THE FACT FTsalt SALT DATABASES

 

The FTsalt solution database (FTsalt53Soln.sda) contains salt solutions evaluated/optimized by the FACT group.  The FTsalt compound database (FTsalt53Base.cdb) contains all stoichiometric solid and liquid salts evaluated/optimized by the FACT group to be thermodynamically consistent with the FTsalt solution database.  Also, a density model is available for some molten salt systems.

 

The salt databases have been under development for over 30 years.  During the period 2000-2003, major additions and modifications were made as part of the FACT Database Consortium Project with funding from the Natural Sciences and Engineering Research Council of Canada and 15 industries (Noranda, INCO, Teck Cominco, Rio Tinto, Alcoa, Shell, Corning, Dupont, Pechiney, St. Gobain Recherche, Schott Glas, Sintef, Norsk Hydro, Mintek, IIS Materials.)

 

Note that data for the system AlF3-NaF-CaF2-LiF-MgF2-Al2O3 are found in the FThall databases and for the entire system Na-K-S-C-O-Cl-H in the FTpulp database.

 

 

                                   Systems and Components

 

The FTsalt databases contain data for pure salts and salt solutions of 29 cations (Li, Na, K, Rb, Cs, Mg, Ca, Sr, Ba, NH4, Mn, Al, Fe(II), Fe(III), Co, Ni, Zn, Pb, La, Ce, Nd, Th, U(III), U(IV), Pu(III), Pu(IV), Cr(II), Cr(III), Mo(V))  and 8 anions (F, Cl, Br, I, NO3, OH, CO3, SO4)  (as well as for dilute solutions of O2- and OH- in the molten salt phase.)  Not all binary and ternary sub-systems have been evaluated and optimized, nor are all composition ranges covered. Sub-systems which have not been evaluated and optimized have been assumed ideal or have been approximated. The sub-systems and composition ranges which have been evaluated and optimized are described in the following. The most accurate calculations will be obtained in or near these sub-systems and composition ranges.

 

Note that when the properties of a multicomponent salt solution are approximated by means of a model from the optimized model parameters for its sub-systems, the approximation will be more accurate in the case of a common-cation or common-anion system than in the case of a reciprocal solution.  (A reciprocal solution is one containing 2 or more cations and 2 or more anions.)  For example, an estimation of the properties of a molten ternary common-anion chloride system ACl-BCl-CCl (abbreviated A,B,C//Cl) from optimized model parameters for its binary sub-systems (ACl-BCl, ACl-CCl and BCl-CCl) will in general be more precise than an estimation of the properties of a molten ternary reciprocal salt solution ACl-BCl-AF-BF (abbreviated A,B//F,Cl) from the optimized model parameters of its binary sub-systems (ACl-BCl, AF-BF, ACl-AF and BCl-BF).

 

Volumetric properties (density) as a function of temperature were entered for most of the pure liquids in the SALT liquid solution of the FTsalt database.  Moreover, a density model (taking into account excess volume upon mixing) is available for the NaCl-KCl-MgCl2-CaCl2, LiF-NaF-KF-MgF2-CaF2 and NaCl-KCl-ZnCl2 molten salt systems. Approximate density calculations may be performed for larger systems such as Li, Na, K, Mg, Ca // Cl, F : all binary common-cation systems of the type LiCl-LiF, MgCl2-MgF2,… and all LiCl-based chloride binary systems of the type LiCl-NaCl, LiCl-MgCl2,… are then assumed to be ideal (in terms of the volumetric properties).

In order to perform density calculations for the SALT liquid solution, the following procedure must be followed : in the Menu Window of Equilib, select the liquid solution FTsalt-SALTA (for LiF-NaF-KF-MgF2-CaF2 or NaCl-KCl-MgCl2-CaCl2) or FTsalt-SALTI (for NaCl-KCl-ZnCl2), and check the box “include molar volumes”.  In the Results Window, the density value (in gram/cm3) calculated from the model is displayed (in parentheses) at the 2nd line of the block corresponding to the liquid phase.  A system density (in gram/cm3) that takes into account the available density data for all phases at equilibrium (liquid + 1 or more solid phases) is displayed below the integral property table.

 

System Li,Na,K,Mg,Ca//Cl,F

Evaluated and optimized at all compositions including all ternary reciprocal systems

[3002, 3008, 3009, 3010].

Density model available for the NaCl-KCl-MgCl2-CaCl2 and LiF-NaF-KF-MgF2-CaF2 molten salt systems [3025, 3026, 3032].

 

System Li,Na,K,Mg,Ca,Mn,Fe(II),Fe(III),Co,Ni,Al//Cl

Molten chloride solution evaluated and optimized at all compositions [3002, 3008, 3013, 3014, 3015, 3016]. (Note that the 2 binary terminal solid solutions in the AlCl3-FeCl3 system remain to be optimized.)

Density model available for the NaCl-KCl-MgCl2-CaCl2 molten salt system [3026].

 

System Li,Na,K,Rb,Cs,Mg,Ca,Sr,Ba//Cl

Molten chloride system evaluated and optimized at all compositions [3002, 3007, 3008, 3011].

Density model available for the NaCl-KCl-MgCl2-CaCl2 molten salt system [3026].

 

System Li,Na,K,Rb,Cs//F,Cl,Br,I,NO3,OH

All binary systems (AX-AY and AX-BX) have been evaluated and optimized, with the exception of: LiI-LiNO3, RbF-RbNO3, RbF-RbOH, RbCl-RbNO3, RbBr-RbOH, RbI-RbNO3, RbI-RbOH, CsF-CsOH, CsCl-CsOH, CsBr-CsOH, CsI-CsOH and CsI-CsNO3 for which ideal liquid solutions are assumed.

All ternary common-ion systems (AX-BX-CX and AX-AY-AZ) of the Li,Na,K,Rb,Cs//F,Cl,Br,I sub-system have been evaluated and optimized.

Reciprocal ternary systems (those containing two cations and two anions) have been optimized only for fluorides and chlorides of Li, Na and K. Other reciprocal ternary interactions are estimated.  Hence, calculations for most multicomponent common-ion systems should be good, but calculations for multicomponent reciprocal systems (containing 2 or more cations and 2 or more anions) will not be as good if any of Rb, Cs, Br, I, NO3 or OH are present [3002, 3004, 3006, 3017].

 

System Li,Na,K//F,Cl,NO3,OH,SO4,CO3

All binary systems (AX-AY and AX-BX) but no ternary common-ion systems (AX-BX-CX and AX-AY-AZ) have been evaluated and optimized except LiF-NaF-KF and LiCl-NaCl-KCl.

The reciprocal ternary systems (those containing two cations and two anions) that have been optimized are: the fluorides and chlorides of Li, Na and K; Na,K//Cl,CO3; Na,K//Cl,SO4 and Na,K//CO3,SO4. Other reciprocal ternary interactions are estimated. Hence, calculations for multicomponent common-ion systems should be good, but calculations for multicomponent reciprocal systems (containing 2 or more cations and 2 or more anions) will usually not be as good if any of NO3, OH, SO4 or CO3 are present [3002, 3003, 3004, 3005].

 

System Li,Na,K,Rb,Cs,La,Ce//Cl

Molten chloride solution. Limited available data (mainly for binary systems) have been evaluated and optimized [3002, 3008, 3018].

 

System Na,K,Ca,Pb//Cl

Molten chloride solution optimized and evaluated (mainly for binary systems when PbCl2 is involved) [3002, 3008, 3019].

 

System Na,K,Mg,Ca,Al,Zn//Cl

Molten chloride solution optimized and evaluated (mainly for binary systems when ZnCl2 is involved) [3002, 3008, 3015, 3016].

Density model available for the NaCl-KCl-MgCl2-CaCl2 and NaCl-KCl-ZnCl2 molten salt systems [3026, 3041].

 

System Li,Th,U(III),U(IV),Pu(III),Pu(IV),Cr(II),Cr(III),Ni(II),Mo(V)//F

Molten fluoride solution optimized and evaluated (dedicated to the LiF-ThF4-UF3-UF4-PuF3-PuF4 system for the so-called Molten Salt Nuclear Reactors).

In order to evaluate the oxido-reduction behaviour of the molten salt solution contained in Ni-Cr-based alloys, the components CrF2, CrF3, NiF2 and MoF5 were added to the liquid phase as ideal components (i.e. their Gibbs energies g0liquid are included, but these components mix ideally with all other components).

 

System Li,Mg,Ca,La,Ce,Nd//F

Limited available data (mainly for binary systems) have been evaluated and optimized.

 

System Li,Mg,Ca,La,Ce,Nd//Cl

Limited available data (mainly for binary systems) have been evaluated and optimized.

 

ReCl3-ReF3 binary systems

(Re = La,Ce,Nd). Approximately optimized at all compositions.

 

Dissolution of O2- and OH- in dilute solution in molten halides

has been modeled and optimized for composition regions where data are available.  For details, see the detailed descriptions of FTsalt-SALTA, FTsalt-SALTB and FTsalt-SALTD under “Description of solutions” in this menu.

 

Systems K,Ca//CO3,SO4  and Ca,Mg,Na//SO4

Approximately optimized at all compositions.

 

 

 

Phases

 

For complete descriptions of all solution phases, click on “Description of solutions” in this menu.

 

 

                                  The Molten Salt Solution

 

The molten salt phase contains all the components in the FTsalt databases.  The modified quasichemical model is used  [1010, 1015, 1016, 1019, 1020, 1021, 1022], generally in the quadruplet approximation [1022] which takes account of short-range-ordering among first-nearest-neighbour cation-anion pairs and second-nearest-neighbour cation-cation and anion-anion pairs.  When AlCl3 is a component, a distinction among 4-coordinated Al[3+] (Al tetra), 5-coordinated Al[3+] (Al penta) and dimeric Al2[6+] is made in the model. The 5-coordinated Al[3+] species (Al penta) was introduced only in order to be consistent with the model used for AlF3-based (cryolitic) systems in the FThall database. See detailed descriptions of FTsalt-SALT, FTsalt-SAL2, FTsalt-LCSO and FTsalt-LSUL by clicking on “Description of solutions” [3002, 3003, 3004, 3005, 3006, 3007, 3008, 3009, 3010, 3011, 3013, 3014, 3015, 3016, 3017, 3018, 3019].

 

 

                                      Solid Solutions

 

In general, for solid solution phases, a sublattice model is used, based on the Compound Energy Formalism [1026].  Estimation of multicomponent properties from binary model parameters is generally performed using a generalized Kohler-Toop technique [1016, 1019].

 

 

A2MX4 Solid Solution

Solid solution with A = Li,Na,K,Rb,Cs on one cationic sublattice, M = Mg,Ca,Mn,Fe(II),Co,Ni,Sr,Ba on the second cationic sublattice, and X = F,Cl on the anionic sublattice.  The following combinations of components have been optimized over their entire composition ranges:

 

(Li,Na,K)2[Mg,Ca,Mn,Fe(II),Co,Ni]Cl4

(Li,Na,K,Rb,Cs)2[Mg,Ca,Sr,Ba]Cl4

(Li,Na,K)2[Mg,Ca]{F,Cl}4

 

See detailed description of FTsalt-AMX4 by clicking on “Description of solutions” [3007, 3008, 3009, 3010, 3011, 3014].

 

Perovskite structure solid solution AMX3

Solid solution with A = Li,Na,K,Rb,Cs on one cationic sublattice,

M = Mg,Ca,Mn,Fe(II),Co,Ni,Sr,Ba on the second cationic sublattice, and X = F,Cl on the anionic sublattice.  The following combinations of components have been optimized over their entire composition ranges:

 

(Li,Na,K)[Mg,Ca,Mn,Fe(II),Co,Ni]Cl3

(Li,Na,K,Rb,Cs)[Mg,Ca,Sr,Ba]Cl3

(Li,Na,K)[Mg,Ca]{F,Cl}3

 

See detailed description of FTsalt-PRVK by clicking on “Description of solutions” [3007, 3008, 3009, 3010, 3011, 3014].

 

Other solid solutions

73 additional evaluated and optimized solid solutions are available in the FTsalt solution database.  These are summarized under “List of compounds and solutions” and detailed descriptions are provided under “Description of solutions.”

 

                               Stoichiometric Solid Salts

Evaluated and optimized properties for over 220 stoichiometric solid salts are found in the FTsalt compound database.  For a list, see “List of compounds and solutions.”