| Budget Amount *help |
¥1,900,000 (Direct Cost: ¥1,900,000)
Fiscal Year 1986: ¥400,000 (Direct Cost: ¥400,000)
Fiscal Year 1985: ¥1,500,000 (Direct Cost: ¥1,500,000)
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| Research Abstract |
In the pretreatment of hot metal by soda ash, the reaction between soda and carbon always proceeds as a side reaction and influences the progress of dephosphorization and desulfurization of hot metal. However, the corelation between these reactions has not been sufficiently understood from the viewpoint of reaction kinetics.
In the present work, the effects of carbon and silica on the rate of dephosphorization of hot metal by soda ash were investigated by examining the change in the composition of both the metal and the gas evolved during a run. The results obtained are as follows:
In the reaction between soda ash and Fe-C melt, soda ash was reduced partly to Na vapor and the gases evolved contained only CO.
For Fe-P-C melts, the dephosphorization proceeded preferentially and the decarburization began after the metal phosphorus content decreased down to 0.05%. The increase in the flux amount from 5 g to 9 g resulted in the increased dephosphorization, but further increase in the flux amount to 15 g produced only the increase of the rate of decarburization.
While, the gases evolved during the period of dephosphorization contained 4 to 6 % <CO_2> and about 50% CO, from which the partial pressure of oxygen was calculated to be <10^(-11)> atm.
When silica was added to the flux, 40 to 60% of <CO_2> and several percent of CO were detected in the gases. This result showed that the reaction between soda ash and silica proceeded so fast and <CO_2> gas produced in the bulk of flux was not utilized for the dephosphorization and the decarburization of hot metal.
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