Papers by Keyword: Borosilicate Glasses

Abstract: The effect of aluminum oxide additives on the phase relations in borosilicate glass based on the system Na₂O–B₂O₃–SiO₂ was investigated by means of the thermodynamic modeling. The phase equilibrium realized in this system was obtained using software package "FactSage" (version 6.4). The effect of aluminum oxide additives on the composition of the crystalline phases and residual melt formed during the cooling of borosilicate melts has been studied. The analysis of the diagrams has allowed establishing the regions of partial and complete melting of the substance depending on the chemical composition. The analysis allows determining the temperature of the melting process of a glassy matrix material. The combination of stable borate, silicate, mixed borosilicate, aluminosilicate and boroaluminate phases were determined for a wide range of compositions and temperatures. Boundaries of the regions formation of these phases depending on the composition and the temperature were determined. It allows assessing the prospects for absorption of elements in radioactive waste immobilization. The modeling of the crystallization melts formed in the studied systems was performed.

Abstract: This paper is report on the physical and optical properties of development barium-borate-rice husk ash (BaBRHA) glass system. The glasses containing BaO in xBaO:(80-x)B₂O₃:20RHA where x = 30, 35, 40 and 45 wt% have been prepared by melt quenching technique. The physical properties of this glass are shown from density data. The optical properties were investigated from refractive index and transmission by using Abbe-refractometer and UV-visible spectrometer respectively.

Abstract: Static short-term corrosion tests were performed to two kinds of borosilicate glasses in deionized water, at 70°C and 150°C, respectively. Same corrosion experiments were also carried out in other leaching agents, such as simulated under ground water of Beishan, sulfuric acid solution (pH=0.5) and potassium hydroxide solution (pH = 13). Experimental results show that both leaching agent and corrosion temperature co-dominate the corrosion process, and the temperature plays more important role. At low temperature of 70°C, the corrosion reaction is controlled by the ion diffusing in DIW at earlier stage. While in PHS, network hydrolysis reaction is the main corrosion mechanism.