Effect of Stirring Energy, Temperature and Flux Composition on Hot Metal Dephosphorization Kinetics

Abstract

In order to extend the applicability of a coupled reaction model to the hot metal dephosphorization process, evaluation method for unknown parameters was investigated. The following points were clarified. (1) Mass transfer coefficient in metal phase was increased in proportion to ∊1/2 and its activation energy was about 125 kJ/mol. (2) Ratio of mass transfer coefficient in metal phase to slag phase did not clearly depend on stirring energy, temperature, or flux composition. (3) Phenomenological rate parameter for CO evolution also did not clearly depend on stirring energy or flux composition but decreased with an increase in temperature. (4) Activity coefficients of FeO and P2O5 in CaF2 and CaCI2 containing oxide slag were able to be estimated by a regular solution model in which the interaction energy was expressed as a function of the CaF2, CaCI2 content. By the application of these results to the coupled reaction model, the change of concentration during the hot metal dephosphorization experiments was calculated without using a parameter fitting method. © 1991, The Iron and Steel Institute of Japan. All rights reserved.