Hafnium solubility determination in soda-lime aluminosilicate glass

Pierrick Chevreux (1, 2) , Annabelle Laplace (1) , Etienne Deloule (2) , Laurent Tissandier (2) , Nicolas Massoni (1)

1 DTCD - Département d'études du Traitement et du Conditionnement des Déchets
2 CRPG - Centre de Recherches Pétrographiques et Géochimiques

The solubility of hafnium dioxide (HfO 2), used as an uranium surrogate, is measured in glass melts belonging to the CaO-Al 2 O 3-SiO 2 and Na 2 O-CaO-Al 2 O 3-SiO 2 systems, under oxidizing and reducing conditions. Two methods have been carried out to determine it and the kinetic factors controlling the HfO 2 dissolution in glass melt have been investigated in order to approach equilibrium. The solubility ranges from 3 to 6.5 mol% HfO 2 in aluminosilicate glasses at temperature between 1250°C and 1400°C, and is not affected by the redox conditions. Conversely, the solubility is modified by the melting temperature and the glass composition. The excess of alkalies or alkaline earths which are not involved in the charge balance of AlO 4 tetrahedrons in the silica network appears to play a significant role. Glass homogeneity is checked by scanning electron microscopy and X-ray diffraction. O 7 are metastable crystals observed in the glass melts. The stability of those crystalline phases mainly depends on the glass composition.

Keywords: Hafnium oxide; solubility; aluminosilicate glass melt; reducing conditions; crystallization

Domains: Nuclear Theory [nucl-th]; Nuclear Experiment [nucl-ex]

Pierrick Chevreux, Annabelle Laplace, Etienne Deloule, Laurent Tissandier, Nicolas Massoni. Hafnium solubility determination in soda-lime aluminosilicate glass. Journal of Non-Crystalline Solids, 2017, 457, pp.13-24. ⟨10.1016/j.jnoncrysol.2016.11.009⟩. ⟨cea-02388996⟩