Sept 24, 2004
SOLUTIONS IN FThall
[FILE]
[FThall-Bath]
Base: FThall
Phase: Bath
Bath NaF-AlF3-CaF2-LiF-MgF2-Al2O3 + dissolved metal (?)
(uncertainties above 1100oC or CR>5 or CR<1.5; ? = metal dissolution)
Components:
FThall-BathA: NaF, AlF3_5coord, AlF3_4coord, Al2F6, CaF2, LiF, MgF2,
Na2O, Al2O3_5coord, Al2O3_4coord, Al2O3, CaO, Li2O, MgO
FThall-Bath?: NaF, AlF3_5coord, AlF3_4coord, Al2F6, CaF2, LiF, MgF2,
Na2O, Al2O3_5coord, Al2O3_4coord, Al2O3, CaO, Li2O, MgO,
Na, Al_5coord, Al_4coord, Al2, Ca, Li, Mg
Selection Type: I (possible 2-phase immiscibility)
This solution corresponds to the liquid electrolyte Na3AlF6-AlF3-Al2O3-CaF2-LiF-MgF2. FThall-BathA corresponds to the fluoride-oxide melt, while FThall-Bath? should be use when metal is equilibrated with the bath (addition of metal dissolution to FThall-BathA).
Never select FThall-Bath simultaneously with FTsalt-SALT or FTsalt-SAL2.
The Modified Quasichemical Model in the Quadruplet Approximation has been used for this solution. The model assumes a non-random mixing of elemental cations and anions on their respective sublattices. 1st and 2nd nearest-neighbour short-range order is calculated by the model by modifying the configurational entropy as a function of 1st and 2nd nearest-neighbour pair energies.
Cations: Na+, Al3+(5 coordinated), Al3+(4 coordinated), Al26+ (2 bridged Al3+), Li+, Ca2+ and Mg2+
Anions: F-, O2- and Va-
Al3+(4 coordinated) is conceptually related to "AlF4-". Al3+(5 coordinated) is conceptually related to "AlF52-". Al3+(6 coordinated) is neglected in the model, so the highest coordination of Al3+ is 5. (This is a limitation of the model). Al3+(6 coordinated) has been neglected because tests showed that its inclusion did not improve the fits to the experimental phase diagram and thermodynamic property data, and increased the complexity of the model which is intended for large database development. Va- is a charged vacancy or electron temporarily located on an anionic position (F-center) whose presence is equivalent to excess metal dissolution in the salt melt.
Limitations:
1 NaF-AlF3-[Na-Al]: the model covers the whole liquid range for P < 3 atm (the Na-NaF liquid miscibility gap cannot be "closed" at high pressures).
2 NaF-AlF3-Al2O3: the model has good predictive capabilities for CR < 5 and CR > 1.5 and for T < 1100oC. A spurious miscibility gap appears for very high CR at NaAlO2-NaAl9O14 co-saturation.
3 In the oxide-free system, the model covers the whole range of composition in the LiF-NaF-MgF2-CaF2-AlF3 system but predictions in the LiF-MgF2-AlF3 system rich in AlF3 are not very good. The error in the calculated liquidus of AlF3 may also be large in the CaF2-AlF3 system.
4 Metal dissolution outside the NaF-AlF3-Al2O3 system is approximate.
Figures:
NaF_AlF3_Bath.fig
Na3AlF6_Al2O3_Bath.fig
CaF2_AlF3_Bath.fig
LiF_AlF3_Bath.fig
MgF2_AlF3_Bath.fig
NaF_CaF2_Bath.fig
NaF_MgF2_Bath.fig
LiF_NaF_Bath.fig
LiF_CaF2_Bath.fig
LiF_MgF2_Bath.fig
MgF2_CaF2_Bath.fig
Na3AlF6_Li3AlF6_Bath.fig
References: 1022, 3012
[FThall-CryH]
Base: FThall
Phase: CryH
Na-Cryolite-H Na3AlF6-Li3AlF6-AlF3-CaF2
High temperature non-stoichiometric cryolite
Components: Na3AlF6, Na3AlF4[2+], AlF4[-], AlF6[3-], Ca3AlF6[3+]
Ca3AlF4[5+], Li3AlF6, Li3AlF4[2+]
Selection Type: + (single phase)
This solution corresponds to the non-stoichiometric high-temperature solid Na3AlF6-AlF3 dissolving excess CaF2 and Li3AlF6. The solution is stable above 525oC and below 1020oC.
A two-sublattice model with the following ions has been used:
Cations: Na+, Li+, Ca2+ and Va0 (neutral vacancy)
Anions: AlF63- and AlF4-
A charge balance, from which the Va0 concentration is calculated, is performed to ensured the electro-neutrality of the solution.
The conductivity of the solid solution can be calculated as a function of T and excess AlF3 using the mole fraction of cationic vacancies (XVa) calculated by EQUILIB and according to the following equation (E.W.Dewing, Metall. Trans. B, vol.9, pp.687-690, 1978):
Log10s = -2288 / T(K) + 4.33412 + log10XVa ohm-1 (XVa from EQUILIB output : see below)
+ 0.57587 gram ( 89.771 wt.% Na3AlF6 FThall
+ 6.5345 wt.% Na3AlF4[2+] FThall
+ 0.22520 wt.% AlF4[-] FThall
+ 3.4689 wt.% AlF6[3-] FThall)
(960.00 C, 1 atm, Na-Cryolite-H, d= 2.8993 g.cm-3)
Mole fraction of sublattice constituents in Na-Cryolite:
Na[+] 0.94559
Va 0.54414E-01 (XVa from EQUILIB output)
------------------------
AlF6[3-] 0.91838
AlF4[-] 0.81622E-01
Figures:
NaF_AlF3_Na-Cryolite-H.fig
Na3AlF6_Li3AlF6_Na-Cryolite-H.fig
References : 3012
[FThall-CryL]
Base: FThall
Phase: CryL
Na-Cryolite-L Na3AlF6-Li3AlF6-[Ca(1.5)AlF6]
Low-temperature solid cryolite Na3AlF6 diss. Ca[2+] & Li[+]
Components: Na3AlF6, AlF6[3-], Ca3AlF6[3+], Li3AlF6
Selection Type: + (single phase)
This solution corresponds to the low-temperature solid Na3AlF6 solution dissolving excess CaF2 and Li3AlF6. The solution is stable below 560oC. There is no dissolution of excess AlF3 as in CryH.
A two-sublattice model with the following ions has been used:
Cations: Na+, Li+, Ca2+ and Va0 (neutral vacancy)
Anions: AlF63- and AlF4-
A charge balance, from which the Va0 concentration is calculated, is performed to ensured the electro-neutrality of the solution.
Figures:
Na3AlF6_Li3AlF6_Na-Cryolyte-L.fig
References: 3012
[FThall-LiCB]
Base: FThall
Phase: LiCB
Li-Cryolite-B Beta-Li3AlF6 dissolving Na[+]
Components: Li3AlF6, Na3AlF6
Selection Type: + (single phase)
This solution corresponds to the low-temperature solid Li3AlF6–b solution dissolving excess Na3AlF6. The solution is stable below 525oC.
A two-sublattice model with the following ions has been used:
Cations: Na+, Li+
Anions: AlF63-
Figures:
Na3AlF6_Li3AlF6_Li-Cryolite-B.fig
References: 3012
[FThall-LiCG]
Base: FThall
Phase: LiCG
Li-Cryolite-G Gamma-Li3AlF6 dissolving Na[+]
Components: Li3AlF6, Na3AlF6
Selection Type: + (single phase)
This solution corresponds to the low-temperature solid Li3AlF6–g solution dissolving excess Na3AlF6. The solution is stable above 475oC and below 650oC.
A two-sublattice model with the following ions has been used:
Cations: Na+, Li+
Anions: AlF63-
Figures:
Na3AlF6_Li3AlF6_Li-Cryolite-G.fig
[FThall-LiCD]
Base: FThall
Phase: LiCD
Li-Cryolite-D Delta-Li3AlF6 dissolving Na[+]
Components: Li3AlF6, Na3AlF6
Selection Type: + (single phase)
This solution corresponds to the low-temperature solid Li3AlF6–d solution dissolving excess Na3AlF6. The solution is stable above 625oC and below 800oC.
A two-sublattice model with the following ions has been used:
Cations: Na+, Li+
Anions: AlF63-
Figures:
Na3AlF6_Li3AlF6_Li-Cryolite-D.fig
[FThall-CrLt]
Base: FThall
Phase: CrLt
Cryolithionite (non-stoichiometric cubic Na3Li3Al2F12 diss. excess Li3AlF6)
use I-option
Components: Na3Li3Al12F12, Li3Li3Al12F12
Selection Type: I (possible 2-phase immiscibility)
This solution corresponds to the non-stoichiometric solid Na3Li3Al2F12 solution dissolving excess Li3AlF6. The solution is stable below 725oC.
A three-sublattice model with the following ions has been used:
Sublattice 1: Na+, Li+ (sublattice stoichiometry = 3)
Sublattice 2: Li+ (sublattice stoichiometry = 3)
Sublattice 3: AlF63- (sublattice stoichiometry = 2)
Figures:
Na3AlF6_Li3AlF6_Cryolithionite.fig
[FThall-NaF]
Base: FThall
Phase: NaF
NaF-ss dissolving LiF (Rocksalt)
use I option
Components: NaF-LiF
Selection Type: I (possible 2-phase immiscibility)
This solution is the NaF-rich solid solution dissolving LiF. It may be stable below 1000oC. In the following figure, the solid phase on the left-hand side is solid LiF(s) (see FThall-LiF).
Do not select FThall-NaF simultaneously with any fluoride solution or fluoride compound from any database other than FThall.
Figures:
LiF_NaF_NaF-ss.fig
[FThall-LiF]
Base: FThall
Phase: LiF
LiF-ss dissolving MgF2
Components: LiF-MgF2
Selection Type: + (single phase)
This solution is the LiF-rich solid solution dissolving MgF2. It may be stable below 850oC.
Do not select FThall-LiF simultaneously with any fluoride solution or fluoride compound from any database other than FThall.
Figures:
LiF_MgF2_LiF-ss.fig
[FThall-MgF2]
Base: FThall
Phase: MgF2
MgF2-ss dissolving LiF
Components: MgF2-LiF
Selection Type: + (single phase)
This solution is the MgF2-rich solid solution dissolving LiF. It may be stable below 1270oC.
Do not select FThall-MgF2 simultaneously with any fluoride solution or fluoride compound from any database other than FThall.
Figures:
LiF_MgF2_MgF2-ss.fig
[FThall-Liq]
Base: FThall
Phase: Liq
Liquid-Alloy Liquid light-metal Al,Mg,Ca,Na
Use I Option (Inf. dil. act. coeff. of Ca in Al is estimated)
Components: Al-Mg-Na-Ca
Selection Type: I (possible 2-phase immiscibility)
This solution is the liquid alloy solution. It encompasses the Al-Na miscibility gap.
Do not select FThall-Liq simultaneously with any metallic phase from any database other than FThall.
Figures:
Al_Na_Liquid.fig
Al_Mg_Liquid.fig
Na_Ca_Liquid.fig
Al_Ca_Liquid.fig
[FThall-FCC]
Base: FThall
Phase: FCC
FCC Al-[Na,Mg] solid solution
Components: Al-Mg-Na
Selection Type: + (single phase)
This solution is the FCC Al-alloy solution dissolving Mg and Na.
Do not select FThall-FCC simultaneously with any metallic phase from any database other than FThall.
Figures:
Al_Mg_FCC.fig
[FThall-HCP]
Base: FThall
Phase: HCP
HCP Mg dissolving Al
Components: Mg-Al
Selection Type: + (single phase)
This solution is the HCP Mg-alloy solution dissolving Al.
Do not select FThall-HCP simultaneously with any metallic phase from any database other than FThall.
Figures:
Al_Mg_HCP.fig
[FThall-BCC]
Base: FThall
Phase: BCC
BCC Ca,Na
Use I-option
Components: Ca-Na
Selection Type: I (possible 2-phase immiscibility)
This solution is the high-temperature BCC Ca-alloy solution dissolving Na. It is also the low-temperature BCC Na-alloy solution dissolving Ca.
Do not select FThall-BCC simultaneously with any metallic phase from any database other than FThall.
Figures:
Na_Ca_BCC.fig
[FThall-AlMg]
Base: FThall
Phase: AlMg
Gamma Al12Mg17 gamma solid solution
Al-Mg defect solid solution - Laves Phase
Components: Al12Mg17-Al-Mg
Selection Type: + (single phase)
This solution is the intermediate Al12Mg17 solid solution often denoted “Gamma”. It usually saturates the Mg-HCP solid solution.
Do not select FThall-AlMg simultaneously with any metallic phase from any database other than FThall.
Figures:
Al_Mg_Gamma.fig
[FThall-Spin]
Base: FThall
Phase: Spin
Spinel MgAl2O4 with dissolved Al2O3
Recommend Option-I
Components: Al3O4[+]-Al1O4[5-]-Mg3O4[2-]-Mg1O4[6-]
Selection Type: I (possible 2-phase immiscibility)
This solution is the spinel solid oxide solution MgAl2O4 dissolving excess Al2O3.
A three-sublattice model has been used with Mg2+ and Al3+ mixing on tetrahedral and octahedral sites while O2- fills the third sublattice.
Do not select FThall-Spin simultaneously with any spinel solution from the FToxid database.
Figures:
MgO_Al2O3_Spinel.fig
[FThall-Mono]
Base: FThall
Phase: Mono
Monoxide Rocksalt MgO-CaO-[Al2O3]
use I option
Components: CaO-MgO-Al2O3
Selection Type: I (possible 2-phase immiscibility)
This solution is the CaO-MgO solid solution which exhibits a miscibility gap. It includes the dissolution of a small amount of Al2O3.
Do not select FThall-Mono simultaneously with FToxid-MeO or FToxid-MONO.
Figures:
MgO_CaO_Monoxide.fig
MgO_Al2O3_Monoxide.fig
[ENDF]