Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7963234 | Journal of Nuclear Materials | 2018 | 41 Pages |
Abstract
In order to immobilize high-level radioactive graphite, silicon carbide based composite materials{ (1-x) SiC· x MgAl2O4 (0.1â¯â¤â¯xâ¤0.4) } were fabricated by solid-state reaction at 1370â¯Â°C for 2â¯h in vacuum. Residual graphite and precipitated corundum were observed in the as-synthesized product, which attributed to the interface reaction of element silicon and magnesium compounds. To further understand the reasons for the presence of graphite and corundum, the effects of mole ratio of Si/C, MgAl2O4 content and non-stoichiometry of MgAl2O4 on the synthesis were investigated. To immobilize graphite better, residual graphite should be eliminated. The target product was obtained when the mole ratio of Si/C was 1.3:1, MgAl2O4 content was xâ¯=â¯0.2, and the mole ratio of Al to Mg in non-stoichiometric MgAl2O4 was 1.7:1. In addition, the interface reaction between magnesium compounds and silicon not graphite was displayed by conducting a series of comparative experiments. The key factor for the occurrence of interface reaction is that oxygen atom is transferred from magnesium compound to SiO gas. Infrared and Raman spectrum revealed the increased disorders of graphite after being synthesized.
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Physical Sciences and Engineering
Energy
Nuclear Energy and Engineering
Authors
Qing Wang, Yuancheng Teng, Lang Wu, Kuibao Zhang, Xiaofeng Zhao, Zhuang Hu,