ORALS

SESSION: MoltenFriPM1-R1	Angell International Symposium on Molten Salt, Ionic & Glass-forming Liquids: Processing and Sustainability (7th Intl. Symp. on Molten Salt, Ionic & Glass-forming Liquids: Processing and Sustainability).
Fri Oct, 25 2019 / Room: Ambrosia A (77/RF)
Session Chairs: Yizhak Marcus; Yuanzheng Yue; Session Monitor: TBA

14:50: [MoltenFriPM107]
Forecast of geometrical structure for T-x-y-z diagram Li,Na,Th,U||F
Vasily Lutsyk¹ ; Anna Zelenaya¹ ; Maria Parfenova² ; Marina Lamueva³ ; ¹Institute of Physical Materials Science SB RAS, Ulan-Ude, Russian Federation; ²Tomsk State University of Control Systems and Radio-electronics, Tomsk, Russian Federation; ³Institute of Physical Materials Science, Ulan-Ude, Russian Federation;
Paper Id: 173 [Abstract]

Geometric structure of four T-x-y diagrams, forming the T-x-y-z diagram of the quaternary system Li,Na,Th,U||F have been thoroughly analyzed, and 3D models of 4 space diagrams have been assembled. On the basis of data for the structure of the bounding binary and ternary systems, a scheme of mono and invariant states for the quaternary system has been formed. This scheme is the basis for the topological forecast of the geometrical structure of the Т-х-y-z diagram for LiF-NaF-ThF₄ -UF₄ (А-B-C-D) system. Nineteen binary compounds R(J) and 30 invariant transformations (2 peritectic, 20 quasiperitectic and 8 eutectic ones) are characterized this quaternary diagram. It is expected that within the quaternary system, 10 invariant reactions involving the melt (6 of quasiperitectic type and 4 of peritectic type) should run. The Т-х-y-z diagram will be formed by 17 hypersurfaces of liquidus. Seven of them correspond to the primary crystallization of lithium and sodium fluorides (A and B) and solid solutions С(D), R2(R11), R4(R12), R7(R15), R8(R16). Ten of them correspond to the primary crystallization of compounds R1, R3, R5, R6, R9, R10, R13, R14, R17, R18. Compound R10 on the edge LiF-UF4 (A-D) has, in both ternary adjoining systems, LiF-NaF-UF4 (A-B-D) and LiF-ThF4-UF4 (А-C-D), the liquidus surfaces of the wedge type. Compound R10 participates only in 2 phase reactions Q14: L+R10→A+R2(R11) and E7: L→A+R10+R2(R11). Therefore, it is assumed that in the Т-х-у-z diagram, the dots Q14 and E7 are joined without the quaternary invariant dot. On the scheme of mono and invariant states, they are joined by a line, corresponding to the reaction L→A+R10+R2(R11). Thus, a liquidus hypersurface of the compound R10 has a counter eR10R11pAR10E7Q14.

References:
1. Beneš O. Thermodynamics of molten salts for nuclear applications. Dissertation. Prague. 2008. 205 p.
2. Beneš O., Beilmann M., Konings R.J.M. Thermodynamic assessment of the LiF-NaF-ThF4-UF4 system // Journal of Nuclear Materials. 2010. Vol. 405. P. 186-198.
3. Phase Diagrams of Nuclear Reactor Materials. ORNL-2548 / ed. by Тhoma R.E. 1956. 205 p.

SESSION: MoltenFriPM2-R1	Angell International Symposium on Molten Salt, Ionic & Glass-forming Liquids: Processing and Sustainability (7th Intl. Symp. on Molten Salt, Ionic & Glass-forming Liquids: Processing and Sustainability).
Fri Oct, 25 2019 / Room: Ambrosia A (77/RF)
Session Chairs: Rasmus Fehrmann; Masahiro Yoshizawa-Fujita; Session Monitor: TBA

16:20: [MoltenFriPM210]
Variants of T-x-y-z Diagrams for Subsystems LiF-LiCl-NaCl-UCl3, LiF-NaF-NaCl-UC3, 7NaF-6UF4-LiF-UF4-UCl3, 3NaF-UF4-LiF-NaF-UCl
Vasily Lutsyk¹ ; Vera Vorob'eva¹ ; Maria Parfenova² ; Marina Lamueva³ ; ¹Institute of Physical Materials Science SB RAS, Ulan-Ude, Russian Federation; ²Tomsk State University of Control Systems and Radio-electronics, Tomsk, Russian Federation; ³Institute of Physical Materials Science, Ulan-Ude, Russian Federation;
Paper Id: 125 [Abstract]

Previously, [1] the possible options for the system Li,Na,U||F,Cl polyhedration were considered. The system LiF-NaCl is eutectical [1] (eutectic 0.415 mole LiF at 685°С), so within the reciprocal system Li,Na,U||F,Cl , diagonal LiF-NaCl is stable. It is also known [2, Р. 88] that a NaF-UF4 system is characterized by 3 eutectics (0.215 mole UF4 at 618°С; 0.28 mole UF4 at 623°С and 0.56 mole UF4 at 680°С), 2 peritectics (0.325 mole UF4 at 648°С and 0.37 mole UF4 at 673°С, 2 congruently melting compounds (R1=3NaF-UF₄, R2=7NaF-6UF₄), and 2 incongruently melting ones (2NaF-UF₄, 5NaF-3UF₄). As a result, it is possible to consider 3 variants of polyhedration: two with the stable diagonal LiF-UCl₃ (LiF-UCl₃, NaF-UCl₃ and LiF-UCl₃, NaCl-UF4), and one with the diagonals LiCl-UF₄, NaCl-UF₄. In the case of polyhedration with the stable diagonals LiF-UCl₃ and 3 diagonals from the apex NaCl, the initial prism of the reciprocal system consists of 5 tetrhedra: LiF-NaF-NaCl-R₁, LiF-UF₄-NaCl-UCl₃, LiF-UF₄--NaCl-R₂, LiF-LiCl-NaCl-UCl₃, and LiF-NaCl-R₁-R₂. When all stable diagonals are of the eutectic type, then the tetrahedron LiF-LiCl-NaCl-UCl₃ is bounded by 5 eutectic binary systems and by LiCl-NaCl. This includes the continuous rows of solid solutions. Systems LiF-NaF-NaCl-R₁, LiF-NaF-NaCl-UCl₃ , and LiF-NaF-UCl₃-R₁ are bounded by 6 binary and 4 ternary eutectic systems. This work has been performed under the program of fundamental research SB RAS (project 0336-2016-0006) and partially supported by the RFBR project 17-08-00875.

References:
1. V. Lutsyk, V. Vorob'еva, M. Parfenova, M. Lamueva. Materials for the Nuclear Reactors of Generation IV: Polyhedration of the Chloride-Fluoride Reciprocal Systems // Sustainable Industrial Processing Summit & Exhibition SIPS-2018. Intl. Symp. on Sustainable Molten Salt and Ionic Liquid Processing. - Id Paper: 96 https://www.flogen.org/sips2018/technical_program.php?a=c51ce410c124a10e0db5e4b97fc2af3 2. Gabcova J., Peschl J., Malinovsky M. et al // Chemicke Zvesti (Chemical Papers). 1976. V. 30. No 6. P. 796-804.
3. Thoma R.E., Editor. Phase Diagrams of Nuclear Reactor Materials, Union Carbide Corp., Oak Ridge, Tennessee, 1959, 205 pp.