2018 - Sustainable Industrial Processing Summit & Exhibition
4-7 November 2018, Rio Othon Palace, Rio De Janeiro, Brazil
| Topological Forecast of 4D T-x-y-z Diagram Li,Na,Rb,La||F Vasily Lutsyk1; Anna Zelenaya1; Maria Parfenova2; 1INSTITUTE OF PHYSICAL MATERIALS SCIENCE SB RAS, Ulan-Ude, Russian Federation; 2TOMSK STATE UNIVERSITY OF CONTROL SYSTEMS AND RADIO-ELECTRONICS, Tomsk, Russian Federation; PAPER: 120/Molten/Regular (Oral) SCHEDULED: 12:35/Tue./Bossa (150/3rd) ABSTRACT: Interest in systems with fluoride metals is due to the fact that they have been considered as a potential component for nuclear reactor fuel in molten salts. Three ternary systems of Li,Na,Rb||F, Li,Rb,La||F and Na,Rb,La||F on the boundary of quaternary system Li,Na,Rb,La||F have been analyzed. Model for the 4th boundary Na,Li,La||F was built earlier [1]. Li,Na,Rb||F has the simplest structure. Its eutectic type is complicated by the compound R=LiRbF<sub>2</sub>, decaying in the solid phase, and is characterized by two invariant equilibria: eutectic one and decomposing of R (dot Y). Space model includes 3 liquidus surfaces, 3 - solidus, 10 - solvus, 22 - ruled ones, and 2 horizontal complexes at temperatures of E and Y, and has 4 monophase regions (А, В, С, R), 9 - 2-phase (L+A, L+В, L+С, A+B, A+C, B+C, A+R, B+R, C+R) and 7 - 3-phase ones (L+A+В, L+A+C, L+B+C, A+B+C, A+C+R, A+B+R, B+C+R). System Li,Rb,La||F is complicated by 5 binary compounds: R<sub>1</sub>=LiRbF<sub>2</sub> - with the exotermic decaying, and 4 incongruently melting R<sub>2</sub>=Rb<sub>3</sub>LaF<sub>6</sub>, R<sub>3</sub>=Rb<sub>2</sub>LaF<sub>5</sub>, R<sub>4</sub>=RbLaF<sub>3</sub>, R<sub>5</sub>=RbLa<sub>2</sub>F<sub>7</sub>. Compounds R3, R5 have endothermic decay and exist in the short temperature interval. Space model consists of 7 liquidus surfaces, 31 ruled surfaces, 6 horizontal complexes and includes 10 2-phase regions (L+A, L+B, L+C, L+R2, L+R3, L+R4, L+R5, R1+R2, A+R2, A+R4) and 16 3-phase regions (L+A+B, L+A+C, L+A+R2, L+A+R4, L+B+R2, L+C+R4, L+C+R5, L+R2+R3, L+R2+R4, L+R3+R4, L+R4+R5, A+R1+R2, A+B+R2, A+R2+R4, A+C+R4, B+R1+R2). 2-phase regions R1+R2, A+R2, A+R4 have a degenerated structure in the form of vertical planes. System Li,Rb,La||F has a similar structure, but is sophisticated by the additional liquidus surface of R1=NaLaF<sub>4</sub>. As a result, there are 3 invariant equilibria, 8 liquidus surfaces, 35 - rules ones and 6 horizontal complexes on the boundary of 28 phase regions (L+A, L+B, L+C, L+R1, L+R2, L+R3, L+R4, L+R5, A+R2, A+R4, R1+R4, L+A+B, L+A+R1, L+A+R2, L+A+R4, L+B+R2, L+C+R1, L+C+R4, L+C+R5, L+R1+R4, L+R2+R3, L+R2+R4, L+R3+R4, L+R4+R5, A+R1+R2, A+R2+R4, A+R1+R4, R1+R4+C). Concentration fields in the 4 ternary systems with the different trajectories of phases have been analyzed [2-3]. 4 ternary systems are used to forecast a topological structure of T-x-y-z diagram Li,Na,Rb,La||F [4] with 6 binary compounds: R<sub>1</sub>=LiRbF<sub>2</sub>, R<sub>2</sub>=NaLaF<sub>4</sub>, R<sub>3</sub>=Rb<sub>3</sub>LaF<sub>6</sub>, R<sub>4</sub>=Rb<sub>2</sub>LaF<sub>5</sub>, R<sub>5</sub>=RbLaF<sub>4</sub>, R<sub>6</sub>=RbLa<sub>2</sub>F<sub>7</sub> (R1 decays in solid, R2-R6 - with incongruently melting, and R3, R5 with endothermic decaying). In the ternary systems there are 14 invariant equilibria. For T-x-y-z diagram Li,Na,Rb,La||F it is forecasted 4 invariant 5-phase equilibria with 9 liquidus hypersurfaces. References: [1] R.N. Savchuk, N.V. Faidyuk, A.A. Omelchuk, V.I. Lutsyk, A.E. Zelenaya, Journal of Inorganic Chemistry, 59 (2014) 780-785. (In Russian) [2] V. Lutsyk, A. Zelenaya, Journal of Physics: Conference Series, 790 (2017), 012020. [3] Y.V. Pogorenko, R.M. Pshenychnyi, V.I. Lutsyk, A.O. Omel'chuk, IOP Conf. Series: Materials Sci. and Eng., 175 (2017), 012039. [4] V.I. Lutsyk, A.E. Zelenaya, Journal of Physics: Conference Series, 790 (2017), 012020. |
