The fluorination of scheelite by ammonium bifluoride

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Z..h, Laptash, 3.1. l,,elnichenko,S.A. Polyshchuk Institute of Chemistry, Par East aranch, AC.

Sci. USSR, Vladivostok,

USSR

The interaction of scheelite with ammonium bifluoride is studied. It was shown that the scheelite reacts with Kfi4HF2 at room temperature in contrast to tungstic oxide and other tungand new sten compounds. Two complexes are formed: (l.H4)3,+'03F3 ;1,H4)2ii03F2.The compounds obtained are light fluorinated

(en-

dothermic peaks at 173 and 90°C correspondingly). The cubic monocrystals

of (hH4)j802F5 was obtained. The cu-

bic form is nonstable and revealed in time a lattice transformation at room temperature to more stable tetragonal form. The last one turn reversible The thermal decomposition

into cubic form at 14O'C. of (I;H4)2;10jF2is studied.