Phase diagram of the system KF-KCl-KBF4-K2TiF6

The phase diagram of the quaternary system KF-KCl-KBF4-K2TiF6 was determine d using the thermal analysis method. Subsequent coupled analysis of the the rmodynamic 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 eutec tic points are e(1): 13 mole % KF, 25 mole % KCl, 62 mole % K2TiF6, t(e1) = 635 degreesC, e(2): 21 mole % KF, 50 mole % KCl, 29 mole % K2TiF6, t(e2) = 620 degreesC, and es: 46 mole % KF, 44 mole % KCl, 10 mole % K2TiF6, t(e3) = 586 degreesC. 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 e(1): 2.8 mole % KF, 5.8 mole % K Cl, 64.5 mole % KBF4, 26.9 mole % K2TiF6, t(e1) = 413 degreesC, e(2): 4.9 m ole % KF, 13.7 mole % KCl, 73.9 mole % KBF4, 7.5 mole % K2TiF6, t(e2) = 389 degreesC, and e(3): 14.0 mole % KF, 11.2 mole % KCl, 74.0 mole % KBF4, 0.8 mole % K2TiF6, t(e3) = 336 degreesC. The inaccuracy in the calculated phas e diagram is +/- 20.7 degreesC.