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

Phase Diagram of the System KF—KCl—KBF₄—K₂TiF₆

M. Chrenková, V. Danielik, A. Silný, and V. Daněk

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

Abstract: The phase diagram of the quaternary system KF-KCl-KBF₄—K₂TiF₆ was determined using the thermal analysis method. Subsequent coupled analysis of the thermodynamic and phase diagram data was performed to obtain thermodynamically consistent phase diagram.In the ternary system KF-KCl-K₂TiF₆ two intermediate compounds, K₃TiF₇ and K₃TiF₆Cl, are formed. The calculated coordinates of the three ternary eutectic points are e₁: 13 mole % KF, 25 mole % KCl, 62 mole % K₂TiF₆, t_e1 = 635°C, e₂: 21 mole % KF, 50 mole % KCl, 29 mole % K₂TiF₆, t_e2 = 620°C, and e₃: 46 mole % KF, 44 mole % KCl, 10 mole % K₂TiF₆, t_e3 = 586°C. The phase diagram was calculated from the binary boundary ones and from the measured quaternary mixtures.Three quaternary eutectic points were found in the quaternary phase diagram KF-KCl-KBF₄-K₂TiF₆ Their coordinates are e₁: 2.8 mole % KF, 5.8 mole % KCl, 64.5 mole % KBF₄, 26.9 mole % K₂TiF₆, t_e1 = 413°C, e₂: 4.9 mole % KF, 13.7 mole % KCl, 73.9 mole % KBF₄, 7.5 mole % K₂TiF₆, t_e2 = 389°C, and e₃: 14.0 mole % KF, 11.2 mole % KCl, 74.0 mole % KBF₄, 0.8 mole %  K₂TiF₆, t_e3 = 336°C. The inaccuracy in the calculated phase diagram is +/- 20.7°C.

Full paper in Portable Document Format: 552a75.pdf

Chemical Papers 55 (2) 75–80 (2001)