Investigation of the amount and composition of the glass phase by the chemical analysis method in samples of zirconium ramming mass on a phosphate binder after heat treatment in the temperature range 800—2200 °C
A procedure for isolating the glass phase and determining its quantity by a chemical method of analysis in zirconium refractories on a phosphate binder after their heat treatment has been developed and certified. The developed technique provides high convergence and reproducibility of the results of determining the amount of glass phase. The chemical composition of the glass phase in the samples from the printed mass based on ZrO2 stabilized by the combined addition of CaO and MgO after heat treatment is determined using known standard chemical analysis methods. It is established that after heat treatment of the samples at 1200 °C, a glass phase is formed, the composition and amount of which practically does not change up to a heat treatment temperature of 1750 °C inclusive. The glass phase, whose amount after quenching at 1200—1750 °C is 4.52—5.10 %, consists mainly of P2O5, CaO and MgO, the ZrO2 content is insignificant. With an increase in the heat treatment temperature to 2000—2200 °C, the chemical composition of the glass phase is observed due to the evaporation of P2O5 and an increase in the ZrO2 content. After heat treatment at temperatures of 2000—2200 °C, a gradual decrease in the amount of glass phase is observed up to 1.17 % due to its partial crystallization upon cooling of the samples.