Oxidization mechanism in CaO-FeOx-SiO2 slag with high iron content was investigated by blowing oxygen into molten slag so as to oxidize Fe（Ⅱ）. The relationship between Fe（Ⅱ） content and oxidizing time at differe...Oxidization mechanism in CaO-FeOx-SiO2 slag with high iron content was investigated by blowing oxygen into molten slag so as to oxidize Fe（Ⅱ）. The relationship between Fe（Ⅱ） content and oxidizing time at different temperatures was obtained by chemical analysis. Microstructure of slag was observed by metallographic microscope and SEM. Phases compositions were ascertained by EDXS and XRD. Grain size and crystallizing quantity of magnetite（Fe3O4） were determined by image analyzer. The oxidizing kinetic equations were deduced. Confirmed by graphical construction method, Fe（Ⅱ） oxidizing reaction in CaO-FeOx-SiO2 slag system is of first order, and the reaction apparent energy Ea is 296.67kJ/mol in the pure oxygen and 340.30kJ/mol in air. The enrichment and crystal growth mechanism of magnetite（Fe3O4） phases were investigated. In oxidizing process, content of fayalite declines, while that of magnetite（Fe3O4） increases, and iron resources enrich into magnetite（Fe3O4） phase. All these provide a theoretical base for compressive utilizing of those slags.展开更多
The isothermal oxidation behavior and mechanism of the TiC-TiB2 multiphase ceramics fabricated by self-propagating high temperature synthesis were studied.The result shows that the oxidation kinetics agrees to the par...The isothermal oxidation behavior and mechanism of the TiC-TiB2 multiphase ceramics fabricated by self-propagating high temperature synthesis were studied.The result shows that the oxidation kinetics agrees to the parabolic rule within the temperature rang of RT to 1000℃. First at 600℃ TiB2 was oxidized to be TiO2. Then both TiB2 and TiC were oxidized to be TiO2 when temperature increased to 1000℃. A compact TiO2 film, the oxidation product, formed on the sample surface, which prevented further oxidation and resulted in a very high oxidation resistance of the sample.展开更多
基金Key Project(50234040) supported by the National Natural Science Foundation of China
文摘Oxidization mechanism in CaO-FeOx-SiO2 slag with high iron content was investigated by blowing oxygen into molten slag so as to oxidize Fe（Ⅱ）. The relationship between Fe（Ⅱ） content and oxidizing time at different temperatures was obtained by chemical analysis. Microstructure of slag was observed by metallographic microscope and SEM. Phases compositions were ascertained by EDXS and XRD. Grain size and crystallizing quantity of magnetite（Fe3O4） were determined by image analyzer. The oxidizing kinetic equations were deduced. Confirmed by graphical construction method, Fe（Ⅱ） oxidizing reaction in CaO-FeOx-SiO2 slag system is of first order, and the reaction apparent energy Ea is 296.67kJ/mol in the pure oxygen and 340.30kJ/mol in air. The enrichment and crystal growth mechanism of magnetite（Fe3O4） phases were investigated. In oxidizing process, content of fayalite declines, while that of magnetite（Fe3O4） increases, and iron resources enrich into magnetite（Fe3O4） phase. All these provide a theoretical base for compressive utilizing of those slags.
文摘The isothermal oxidation behavior and mechanism of the TiC-TiB2 multiphase ceramics fabricated by self-propagating high temperature synthesis were studied.The result shows that the oxidation kinetics agrees to the parabolic rule within the temperature rang of RT to 1000℃. First at 600℃ TiB2 was oxidized to be TiO2. Then both TiB2 and TiC were oxidized to be TiO2 when temperature increased to 1000℃. A compact TiO2 film, the oxidation product, formed on the sample surface, which prevented further oxidation and resulted in a very high oxidation resistance of the sample.
