Assessment of P2O5 Activity Coefficients in Molten Slags.

Abstract

From a critical review of the existing experimental data, the free energy equations are presented. A new estimate is made of the standard free energy of formation of the hypothetical pure liquid P2O5, which is used in calculating the P2O5 activity coefficients from the experimental data of independent studies of slag–metal reactions. It is found that in low P2O5 slags, log( γP2O5) is a linear function of CaO from 0 to 60%, independent of temperature. Whereas, in slags containing P2O5 > 10%, log(γP2O5) is a linear function of CaO content > 40% only and increases with an increasing temperature. A novel concept of a slag–P2O5 emf sensor is presented for experimental evaluation.