Mechanism of Dephosphorization with CaO–SiO₂–Fe_tO Slags Containing Mesoscopic Scale 2CaO·SiO₂ Particles

Abstract

Dephosphorization of a liquid Fe–5mass%P alloy with a solid–liquid coexisting flux in which 2CaO·SiO₂ particles (20 to 50 µm) are uniformly dispersed in CaO–SiO₂–Fe_tO slags has been studied at 1 400°C. For the slag with high SiO₂ and low T.Fe contents, the change of slag composition is small and the fraction of 2CaO·SiO₂ particles to slag increases slightly during dephosphorization in which the L_p^solid/slag and L_p^slag/metal values are low. For the slag with moderate SiO₂ and high T.Fe contents, the change of slag composition is considerable and the fraction of 2CaO·SiO₂ particles to slag increases considerably during dephosphorization in which the L_p^solid/slag and L_p^slag/metal values are high at initial period, but these values decrease with time. For the slag with low SiO₂ and high T.Fe contents, the change of slag composition is small and the fraction of 2CaO·SiO₂ particles to slag decreases slightly during dephosphorization in which the L_p^slag/metal and L_p^solid/slag values are high, but L_p^solid/slag value decreases considerably even with small change of slag composition.