1985 Volume 71 Issue 1 Pages 63-69
The experiments of the dephosphorization of liquid iron by Na2O-SiO2 flux containing Fe2O3 were carried out at temperatures of 1 550, 1 600 and 1 650°C, and kinetics of the reaction was studied.
The distribution ratio of phosphorus obtained from the experiments was expressed as follow :
log LP=log (%P)/[%P]=0.092(%Na2O)+2.5 log(%FetO)-3.79 (1 600°C)
The rate of dephosphorization was analysed on the assumption that the reaction was first order, and the reaction rate constant obtained was 0.12-2.40 ×10-2 cm/s. The apparent activation energy of the reaction obtained was 13-34 kcal/mol. The reaction rate constant showed a strong correlation with the distribution ratio of phosphorus obtained from the experiment.
The diffusion of phosphorus from slag-liquid iron interface to slag phase was considered as the ratedetermining step in the dephosphorization reaction.