peritectic Study of the Stable Tetrahedron LiF-KF-KCl-K2WO4 of the Quinary Reciprocal System Li,K||F,Cl,WO4 Authors: Pichkaev О. V., Dvoryanova Е. М., Garkushin I. K. The stable tetrahedron LiF-KF-KCl-K2WO4 of the quinary reciprocal system Li,K||F,Cl,WO4 was studied by differential thermal analysis, and the characteristics of eutectic and peritectic were determined.