Evaluation of rare earth on layered silicates under subcritical conditions: Effect of the framework and interlayer space composition

Clay-based minerals are considered to be an important component in backfill barriers due to both their ability to seal and adsorb radioactive waste and to interact chemically with it under subcritical conditions. Herein, we describe a systematic study of the properties of layered silicates that coul...

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Detalles Bibliográficos
Autores: Chain, P., Cota, Agustín, Pavón, Esperanza, Pazos, M. Carolina, Alba, María D.
Tipo de recurso: artículo
Fecha de publicación:2013
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/97155
Acceso en línea:http://hdl.handle.net/10261/97155
Access Level:acceso abierto
Palabra clave:Subcritical conditions
Hydrothermal 35 treatment
Rare-earth
Radioactive waste
Engineered barrier
X-ray diffraction
MAS-NMR
Disilicates
Bentonite
Smectite
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spelling Evaluation of rare earth on layered silicates under subcritical conditions: Effect of the framework and interlayer space compositionChain, P.Cota, AgustínPavón, EsperanzaPazos, M. CarolinaAlba, María D.Subcritical conditionsHydrothermal 35 treatmentRare-earthRadioactive wasteEngineered barrierX-ray diffractionMAS-NMRDisilicatesBentoniteSmectiteClay-based minerals are considered to be an important component in backfill barriers due to both their ability to seal and adsorb radioactive waste and to interact chemically with it under subcritical conditions. Herein, we describe a systematic study of the properties of layered silicates that could affect their hydrothermal reactivity, namely type of layers, octahedral occupancy, origin and total amount of the layer charge, and nature of the interlayer cation. The silicates studied were selected on the basis of their different characteristics associated with these properties and were treated hydrothermally at 300 °C for 48 h in a 7.3 · 10− 2 M Lu(NO3)3 · 3.6H2O solution. The final products were analyzed by X-ray diffraction and solid-state NMR spectroscopy. All the layered silicates studied were found to be able to generate a Lu2Si2O7 phase after hydrothermal treatment under subcritical conditions, thereby confirming the participation of a chemical mechanism of the clay barrier generating phases being stables with temperature and pH conditions. However, the extent of this reaction depends to a large extent on the physicochemical properties of the framework and the interlayer space composition, such as the presence or absence of an octahedral sheet, the degree of occupancy of this sheet, and the origin and total layer charge. Therefore, this study allows tuning the clay mineral framework characteristic that favors the rare earth cations (as trivalent actinide simulator) immobilization.Peer ReviewedElsevier2014201420132014info:eu-repo/semantics/articlehttp://purl.org/coar/resource_type/c_6501http://hdl.handle.net/10261/97155reponame:DIGITAL.CSIC. Repositorio Institucional del CSICinstname:Consejo Superior de Investigaciones Científicas (CSIC)Inglésinfo:eu-repo/semantics/openAccessoai:digital.csic.es:10261/971552026-05-22T06:33:51Z
dc.title.none.fl_str_mv Evaluation of rare earth on layered silicates under subcritical conditions: Effect of the framework and interlayer space composition
title Evaluation of rare earth on layered silicates under subcritical conditions: Effect of the framework and interlayer space composition
spellingShingle Evaluation of rare earth on layered silicates under subcritical conditions: Effect of the framework and interlayer space composition
Chain, P.
Subcritical conditions
Hydrothermal 35 treatment
Rare-earth
Radioactive waste
Engineered barrier
X-ray diffraction
MAS-NMR
Disilicates
Bentonite
Smectite
title_short Evaluation of rare earth on layered silicates under subcritical conditions: Effect of the framework and interlayer space composition
title_full Evaluation of rare earth on layered silicates under subcritical conditions: Effect of the framework and interlayer space composition
title_fullStr Evaluation of rare earth on layered silicates under subcritical conditions: Effect of the framework and interlayer space composition
title_full_unstemmed Evaluation of rare earth on layered silicates under subcritical conditions: Effect of the framework and interlayer space composition
title_sort Evaluation of rare earth on layered silicates under subcritical conditions: Effect of the framework and interlayer space composition
dc.creator.none.fl_str_mv Chain, P.
Cota, Agustín
Pavón, Esperanza
Pazos, M. Carolina
Alba, María D.
author Chain, P.
author_facet Chain, P.
Cota, Agustín
Pavón, Esperanza
Pazos, M. Carolina
Alba, María D.
author_role author
author2 Cota, Agustín
Pavón, Esperanza
Pazos, M. Carolina
Alba, María D.
author2_role author
author
author
author
dc.subject.none.fl_str_mv Subcritical conditions
Hydrothermal 35 treatment
Rare-earth
Radioactive waste
Engineered barrier
X-ray diffraction
MAS-NMR
Disilicates
Bentonite
Smectite
topic Subcritical conditions
Hydrothermal 35 treatment
Rare-earth
Radioactive waste
Engineered barrier
X-ray diffraction
MAS-NMR
Disilicates
Bentonite
Smectite
description Clay-based minerals are considered to be an important component in backfill barriers due to both their ability to seal and adsorb radioactive waste and to interact chemically with it under subcritical conditions. Herein, we describe a systematic study of the properties of layered silicates that could affect their hydrothermal reactivity, namely type of layers, octahedral occupancy, origin and total amount of the layer charge, and nature of the interlayer cation. The silicates studied were selected on the basis of their different characteristics associated with these properties and were treated hydrothermally at 300 °C for 48 h in a 7.3 · 10− 2 M Lu(NO3)3 · 3.6H2O solution. The final products were analyzed by X-ray diffraction and solid-state NMR spectroscopy. All the layered silicates studied were found to be able to generate a Lu2Si2O7 phase after hydrothermal treatment under subcritical conditions, thereby confirming the participation of a chemical mechanism of the clay barrier generating phases being stables with temperature and pH conditions. However, the extent of this reaction depends to a large extent on the physicochemical properties of the framework and the interlayer space composition, such as the presence or absence of an octahedral sheet, the degree of occupancy of this sheet, and the origin and total layer charge. Therefore, this study allows tuning the clay mineral framework characteristic that favors the rare earth cations (as trivalent actinide simulator) immobilization.
publishDate 2013
dc.date.none.fl_str_mv 2013
2014
2014
2014
dc.type.none.fl_str_mv info:eu-repo/semantics/article
http://purl.org/coar/resource_type/c_6501
format article
dc.identifier.none.fl_str_mv http://hdl.handle.net/10261/97155
url http://hdl.handle.net/10261/97155
dc.language.none.fl_str_mv Inglés
language_invalid_str_mv Inglés
dc.rights.none.fl_str_mv info:eu-repo/semantics/openAccess
eu_rights_str_mv openAccess
dc.publisher.none.fl_str_mv Elsevier
publisher.none.fl_str_mv Elsevier
dc.source.none.fl_str_mv reponame:DIGITAL.CSIC. Repositorio Institucional del CSIC
instname:Consejo Superior de Investigaciones Científicas (CSIC)
instname_str Consejo Superior de Investigaciones Científicas (CSIC)
reponame_str DIGITAL.CSIC. Repositorio Institucional del CSIC
collection DIGITAL.CSIC. Repositorio Institucional del CSIC
repository.name.fl_str_mv
repository.mail.fl_str_mv
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score 15,811543

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