Evolution of chromium, manganese and iron oxidation state during conversion of nuclear waste melter feed to molten glass

0532743 - ÚSMH 2021 RIV NL eng J - Článek v odborném periodiku
Guillen, D.P. - Lee, S. - Hrma, P. - Traverso, J. - Pokorný, Richard - Kloužek, Jaroslav - Kruger, A.A.
Evolution of chromium, manganese and iron oxidation state during conversion of nuclear waste melter feed to molten glass.
Journal of Non-Crystalline Solids. Roč. 531, MAR 1 (2020), č. článku 119860. ISSN 0022-3093. E-ISSN 1873-4812
Institucionální podpora: RVO:67985891
Klíčová slova: Vitrification * X-ray near-edge spectroscopy * X-ray diffraction * Evolved gas analysis * Feed expansion tests * Oxidation state
Obor OECD: Ceramics
Impakt faktor: 3.531, rok: 2020
Způsob publikování: Omezený přístup
https://www.sciencedirect.com/science/article/abs/pii/S0022309319307306?via%3Dihub

Oxidation state and chemical conversion of three surrogate nuclear high-level waste melter feeds heat treated to temperatures between 500 and 1200 degrees C were studied using X-ray near-edge structure, feed expansion tests, X-ray diffraction, and evolved gas analyses. For the high-chromium feed (3.00 mass% Cr2O3 in glass), the average Cr oxidation state was predominately Cr3+ at the lowest and highest heat-treatment temperatures and Cr6+ at intermediate temperatures while the Fe coordination shifted from octahedral to non-centrosymmetric tetrahedral at higher temperatures with Fe oxidation state unchanged. For the high-manganese-high-iron feed (3.23 mass% MnO and 16.01 mass% Fe2O3 in glass), the average Mn oxidation state decreased from 4 to similar to 2 while the Fe oxidation state shifted towards increasing ferrous content and changed from five-fold coordination to tetrahedral. For the high-alumina feed (24.02 mass% Al2O3 in glass), average Fe coordination did not change, but Fe oxidation state shifted towards higher ferrous content with increasing temperature.
Trvalý link: http://hdl.handle.net/11104/0312375