VAPORIZATION IN THE SYSTEM CAO-P2O5-SIO2

Vaporization in the system CaO-P2O5-SiO2 has been investigated over a wide range of compositions and temperatures by high-temperature mass s pectrometry. It has been established that silicon dioxide added to cal cium meta-, poly-, and diphosphate leads to a decrease in partial pres sures of the products of dissociation, whereas when added to orthophos phate it increases these pressures. Thermodynamic calculations for the reactions of thermal dissociation of calcium phosphates mixture with silica have been made.