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

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 Na₂O 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.