Katsumi Mori1, Shoichi Hiwasa2 and Yasuji Kawai1
1Faculty of Engineering, Kyushu University, Fukuoka
The dissolution rate of oxygen into liquid iron at 1873 K was investigated by melting the iron under the FeO-CaO-SiO2 slags in the resistance or induction furnace and determining the oxygen content of iron samples taken at an appropriate time interval. The results are as follows:
(1) The oxygen content in the metal increased nearly exponetially with time. The reaction rate was increased by induction stirring and was deemed to be controlled by the mass transport steps.
(2) Using the two-film theory, overall mass-transfer coefficients were calculated to be 1.3∼4.3×10-3 kg/m2s for runs in the resistance furnace and 4.4∼7.6×10-3 kg/m2s in the induction furnace. The value of mass-transfer coefficient in the metal layer, km, was calculated to be 1.96×10-4 m/s from runs with liquid iron oxide slag and values of ks in the slag layer were 0.2∼3.1×10-5 m/s.
(3) From these values of km and ks it was found that the resistances to the mass transport both in the metal and slag layers were the same order and the reaction was controlled by both steps.
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