1997 Volume 37 Issue 10 Pages 929-935
A mathematical model describing the simultaneous reactions in multi components system, such as hot metal pretreatment in which bulk flow from the bulk to the slag metal interface occurs, is proposed in order to exactly evaluate the mass transfer in the boundary films resulting from diffusion and that from bulk flow, respectively. This model, furthermore, allows accurate estimation of interfacial concentrations and of chemical reactions at interface.
The model is applied to the experimental data reported in literatures considering the mass transfer in slag phase, that of in metal phase, and chemical reaction at slag metal interface as the rate controlling steps. The determined kinetic parameters in this model lead to the following conclusions;
(1) To describe the decarburization rate, it is necessary to take the retarding phenomena at high interfacial oxygen partial pressure into consideration.
(2) The chemical reaction resistance of silicon reaction should be considered.
(3) The stirring of the bath by bottom blowing gas tends to accelerate the mass transfer in the metal phase more than that of the slag phase, compared with that by mechanically rotated rod.
