Zirconium chloride (ZrCl4), (T-4)- → HCID 131716173, compound

Consider first the stripping generation, given as (78%) KCl-(22%) NaCl molten salt solvent. The phase diagram for NaCl-ZrCl4 (Howell, Sommer, and Kellogg, Trans. AIME, J. Metals, 209, 193, 1957) is shown in FIG. 1; the NaCl-KCl is expected to be similar in structure although differing in detail. The operating point for the distillation system is near the ternary eutectic at 63% ZrCl4, near which are shown curves of constant ZrCl4 vapor pressure. It may be seen that approximately 1 atm of vapor pressure may be obtained near 360° C., similar to the ternary ZrCl4 -KCl-NaCl system. As the temperature of the bottoms product stream is increased in the stripping system, the vapor pressure rises, and ZrCl4 will be evolved from the stream. However, as the ZrCl4 content of the mixture begins to fall, the fusion temperature begins to rise rapidly, such that when the ZrCl4 mole fraction has been reduced to 33%, the melting point has increased to 646° C., corresponding to the stable Na2ZrCl 6 double salt. (Note that in the case of the ternary NaCl-KCl-ZrCl4 system, the most stable double salt would be K2ZrCl6, which has an even higher melting point of 799° C.). Therefore, to prevent precipitation of solids in the stripper, stripping must be carried out at least at 799° C.

ORD record

ord-c51d13e64499490891bf7f44ef7104e4

Source dataset

uspto-grants-1989_10

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US04874475