抄録
Distribution equilibrium of phosphorous between silicon based alloys and CaO+Al2O3+SiO2 fluxes saturated with Al2O3 or calcium–aluminates was investigated at 1873 K. It was found that almost all the phosphorous in flux exist as phosphide ion: P3− in the experimental composition range. Distribution ratio of phosphorous between metal and flux: LP can be related to the flux composition. When the XCaO⁄(XCaO+XSiO2) ratio in flux increases from 0.38 to 0.85, log IP increases from −2 to 0.4. These experimental results suggest that the dephosphorization reaction expressed as: P(in Si)+(3/2)O2−(in Flux)=P3−(in Flux)+(3/4)O2(g) can proceed at the silicon refining by flux treatment and that the phosphorous removal process becomes more effective if the process is carried out under the conditions of high basicity, low oxygen potential, and high temperature.
