Condensed System LiF-NaF-ZrF₄-Phase Equilibria and Crystallographic Data.

Protection of nuclear graphite toward fluoride molten salt by glassy carbon deposit

“…PXRD analysis on the resulting cooled fluoride salt, after heating at 500°C, showed the presence of these three phases. A melting temperature of 436°C was determined for our synthesized fluoride salt by differential scanning calorimetry in good agreement with the literature: 425°C [7] and 436°C [8].…”

“…This may be due to a poorly crystalline Na 7 Zr 6 F 31 phase and the possible Na insertion in the Li 2 ZrF 6 phase. Although such a solid solution was not mentioned in the literature [7,8], it occurs in analogous Th phases (Na,Li) 7 Th 6 F 31 [20]. This observed divergence was increased when analysing the molten salt after impregnation with graphite.…”

“…The purity of the obtained ZrF 4 , NaF and LiF powders was confirmed by PXRD and 19 F MAS-NMR. The molar composition of the ternary eutectic fluoride salt corresponds to 27.0 mol.% LiF, 36.5 mol.% NaF and 36.5 mol.% ZrF 4 [7][8]. This composition, represented by the empty circle in the ternary diagram (ZrF 4 -NaF-LiF) represented in Fig.…”

“…Representation of the ternary phase diagram in Fig. 2 was taken from the study of Thoma et al [8] without taken into account the Li 4 ZrF 8 phase [9,10]. PXRD analysis on the resulting cooled fluoride salt, after heating at 500°C, showed the presence of these three phases.…”

Thermodynamic study of LiF–BeF2–ZrF4–UF4 system

“…The assessment of LiF-ZrF 4 system was based on the experimental data from Thoma at al. [7,8]. It consists of Fig.…”