| About this Abstract |
| Meeting |
MS&T24: Materials Science & Technology
|
| Symposium
|
Glasses and Optical Materials: Current Issues and Functional Applications
|
| Presentation Title |
Investigation of the Alkali and Alkali-Earth Effect on Crystallization of SnO2 in LAW Glasses for WTP |
| Author(s) |
Arumala J. Lere-Adams, John McCloy |
| On-Site Speaker (Planned) |
Arumala J. Lere-Adams |
| Abstract Scope |
A simulant low-activity waste (LAW) base glass with varying mole fractions of Al2O3 and Na2O, and comparatively low molar amount of smaller cations as well as oxyanions is investigated to understand the deviation in crystal fractions of SnO2 (that can form when melter temps drop below 1100°C) by gradually replacing one alkali/alkaline earth cation by another (in this case Na with Ca). The forced crystallization of Al-containing phases is projected resulting in a residual glass more enriched with less-durable components (alkali and borate) in the starting melt. Powder XRD quantifies the target phase fraction while critical transition temperatures (Tg, Tc) are measured using differential scanning calorimetry (DSC). Down-selected glasses are isothermally heat treated to induce phase formation and canister centerline cooling (CCC) to model the melter process at the Waste Treatment and Immobilization Plant (WTP). The bond structure in the crystallized phases is investigated with Raman spectroscopy. |