Phosphate Capacity of CaO-SiO2-MnO-FeO Slag Saturated with MgO

The Phosphate capacity of CaO-SiO2-MnO-FeO slag saturated with MgO was analyzed at 1723 K. The main aim was to study the effect of basicity on the phosphate capacity and stability of phosphate ions present in the lime slag. The experiment were performed in an electric furnace equipped with SiC as a heating element and a mullite reaction tube. Fourier Transform Infrared (FT-IR) spectroscopy was applied to incorporate phosphorus into the silicate network. The excess free energy of P2O5 present in the lime-slag was used as a function of universal basicity index. Phosphate capacity was shown to be independent of the MnO to Sio2 ratio in lime slag it was only affected by the increased temperature, it increased as the temperature is increased. The results show that the stable phosphate ions in lime-based slag can be changed from monomeric to polymeric species as the basicity decreases and the MnSiO2 ratio changes in MnO-contaning slag does not affect the basicity to phosphate stability.