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

Phase Diagram of the KF—K₂Mo0₄—B₂0₃ System

O. Patarák, Z. Jantáková, and V. Daněk

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

Abstract: In the binary system KF-K₂MoO₄ two eutectics with the coordinates 30 mole % K₂MoO₄, 720°C and 59 mole % K₂MoO₄, 745°C were found. The additive compound K₃FMoO₄ melts congruently at 751°C. In the binary system KF-B₂O₃ the liquidus curve decreases monotonically with the increasing content of B₂O₃. The inflection point was found in the course of the liquidus curve of K₂MoO₄ in the binary K₂MoO₄-B₂O₃ system. The strong positive deviation from ideal behaviour was ascribed to the formation of heteropolyanions [BMo₆O₂₄]^9- in the melt.The liquidus surfaces of KF, K₃FMoO₄, and K₂MoO₄ are present in the investigated part of the ternary system KF-K₂MoO₄-B₂O₃. No ternary eutectic point was found. The greatly enlarged liquidus surface of K₂MoO₄ was ascribed to the substitution of oxygen atoms of the coordination sphere of molybdenum in the heteropolyanions by fluorine ones.

Full paper in Portable Document Format: 476a342.pdf

Chemical Papers 47 (6) 342–345 (1993)