Crystallization behavior during melt-processing of ceramic waste forms

JOURNAL OF NUCLEAR MATERIALS

卷:473

Article

Tumurugoti, Priyatham¹  Sundaram, S. K.¹  Misture, Scott T.¹  Marra, James C.²  Amoroso, Jake² 

[1] Alfred Univ, New York State Coll Ceram, Kazuo Inamori Sch Engn, Alfred, NY 14802 USA

[2] Savannah River Natl Lab, Aiken, SC 29808 USA

关键词: Waste form;    Crystallization;    DSC;    XRD;    Melt processing;   

DOI  :  10.1016/j.jnucmat.2016.02.023

来源: Elsevier

【 摘 要 】

Multiphase ceramic waste forms based on natural mineral analogs are of great interest for their high chemical durability, radiation resistance, and thermodynamic stability. Melt-processed ceramic waste forms that leverage existing melter technologies will broaden the available disposal options for high-level nuclear waste. This work reports on the crystallization behavior in selected melt-processed ceramics for waste immobilization. The phase assemblage and evolution of hollandite, zirconolite, pyrochlore, and perovskite type structures during melt processing were studied using thermal analysis, x-ray diffraction, and electron microscopy. Samples prepared by melting followed by annealing and quenching were analyzed to determine and measure the progression of the phase assemblage. Samples were melted at 1500 degrees C and heat-treated at crystallization temperatures of 1285 degrees C and 1325 degrees C corresponding to exothermic events identified from differential scanning calorimetry measurements. Results indicate that the selected multiphase composition partially melts at 1500 degrees C with hollandite coexisting as crystalline phase. Perovskite and zirconolite phases crystallized from the residual melt at temperatures below 1350 degrees C. Depending on their respective thermal histories, different quenched samples were found to have different phase assemblages including phases such as perovskite, zirconolite and TiO2. Published by Elsevier B.V.

【 授权许可】

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