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The fate of smectite in KOH solutions

Bauer, A. 1; Lanson, B.; Ferrage, E.; Emmerich, K. 2; Taubald, H.; Schild, D. ORCID iD icon 1; Velde, B.
1 Forschungszentrum Karlsruhe (FZKA)
2 Fakultät für Bauingenieur-, Geo- und Umweltwissenschaften – Institut für Mineralogie und Geochemie (IMG), Karlsruher Institut für Technologie (KIT)


The aim of the present study was to investigate the detailed evolution of the SAz-1 smectite in 1 M KOH at 80 °C at a solid/liquid ratio of 1/80. AFM observations indicated no change in crystal size or shape. XRD measurements at 40% relative humidity revealed changes in expandability of the smectite. The (001) reflection profile of smectite was modeled using a trial-and-error approach. The results indicate that with increasing run time, the number of non-expandable layers with zero or one water layer increases and that the coherent scattering domain size of the smectite decreases. IR spectroscopy of the reacted smectite suggests that there is no change from the initial clay products. The dehydroxylation temperature showed a slight decrease from 619 to 605 °C. STA measurements demonstrated that the cis-vacant character of the octahedral sheet remained nearly unchanged throughout the experiment. Determination of the average layer charge showed a continuous increase from 0.32 to 0.42 eq/(Si/Al)$_{4}$O$_{10}$, whereas the layer charge distribution indicated the appearance of high charged smectite layers with a charge of ~ 0.6 eq/(Si/Al)$_{4}$O$_{10}$ and the disappearance of the low charged layers. ... mehr

Postprint §
DOI: 10.5445/IR/110065416
Veröffentlicht am 23.02.2023
DOI: 10.2138/am.2006.2151
Zitationen: 24
Web of Science
Zitationen: 21
Zitationen: 20
Cover der Publikation
Zugehörige Institution(en) am KIT Institut für Nukleare Entsorgung (INE)
Publikationstyp Zeitschriftenaufsatz
Publikationsdatum 01.08.2006
Sprache Englisch
Identifikator KITopen-ID: 110065416
HGF-Programm 32.27.02 (POF I, LK 01) Anwendungsorientierte Untersuchungen
Erschienen in American Mineralogist
Band 91
Heft 8-9
Seiten 1313-1322
Nachgewiesen in Scopus
Web of Science
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