Phase diagram of the system KFKBF 4K 2TiF 6

Abstract

The phase diagrams of the binary system KBF 4K 2TiF 6 and of the ternary system KFKBF 4K 2TiF 6 were determined using the thermal analysis method. The subsequent coupled analysis of the thermodynamic and phase diagram data was performed to obtain a thermodynamically consistent phase diagram. In the system KFKBF 4K 2TiF 6, the intermediate compound K 3TiF 7 is formed. The K 3TiF 7KBF 4 joint divides the ternary system into two simple eutectic ones. The calculated coordinates of the two ternary eutectic points are: e 1: 26 mol% KF, 69 mol% KBF 4, 5 mol% K 2TiF 6, t e1 = 448°C; and e 2: 4 mol% KF, 69 mol% KBF 4, 27 mol% K 2TiF 6, t e2 = 440°C. The system KBF 4K 2TiF 6 is a simple eutectic one with the calculated coordinates of the eutectic point being 28 mol% K 2TiF 6 and 448°C. The probable inaccuracy in the calculated ternary phase diagram is 11.5°C.