Chavda, M.A., Kinoshita, H. and Provis, J.L. orcid.org/0000-0003-3372-8922 (2014) Phosphate modification of calcium aluminate cement to enhance stability for immobilisation of metallic wastes. Advances in Applied Ceramics, 113 (8). pp. 453-459. ISSN 1743-6753
Abstract
Cementing systems based on calcium aluminate cement (CAC) have been studied as an alternative cement matrix for the encapsulation of intermediate level wastes (ILWs) arising from the nuclear industry. Calcium aluminate cement based systems have great potential for the incorporation of aluminium containing ILW owing to the near neutral internal pH of these binders. However, CAC based binders usually undergo phase conversion from the metastable hydration phases C3AH6 and/or C2AH8 to the stable C3AH6, resulting in strength regression and dimensional instability. The present study investigates the feasibility of CAC modification to prevent this detrimental process of phase conversion. Two different types of sodium phosphates are used to modify a CAC system, and the setting behaviour and the mineralogy of the binder products were studied. It is shown that it is possible to avoid the conventional phase conversion of CAC hydrates due to the formation of an amorphous aluminate phase in place of the metastable hydrates, leading to the production of a phase assemblage, which is stable for at least 180 days.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2014 Institute of Materials, Minerals and Mining. This is an author produced version of a paper subsequently published in Advances in Applied Ceramics. Uploaded in accordance with the publisher's self-archiving policy. |
Keywords: | Calcium aluminate cement; Phosphate; Conversion; Inhibition; TGA; XRD |
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) |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 25 Apr 2016 14:46 |
Last Modified: | 25 Apr 2016 14:55 |
Published Version: | http://dx.doi.org/10.1179/1743676114Y.0000000147 |
Status: | Published |
Publisher: | Taylor & Francis |
Refereed: | Yes |
Identification Number: | 10.1179/1743676114Y.0000000147 |
Related URLs: | |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:97726 |