu, F. (2011) Optimization of foundry sand characteristics of soda-activated calcium bentonite. Applied Clay Science, 52, 104–108.CrossRefGoogle Scholar
Emmerich, K. (2011) Thermal analysis for characterisation and processing of industrial minerals. Pp 129–170 in: EMU Notes in Mineralogy: Advances in the Characterization of Industrial Minerals (Christidis, G., editor). Mineralogical Society, London.Google Scholar
Emmerich, K., Kahr, G. & Madsen, F.T. (1999) Dehydroxylation behavior of heat-treated and steam-treated homoionic cis-vacant montmorillonites. Clays and Clay Minerals, 47, 591–604.CrossRefGoogle Scholar
Fahn, R. (1964) Möglichkeiten und Methoden zur Unterscheidung industriell erzeugter Aktivbentonite von natürlichen Natriumbentoniten. Berichte der Deutschen Keramischen Gesellschaft, 41, 546–550.Google Scholar
Günister, E., Güngör, N. & Ece, O.I. (2006) The investigations of influence of BDTDACI and DTABr surfactants on rheologic, elektrokinetic and XRD properties of Na-activated bentonite dispersions. Materials Letters, 60, 666–673.Google Scholar
Hofmann, E., Büchi, U.P., Iberg, R. & Peters, T. (1975) Vorkommen, petrografische, tonmineralogische und technologische Eigenschaften von Bentoniten im schweizerischen Molassebecken, Kümmerly & Frey Geographischer Verlag, 51, 54.Google Scholar
Hofmann, U. & Endell, K. (1936) British Patent 458240.Google Scholar
İş–çi, S., Günister, E., Alemdar, A., Ece, Ö.I. & Güngör, N. (2008) The influence of DTABr surfactant on the elektrokinetic and rheological properties of sodaactivated bentonite dispersions. Materials Letters, 62, 81–84.Google Scholar
Karagüzel, C., Çetinel, T., Boylu, F., Çinku, K. & Çelik, M.S. (2010) Activation of (Na, Ca)-bentonites with soda and MgO and their utilization as drilling mud. Applied Clay Science, 48, 398–404.Google Scholar
Kaufhold, S., Dohrmann, R., Koch, D. & Houben, G. (2008) The pH of aqueous bentonites suspensions. Clays and Clay Minerals, 56, 338–343.Google Scholar
Kim, J.-W., Lee, Y.-D. & Lee, H.-G. (2001) Decomposition of Na2CO3 by interaction with SiO2 in mold flux of steel continuous casting. ISIJ International, 41, 116–123.CrossRefGoogle Scholar
Lagaly, G. (1989) Principles of flow of kaolin and bentonite dispersions. Applied Clay Science, 4, 105–123.Google Scholar
Lagaly, G., Müller-Vonmoos, M., Kahr, G. & Fahn, R. (1981) Vorgänge bei der Sodaaktivierung von Bentoniten am Beispiel eines Bentonits von Neuseeland. Keramische Zeitschrift, 33, 278–283.Google Scholar
Lebedenko, F. & Plee, D. (1988) Some considerations on the ageing of Na2CO3-activated bentonites. Applied Clay Science, 3, 1–10.Google Scholar
Mackenzie, R.C. & Bishui, B.M. (1958) The montmorillonite differential curve. II. Effect of exchangeable cations on the dehydroxylation of normal montmorillonite. Clay Minerals Bulletin, 20, 276–286.Google Scholar
Meyer, W. (1972) Eine Methode zur Qualitätsbestimmung von Bentonit. Gießerei-Rundschau, 19, 66–69.Google Scholar
Smykatz-Kloss, W. (1967) Über die Möglichkeit der halbquantitativen Mineralbestimmung mit der DTA ohne Flächenintegration. Contributions to Mineralogy and Petrology, 9, 481–502.Google Scholar
Smykatz-Kloss, W. (1974) Differential Thermal Analysis: Minerals, Rocks and Inorganic Materials. Springer Verlag, Berlin, 185 pp.Google Scholar
Steudel, A., Batenburg, L., Fischer, H., Weidler, P.G. & Emmerich, K. (2009) Alteration of swellable clays by acid treatment. Applied Clay Science, 44, 105–115.Google Scholar
Tributh, H. & Lagaly, G. (1986) Aufbereitung und Identifizierung von Boden-und Lagerstättentonen Teil I: Aufbereitung der Proben im Labor. GIT Fachzeitschrift für das Laboratorium, 30, 524–529.Google Scholar
Wilburn, F.W., Metcalfe, S.A. & Warburton, R.S. (1965) Differential thermal analysis, differential thermogravimetric analysis, and high temperature microscopy of reactions between the major components of a sheet glass batch. Glass Technology, 6, 107–114.Google Scholar
Wolters, F., Lagaly, G., Kahr, G., Nüesch, R. & Emmerich, K. (2009) A comprehensive characterization of dioctahedral smectites. Clays and Clay Minerals, 57, 115–133.Google Scholar
Yildiz, N., Saikaya, Y. & Çalimli, A. (1999) The effect of the electrolyte concentration and pH on the rheological properties of the original and the Na2CO3-activated Kütahya bentonite. Applied Clay Science, 14, 319–327.CrossRefGoogle Scholar