钼电极加热对放射性硼硅酸盐玻璃显微结构与性能影响研究

Effect of Molybdenum Electrode Heating on Microstructure and Properties of Radioactive Borosilicate Glass

硼硅酸盐玻璃被广泛应用于放射性废物的固化处理。在等离子体高温熔融系统中,含放射性核素的硼硅酸盐玻璃熔池底部和远离热源区域的玻璃体温度相对较低,熔池流动均匀性较差,极大阻碍出料过程。通过引入钼电极辅助加热熔池的方法,探究钼电极对放射性硼硅酸盐玻璃显微结构与性能的影响。实验结果表明,玻璃配方中Na_(2)O质量分数为10%时,能够避免出料玻璃体中析出杂质-钼酸钠和氧化钼;投入钼电极后,电极间玻璃液的初始大电阻特性使其释放大量焦耳热,熔池温度分布均匀性和流动性得到了改善,从而有效促进了出料过程,出料玻璃体重量提升约8.2%、密度提升约14.6%、抗压强度提升约13.6%。本文为开发一种废物容量大、运行时间长的等离子体高温熔融系统提供一定的解决思路。

Borosilicate glass is widely used in the solidification of radioactive waste.In the plasma high temperature melting system,the bottom of the borosilicate glass melting pool containing radionuclides and the glass body far from the heat source have low temperature,which leads to poor flow uniformity of the molten pool and greatly hinders the process of waste discharge.In this paper,the effect of molybdenum electrode on the structure and properties of radioactive borosilicate glass is investigated by introducing molybdenum electrode to assist heating the molten pool.The experimental results show that sodium molybdate and molybdenum oxide can be avoided when the mass fraction of Na_(2)O in the glass formula is 10%.After the molybdenum electrode was put into use,the initial high resistance characteristics of the molten glass between the electrodes made it release a lot of Joule heat,and the temperature distribution uniformity and fluidity of the molten pool were improved,thus effectively promoting the discharging process.The weight,density and compressive strength of the discharged glass increased by about 8.2%,14.6%and 13.6% respectively. This paper can provide some solutions for developing a high temperature plasma melting system with large waste capacity and long running time.