A manganese distribution prediction model for CaO–SiO 2 –FeO–MgO–MnO–Al 2 O 3 slags based on IMCT

Abstract

A thermodynamic model for predicting manganese distribution ratio L _Mn and manganese capacity C _Mn of CaO–SiO₂–FeO–MgO–MnO–Al₂O₃ slags, i.e. IMCT-L _Mn and IMCT-C _Mn models, has been developed by using a thermodynamic model for calculating mass action concentration of ion couples or structural units in the slags based on the ion–molecule coexistence theory (IMCT). The developed IMCT-L _Mn and IMCT-C _Mn models have been verified with the experiment results of CaO–SiO₂–FeO–MgO–MnO–Al₂O₃, CaO–SiO₂–MgO–FeO–Fe₂O₃–MnO–P₂O₅, CaO–SiO₂–MgO–FeO–Fe₂O₃–MnO–Al₂O₃–P₂O₅ slags reported by different researchers, a total of 200 industrial measurements with large compositional variations and predicted results by summarised five L _Mn models and two C _Mn models. The developed thermodynamic model for calculating manganese distribution ratio can determine quantitatively the respective manganese distribution ratio L _Mn,i and the respective manganese capacity C _Mn,i of four demanganisation products as MnO, , and . A significant difference of demanganisation abilities among FeO, FeO + Al₂O₃ and FeO + SiO₂ can be found as 98, 1.8 and 0.2%. By comparing binary and complex basicity, the optical basicity is recommended to describe the relationship between basicity and manganese distribution ratio. With the aid of the current model, the co-effects of the ratio and optical basicity on the L _Mn and C _Mn of CaO–SiO₂–FeO–MgO–MnO–Al₂O₃ slags are investigated.