Effect of Fe2O3/ZnO on Two Glass Compositions for Solidification of Swedish Nuclear Wastes

Autor: Larry L. Hench, J. L. Nogues
Rok vydání: 1981
Předmět:
Zdroj: MRS Proceedings. 11
ISSN: 1946-4274
0272-9172
DOI: 10.1557/proc-11-273
Popis: Replacement of half of the ZnO in an alkali-zinc-borosilicate nuclear waste glass with Fe2O3 degrades leach resistance by approximately a factor of 3. Leach rates for the higher ZnO containing glass after 28 days are generally in the range of 5.10−5 g.cm−2.d−1 for B3+, Al3+, Mo6+; 2.10−5 g.cm−2.d for Na+, Si4+; and 2 to 7.10−6 g.cm−2.d−1 for Fe3+ and Zn2+. The surface of both types of glass appears to be protected by dual protective layers, one rich in SiO2 and a second very thin film rich in multivalent species. The second film that contains a mixture of Zn and Fe is less effective as a diffusion barrier and is less resistant to network breakdown than the film without the Fe3+. This apparently is because a critical concentration of multivalence species is necessary to stabilize the second protective film. Differences in SA/V ratios affect the formation of the protective films and the rates of surface damage of the glass.
Databáze: OpenAIRE
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