Hot Metal Dephosphorization Process using Solid Phase Precipitation

The importance of dicalcium silicate in slag has been highlighted for improvement in the reaction efficiency in the hot metal dephosphorization process. A new kinetic simulation model of hot metal dephosphorization was developed. This model considers the phosphorus partition between the liquid slag and the precipitated dicalcium silicate (C_2S) solid phase. The mass transfer between the liquid slag and the precipitated solid phase is also taken into account in addition to that between molten metal and liquid slag. The effect of the flux addition method on dephosphorization was calculated. The dephosphorization rate was considerably higher in the case of continuous addition because of the low PO_ content in the liquid slag due to the sweep out effect of C_2S. Although experiments to verify this model are necessary, this result has proved the possibility of increasing the dephosphorization rate by the precipitation of C_2S.報