View More View Less
  • 1 Faculté des Sciences de Bizerte Laboratoire de Thermodynamique 7021 Zarzouna- Bizerte Tunisie 7021 Zarzouna- Bizerte Tunisie
  • 2 Université de Toulon et du Var Laboratoire de Physico-Chimie du Matériau et du Milieu Marin Laboratoire de Physico-chimie du Matériau et du Milieu Marin 83957 La Garde cedex France 83957 La Garde cedex France
  • 3 Université de Toulon et du Var Laboratoire de Physico-chimie du Matériau et du Milieu Marin 83957 La Garde cedex France 83957 La Garde cedex France
  • 4 Université Aix Marseille Laboratoire TECSEN-UMR 6122, Faculté de St-Jerôme III Avenue Normandie Niemen, case 251 13397 Marseille cedex 20 France III Avenue Normandie Niemen, case 251 13397 Marseille cedex 20 France
Restricted access

Abstract  

Study of solid-liquid phase diagram of LiPO3-Pb(PO3)2 binary system, in certain calcination conditions, shows the existence of several metastable phasis. When heated at a temperature of 723 K the binary mixtures lead uncompletely to a defined compound Pb2Li(PO3). On heating these ternary solid mixtures, three eutectic reactions have been observed: LiPO3+Pb(PO3)2→Liquid at a temperature of 793 K(1) LiPO3+Pb2Li(PO3)5→Liquid at a temperature of 843 K (2) Pb2Li(PO3)5+Pb(PO3)2→Liquid at a temperature of 891 K (3) The metastable liquid phase appears in the system at temperature of 793 K. DTA experiments performed on the binary LiPO3-Pb(PO3)2 mixtures, show a superposition of two diagrams. The first one is metastable and the second represents the stable equilibrium phase diagram. Measurements of liquid enthalpy of binary LiPO3-Pb(PO3)2 system at temperature of 979.65 K were reported. The corresponding values were very small and so the binary system can be considered as athermal. Assuming an ideal behaviour, the liquidus curves in the metastable diagram were calculated and the eutectic reaction (LiPO3-Pb(PO3)2→Liquid) was confirmed at 793 K.