Composition Change During Melting Of Lead Halide Oxyphosphate Glasses

Composition change during melting of Pb0-PbBr2-PbF2-P205 glasses has been studied. The relationship between the chemical analysis compositions and volatilisation of components was studied. Several possible chemical reactions in glass melts are discussed and relevant chemical thermodynamic calculations carried out. The results show that the composition change during melting is mainly attributed to chemical reactions between phosphorus and halogens (fluorine and/or bromine) and/or oxygen. When a sample contains high phosphorus and low fluorine content and/or phosphorus content, the losses of phosphorus and fluorine are dominant. Results of chemical thermodynamic calculation are consistent with the above results and discussion.