A Consideration of Thermodynamic Properties of Binary Liquid Alloys with Negative Deviation of Activities from Raoult’s Law based on Associated Solution Model

Thermodynamic models for predicting dephosphorisation ability and potential of CaO–FeO–Fe2O3–Al2O3–P2O5slags during secondary refining process of molten steel based on ion and molecule coexistence theory

“…Actually, the classical hypotheses of the IMCT 30,31,[34][35][36][37][38][39][40][41] are to some degree similar with those of the associated solution model, [70][71][72][73][74][75] especially the ideal associated solution model. 70,71 The defined N i of the structural unit i or ion couple (Me 2þ þ O 22 ) in slags by equation (3) based on the IMCT looks like the defined activity a R, i by the molecular theory.…”

Coupling relationship between dephosphorisation and desulphurisation abilities or potentials for CaO–FeO–Fe2O3–Al2O3–P2O5slags over a large variation range of slag oxidisation ability during secondary refining process of molten steel

“…It has been pointed out by Yang et al 53 that classical hypotheses of the IMCT are to some degree similar with those of the associated solution model, [65][66][67][68] especially the ideal associated solution model. 69,70 The thermodynamic models for predicting dephosphorisation ability 53 and potential 53 as well as desulphurisation ability 54 and potential 55 of CaO-FeO-Fe 2 O 3 -Al 2 O 3 -P 2 O 5 slags equilibrated with liquid iron have been developed based on the IMCT according to the original experimental data from Ban-ya et al 20 Under this circumstance, the coupling relationship between dephosphorisation and desulphurisation abilities or potentials for the slags equilibrated with liquid iron has been proposed through deleting slag oxidisation ability expressed by the comprehensive mass action concentration N FetO of iron oxides and verified in the first part of this seriate study. The influences of slag chemical composition including reaction abilities of components described by the mass action concentration N i , slag basicity, and the comprehensive influence of iron oxides Fe t O and basic oxide CaO on the proposed coupling relationships between dephosphorisation and desulphurisation abilities or potentials for the slags in reducing and oxidising zones will be further investigated.…”

“…53 that classical hypotheses of the IMCT are to some degree similar with those of the associated solution model, 65–68 especially the ideal associated solution model. 69,70 The thermodynamic models for predicting dephosphorisation ability 53 and potential 53 as well as desulphurisation ability 54 and potential 55 of CaO–FeO–Fe 2 O 3 –Al 2 O 3 –P 2 O 5 slags equilibrated with liquid iron have been developed based on the IMCT according to the original experimental data from Ban-ya et al . 20 Under this circumstance, the coupling relationship between dephosphorisation and desulphurisation abilities or potentials for the slags equilibrated with liquid iron has been proposed through deleting slag oxidisation ability expressed by the comprehensive mass action concentration of iron oxides and verified in the first part of this seriate study.…”

“…89,90 that oxygen potential of slags greater than 10 −13 Pa results in formation of phosphate in slags, whereas under more reducing conditions, phosphide will account for most of phosphorus in slags. The formation reaction of phosphate or phosphide in slags can be described by 89,90 The defined phosphate capacity by Wagner 35 based on gas–slag dephosphorisation equilibrium reaction in equation (A1) can be described as 89,90 Similar to the defined phosphate capacity by Wagner, 35 phosphide capacity can also be defined according to gas–slag dephosphorisation equilibrium reaction in equation (A2) as 89,90 The oxygen potential of metallurgical slags is controlled by (Fe t O)–{O 2 } equilibrium reaction as 70–73 It has widely been verified and accepted that the determined oxygen potential of metallurgical slags by equation (A5) is usually much greater than 10 −13 Pa. Thus, phosphorus in metallurgical slags will exist as monomer phosphate , rather than phosphide , under the condition of phosphorus content in slags not high enough. The defined sulphide capacity by Richardson and Fincham…”

“…The oxygen potential of metallurgical slags is controlled by (Fe t O)–{O 2 } equilibrium reaction as 70–73 …”