Investigation of the Effect of Milling Duration on a Ce-Gd Doped Zirconolite Phase Assemblage Synthesised by Hot Isostatic Pressing
Merve Kuman,
Laura J. Gardner,
Lewis R. Blackburn,
Martin C. Stennett,
Neil C. Hyatt,
Claire L. Corkhill
Affiliations
Merve Kuman
NucleUS Immobilisation Science Laboratory, Department of Materials Science and Engineering, University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield S1 3JD, UK
Laura J. Gardner
NucleUS Immobilisation Science Laboratory, Department of Materials Science and Engineering, University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield S1 3JD, UK
Lewis R. Blackburn
NucleUS Immobilisation Science Laboratory, Department of Materials Science and Engineering, University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield S1 3JD, UK
Martin C. Stennett
NucleUS Immobilisation Science Laboratory, Department of Materials Science and Engineering, University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield S1 3JD, UK
Neil C. Hyatt
NucleUS Immobilisation Science Laboratory, Department of Materials Science and Engineering, University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield S1 3JD, UK
Claire L. Corkhill
NucleUS Immobilisation Science Laboratory, Department of Materials Science and Engineering, University of Sheffield, Sir Robert Hadfield Building, Mappin Street, Sheffield S1 3JD, UK
Zirconolite is a candidate ceramic wasteform under consideration for the immobilisation of the UK civil PuO2 inventory. In the present work, a baseline dual-substituted zirconolite with the target composition (Ca0.783Gd0.017Ce0.2)(Zr0.883Gd0.017Ce0.1)(Ti1.6Al0.4)O7 was fabricated by hot isostatic pressing (HIPing). In order to optimise the microstructure properties and improve the obtained yield of the zirconolite phase, a range of planetary ball milling parameters were investigated prior to consolidation by HIP. This included milling the batched oxide precursors at 400 rpm for up to 120 min, the pre-milling of CeO2 (PuO2 surrogate) to reduce the particle size and using a CeO2 source with finer particle size (3-edge X-ray absorption spectroscopy was utilised to determine the Ce oxidation state. In this study, the ideal milling parameter for the fabrication of zirconolite waste forms was defined as 60 min at 400 rpm.
