Baqer, Y orcid.org/0000-0002-1195-8797, Chen, X orcid.org/0000-0002-2053-2448, Rochelle, C et al. (1 more author) (2020) Modelling of multi-minerals kinetic evolution in hyper-alkaline leachate for a 15-year experiment. Environmental Science and Pollution Research, 27. pp. 35604-35617. ISSN 0944-1344
Abstract
Cement has been widely used for low- to intermediate-level radioactive waste management; however, the long-term modelling of multiple mineral transfer between the cement leachate and the host rock of a geological disposal facility remains a challenge due to the strong physical-chemical interactions within the chemically disturbed zone. This paper presents a modelling study for a 15-year experiment simulating the reaction of crystalline basement rock with evolved near-field groundwater (pH = 10.8). A mixed kinetic equilibrium (MKE) modelling approach was employed to study the dolomite-rich fracture-filling assemblage reacting with intermediate cement leachate. The study found that the mineralogical and geochemical transformation of the system was driven by the kinetically controlled dissolution of the primary minerals (dolomite, calcite, quartz, k-feldspar and muscovite). The initial high concentration of calcium ions appeared to be the main driving force initiating the dedolomitization process, which played a significant role in the precipitation of secondary talc, brucite and Mg-aluminosilicate minerals. The modelling study also showed that most of the initially precipitated calcium silicon hydrate phases redissolved and formed more stable calcium silicon aluminium hydrate phases. The findings highlight the importance of a deep and insightful understanding of the geochemical transformations based on the type and characteristics of the host rock, where the system is under out of equilibrium conditions, and the rates of mineral reactions.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © Springer-Verlag GmbH Germany, part of Springer Nature 2020. This is an author produced version of an article published in Environmental Science and Pollution Research. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | Cement; Radioactive waste disposal; Mineral evolution; Modelling; Cement leachate; Alkaline fluids; PHREEQC |
Dates: |
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Institution: | The University of Leeds |
Academic Units: | The University of Leeds > Faculty of Engineering & Physical Sciences (Leeds) > School of Civil Engineering (Leeds) |
Depositing User: | Symplectic Publications |
Date Deposited: | 07 Jul 2020 14:08 |
Last Modified: | 29 Jun 2021 00:38 |
Status: | Published |
Publisher: | Springer |
Identification Number: | 10.1007/s11356-020-09875-x |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:162890 |