A Thermodynamic Model for Representation Reaction Abilities of Structural Units in Full Composition Range of Fe-Si Binary Melts Based on the Atom-Molecule Coexistence Theory

2013 ◽  
Vol 84 (8) ◽  
pp. 784-811 ◽  
Author(s):  
Xue-min Yang ◽  
Meng Zhang ◽  
Peng-cheng Li ◽  
Jin-yan Li ◽  
Jian Zhang
Keyword(s):  
Thermodynamic Model ◽  
Composition Range ◽  
Structural Units ◽  
Coexistence Theory

Calculation Model of Mass Action Concentrations for CaO-MnO-FeO-SiO2-MgO-Al2O3 Slags Based on the Ion and Molecule Coexistence Theory

2012 ◽  
Vol 476-478 ◽  
pp. 134-138
Author(s):  
Xiao Hong Yang ◽  
Xiao Chun Ma ◽  
Cheng Chuan Wu ◽  
Guo Guang Cheng
Keyword(s):  
Phase Diagrams ◽  
Thermodynamic Model ◽  
Slag System ◽  
Calculation Model ◽  
Mass Action ◽  
Structural Units ◽  
Coexistence Theory ◽  
Slag Structure ◽  
Calculation Results ◽  
Good Agreement

According to the ion and molecule coexistence theory (IMCT) of slag structure and corresponding phase diagrams, a thermodynamic model for calculating mass action concentrations of structural units or ion couples of CaO-MnO-FeO-SiO2-MgO-Al2O3 slags was established. Equilibrium mass action concentrations of each structure unit were gained. And the calculation results of NFeO and NMnO were compared with measured aFeO and aMnO. The comparison shows that the calculated values of NFeO and NMnO are in good agreement with the reported measured values of aFeO and aMnO, so this calculating model could fairly describe the characteristics of the slag system.

scholarly journals Thermodynamic properties prediction of Mg-Al-Zn melts based on the atom and molecule coexistence theory

2019 ◽  
Vol 55 (2) ◽  
pp. 135-145
Author(s):  
Man-Cang Zhang ◽  
Sheng-Chao Duan ◽  
Rong-Huan Xu ◽  
Ming Zou ◽  
Shi-Wen Dong ◽  
...  
Keyword(s):  
Free Energy ◽  
Thermodynamic Properties ◽  
Gibbs Free Energy ◽  
Energy Function ◽  
Composition Range ◽  
Mass Action ◽  
Free Energy Function ◽  
Structural Units ◽  
Coexistence Theory ◽  
Calculated Mass

A developed and verified thermodynamic model based on the atom and molecule coexistence theory (AMCT) is employed to predict activities relative to pure liquids in standard state in Mg-Al, Mg-Zn, Al-Zn and Mg-Al-Zn melts through the calculated mass action concentrations of structural units, i.e., Ni. According to AMCT, Ni can be extrapolated and calculated by the chemical equilibrium constant of a structural molecule, i.e., Ki, in the Mg-Al-Zn ternary system and binary subsystems. In this paper, the standard Gibbs free energy function, for reported activities and mixing thermodynamic properties in Mg-Al, Mg-Zn and Al-Zn melts, was regressed and optimized. The results showed that Ki and Ni were deduced by Gibbs free energy function at the studied temperature. The results of calculating thermodynamic properties in the full composition range for liquid Mg-Al-Zn from 880 to 1100 K, as well as Mg-Al from 923 to 1073 K, Mg-Zn from 880 to 973 K and Al-Zn from 1000 to 1073 K, are presented in the paper by coupling with Ni and AMCT. An excellent agreement is noticed between the calculated values of this study and measured thermodynamic data from the references, suggesting that the AMCT can be well applied to describe and predict the activities of the Mg-Al-Zn system and its subsystems.

A Thermodynamic Model for Representation Reaction Abilities of Structural Units in Fe-S Binary Melts Based on the Atom-Molecule Coexistence Theory

2012 ◽  
Vol 43 (6) ◽  
pp. 1358-1387 ◽  
Author(s):  
Xue-Min Yang ◽  
Meng Zhang ◽  
Peng-Cheng Li ◽  
Jin-Yan Li ◽  
Jian-Liang Zhang ◽  
...  
Keyword(s):  
Thermodynamic Model ◽  
Structural Units ◽  
Coexistence Theory

A Thermodynamic Model for Evaluation of Mass Action Concentrations of La2O3-Al2O3-CaF2-CaO-MgO Slags for Electroslag Remelting Based on the Ion and Molecule Coexistence Theory

2013 ◽  
Vol 32 (6) ◽  
pp. 541-550 ◽  
Author(s):  
Chengchuan Wu ◽  
Guoguang Cheng ◽  
Jun Tian
Keyword(s):  
Phase Diagrams ◽  
Thermodynamic Model ◽  
Mass Fraction ◽  
Electroslag Remelting ◽  
Mass Action ◽  
Coexistence Theory ◽  
Maximum Value ◽  
Mass Action Concentration ◽  
Increasing Temperature ◽  
Good Agreement

AbstractAccording to the ion and molecule coexistence theory (IMCT) for molten slags and corresponding phase diagrams, a thermodynamic model for the evaluation of mass action concentrations (designated by Ni for structure unit i) for La2O3-Al2O3, La2O3-Al2O3-CaF2, La2O3-Al2O3-CaF2-CaO, La2O3-Al2O3-CaF2-MgO and La2O3-Al2O3-CaF2-CaO-MgO slag systems for electroslag remelting (ESR) has been formulated. The influencing factors for the mass action concentration of La2O3, such as mass fraction of Al2O3, CaF2, CaO and MgO and temperature, were investigated. The results show that when the mole fraction of La2O3 is at 0.495, the mass action concentration of La2O3 · Al2O3 achieves its maximum value 0.946 in the La2O3-Al2O3 binary slag. In a composition area of La2O3: 10wt% ∼ 45wt%, Al2O3: 0wt% ∼ 50wt% and CaF2: 20wt% ∼ 70wt% of the La2O3-Al2O3-CaF2 ternary slag at 1873 K, the results show that the calculated values of NLa2O3 are in good agreement with the reported measured values of aLa2O3. The iso-curves of NLa2O3 is also drawn from the calculated results, which reveals that the mass action concentration of La2O3 decreases with the increasing of the Al2O3 and CaF2 content, and Al2O3 is stronger than CaF2 in decreasing the mass action concentration of La2O3. However, in La2O3-Al2O3-CaF2-CaO, La2O3-Al2O3-CaF2-MgO and La2O3-Al2O3-CaF2-CaO-MgO slag systems, the mass action concentration of La2O3 increases with the increasing of the MgO and CaO content, and CaO is stronger than MgO in increasing the mass action concentration of La2O3. In addition, the mass action concentration of La2O3 increases with the increasing temperature at the composition of 30wt%La2O3, 10wt%Al2O3, 40wt%CaF2, 10wt%MgO and 10wt%CaO.

A Thermodynamic Model for Evaluation of Mass Action Concentrations of Ce2O3-contained Slag Systems Based on the Ion and Molecule Coexistence Theory

2013 ◽  
Vol 32 (3) ◽  
pp. 207-214 ◽  
Author(s):  
Chengchuan Wu ◽  
Guoguang Cheng ◽  
Hu Long ◽  
Xiaohong Yang
Keyword(s):  
Phase Diagrams ◽  
Thermodynamic Model ◽  
Mass Fraction ◽  
Aluminum Content ◽  
Mass Action ◽  
Coexistence Theory ◽  
Cerium Content ◽  
Maximum Value ◽  
Mass Action Concentration ◽  
Good Agreement

AbstractAccording to the ion and molecule coexistence theory (IMCT) for molten slags and corresponding phase diagrams, a thermodynamic model for the evaluation of mass action concentrations (designated by Ni for structure unit i) for Ce2O3-Al2O3, CaO-Al2O3-Ce2O3 and CaO-Al2O3-SiO2-Ce2O3 slag systems has been formulated. The results show that when the mole fraction of Ce2O3 is at 0.49 in the binary slag, the mass action concentration of Ce2O3·Al2O3 achieves its maximum value 0.90. In a composition area of CaO/Al2O3 (mass fraction ratio) from 0.7 to 1.5 and Ce2O3 content (mass fraction) from 0 to 45% of the ternary slag at 1773 K, the results show that trends of calculated NAl2O3 are in good agreement with reported measured trends of aAl2O3. The iso-curves of NCe2O3 and NCaO are also drawn from the calculated results. A thermodynamic model of the equilibrium between 55.83%CaO-23%Al2O3-11.17%SiO2-10%Ce2O3 quaternary slag and molten steel containing aluminum has been further discussed. Results indicate that certain content of Ce would be dissolved in steel, which increases with the increasing of temperature and aluminum content, and when the aluminum content is 0.02%, the corresponding cerium content is in the range of 1.87 to 13.30 ppm at 1873 K. In summary, using Ce2O3 to replace Al2O3 can effectively reduce NAl2O3, certain content of Ce can dissolved in steel.

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