ORALS

SESSION: MoltenWedAM-R11	Kipouros International Symposium (8th Intl. Symp. on Sustainable Molten Salt, Ionic & Glass-forming Liquids & Powdered Materials)
Wed. 30 Nov. 2022 / Room: Game
Session Chairs: Amr Henni; Session Monitor: TBA

12:20: [MoltenWedAM03] OS
4D Computer Models of T-x-y-z Diagrams Within the Tetrahedrized Fluoride-Chloride Quaternary Reciprocal Systems To Design The Fuels of Nuclear Reactor Generation 4
Vera Vorob'eva¹ ; Anna Zelenaya¹ ; Vasily Lutsyk¹ ; Marina Lamueva² ; Maria Parfenova¹ ; ¹Institute of Physical Materials Science SB RAS, Ulan-Ude, Russian Federation; ²Institute of Physical Materials Science, Ulan-Ude, Russian Federation;
Paper Id: 210 [Abstract]

The fuel compositions for molten-salt nuclear reactor of the 4th generation are usually fluorides of metals with a small cross-section of neutron capture [1-3]. Сhloride systems, compared to fluoride, have higher vapor pressures and lower thermodynamic stability at high temperatures. At the same time, they are less aggressive in relation to the structure of the material and have lower melting temperatures. Therefore, in order to ensure the more reliable operation of the next generation reactors, it is necessary to consider chemical processes and equilibrium in mutual fluoride-chloride systems. Among the binary systems composed of fluoride or chlorides of alkaline metals and uranium (plutonium) we can say, that all fluoride systems forming ternary M1,M2,U(Pu)||F (M1,M2=Li,Na,K,Rb) are experimentally studied in more or less detail. But the chloride systems M1,M2,U(Pu)||Cl (M1,M2=Li,Na,K,Rb) have been studied much less. And there is no information about the study of ternary reciprocal systems M,U(Pu)||F,Cl (M=Li,Na,K,Rb). Accordingly, the polyhedration of the M1,M2,U(Pu)||F,Cl (M1,M2=Li,Na,K,Rb) quaternary reciprocal systems can only be multivariate, and the construction of 4D computer models T-x-y-z diagrams of the resulting subsystems - virtual. Four variants of the Li,Na,U||F,Cl system polyhedration are discussed and 3 quintets of four- dimensional T-x-y-z diagrams for the quaternary systems have been forecasted. This work was been performed under the program of fundamental research SB RAS (project 0336-2019-0008), and it was partially supported by the RFBR project 19-38-90035.

References:
1. Thoma R.E., Editor. Phase Diagrams of Nuclear Reactor Materials. – Union Carbide\nCorp., Oak Ridge, Tennessee, 1959. – 205 pp.\n2. Gabcova J., Peschl J., Malinovsky M. et al //Chemicke Zvesti (Chemical Papers). 1976.\nV. 30. No 6. P. 796-804.\n3. Vorob’eva V., Zelenaya A., Lutsyk V., Lamueva M. T-x-y-z Diagram Prediction for the\nQuaternary System Li,Na,Ca,La||F // IOP Conference Series: Materials Science and Engineering.\n- 2020. - V. 1000, 012007.

SESSION: NonferrousWedAM-R5	8th Intl. Symp. on Sustainable Non-ferrous Smelting & Hydro/Electrochemical Processing
Wed. 30 Nov. 2022 / Room: Arcadia 2
Session Chairs: Vasily Lutsyk; Tatyana Aleksandrova; Session Monitor: TBA

11:30: [NonferrousWedAM01] OS
Verifications of T-x-y Diagrams FeO-SiO2-Fe2O3 & Mg2SiO4-CaAl2Si2O8-SiO2
Vasily Lutsyk¹ ; Marina Lamueva² ; Anna Zelenaya¹ ; Maria Parfenova¹ ; ¹Institute of Physical Materials Science SB RAS, Ulan-Ude, Russian Federation; ²Institute of Physical Materials Science, Ulan-Ude, Russian Federation;
Paper Id: 277 [Abstract]

3D computer models for T-x-y diagrams of real systems FeO-SiO2-Fe2O3 and Mg2SiO4-CaAl2Si2O8-SiO2 and for their prototypes (with the expanded borders between the phase regions) have been elaborated [1-4]. Afterwards the 3D-puzzles of the exploded phase diagrams (PD) with the phase regions and with the clusters of phase regions as its elements have been printed. When preparing the technical specifications for the phase regions prototyping, the peculiarities of each region or the regions clusters have been thoroughly explained.<br />The T–x–y computer model for pseudo-ternary system Mg2SiO4–CaAl2Si2O8–SiO2 contains the immiscibility surface, five liquidus surfaces, 23 ruled surfaces, 4 horizontal complexes at the temperatures of invariant points, 20 phase regions. The calculation of crystallization paths was carried out. Using the diagrams of vertical and horizontal mass balances permit to analyze the crystallization stages and obtain the sets of microconstituents for the given mass centers. <br />The assembly of 3D model of phase diagram is the final stage of its study by the methods of thermal analysis and X-ray diffraction, and the correction of curvature of curves and surfaces in agreement with the thermodynamic parameters of components and new compounds. If there is the contradictory data, then different variants of PD are assembled. The PD computer model permits to compile the scheme of equilibrium crystallization in the concentration fields of various dimensions (point, line (curve) fragment and fragment of the concentration triangle plane) formed during orthogonal projection of all PD surfaces. This procedure is the main step in decoding the genotype of a heterogeneous material. The concentration fields with unique sets of micro-constituents are revealed as a result of calculation of the qualitative and quantitative composition of microstructure elements. In this case, a list of concentration fields with micro-constituents, which does not differ from the microconstituents of neighboring fields of smaller or the same dimension is compiled. <br />Analysis of two variants of FeO-SiO2-Fe2O3 PD showed that the presence of immiscibility surface of two melts does not affect the micro-constituents set of the heterogeneous ceramic materials of this system. In the case of application of the ultrafast cooling technology of initial melt and its heterogeneous states at various stages of crystallization, the final set of formed materials can be significantly expanded. <br />This work was been performed under the program of fundamental research SB RAS (project 0270-2021-0002) and it was partially supported by the RFBR project 19-38-90035.

References:
1. Parfenova M., Bimbaev E., Lutsyk V., Zelenaya A. 3D computer model and crystallization paths for system FeO-SiO2-Fe2O3 // Book of Abstracts of 12th Conference for Young Scientists in Ceramics, Novi Sad (Serbia), Oct. 18-21. 2017. P. 117-118.\n2. Parfenova M., Lamueva M., Zelenaya A., Lutsyk V.. Crystallization paths in the systems FeO-SiO2-Fe2O3 and Mg2SiO4-CaAl2Si2O8-SiO2 // 5th International Student Conference on Technical Sciences, Bor Lake (Serbia), 28 Sept - 1 Oct. 2018. Р..\n3. Lutsyk V.I., Zelenaya А.E. 3D мodel of Т-х-y diagram Mg2SiO4–CaAl2Si2O8–SiO2 for calculation of crystallization paths // Journal «Melts». 2017. №5. P. 382-391 (In Russian)\n4. Lutsyk V.I., Zelenaya A.E., Lamueva M.V. Calculation of Phase Trajectories for Microstructural Analysis in Liquidus Fields of Cristobalite and Tridymite for System FeO-SiO2-Fe2O3 // Journal of Physics: Conference Series. 2020. V. 1441. 012011.