1. Action of a clay suspension on an Fe(0) surface under anoxic conditions: Characterization of neoformed minerals at the Fe(0)/solution and Fe(0)/atmosphere interfaces
- Author
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Lise Salsi, Frédéric Villiéras, Sandrine Mathieu, Isabelle Bihannic, Camille Rivard, Odile Barres, Manuel Pelletier, Pierre Le Pape, Nicolas Michau, Sylvie Migot, Renaud Gley, Géosciences Paris Sud (GEOPS), Université Paris-Sud - Paris 11 (UP11)-Centre National de la Recherche Scientifique (CNRS), Département Caractérisation et Elaboration des Produits Issus de l'Agriculture (CEPIA), Institut National de la Recherche Agronomique (INRA), Laboratoire Interdisciplinaire des Environnements Continentaux (LIEC), Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Terre et Environnement de Lorraine (OTELo), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), GeoRessources, Institut national des sciences de l'Univers (INSU - CNRS)-Centre de recherches sur la géologie des matières premières minérales et énergétiques (CREGU)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Institut Jean Lamour (IJL), Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), Agence Nationale pour la Gestion des Déchets Radioactifs (ANDRA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Terre et Environnement de Lorraine (OTELo), Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS)-Institut Ecologie et Environnement (INEE), Centre National de la Recherche Scientifique (CNRS)-Centre National de la Recherche Scientifique (CNRS), European Synchrotron Radiation Facility (ESRF), and Université de Lorraine (UL)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS)
- Subjects
IRON CORROSION ,Materials science ,METALLIC IRON ,[SDU.STU.PE]Sciences of the Universe [physics]/Earth Sciences/Petrography ,GEOLOGICAL DISPOSAL CONDITIONS ,Microanalysis ,FE ,Autoclave ,chemistry.chemical_compound ,Geochemistry and Petrology ,[SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry ,Environmental Chemistry ,Suspension (vehicle) ,[SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces, environment ,TEMPERATURE ,[SDU.STU.AG]Sciences of the Universe [physics]/Earth Sciences/Applied geology ,FOIL method ,ComputingMilieux_MISCELLANEOUS ,Magnetite ,Mineral ,Metallurgy ,SMECTITE INTERACTION ,ARGILLITE ,Pollution ,Chemical engineering ,chemistry ,IN-SITU INTERACTION ,MULTITECHNIQUE ,Transmission electron microscopy ,[SDE]Environmental Sciences ,Clay minerals ,90 DEGREES-C ,[SDU.STU.MI]Sciences of the Universe [physics]/Earth Sciences/Mineralogy - Abstract
International audience; To better understand the reaction mechanisms involved at the Fe(0)/clay minerals interface, we investigate in the present study the reaction between an Fe(0) surface and a clay suspension extracted from the Callovo-Oxfordian claystone (COx). Batch experiments were carried out under anoxic conditions in sealed autoclave, at 90 degrees C to mimic predicted radioactive waste disposal conditions. An Fe(0) foil was introduced into the autoclave so that the lower part of the foil was immersed in the clay suspension while the upper part was contacted with the atmosphere of the experimental setup. After two months, the mineralogical deposits that precipitated at the surface of the Fe(0) foil were analyzed using multiple techniques, namely X-ray diffraction (XRD), scanning/transmission electron microscopy associated to microanalysis (SEM/TEM-EDXS), and micro-spectroscopic measurements (l-FTIR and l-Raman). Both parts of the Fe(0) foil were then shown to react: magnetite was the main resulting mineral formed at the Fe(0) surface in the atmospheric conditions whereas serpentine 1:1 phyllosilicates were the main end-products in the clay suspension. The analyses performed on the immersed part of the foil revealed a spatial heterogeneity in both serpentine cristallochemistry and morphology, with a gradient from the Fe(0) contact point toward the clay suspension. A pure Fe-Si phyllosilicate ring was observed at the direct contact point with the Fe(0) foil and a progressive incorporation of Al instead of Fe into the clay phases was identified as deposit thickness increased from the Fe(0) surface to the clay suspension. Our findings suggest that reaction mechanisms include several steps, corresponding to successive regimes depending on the availability of the main reactive elements at the Fe(0)/solution interface, namely Fe, Si and Al. Thus, our results provide new information to support the understanding of both mineral organization and composition at the clay/Fe(0) interface.
- Published
- 2015
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