Mason, A.R., Tocino, F.Y., Stennett, M.C. orcid.org/0000-0002-8363-9103 et al. (1 more author) (2020) Molten salt synthesis of Ce doped zirconolite for the immobilisation of pyroprocessing wastes and separated plutonium. Ceramics International, 46 (18 (A)). pp. 29080-29089. ISSN 0272-8842
Abstract
Molten salt mediated synthesis of zirconolite Ca0.9Zr0.9Ce0.2Ti2O7 was investigated, as a target ceramic matrix for the clean-up of waste molten salts from pyroprocessing of spent nuclear fuels and the immobilisation of separated plutonium. A systematic study of reaction variables, including, reaction temperature, time, atmosphere, reagents and composition, was made to optimise the yield of the target zirconolite phase. Zirconolite 2 M and 3T polytypes were formed as the major phase (with minor perovskite) between 1000 – 1400 °C, in air, with the relative proportion of 2 M polytype increasing with temperature. Synthesis under 5% H2/N2 or Ar increased the proportion of minor perovskite phase and reduced the yield of the zirconolite phase. The yield of zirconolite polytypes was maximised with the addition of 10 wt% TiO2 and 5 wt% TiO2, yielding 91.7 ± 2.0 wt% zirconolite, primarily as the 2 M polytype, after reaction at 1200 °C for 2 h, in air. The particle size and morphology of the zirconolite product bears a close resemblance to that of the TiO2 precursor, demonstrating a dominant template growth mechanism. Although the molten salt mediated synthesis of zirconolite is effective at lower reaction temperature and time, compared to reactive sintering, this investigation has demonstrated that the approach does not offer any clear advantage with over conventional reactive sintering for the envisaged application.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2020 Published by Elsevier Ltd. This is an author produced version of a paper subsequently published in Ceramics International. Uploaded in accordance with the publisher's self-archiving policy. Article available under the terms of the CC-BY-NC-ND licence (https://creativecommons.org/licenses/by-nc-nd/4.0/). |
Keywords: | Nuclear applications (E); Spectroscopy (B); Molten salt synthesis |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Engineering (Sheffield) > Department of Materials Science and Engineering (Sheffield) |
Funding Information: | Funder Grant number EPSRC EP/L015390/1 ENGINEERING AND PHYSICAL SCIENCE RESEARCH COUNCIL EP/S011935/1 ENGINEERING AND PHYSICAL SCIENCE RESEARCH COUNCIL EP/N017870/1 NUCLEAR DECOMMISSIONING AUTHORITY UNSPECIFIED ENGINEERING AND PHYSICAL SCIENCE RESEARCH COUNCIL (EPSRC) UNSPECIFIED |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 27 Aug 2020 10:04 |
Last Modified: | 26 Jan 2022 10:31 |
Status: | Published |
Publisher: | Elsevier BV |
Refereed: | Yes |
Identification Number: | 10.1016/j.ceramint.2020.08.080 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:164861 |