Analysis of Dephosphorization Reaction Using a Simulation Model of Hot Metal Dephosphorization by Multiphase Slag

In most cases, the slag used in hot metal dephosphorization is saturated with dicalcium silicate in the solid phase and the partition ratio of phosphorus between dicalcium silicate and the liquid slag is high. This indicates the important role of clicalcium silicate in dephosphorization. To understand the reaction kinetics and identify optimum treatment conditions, it is very important to know the influence of the solid phases in the slag. In this study, a new reaction model for hot metal dephosphorization that considers the effects of dicalcium silicate and the dissolution rate of lime is applied to simulate laboratory-scale experiments. The calculated results are in good agreement with the experimental results for various slag compositions and methods of flux and oxidizer addition. The influence of various factors on the reaction efficiency is discussed using this simulation model. The optimum basicity and combination of stirring energy and oxidizer supply rate are found. The importance of the precipitation behavior of the solid phase in slag is clarified.