Weathering of an argillaceous rock in the presence of atmospheric conditions: A flow-through experiment and modelling study

Autor: Clémence Fauchet, Nicolas C.M. Marty, Joachim Tremosa, Francis Claret, M. Lundy, Christophe Tournassat, Benoît Madé, Adeline Lach, Sylvain Grangeon, Catherine Lerouge
Přispěvatelé: Bureau de Recherches Géologiques et Minières (BRGM) (BRGM), Agence Nationale pour la Gestion des Déchets Radioactifs (ANDRA), Institut de Physique du Globe de Paris (IPGP), Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-IPG PARIS-Université Paris Diderot - Paris 7 (UPD7)-Université de La Réunion (UR)-Centre National de la Recherche Scientifique (CNRS)
Jazyk: angličtina
Rok vydání: 2018
Předmět:
010504 meteorology & atmospheric sciences
[SDU.STU.GP]Sciences of the Universe [physics]/Earth Sciences/Geophysics [physics.geo-ph]
Dolomite
Geochemistry
Carbonate minerals
[SDU.STU]Sciences of the Universe [physics]/Earth Sciences
Weathering
engineering.material
010502 geochemistry & geophysics
01 natural sciences
chemistry.chemical_compound
Geochemistry and Petrology
[SDU.STU.GC]Sciences of the Universe [physics]/Earth Sciences/Geochemistry
Environmental Chemistry
[SDU.ENVI]Sciences of the Universe [physics]/Continental interfaces
environment
Dissolution
ComputingMilieux_MISCELLANEOUS
0105 earth and related environmental sciences
Calcite
Radioactive waste
Pollution
Tailings
chemistry
engineering
Environmental science
Pyrite
[SDU.STU.MI]Sciences of the Universe [physics]/Earth Sciences/Mineralogy
Zdroj: Applied Geochemistry
Applied Geochemistry, Elsevier, 2018, 96, pp.252-263. ⟨10.1016/j.apgeochem.2018.07.005⟩
ISSN: 0883-2927
Popis: The construction of a repository for high-level radioactive waste (HLW) in a deep clay formation will produce large volumes of excavated rock that must be stored of at the surface. This material will be weathered for decades to century, and its evolution with time must be assessed in order to decide on its future technological use (i.e. backfill materials of HLW repository) and to evaluate its impact on the surrounding environment (e.g. acid drainage). Predictive modelling that required a consistent set of kinetic data must be used for such evaluation. To this end, the kinetics of mineralogical transformations were investigated on an argillaceous rock from the tailings stored at the surface of an underground research laboratory (Callovian-Oxfordian – COx – argillaceous rock, Bure, France). Mineralogical analysis and flow-through experiments were combined in order to quantify the oxidation kinetics of this material. Deionized water was brought into equilibrium with the atmosphere and was percolated through a suspension of powdered COx rock. Examination of the samples prior to and after the experiments showed that the main transformations were pyrite oxidation associated with calcite and dolomite dissolution. The acidity produced by pyrite oxidation was totally buffered by the dissolution of carbonate minerals that in turn affected the composition of the clay exchanger. Geochemical modelling was used to confirm the relevance of a selected mineralogical assemblage with associated kinetic parameters in order to evaluate the extent of COx rock weathering with time.
Databáze: OpenAIRE
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