ISSN print edition: 0366-6352 ISSN electronic edition: 1336-9075 Registr. No.: MK SR 9/7 Published monthly

Viscosity of Melts of the System KCl—KBF₄—K₂TiF₆

D. K. Nguyen and V. Daněk

Institute of Inorganic Chemistry, Slovak Academy of Sciences, SK-842 36 Bratisla

Abstract: The viscosity of melts of the system KCl-KBF₄-K₂TiF₆ has been measured by means of the computerized torsional pendulum method. The viscosity of KCl is higher than that of KBF4 at the same temperature, most probably due to the substantial overheating of KBF₄. In the ternary system the viscosity increases with increasing content of K₂TiF₆. Additivity of logarithms of viscosity was adopted as the ideal behaviour of the mixture. Negative deviations from such additive behaviour were found in the binary system KCl-KBF₄ probably due to the breaks of the weak B-Cl-B bridges caused by the excess of Cl- ions. Positive deviations from the ideal behaviour were found in the binaries KCl-K₂TiF₆ and KBF₄-K₂TiF₆ due to the formation of larger anions TiF₆Cl^3- and TiF₇^3- caused by the reactionsK₂TiF₆(1) + KCl(l) = K₃TiF₆Cl(l). KBF₄(l) + K₂TiF₆(l) = K₃TiF₇(l) + BF₃(g)Statistically significant ternary interaction confirmed that the above chemical reactions take place also in the ternary system.

Full paper in Portable Document Format: 512a73.pdf

Chemical Papers 51 (2) 73–77 (1997)