Competition Between Internal and Surface Crystallization in Glass-ceramics Developed for Actinides Immobilization

2003 ◽  
Vol 807 ◽  
Author(s):  
Pascal Loiseau ◽  
Daniel Caurant ◽  
Odile Majerus ◽  
Nöel Baffier ◽  
Catherine Fillet
Keyword(s):  
Crystalline Phase ◽  
Treatment Duration ◽  
Preparation Method ◽  
Glass Ceramics ◽  
Minor Actinides ◽  
Surface Crystallization ◽  
Waste Forms ◽  
Trivalent Actinides ◽  
Structure And Microstructure ◽  
Ceramic Matrices

ABSTRACTGlass-ceramic matrices containing zirconolite (nominally CaZrTi2O7) as the only crystalline phase in their bulk can be considered as good candidates for actinide-rich nuclear wastes (containing minor actinides or Pu) immobilization. In this study, three different methods are envisaged and compared to prepare such waste forms using neodymium as trivalent actinides surrogate. Independently on the preparation method, zirconolite is shown to be the only crystalline phase to nucleate in the bulk. However, crystallization of silicate phases (titanite CaTiSiO5 + anorthite CaAl2Si2O8) can occur from samples surface and can compete with zirconolite crystallization. The effect of the crystal growth thermal treatment duration (2–300 h) at high temperature (1050–1200°C) on glass-ceramics structure and microstructure is studied. In the oxides system studied here, it appears that zirconolite is not thermodynamically stable in comparison with titanite but, for kinetics reasons, such transformation will not occur during waste forms disposal.

Low-temperature fabrication of glass-based iodine waste forms via a novel preparation method

2021 ◽  
pp. 122186
Author(s):  
Biao Wu ◽  
Meng Yan ◽  
Fen Luo ◽  
Xiaoyan Shu ◽  
Yi Liu ◽  
...  
Keyword(s):  
Low Temperature ◽  
Preparation Method ◽  
Waste Forms

Hot isostatically pressed Y2Ti2O7 and Gd2Ti2O7 pyrochlore glass-ceramics as potential waste forms for actinide immobilization

2019 ◽  
Vol 39 (4) ◽  
pp. 1546-1554 ◽  
Author(s):  
Tao Wei ◽  
Yingjie Zhang ◽  
Linggen Kong ◽  
Young Jip Kim ◽  
Alan Xu ◽  
...  
Keyword(s):  
Glass Ceramics ◽  
Waste Forms

Novel Glass-Ceramics for Dental Application by Sol Gel Technique

2008 ◽  
Vol 396-398 ◽  
pp. 153-156 ◽  
Author(s):  
Xanthippi Chatzistavrou ◽  
E. Hatzistavrou ◽  
Nikolaos Kantiranis ◽  
Lambrini Papadopoulou ◽  
Eleana Kontonasaki ◽  
...  
Keyword(s):  
Glass Ceramic ◽  
Preparation Method ◽  
Sol Gel ◽  
Glass Ceramics ◽  
Dental Restorations ◽  
Gel Technique ◽  
Gel Preparation ◽  
Dental Applications ◽  
Potential Use

The aim of this study was the fabrication using a sol-gel technique of a new glass-ceramic with potential use in dental applications. The characterization of the composition and microstructural properties of the produced material confirmed the similarity between the new sol-gel derived glass-ceramic and a commercial leucite based fluorapatite dental glass-ceramic. The produced material has potential application in dental restorations and it is expected to exhibit better control of composition, microstructure and properties due to the intrinsic advantages of the sol-gel preparation method.

Preparation of Glass-Ceramics Using Molybdenum Tailings

2011 ◽  
Vol 284-286 ◽  
pp. 1431-1434 ◽  
Author(s):  
Jin Rui Zhang ◽  
Ru Wang
Keyword(s):  
Heat Treatment ◽  
Thermal Analysis ◽  
Differential Thermal Analysis ◽  
Crystalline Phase ◽  
Glass Ceramics ◽  
Chemical Properties ◽  
The Other ◽  
Raw Material ◽  
Physical Chemical ◽  
Nucleation Agents

In order to utilization the molybdenum tailings which be deposited in large quantities. Test used it to prepare glass-ceramics as main raw material, TiO2 as nucleation agents and CaO-Al2O3-SiO2 system and wollastonite as the principal crystalline phase. Heat treatment system of glass-ceramics was based on the differential thermal analysis. The crystalline phase, microstructure and characteristics of glass-ceramics were analysis by XRD, SEM and physical, chemical properties test. The result shows that the performance of glass-ceramics was superior to the other types of building decoration stone.

HIPed Tailored Pyrochlore-Rich Glass-Ceramic Waste Forms for the Immobilization of Nuclear Waste

2008 ◽  
Vol 1124 ◽  
Author(s):  
Melody Lyn Carter ◽  
Hui Li ◽  
Yingjie Zhang ◽  
Andrew L Gillen ◽  
Eric R Vance
Keyword(s):  
Nuclear Waste ◽  
Glass Ceramic ◽  
Glass Ceramics ◽  
Spectroscopic Characterization ◽  
Chemical Durability ◽  
Intermediate Level ◽  
Crystalline Phases ◽  
Waste Forms ◽  
Ceramic Samples

AbstractHot isostatically pressed (HIPed) glass-ceramics for the immobilization of uranium-rich intermediate-level wastes and Hanford K-basin sludges were designed. These were based on pyrochlore-structured Ca(1-x)U(1+y)Ti2O7 in glass, together with minor crystalline phases. Detailed microstructural, diffraction and spectroscopic characterization of selected glass-ceramic samples has been performed, and chemical durability is adequate, as measured by both MCC-1 and PCT-B leach tests.

Crystallization Behavior and Microstructure of B2O3-Al2O3-SiO2 Glass-Ceramics

2008 ◽  
Vol 51 ◽  
pp. 149-154
Author(s):  
Han Ning Xiao ◽  
Tao Sun ◽  
Hua Bin Liu ◽  
Yin Cheng
Keyword(s):  
Activation Energy ◽  
Metal Oxides ◽  
Crystalline Phase ◽  
Crystallization Behavior ◽  
Glass Ceramics ◽  
Earth Metal ◽  
Crystallization Activation Energy ◽  
Alkali Earth Metal ◽  
Alkali Earth ◽  
Bulk Crystallization

The influences of B2O3/SiO2 ratio and different alkali earth metal oxides MO (M= Ba, Mg, Ca) on the crystallization behavior of B2O3-Al2O3-SiO2 (BAS) glass were investigated by means of DSC, XRD and SEM. With the reduction of B2O3/SiO2 ratio, the crystallization activation energy increases at first and then decreases, reaching the minimum value of 375.4 kJ·mol-1 when the B2O3/SiO2 ratio is 2.2. The crystalline indices (n) are all more than 4, which indicates that the glass is in bulk crystallization. When the glass was heated to 800°C, the primary precipitated crystalline phase was Al4B2O9. With the increase of temperature up to 1100°C, Al18B4O33 and Al5BO9 appeared and became the major crystalline phases in BAS glass-ceramics.

The local structure of gadolinium vanadate–tellurate glasses and glass ceramics: Te2V2O9 crystalline phase

2009 ◽  
Vol 20 (5) ◽  
pp. 801-805 ◽  
Author(s):  
Simona Rada ◽  
Maria Bosca ◽  
Eugen Culea ◽  
Marius Rada ◽  
Viorel Dan ◽  
...  
Keyword(s):  
Crystalline Phase ◽  
Local Structure ◽  
Glass Ceramics

Surface crystallization and phase evolution of BaO–SrO–TiO2–SiO2–Al2O3-based glass ceramics

2017 ◽  
Vol 130 (1) ◽  
pp. 221-228 ◽  
Author(s):  
M. Kosmal ◽  
M. Reben ◽  
P. Pichniarczyk ◽  
M. Ziąbka ◽  
S. J. Skrzypek
Keyword(s):  
Glass Ceramics ◽  
Phase Evolution ◽  
Surface Crystallization
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