| Budget Amount *help |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1987: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1986: ¥1,200,000 (Direct Cost: ¥1,200,000)
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| Research Abstract |
In the almost smelting reaction, gas bubbles are inevitably formed and interfacial area of slag-metal reaction deviates from geometrical configuration of both phase. In order to precisely investigate the mechanism of slag-metal reaction, therefore, the roles of gas-metal and gas-slag interface can not be neglected for thinking of what is the rate controlling step.
In the present work, molten slag containing FeO or MnO was reacted with carbon bearing liquid iron in the thin crucible and the processes were followed by gas analysis using a quadrupole mass spectrometer. In addition, the change of three reaction interfaces of slag-metal, gas-metal, and gas-slag was observed by X-ray fluoroscopy. The X-ray image was enhanced by computer-aided image processor and respective two-dimentional interface was quantitavely determined in short time interval by means of following algorism: (a) Measurement of boundary length of each phase, L_S,L_M,L_G, (b) Calculation of respective interface, A_<S/M>,A_
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<S/G>,A_<G/M>, according to the equations of _<S/M>=t (L_S+L_M-L_G)/2, A_<S/G>=t (L_S-L_M+L_G)/2, A_<G/M>=t (-L_S+L_M+L_G)/2. Where, "t" denotes a inner thickness of crucible.
1. The microstructure of respective interface during slag-metal-gas reaction could be sharply observed by applying computer-aided image processing technique to the X-ray fluoroscopy. The cellular structure was found at slag-metal interface and bubble growth was seen to closely relate with the motion of cells.
2. It was found that carbon dioxide was included in the exhaust gas generated during the reduction of FeO or MnO reduction and Oxygen pressure of metal-gas interface was about ten times higher than that of slag-gas interface.
3. When the reduction rate of MnO was analysed by using the effective area of respective interface, it was suggested that gas-slag interface was determining the overall rate of reaction. On the other hand, in the reduction of FeO, especially in case of high FeO concentration, the rates might be governed by gas-metal reaction, namely Boudouard reaction. Less
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