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1.
All available thermodynamic and phase diagram data have been critically assessed for all phases in the CaO-Al2O3, Al2O3-SiO2, and CaO-Al2O3-SiO2 systems at 1 bar pressure from 298 K to above the liquidus temperatures. All reliable data for the binary systems have been
simultaneously optimized to obtain, for each system, one set of model equations for the Gibbs energy of the liquid slag and
all solid phases as functions of composition and temperature. The modified quasichemical model was used for the slag. With
these binary parameters and those from the optimization of the CaO-SiO2 system reported previously, the quasichemical model was used to predict the thermodynamic properties of the ternary slag.
Two additional small ternary parameters were required to reproduce the ternary phase diagram and ternary activity data to
within experimental error limits. The calculated optimized phase diagram and thermodynamic properties are self-consistent
and are the most reliable currently available estimates of the true values. 相似文献
2.
A complete critical evaluation of all available phase diagram and thermodynamic data has been performed for all condensed
phases of the LiF-NaF-KF-MgF2-CaF2 system and optimized model parameters have been found. The model parameters obtained for binary and ternary subsystems can
be used to predict thermodynamic properties and phase equilibria for the multicomponent system. The modified quasi-chemical
model for short-range ordering (SRO) was used for the molten salt phase. For solutions with NaF or KF together with MgCl2 or CaCl2, the calculations indicate a large degree of ordering on the cationic sublattice, with Mg-alkali and Ca-alkali second-nearest-neighbor
(SNN) pairs being favored. 相似文献
3.
Weiming Huang Mats Hillert Xizhen Wang 《Metallurgical and Materials Transactions A》1995,26(9):2293-2310
The phase equilibrium and thermodynamic information of the CaO-MgO-SiO2 system at 1 atm was reviewed and assessed by using thermodynamic models for the Gibbs energy of all the phases. The assessment
was based on recent assessments of the CaO-MgO, CaO-SiO2, and MgO-SiO2 systems. Two thermodynamic models were used: the two-sublattice model for ionic liquids for the liquid phase, and the compound
energy model for the solid solution phases. The model parameters were evaluated by fitting to the selected experimental data
by means of a computer program, which can accommodate a variety of experimental data. A consistent set of parameters was obtained
that sat-isfactorily described most of the experimental information. The models were found to be well-suited for the present
system, and only a small number of adjustable parameters were needed. Extensive comparisons were made between the calculations
and experimental data.
Formerly Research Associate, Royal Institute of Technology 相似文献
4.
A complete critical evaluation of all available phase-diagram and thermodynamic data has been performed for all condensed phases of the LiCl-NaCl-KCl-RbCl-CsCl-MgCl2-CaCl2 system, and optimized model parameters have been found. The model parameters obtained for binary and ternary subsystems can be used to predict thermodynamic properties and phase equilibria for the multicomponent system. The modified quasi-chemical model for short-range ordering was used for the molten salt phase. Particularly in solutions with MgCl2 and KCl, RbCl, or CsCl, the calculations indicate a large dregree of ordering on the cationic sublattice, with Mg-Alkali second-nearest-neighbor pairs being favored. 相似文献
5.
6.
Sergei A. Degterov Arthur D. Pelton 《Metallurgical and Materials Transactions B》1999,30(6):1033-1044
Recently, a thermodynamic database was developed for the calculation of equilibria involved in the production of copper. The
present study is concerned with the further development of the thermodynamic models and the database of model parameters for
the matte, slag, and blister copper phases with a view to including Pb in the database and permitting calculations in the
seven-component system Pb-Cu-Ca-Fe-Si-O-S. Thermodynamic and phase equilibrium data available in the literature are reviewed,
critically assessed, and optimized with the modified quasi-chemical model. When used with the Gibbs energy minimization software
and other databases of the FACT thermodynamic computing system, the database developed in the present study can be used for
the calculation of matte-slag-copper-gas phase equilibria during copper smelting and converting.
The distribution of lead among these phases can be computed. For example, the distribution of lead among matte, silica-saturated
slag, and copper has been calculated at metal saturation, or under fixed partial pressure of SO2, and has been compared with the available experimental data. The Pb distributions among the equilibrium phases have been
calculated under various conditions, which are difficult to study experimentally, such as at magnetite saturation or under
various oxygen partial pressures and iron to silica ratios in the slag. 相似文献
7.
All available thermodynamic and phase diagram data have been critically assessed for all phases in the MnO-TiO2, MgO-TiO2, FeO-TiO2, Ti2O3-TiO2, Na2O-TiO2, and K2O-TiO2 systems at 1 bar pressure from 298 K to above the liquidus temperatures. All reliable thermodynamic and phase diagram data
have been simultaneously optimized to obtain, for each system, one set of model equations for the Gibbs energy of the liquid
slag as a function of composition and temperature and equations for the Gibbs energies of all compounds as functions of temperature.
The modified quasichemical model was used for the molten slag phases. 相似文献
8.
A complete critical evaluation of all available ternary reciprocal phase diagram data has been performed for all condensed phases of the LiF-LiCl-NaF-NaCl-KF-KCl-MgF2-MgCl2-CaF2-CaCl2 system and optimized model parameters have been found. The model parameters obtained for ternary reciprocal subsystems can be used to predict thermodynamic properties and phase equilibria for the multicomponent reciprocal system. The modified quasi-chemical model in the quadruplet approximation was used for the molten salt phase. This model takes into account, simultaneously, both first-nearest-neighbor (FNN) and second-nearest-neighbor (SNN) short-range-ordering (SRO) and the coupling between them. The predictions are significantly better than those obtained with previous models. 相似文献
9.
In-Ho Jung Youn-Bae Kang Sergei A. Decterov Arthur D. Pelton 《Metallurgical and Materials Transactions B》2004,35(2):259-268
All available thermodynamic and phase-diagram data have been critically evaluated and optimized for the liquid-slag phase
and for all solid phases at 1 bar pressure from 298 K to above the liquidus temperatures for the systems MnO-Al2O3 and MnO-Al2O3-SiO2, and a database of model parameters has been prepared. The modified quasichemical model was employed for the molten-slag
phase. Calculations using the database were performed with applications to inclusion engineering for Mn/Si killed steel. 相似文献
10.
YbCl3-MCl (M = Na, K, Rb, Cs) systems were optimized and calculated using the CALPHAD (CALculation of PHAse Diagram) technique. The modified quasi-chemical model in the pair-approximation for short-range ordering was used to describe the Gibbs energies of liquid phase in the systems. On the basis of the measured phase diagram data and experimental thermodynamic properties, a series of thermodynamic functions were optimized and calculated through an interactive computer-assisted analysis. Furthermore, some reasonable discussions on the thermodynamic parameters for these strong interaction binary systems were carried out. The results showed that the optimized parameters and experimental data are thermodynamically self-consistent. 相似文献
11.
Li ZENG Yu WANG Li-kai FAN Bing XIE 《钢铁研究学报(英文版)》2014,21(10):910-914
Optimization of the phase diagram of FeO-V20a system is a part of an on-going research project to develop a self-consistent multi-component thermodynamic database for vanadium slag from hot metal. Due to the lack o{ ex- perimental data for optimization, a novel experimental investigation has been carried out by thermal analysis (DSC) with a series of slags on different V2 03 contents (i. e. 3mass%- 12mass%). All available thermodynamic and phase diagram data for the binary systems have been simultaneously optimized with CALPHAD (Calculation of Phase Dia- grams) methods to give one set of model equations for the Gibbs free energy of the liquid slag as functions of compo- sition and temperature. The modified quasi-chemical model was used to describe the binary slag system. It was dem- onstrated that the calculated phase diagram with the optimized parameters was in good agreement with the experi- mental data. 相似文献
12.
Using the CALPHAD (Calculation of Phase Diagram) technique, the DyCl3-MCl (M = Na, K, Rb, Cs) systems were optimized and calculated. The modified quasi-chemical model in the pair approximation for short-range ordering was used to describe the Gibbs energies of the liquid phase in these systems. From the measured phase diagram data and experimental thermodynamic properties, a series of thermodynamic functions were optimized base on an interactive computer-assisted analysis. The optimized parameters and the experimental data were thermodynamically self-consistent. The optimized results were discussed. 相似文献
13.
A thermodynamic database for copper smelting and converting 总被引:1,自引:0,他引:1
The thermodynamic properties of the slag, matte, and liquid copper phases in the Cu-Ca-Fe-Si-O-S system have been critically
assessed and optimized over the ranges of compositions of importance to copper smelting/converting based on thermodynamic
and phase equilibria information available in the literature and using the modified quasichemical model. A thermodynamic database
has been developed, which can be used for the calculation of matte-slag-copper-gas phase equilibria of interest for the production
of copper. The model reproduces within experimental error limits all available experimental data on phase diagrams, matte-alloy
miscibility gap and tie-lines, enthalpies of mixing, and activities of Cu and S in the matte and liquid alloy. The calculated
solubilities of Cu in both S-free slag and slag equilibrated with matte are also in good agreement with experiment under all
studied conditions, such as at SiO2 saturation, in equilibrium with Fe, Cu, or Cu-Au alloys, at fixed oxygen or SO2 partial pressures and at different contents of CaO in the slag. Sulfide contents (sulfide capacities) of the slags are predicted
within experimental error limits from the modified Reddy-Blander model, with no adjustable parameters. As an example of the
application of the database, the stability field of matte/slag equilibrium is calculated, and the matte and slag compositions
are plotted vs iron to silica ratio in the slag at various SO2 pressures over this field. The matte-slag two-phase field is limited by the calculated lines corresponding to precipitation
of copper, silica, and magnetite. 相似文献
14.
15.
In-Ho Jung Sergei A. Decterov Arthur D. Pelton 《Metallurgical and Materials Transactions B》2004,35(5):877-889
A complete literature review, critical evaluation, and thermodynamic modeling of the phase diagrams and thermodynamic properties
of all oxide phases in the FeO-Fe2O3-MgO-SiO2 system at 1 bar total pressure are presented. Optimized model equations for the thermodynamic properties of all phases are
obtained, which reproduce all available thermodynamic and phase-equilibrium data within experimental error limits from 25
°C to above the liquidus temperatures at all compositions and oxygen partial pressures. The complex phase relationships in
the system have been elucidated, and discrepancies among the data have been resolved. The database of the model parameters
can be used along with software for Gibbs-energy minimization in order to calculate all thermodynamic properties and any type
of phase-diagram section. The modified quasichemical model was used for the liquid-slag phase. Sublattice models, based upon
the compound-energy formalism, were used for the olivine, spinel, pyroxene, and monoxide solid solutions. The use of physically
reasonable models means that the models can be used to predict thermodynamic properties and phase equilibria in composition
and temperature regions where data are not available. 相似文献
16.
Weiming Huang 《Metallurgical and Materials Transactions A》1996,27(11):3591-3600
The phase equilibrium and thermodynamic information of the Nb-N system was reviewed and assessed by using thermodynamic models
for the Gibbs energy of individual phases. Although there was a large amount of experimental information of the system, heat
capacity data of the Nb2N and NbN were not available either in low or high temperatures. In the present study, low-temperature heat capacity and theo
S
298 values were estimated using estimated entropy Debye temperatures. Only the Nb2N (hcp) and NbN (fcc) nitrides were considered to be the true binary phases and were included in the present evaluation in
addition to the N2 gas, liquid, andα-solid solution (bcc). Three thermodynamic models were used: a two-sublattice model for the solid solution phases, a substitutional
model for the liquid phase, and an ideal-gas model for the N2 gas. The model parameters were evaluated by fitting to the selected data by means of a computer program. A consistent set
of parameters was obtained which satisfactorily described most of the experimental and estimated data. 相似文献
17.
Available thermodynamic and phase diagram data have been critically assessed for all phases in the CrO-Cr2O3-SiO2-CaO system from 298 K to above the liquidus temperatures at all compositions under reducing conditions and at low CaO concentrations
under oxidizing conditions. All reliable data have been simultaneously optimized to obtain one set of model equations for
the Gibbs energy of the liquid slag and all solid phases as functions of composition and temperature. The modified quasichemical
model was used for the slag. The models permit phase equilibria to be calculated for regions of composition, temperature,
and oxygen potential where data are not available. 相似文献
18.
The possibility of calculating the thermodynamic equilibrium data in the metal extraction system UO2Cl2—TBP by using the existing theories of solution is discussed. A systematic thermodynamic approach for calculating component activity coefficients in the ternary organic phase is described. Seven models have been investigated and compared for calculation of the activity coefficients of non-electrolytes in organic phases. Among them, the Scatchard-Hildebrand model and Guggenheim quasi-lattice model are the most simple and convenient for practical use. 相似文献
19.
P. Coursol A. D. Pelton P. Chartrand M. Zamalloa 《Metallurgical and Materials Transactions B》2005,36(6):825-836
The phase diagram of the CaSO4-Na2SO4-Ca3(AsO4)2-Na3(AsO4) system was measured by differential thermal analysis and by an equilibration and quenching technique. Thermodynamic models
were developed giving the Gibbs energies of all phases as functions of temperature and composition. Optimized model parameters
were obtained by assessment of all available thermodynamic and phase equilibrium data. The models, which reproduce all the
data within experimental error limits, were used to calculate the liquidus surface of the system. The modified quasi-chemical
model in the quadruplet approximation was used for the liquid solution. For the various solid solution phases, the modified
quasi-chemical model, which accounts simultaneously for short-range-ordering among first-nearest-neighbor (FNN) and second-nearest-neighbor
(SNN) pairs, was used for the first time within the framework of the compound energy formalism. The distinction between true
model parameters and formalism parameters is made. Implications of the work for the potential use of sulfate fluxes for copper
refining are discussed. 相似文献
20.
Optimization of the phase diagram of FeO-V2O3 system is a part of an on-going research project to develop a self-consistent multi-component thermodynamic database for vanadium slag from hot metal.Due to the lack of experimental data for optimization,a novel experimental investigation has been carried out by thermal analysis(DSC)with a series of slags on different V2O3 contents(i.e.3mass%-12mass%).All available thermodynamic and phase diagram data for the binary systems have been simultaneously optimized with CALPHAD(Calculation of Phase Diagrams)methods to give one set of model equations for the Gibbs free energy of the liquid slag as functions of composition and temperature.The modified quasi-chemical model was used to describe the binary slag system.It was demonstrated that the calculated phase diagram with the optimized parameters was in good agreement with the experimental data. 相似文献