Effect of Initial [Si] Content on the Lime Efficiency on the Dephosphorization

Abstract

Hot metal dephosphorization slag is in the state in which solid and liquid coexist. However, in the previous reaction analysis, the contribution of solid phase is not taken into consideration in many cases because of the lack of thermodynamic and kinetic theory understanding. In this research, dephosphorization examination was conducted. In this examination the solid phase existing during the reaction was changed by changing initial concentration of Si in the hot metal. And relationship between type of solid phase in slag and dephosphorization efficiency was investigated.
The results are summarized as follows: The range of Δ [Si] exists where dephosphorization efficiency is improved. The dephosphorization reaction in a solid and liquid coexistence slag is greatly influenced by the solid phase that precipitates in the slag. Dephosphorization efficiency improves in the 2CaO·SiO₂ crystallizing range. This improvement can be explained by concentration of phosphorus in the solid phase.