Dephosphorization tests of chromium containing molten iron by CaO-based flux have been carried out by an induction furnace. The following results were obtained: (1) When the carbon content in metal was high enough, chromium containing molten iron was able to be dephosphorized by CaO-CaF2-FeO flux. In this case, oxygen partial pressure at the slag and metal interface was calculated to be about 10-12Pa. (2) The higher ratio of CaF2/(CaO + CaF2) and of CaO/O in flux were effective for the dephosphorization without the oxidization of chromium. Based on these results, 200 ton scale industrial tests have been carried out by the hot metal pretreatment station at Yawata Works. By the combination of the flux injection method and the oxygen top blowing method, it was clarified that the dephosphorization without chromium oxidation and the suppression of temperature drop were able to be achieved simultaneously.
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