Theoretical and experimental investigations of the quinary mutual system of fluorides and chlorides of lithium, sodium, potassium and strontium

Simplicial division of phase diagram of quinary mutual system Li, Na, K, Sr, long F, Cl is carried out using the method of three-dimensional involutes and the theory of graphs. It is established that the singular tree of the system consists of seven pentatops and six joining tetrahedrons. The low-melting eutectics, rich with fluoride salts, corresponds to pentatop (1) (LiF)2-(NaF)2-(KF)2-SrF2- (KCl)2, rich with chloride salts (LiCl)2-(NaCl)2-(KCl)2- K2SrCl4-SrFCl-to pentatop (5). Composition and melting temperatures (433 and 313 deg C) of quinary points of nonvariant equilibrium are determined experimentally using the projection-thermal method and with an aid of thermal cross-section using the DTA method