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Meng Zhang - One of the best experts on this subject based on the ideXlab platform.

  • a thermodynamic model of sulfur distribution ratio between cao sio2 mgo feo mno al2o3 slags and Molten Steel during lf refining process based on the ion and molecule coexistence theory
    Metallurgical and Materials Transactions B-process Metallurgy and Materials Processing Science, 2011
    Co-Authors: Xuemin Yang, Guoming Chai, Meng Zhang, Fei Wang
    Abstract:

    A thermodynamic model for calculating the sulfur distribution ratio between ladle furnace (LF) refining slags and Molten Steel has been developed by coupling with a developed thermodynamic model for calculating the mass action concentrations of structural units in LF refining slags, i.e., CaO–SiO2–MgO–FeO–MnO–Al2O3 hexabasic slags, based on the ion and molecule coexistence theory (IMCT). The calculated mass action concentrations of structural units in CaO–SiO2–MgO–FeO–Al2O3–MnO slags equilibrated or reacted with Molten Steel show that the calculated equilibrium mole numbers or mass action concentrations of structural units or ion couples, rather than mass percentage of components, in the slags can represent their reaction abilities. The calculated total sulfur distribution ratio shows a reliable agreement with the measured or the calculated sulfur distribution ratio between the slags and Molten Steel by other models under the condition of choosing oxygen activity based on (FeO)–[O] equilibrium. Meanwhile, the developed thermodynamic model for calculating sulfur distribution ratio can quantitatively determine the respective contribution of free CaO, MgO, FeO, and MnO in the LF refining slags. A significant difference of desulfurization ability among free component as CaO, MgO, FeO, and MnO has been found with approximately 87–93 pct, 11.43–5.85 pct, 0.81–0.60 pct and 0.30–0.27 pct at both middle and final stages during LF refining process, respectively. A large difference of oxygen activity is found in Molten Steel at the slag–metal interface and in bulk Molten Steel. The oxygen activity in Molten Steel at the slag–metal interface is controlled by (FeO)–[O] equilibrium, whereas the oxygen activity in bulk Molten Steel is controlled by [Al]–[O] equilibrium. Decreasing the high-oxygen-activity boundary layer beneath the slag–metal interface can promote the desulfurization reaction rate effectively or shorten the refining period during the LF refining process.

  • a thermodynamic model of phosphorus distribution ratio between cao sio2 mgo feo fe2o3 mno al2o3 p2o5 slags and Molten Steel during a top bottom combined blown converter Steelmaking process based on the ion and molecule coexistence theory
    Metallurgical and Materials Transactions B-process Metallurgy and Materials Processing Science, 2011
    Co-Authors: Xuemin Yang, Jianping Duan, Yongliang Zhang, Meng Zhang, Jianchang Wang
    Abstract:

    A thermodynamic model for calculating the phosphorus distribution ratio between top-bottom combined blown converter Steelmaking slags and Molten Steel has been developed by coupling with a developed thermodynamic model for calculating mass action concentrations of structural units in the slags, i.e., CaO-SiO2-MgO-FeO-Fe2O3-MnO-Al2O3-P2O5 slags, based on the ion and molecule coexistence theory (IMCT). Not only the total phosphorus distribution ratio but also the respective phosphorus distribution ratio among four basic oxides as components, i.e., CaO, MgO, FeO, and MnO, in the slags and Molten Steel can be predicted theoretically by the developed IMCT phosphorus distribution ratio prediction model after knowing the oxygen activity of Molten Steel at the slag-metal interface or the Fe (t) O activity in the slags and the related mass action concentrations of structural units or ion couples in the slags. The calculated mass action concentrations of structural units or ion couples in the slags equilibrated or reacted with Molten Steel show that the calculated equilibrium mole numbers or mass action concentrations of structural units or ion couples, rather than the mass percentage of components, can present the reaction ability of the components in the slags. The predicted total phosphorus distribution ratio by the developed IMCT model shows a reliable agreement with the measured phosphorus distribution ratio by using the calculated mass action concentrations of iron oxides as presentation of slag oxidation ability. Meanwhile, the developed thermodynamic model for calculating the phosphorus distribution ratio can determine quantitatively the respective dephosphorization contribution ratio of Fe (t) O, CaO + Fe (t) O, MgO + Fe (t) O, and MnO + Fe (t) O in the slags. A significant difference of dephosphorization ability among Fe (t) O, CaO + Fe (t) O, MgO + Fe (t) O, and MnO + Fe (t) O has been found as approximately 0.0 pct, 99.996 pct, 0.0 pct, and 0.0 pct during a combined blown converter Steelmaking process, respectively. There is a great gradient of oxygen activity of Molten Steel at the slag-metal interface and in a metal bath when carbon content in a metal bath is larger than 0.036 pct. The phosphorus in Molten Steel beneath the slag-metal interface can be extracted effectively by the comprehensive effect of CaO and Fe (t) O in slags to form 3CaO center dot P2O5 and 4CaO center dot P2O5 until the carbon content is less than 0.036 pct during a top-bottom combined blown Steelmaking process.

  • a thermodynamic model of phosphorus distribution ratio between cao sio2 mgo feo fe2o3 mno al2o3 p2o5 slags and Molten Steel during a top bottom combined blown converter Steelmaking process based on the ion and molecule coexistence theory
    Metallurgical and Materials Transactions B-process Metallurgy and Materials Processing Science, 2011
    Co-Authors: Xuemin Yang, Jianping Duan, Yongliang Zhang, Meng Zhang, Chengbin Shi, Jianchang Wang
    Abstract:

    A thermodynamic model for calculating the phosphorus distribution ratio between top–bottom combined blown converter Steelmaking slags and Molten Steel has been developed by coupling with a developed thermodynamic model for calculating mass action concentrations of structural units in the slags, i.e., CaO-SiO2-MgO-FeO-Fe2O3-MnO-Al2O3-P2O5 slags, based on the ion and molecule coexistence theory (IMCT). Not only the total phosphorus distribution ratio but also the respective phosphorus distribution ratio among four basic oxides as components, i.e., CaO, MgO, FeO, and MnO, in the slags and Molten Steel can be predicted theoretically by the developed IMCT phosphorus distribution ratio prediction model after knowing the oxygen activity of Molten Steel at the slag–metal interface or the Fe t O activity in the slags and the related mass action concentrations of structural units or ion couples in the slags. The calculated mass action concentrations of structural units or ion couples in the slags equilibrated or reacted with Molten Steel show that the calculated equilibrium mole numbers or mass action concentrations of structural units or ion couples, rather than the mass percentage of components, can present the reaction ability of the components in the slags. The predicted total phosphorus distribution ratio by the developed IMCT model shows a reliable agreement with the measured phosphorus distribution ratio by using the calculated mass action concentrations of iron oxides as presentation of slag oxidation ability. Meanwhile, the developed thermodynamic model for calculating the phosphorus distribution ratio can determine quantitatively the respective dephosphorization contribution ratio of Fe t O, CaO + Fe t O, MgO + Fe t O, and MnO + Fe t O in the slags. A significant difference of dephosphorization ability among Fe t O, CaO + Fe t O, MgO + Fe t O, and MnO + Fe t O has been found as approximately 0.0 pct, 99.996 pct, 0.0 pct, and 0.0 pct during a combined blown converter Steelmaking process, respectively. There is a great gradient of oxygen activity of Molten Steel at the slag–metal interface and in a metal bath when carbon content in a metal bath is larger than 0.036 pct. The phosphorus in Molten Steel beneath the slag–metal interface can be extracted effectively by the comprehensive effect of CaO and Fe t O in slags to form 3CaO·P2O5 and 4CaO·P2O5 until the carbon content is less than 0.036 pct during a top–bottom combined blown Steelmaking process.

Xuemin Yang - One of the best experts on this subject based on the ideXlab platform.

  • thermodynamic models for predicting dephosphorisation ability and potential of cao feo fe2o3 al2o3 p2o5 slags during secondary refining process of Molten Steel based on ion and molecule coexistence theory
    Ironmaking & Steelmaking, 2016
    Co-Authors: Xuemin Yang, Guoming Chai, M Zhang, Q Liang, J Zhang
    Abstract:

    Thermodynamic models for predicting phosphorus distribution ratio LP and phosphate capacity of CaO–FeO–Fe2O3–Al2O3–P2O5 slags during secondary refining process of Molten Steel, according to the ion and molecule coexistence theory (IMCT), i.e. IMCT–LP and IMCT– models, have been developed by coupling with the developed thermodynamic model for calculating the mass action concentrations Ni of structural units or ion couples in the slags, i.e. the IMCT–Ni model, based on the IMCT. The developed IMCT–LP and IMCT– models have been verified with the experimental results from the literature and the predicted results by the summarised five LP models and three models. Besides the total dephosphorisation ability and potential of the slags as LP and , the respective phosphorus distribution ratio LP,i and the respective phosphate capacity of six dephosphorisation products as P2O5, 3FeO·P2O5, 4FeO·P2O5, 2CaO·P2O5, 3CaO·P2O5 and 4CaO·P2O5 can also reliably be predicted by the developed IMCT–LP and IMCT– models. 3CaO·P2O...

  • a thermodynamic model of sulfur distribution ratio between cao sio2 mgo feo mno al2o3 slags and Molten Steel during lf refining process based on the ion and molecule coexistence theory
    Metallurgical and Materials Transactions B-process Metallurgy and Materials Processing Science, 2011
    Co-Authors: Xuemin Yang, Guoming Chai, Meng Zhang, Fei Wang
    Abstract:

    A thermodynamic model for calculating the sulfur distribution ratio between ladle furnace (LF) refining slags and Molten Steel has been developed by coupling with a developed thermodynamic model for calculating the mass action concentrations of structural units in LF refining slags, i.e., CaO–SiO2–MgO–FeO–MnO–Al2O3 hexabasic slags, based on the ion and molecule coexistence theory (IMCT). The calculated mass action concentrations of structural units in CaO–SiO2–MgO–FeO–Al2O3–MnO slags equilibrated or reacted with Molten Steel show that the calculated equilibrium mole numbers or mass action concentrations of structural units or ion couples, rather than mass percentage of components, in the slags can represent their reaction abilities. The calculated total sulfur distribution ratio shows a reliable agreement with the measured or the calculated sulfur distribution ratio between the slags and Molten Steel by other models under the condition of choosing oxygen activity based on (FeO)–[O] equilibrium. Meanwhile, the developed thermodynamic model for calculating sulfur distribution ratio can quantitatively determine the respective contribution of free CaO, MgO, FeO, and MnO in the LF refining slags. A significant difference of desulfurization ability among free component as CaO, MgO, FeO, and MnO has been found with approximately 87–93 pct, 11.43–5.85 pct, 0.81–0.60 pct and 0.30–0.27 pct at both middle and final stages during LF refining process, respectively. A large difference of oxygen activity is found in Molten Steel at the slag–metal interface and in bulk Molten Steel. The oxygen activity in Molten Steel at the slag–metal interface is controlled by (FeO)–[O] equilibrium, whereas the oxygen activity in bulk Molten Steel is controlled by [Al]–[O] equilibrium. Decreasing the high-oxygen-activity boundary layer beneath the slag–metal interface can promote the desulfurization reaction rate effectively or shorten the refining period during the LF refining process.

  • a thermodynamic model of phosphorus distribution ratio between cao sio2 mgo feo fe2o3 mno al2o3 p2o5 slags and Molten Steel during a top bottom combined blown converter Steelmaking process based on the ion and molecule coexistence theory
    Metallurgical and Materials Transactions B-process Metallurgy and Materials Processing Science, 2011
    Co-Authors: Xuemin Yang, Jianping Duan, Yongliang Zhang, Meng Zhang, Jianchang Wang
    Abstract:

    A thermodynamic model for calculating the phosphorus distribution ratio between top-bottom combined blown converter Steelmaking slags and Molten Steel has been developed by coupling with a developed thermodynamic model for calculating mass action concentrations of structural units in the slags, i.e., CaO-SiO2-MgO-FeO-Fe2O3-MnO-Al2O3-P2O5 slags, based on the ion and molecule coexistence theory (IMCT). Not only the total phosphorus distribution ratio but also the respective phosphorus distribution ratio among four basic oxides as components, i.e., CaO, MgO, FeO, and MnO, in the slags and Molten Steel can be predicted theoretically by the developed IMCT phosphorus distribution ratio prediction model after knowing the oxygen activity of Molten Steel at the slag-metal interface or the Fe (t) O activity in the slags and the related mass action concentrations of structural units or ion couples in the slags. The calculated mass action concentrations of structural units or ion couples in the slags equilibrated or reacted with Molten Steel show that the calculated equilibrium mole numbers or mass action concentrations of structural units or ion couples, rather than the mass percentage of components, can present the reaction ability of the components in the slags. The predicted total phosphorus distribution ratio by the developed IMCT model shows a reliable agreement with the measured phosphorus distribution ratio by using the calculated mass action concentrations of iron oxides as presentation of slag oxidation ability. Meanwhile, the developed thermodynamic model for calculating the phosphorus distribution ratio can determine quantitatively the respective dephosphorization contribution ratio of Fe (t) O, CaO + Fe (t) O, MgO + Fe (t) O, and MnO + Fe (t) O in the slags. A significant difference of dephosphorization ability among Fe (t) O, CaO + Fe (t) O, MgO + Fe (t) O, and MnO + Fe (t) O has been found as approximately 0.0 pct, 99.996 pct, 0.0 pct, and 0.0 pct during a combined blown converter Steelmaking process, respectively. There is a great gradient of oxygen activity of Molten Steel at the slag-metal interface and in a metal bath when carbon content in a metal bath is larger than 0.036 pct. The phosphorus in Molten Steel beneath the slag-metal interface can be extracted effectively by the comprehensive effect of CaO and Fe (t) O in slags to form 3CaO center dot P2O5 and 4CaO center dot P2O5 until the carbon content is less than 0.036 pct during a top-bottom combined blown Steelmaking process.

  • a thermodynamic model of phosphorus distribution ratio between cao sio2 mgo feo fe2o3 mno al2o3 p2o5 slags and Molten Steel during a top bottom combined blown converter Steelmaking process based on the ion and molecule coexistence theory
    Metallurgical and Materials Transactions B-process Metallurgy and Materials Processing Science, 2011
    Co-Authors: Xuemin Yang, Jianping Duan, Yongliang Zhang, Meng Zhang, Chengbin Shi, Jianchang Wang
    Abstract:

    A thermodynamic model for calculating the phosphorus distribution ratio between top–bottom combined blown converter Steelmaking slags and Molten Steel has been developed by coupling with a developed thermodynamic model for calculating mass action concentrations of structural units in the slags, i.e., CaO-SiO2-MgO-FeO-Fe2O3-MnO-Al2O3-P2O5 slags, based on the ion and molecule coexistence theory (IMCT). Not only the total phosphorus distribution ratio but also the respective phosphorus distribution ratio among four basic oxides as components, i.e., CaO, MgO, FeO, and MnO, in the slags and Molten Steel can be predicted theoretically by the developed IMCT phosphorus distribution ratio prediction model after knowing the oxygen activity of Molten Steel at the slag–metal interface or the Fe t O activity in the slags and the related mass action concentrations of structural units or ion couples in the slags. The calculated mass action concentrations of structural units or ion couples in the slags equilibrated or reacted with Molten Steel show that the calculated equilibrium mole numbers or mass action concentrations of structural units or ion couples, rather than the mass percentage of components, can present the reaction ability of the components in the slags. The predicted total phosphorus distribution ratio by the developed IMCT model shows a reliable agreement with the measured phosphorus distribution ratio by using the calculated mass action concentrations of iron oxides as presentation of slag oxidation ability. Meanwhile, the developed thermodynamic model for calculating the phosphorus distribution ratio can determine quantitatively the respective dephosphorization contribution ratio of Fe t O, CaO + Fe t O, MgO + Fe t O, and MnO + Fe t O in the slags. A significant difference of dephosphorization ability among Fe t O, CaO + Fe t O, MgO + Fe t O, and MnO + Fe t O has been found as approximately 0.0 pct, 99.996 pct, 0.0 pct, and 0.0 pct during a combined blown converter Steelmaking process, respectively. There is a great gradient of oxygen activity of Molten Steel at the slag–metal interface and in a metal bath when carbon content in a metal bath is larger than 0.036 pct. The phosphorus in Molten Steel beneath the slag–metal interface can be extracted effectively by the comprehensive effect of CaO and Fe t O in slags to form 3CaO·P2O5 and 4CaO·P2O5 until the carbon content is less than 0.036 pct during a top–bottom combined blown Steelmaking process.

Jianchang Wang - One of the best experts on this subject based on the ideXlab platform.

  • a thermodynamic model of phosphorus distribution ratio between cao sio2 mgo feo fe2o3 mno al2o3 p2o5 slags and Molten Steel during a top bottom combined blown converter Steelmaking process based on the ion and molecule coexistence theory
    Metallurgical and Materials Transactions B-process Metallurgy and Materials Processing Science, 2011
    Co-Authors: Xuemin Yang, Jianping Duan, Yongliang Zhang, Meng Zhang, Jianchang Wang
    Abstract:

    A thermodynamic model for calculating the phosphorus distribution ratio between top-bottom combined blown converter Steelmaking slags and Molten Steel has been developed by coupling with a developed thermodynamic model for calculating mass action concentrations of structural units in the slags, i.e., CaO-SiO2-MgO-FeO-Fe2O3-MnO-Al2O3-P2O5 slags, based on the ion and molecule coexistence theory (IMCT). Not only the total phosphorus distribution ratio but also the respective phosphorus distribution ratio among four basic oxides as components, i.e., CaO, MgO, FeO, and MnO, in the slags and Molten Steel can be predicted theoretically by the developed IMCT phosphorus distribution ratio prediction model after knowing the oxygen activity of Molten Steel at the slag-metal interface or the Fe (t) O activity in the slags and the related mass action concentrations of structural units or ion couples in the slags. The calculated mass action concentrations of structural units or ion couples in the slags equilibrated or reacted with Molten Steel show that the calculated equilibrium mole numbers or mass action concentrations of structural units or ion couples, rather than the mass percentage of components, can present the reaction ability of the components in the slags. The predicted total phosphorus distribution ratio by the developed IMCT model shows a reliable agreement with the measured phosphorus distribution ratio by using the calculated mass action concentrations of iron oxides as presentation of slag oxidation ability. Meanwhile, the developed thermodynamic model for calculating the phosphorus distribution ratio can determine quantitatively the respective dephosphorization contribution ratio of Fe (t) O, CaO + Fe (t) O, MgO + Fe (t) O, and MnO + Fe (t) O in the slags. A significant difference of dephosphorization ability among Fe (t) O, CaO + Fe (t) O, MgO + Fe (t) O, and MnO + Fe (t) O has been found as approximately 0.0 pct, 99.996 pct, 0.0 pct, and 0.0 pct during a combined blown converter Steelmaking process, respectively. There is a great gradient of oxygen activity of Molten Steel at the slag-metal interface and in a metal bath when carbon content in a metal bath is larger than 0.036 pct. The phosphorus in Molten Steel beneath the slag-metal interface can be extracted effectively by the comprehensive effect of CaO and Fe (t) O in slags to form 3CaO center dot P2O5 and 4CaO center dot P2O5 until the carbon content is less than 0.036 pct during a top-bottom combined blown Steelmaking process.

  • a thermodynamic model of phosphorus distribution ratio between cao sio2 mgo feo fe2o3 mno al2o3 p2o5 slags and Molten Steel during a top bottom combined blown converter Steelmaking process based on the ion and molecule coexistence theory
    Metallurgical and Materials Transactions B-process Metallurgy and Materials Processing Science, 2011
    Co-Authors: Xuemin Yang, Jianping Duan, Yongliang Zhang, Meng Zhang, Chengbin Shi, Jianchang Wang
    Abstract:

    A thermodynamic model for calculating the phosphorus distribution ratio between top–bottom combined blown converter Steelmaking slags and Molten Steel has been developed by coupling with a developed thermodynamic model for calculating mass action concentrations of structural units in the slags, i.e., CaO-SiO2-MgO-FeO-Fe2O3-MnO-Al2O3-P2O5 slags, based on the ion and molecule coexistence theory (IMCT). Not only the total phosphorus distribution ratio but also the respective phosphorus distribution ratio among four basic oxides as components, i.e., CaO, MgO, FeO, and MnO, in the slags and Molten Steel can be predicted theoretically by the developed IMCT phosphorus distribution ratio prediction model after knowing the oxygen activity of Molten Steel at the slag–metal interface or the Fe t O activity in the slags and the related mass action concentrations of structural units or ion couples in the slags. The calculated mass action concentrations of structural units or ion couples in the slags equilibrated or reacted with Molten Steel show that the calculated equilibrium mole numbers or mass action concentrations of structural units or ion couples, rather than the mass percentage of components, can present the reaction ability of the components in the slags. The predicted total phosphorus distribution ratio by the developed IMCT model shows a reliable agreement with the measured phosphorus distribution ratio by using the calculated mass action concentrations of iron oxides as presentation of slag oxidation ability. Meanwhile, the developed thermodynamic model for calculating the phosphorus distribution ratio can determine quantitatively the respective dephosphorization contribution ratio of Fe t O, CaO + Fe t O, MgO + Fe t O, and MnO + Fe t O in the slags. A significant difference of dephosphorization ability among Fe t O, CaO + Fe t O, MgO + Fe t O, and MnO + Fe t O has been found as approximately 0.0 pct, 99.996 pct, 0.0 pct, and 0.0 pct during a combined blown converter Steelmaking process, respectively. There is a great gradient of oxygen activity of Molten Steel at the slag–metal interface and in a metal bath when carbon content in a metal bath is larger than 0.036 pct. The phosphorus in Molten Steel beneath the slag–metal interface can be extracted effectively by the comprehensive effect of CaO and Fe t O in slags to form 3CaO·P2O5 and 4CaO·P2O5 until the carbon content is less than 0.036 pct during a top–bottom combined blown Steelmaking process.

J Zhang - One of the best experts on this subject based on the ideXlab platform.

Guoming Chai - One of the best experts on this subject based on the ideXlab platform.

  • coupling relationship between dephosphorisation and desulphurisation abilities or potentials for cao feo fe2o3 al2o3 p2o5 slags over a large variation range of slag oxidisation ability during secondary refining process of Molten Steel
    Ironmaking & Steelmaking, 2018
    Co-Authors: Xuwen Yang, Guoming Chai, M Zhang, Demin Duan, J Zhang
    Abstract:

    The coupling relationships between dephosphorisation and desulphurisation abilities or potentials for CaO–FeO–Fe2O3–Al2O3–P2O5 slags during secondary refining process of Molten Steel have been prop...

  • thermodynamic models for predicting dephosphorisation ability and potential of cao feo fe2o3 al2o3 p2o5 slags during secondary refining process of Molten Steel based on ion and molecule coexistence theory
    Ironmaking & Steelmaking, 2016
    Co-Authors: Xuemin Yang, Guoming Chai, M Zhang, Q Liang, J Zhang
    Abstract:

    Thermodynamic models for predicting phosphorus distribution ratio LP and phosphate capacity of CaO–FeO–Fe2O3–Al2O3–P2O5 slags during secondary refining process of Molten Steel, according to the ion and molecule coexistence theory (IMCT), i.e. IMCT–LP and IMCT– models, have been developed by coupling with the developed thermodynamic model for calculating the mass action concentrations Ni of structural units or ion couples in the slags, i.e. the IMCT–Ni model, based on the IMCT. The developed IMCT–LP and IMCT– models have been verified with the experimental results from the literature and the predicted results by the summarised five LP models and three models. Besides the total dephosphorisation ability and potential of the slags as LP and , the respective phosphorus distribution ratio LP,i and the respective phosphate capacity of six dephosphorisation products as P2O5, 3FeO·P2O5, 4FeO·P2O5, 2CaO·P2O5, 3CaO·P2O5 and 4CaO·P2O5 can also reliably be predicted by the developed IMCT–LP and IMCT– models. 3CaO·P2O...

  • a thermodynamic model of sulfur distribution ratio between cao sio2 mgo feo mno al2o3 slags and Molten Steel during lf refining process based on the ion and molecule coexistence theory
    Metallurgical and Materials Transactions B-process Metallurgy and Materials Processing Science, 2011
    Co-Authors: Xuemin Yang, Guoming Chai, Meng Zhang, Fei Wang
    Abstract:

    A thermodynamic model for calculating the sulfur distribution ratio between ladle furnace (LF) refining slags and Molten Steel has been developed by coupling with a developed thermodynamic model for calculating the mass action concentrations of structural units in LF refining slags, i.e., CaO–SiO2–MgO–FeO–MnO–Al2O3 hexabasic slags, based on the ion and molecule coexistence theory (IMCT). The calculated mass action concentrations of structural units in CaO–SiO2–MgO–FeO–Al2O3–MnO slags equilibrated or reacted with Molten Steel show that the calculated equilibrium mole numbers or mass action concentrations of structural units or ion couples, rather than mass percentage of components, in the slags can represent their reaction abilities. The calculated total sulfur distribution ratio shows a reliable agreement with the measured or the calculated sulfur distribution ratio between the slags and Molten Steel by other models under the condition of choosing oxygen activity based on (FeO)–[O] equilibrium. Meanwhile, the developed thermodynamic model for calculating sulfur distribution ratio can quantitatively determine the respective contribution of free CaO, MgO, FeO, and MnO in the LF refining slags. A significant difference of desulfurization ability among free component as CaO, MgO, FeO, and MnO has been found with approximately 87–93 pct, 11.43–5.85 pct, 0.81–0.60 pct and 0.30–0.27 pct at both middle and final stages during LF refining process, respectively. A large difference of oxygen activity is found in Molten Steel at the slag–metal interface and in bulk Molten Steel. The oxygen activity in Molten Steel at the slag–metal interface is controlled by (FeO)–[O] equilibrium, whereas the oxygen activity in bulk Molten Steel is controlled by [Al]–[O] equilibrium. Decreasing the high-oxygen-activity boundary layer beneath the slag–metal interface can promote the desulfurization reaction rate effectively or shorten the refining period during the LF refining process.

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