Print Email Facebook Twitter Alteration of swelling clay minerals by acid activation Title Alteration of swelling clay minerals by acid activation Author Steudel, A. Batenburg, L.F. Fischer, H.R. Weidler, P.G. Emmerich, K. TNO Industrie en Techniek Publication year 2009 Abstract The bulk material of six dioctahedral and two trioctahedral swellable clay minerals was leached in H2SO4 and HCl at concentrations of 1.0, 5.0 and 10.0 M at 80 °C for several hours. Alteration of the clay mineral structures was dependent on the individual character of each mineral (chemical composition and initial particle size). Acid attack dissolved the octahedral sheets by interlayer and edge attack. The number of substitutions by Mg or Fe in the octahedral sheet of the clay minerals promoted the dissolution of these layers and the formation of a silica phase. The dissolution of the octahedral cations occurred in the following order: Mg > Fe > Al. The dioctahedral smectites were more stable than the trioctahedral smectites and vermiculites; the behavior of trioctahedral smectites against acid was similar to that of vermiculites. The acid activated smectites displayed still the ability to exchange cations. The obtained materials had a lower layer charge, lower CEC and higher specific surface area than the crude materials but still adsorbed very large organic cations like dodecylammonium ions. The reaction with the acid caused particle splitting within the octahedral sheet. A model of dissolution and particle splitting is proposed. © 2009 Elsevier B.V. All rights reserved. Subject MaterialsAcid activationBentoniteCECDissolutionSmectiteVermiculiteBentoniteClay alterationDissolutionLeachingMineralsPositive ionsSilicaSilicate mineralsSwellingAcid activationAcid attacksBulk materialsCECChemical compositionsCrude materialsLayer chargesMineral structuresOctahedral cationsOctahedral sheetsOrganic cationsParticle splittingSmectitesSpecific surfacesSwelling claysVermiculiteClay minerals To reference this document use: http://resolver.tudelft.nl/uuid:29458ad1-429f-4598-a4ab-e5764ba8a528 TNO identifier 241470 ISSN 0169-1317 Source Applied Clay Science, 44 (1-2), 105-115 Document type article Files To receive the publication files, please send an e-mail request to TNO Library.