Hostname: page-component-586b7cd67f-t7czq Total loading time: 0 Render date: 2024-11-22T21:15:21.376Z Has data issue: false hasContentIssue false

Quantitative In Situ Study of the Dehydration of Bentonite-Bonded Molding Sands

Published online by Cambridge University Press:  01 January 2024

Guntram Jordan*
Affiliation:
Department für Geo- und Umweltwissenschaften, Ludwig-Maximilians-Universität München, Theresienstr. 41, 80333 München, Germany
Constanze Eulenkamp
Affiliation:
Department für Geo- und Umweltwissenschaften, Ludwig-Maximilians-Universität München, Theresienstr. 41, 80333 München, Germany
Elbio Calzada
Affiliation:
Technische Universita¨t München, FRM II, Lichtenbergstr.1, 85748 Garching, Germany
Burkhard Schillinger
Affiliation:
Technische Universita¨t München, FRM II, Lichtenbergstr.1, 85748 Garching, Germany
Markus Hoelzel
Affiliation:
Technische Universita¨t München, FRM II, Lichtenbergstr.1, 85748 Garching, Germany
Alexander Gigler
Affiliation:
Department für Geo- und Umweltwissenschaften, Ludwig-Maximilians-Universität München, Theresienstr. 41, 80333 München, Germany
Helge Stanjek
Affiliation:
RWTH Aachen, Ton- und Grenzflächenmineralogie, Wüllnerstr. 2, 52065 Aachen, Germany
Wolfgang W. Schmahl
Affiliation:
Department für Geo- und Umweltwissenschaften, Ludwig-Maximilians-Universität München, Theresienstr. 41, 80333 München, Germany
*
*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.

Bentonite-bonded molding sand is one of the most common mold materials used in metal casting. The high casting temperatures cause dehydration and alteration of the molding sand, thereby degrading its reusability. Neutron radiography and neutron diffraction were applied to study these processes by using pure bentonite-quartz-water mixtures in simulation casting experiments. The aim of the experiments was to compare the dehydration behavior of raw and recycled mold material in order to assess possible causes of the limited reusability of molding sands in industrial application. Neutron radiography provided quantitative data for the local water concentrations within the mold material as a function of time and temperature. Dehydration zones, condensation zones, and areas of pristine hydrated molding sand could be established clearly. The kinematics of the zones was quantified. Within four cycles of de- and rehydration, no significant differences in water kinematics were detected. The data, therefore, suggest that the industrial handling (molding-sand additives and the presence of metal melt) may have greater effects on molding-sand reusability than the intrinsic properties of the pure bentonite–quartz–water system.

Type
Research Article
Copyright
Copyright © Clay Minerals Society 2013

References

Aldushin, K. Jordan, G. Aldushina, E. and Schmahl, W.W., 2007 On the kinetics of ion-exchange in phlogopite — an in situ AFM study Clays and Clay Minerals 55 339347.CrossRefGoogle Scholar
Ben Brahim, J. Besson, G. and Tchoubar, C., 1984 Etude des profils des bandes de diffraction X d’une beidellite-Na hydratée à deux couches d’eau. Détermination du mode d’empilement des feuillets et des sites occupés par l’eau Journal of Applied Crystallography 179188.CrossRefGoogle Scholar
Bérend, I. Cases, J.M. Francois, M. Uriot, J.P. Michot, L. Masion, A. and Thomas, F., 1995 Mechanism of adsorption and desorption of water vapor by homoionic montmor-illonite: 2. The Li2+, Na+, K+, Rb+ and Cs+ exchanged forms Clays and Clay Minerals 43 324336.CrossRefGoogle Scholar
Bradley, W.F. Grim, R.E. and Clark, G.F., 1937 A study of the behavior of montmorillonite upon wetting Zeitschrift für Kristallographie 97 260270.Google Scholar
Bray, H.J. and Redfern, S.A.T., 1999 Kinetics of dehydration of Ca-montmorillonite Physics and Chemistry of Minerals 26 591600.CrossRefGoogle Scholar
Cases, J.M. Bérend, I. Besson, G. Francois, M. Uriot, J.-P. Thomas, F. and Poirier, J., 1992 Mechanism of adsorption and desorption of water vapor by homoinonic montmorillonite. 1. The sodium-exchanged form Langmuir 8 27302739.CrossRefGoogle Scholar
Cases, J.M. Bérend, I. Francois, M. Uriot, J.P. Michot, L.J. and Thomas, F., 1997 Mechanism of adsorption and desorption of water vapor by homoionic montmorillonite: 3. The Mg2+, Ca2+, Sr2+ and Ba2+ exchanged forms Clays and Clay Minerals 45 822.CrossRefGoogle Scholar
Collins, D.R. Fitch, A.N. and Catlow, C.R., 1992 Dehydration of vermiculite and montmorillonite: A time resolved powder neutron diffraction study Journal of Materials Chemistry 2 865873.CrossRefGoogle Scholar
Couture, R., 1985 Steam rapidly reduces the swelling capacity of bentonite Nature 318 5052.CrossRefGoogle Scholar
Dieng, M.A., 2005 Der Wasseraufnahmeversuch nach DIN 18132 in einem neu entwickelten Gerät Bautechnik 82 2832.CrossRefGoogle Scholar
El-Barawy, K.A. Girgis, B.S. and Felix, N.S., 1986 Thermals treatment of some pure smectites Thermochimica Acta 98 181189.CrossRefGoogle Scholar
Ferrage, E. Lanson, B. Malikova, N. Plançon, A Sakharov BA and Drits, V.A., 2005 New insights on the distribution of interlayer water in Bi-hydrated smectite from X-ray profile modeling of 00l reflections Chemistry of Materials 17 34993512.CrossRefGoogle Scholar
Ferrage, E. Lanson, B. Sakharov, B.A. and Drits, V.A., 2005 Investigation of smectite hydration properties by modeling of X-ray diffraction patterns: Part I. Montmorillonite hydration properties American Mineralogist 90 13581374.CrossRefGoogle Scholar
Ferrage, E. Kirk, C. Cressey, G. and Cuadros, J., 2007 Dehydration of Ca-montmorillonite at the crystal scale. Part 1. Structure evolution American Mineralogist 92 9941006.CrossRefGoogle Scholar
Ferrage, E. Kirk, C. Cressey, G. and Cuadros, J., 2007 Dehydration of Ca-montmorillonite at the crystal scale. Part 2. Mechanisms and kinetics American Mineralogist 92 10071017.CrossRefGoogle Scholar
Ferrage, E. Lanson, B. Sakharov, B.A. Geoffroy, N. Jacquot, E. and Drits, V.A., 2007 Investigation of dioctahedral smectite hydration properties by modeling of X-ray diffraction profiles: Influence of layer charge and charge location American Mineralogist 92 17311743.CrossRefGoogle Scholar
Fijal-Kirejczyk, I.M. Milczarek, J.J. and Zoladek-Nowak, J., 2011 Neutron radiography observations of inner wet region in drying of quartz sand cylinder Nuclear Instruments and Methods in Physics Research A 651 205210.CrossRefGoogle Scholar
Grefhorst, C. Podobed, O. and Böhnke, S., 2005 Bentonitgebundene Formstoffe: Umlaufverhalten von Bentoniten unter besonderer Betrachtung des Kreislaufsystems und der Nasszugfestigkeit Gießerei 92 6367.Google Scholar
Guggenheim, S. and Koster van Groos, A.F., 1992 High-pressure differential thermal analysis (HP-DTA). I. Dehydration reactions at elevated pressures in phyllosilicates Journal of Thermal Analysis 38 17011728.CrossRefGoogle Scholar
Guggenheim, S. and Koster van Groos, A.F., 2001 Baseline studies of the Clay Minerals Society Source Clays: thermal analysis Clays and Clay Minerals 49 433443.CrossRefGoogle Scholar
Hassanein, R.K., 2006 Correction methods for the quantitative evaluation of thermal neutron tomography Switzerland ETH Zürich.Google Scholar
Hoelzel, M. Senyshyn, A J N Boysen, H. Schmahl, W. and Fuess, H., 2012 High-resolution neutron powder diffractometer SPODI at research reactor FRM II Nuclear Instruments and Methods in Physics Research A 667 3237.CrossRefGoogle Scholar
Jasmund, K. and Lagaly, G. e., 1993 Tonminerale und Tone Darmstadt, Germany Steinkopff Verlag.CrossRefGoogle Scholar
Komadel, P. Hrobáriková, J. Smrčok, L. and Koppelhuber-Bitschnau, B., 2002 Hydration of reduced-charge montmorillonite Clay Minerals 37 543550.CrossRefGoogle Scholar
Koster van Groos, A.F. and Guggenheim, S., 1984 The effect of pressure on the dehydration reaction of interlayer water in Na-montmorillonite (SWy-1) American Mineralogist 69 872876.Google Scholar
Luo, X., 2007 Study of infrastructure materials using neutron radiography and diffraction Knoxville, USA University of Tennessee.Google Scholar
Moore, D.M. Reynolds, R.C. Jr., 1997 X-ray Diffraction and Identification and Analysis of Clay Minerals Oxford, UK and New York Oxford University Press.Google Scholar
Norrish, N., 1954 The swelling of montmorillonite Discussions of the Faraday Society 18 120133.CrossRefGoogle Scholar
Sanchez-Pastor, N. Aldushin, K. Jordan, G. and Schmahl, W.W., 2010 K+ -Na+ exchange in phlogopite on the scale of a single layer Geochimica et Cosmochimica Acta 74 19541962.CrossRefGoogle Scholar
Schillinger, B. Calzada, E. and Lorenz, K., 2006 Modern neutron imaging: Radiography, tomography, dynamic and phase contrast imaging with neutrons Solid State Phenomena 112 6172.CrossRefGoogle Scholar
Schillinger, B. Calzada, E. Eulenkamp, C. Jordan, G. and Schmahl, W.W., 2011 Dehydration of moulding sand in simulated casting process examined with neutron radiography Nuclear Instruments and Methods in Physics Research A 651 312314.CrossRefGoogle Scholar
Tilch, W., 2004 Ermittlung des Aufbereitungsverhaltens bentonitgebundener Formstoffe (Betriebssande) Gießerei-Praxis 1/2004 1218.Google Scholar
Ufer, K. Roth, G. Kleeberg, R. Stanjek, H. Dohrmann, R. and Bergmann, J., 2004 Description of X-ray powder pattern of turbostratically disordered layer structures with a Rietveld compatible approach Zeitschrift für Kristallographie 219 519527.CrossRefGoogle Scholar
Ufer, K. Stanjek, H. Roth, G. Dohrmann, R. Kleeberg, R. and Kaufholf, S., 2008 Quantitative phase analysis of bentonites by the Rietveld method Clays and Clay Minerals 56 272282.CrossRefGoogle Scholar
Wilson, J. Cuardros, J. and Cressey, G., 2004 An in situ time-resolved XRD-PSD investigation into Na-montmorillonite interlayer and particle rearrangement during dehydration Clays and Clay Minerals 52 180191.CrossRefGoogle Scholar
Wu, J. Low, P.F. and Roth, C.B., 1989 Effects of octahedraliron reduction and swelling pressure on interlayer distances in Na-nontronite Clays and Clay Minerals 37 211218.Google Scholar
Zabat, M. and Van Damme, H., 2000 Evaluation of the energy barrier for dehydration of homoionic (Li, Na, Cs, Mg, Ca, Ba, Alx(OH)yz+ and La)-montmorillonite by a differentiation method Clay Minerals 35 357363.CrossRefGoogle Scholar