Activity of MgO in CaO–SiO<sub>2</sub>–MgO–Al<sub>2</sub>O<sub>3</sub> Melts for Blast Furnace Slag at 1873 K

In this paper, slag-metal equilibrium experiments have been carried out for the determination of activity MgO in CaO–SiO2–MgO–Al2O3 melts blast furnace slag at T=1873 K using Sn as metal solvent and CaF2–MgO reference slag. Based on obtained experimental results, iso-activity contour system was plotted. The effects R(w(CaO)/w(SiO2)) w(MgO)/w(Al2O3) also discussed. R structure were analyzed by Fourier transform infrared spectroscopy (FT-IR). results show that when w(Al2O3)=20% w(MgO)/w(Al2O3)=0.50, increased with increase R. When R=1.30, w(MgO)/w(Al2O3). Through analysis FT-IR, amount free oxygen ions (O2−) increases or slag, these interact bridge (O0) silicate, resulting gradual depolymerization complex Si–O