Phosphorous partition between 2CaO·SiO2 particles and CaO-SiO2-FetO slags

Abstract

The behavior of phosphorous transfer from P2O 5-containing CaO-SiO2-FetO slags to 2CaO · SiO2 particles homogeneously dispersed in slag has been studied by using a microprobe analysis. The maximum phosphorus distribution ratio between 2CaO · SiO2 particle and slag is obtained at the nose composition of 2CaO · SiO2 primary phase region in CaO-SiO2-FetO phase diagram and the temperature dependence of this distribution ratio is small. The phosphorous transfer rate from slag to a 2CaO · SiO2 particle with 20 to 50 μm is considerably fast and a 2CaO · SiO2 particle changes to the particle with the composition of 2CaO · SiO2-3CaO · P 2O5 solid solution within 5 s. In the case of particles present in cluster, only the rim part (5 μm) of a particle changes to the composition of 2CaO · SiO2-3CaO · P2O 6 solid solution within 5 s, but small size particles with 3 to 8 μm completely change to the particles with the composition of 2CaO · SiO2-3CaO · P2O5 solid solution within 5 s. © 2006 ISIJ.