Effect of Molybdenum Electrode Heating on Microstructure and Properties of Radioactive Borosilicate Glass
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摘要: 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Na2O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。Abstract: 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.
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Key words:
- Thermal plasma /
- Borosilicate glass /
- Molybdenum electrode /
- Compressive strength
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图 1 熔融炉底部钼电极安装位置示意图
Figure 1. Schematic Diagram of Installation Position of Molybdenum Electrode at the Bottom of Melting Furnace
图 2 Na2O-30%下出料玻璃体显微结构及XRD谱线图
2θ—衍射角
Figure 2. Microstructure of Glass with Na2O-30% and XRD Diagram
表 1 玻璃体配方
Table 1. Composition of Glass
成分 SiO2 B2O3 CaO Al2O3 TiO2 Na2O 质量分数/% 45~60 10~18 0~10 5~8 0~3 10~30 
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表 2 2种工况对出料情况及玻璃体性能的影响
Table 2. Effects on Discharge and Properties of Glass under Different Conditions
工况 质量/kg 密度/(g·cm−3) 抗压强度/MPa 不投入钼电极 29.80 2.25±0.003 48.6±1.9 投入钼电极 32.25 2.58±0.002 55.2±2.4
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[1] 徐文兵,吕永红,陈明周,等. 热等离子体处理模拟放射性废物试验研究[J]. 核动力工程,2015, 36(6): 175-179. [2] 马特奇,梁威,徐辉,等. 放射性废物玻璃固化体溶解行为及机理研究进展[J]. 核化学与放射化学,2019, 41(5): 411-417. [3] OJOVAN M I, LEE W E. Glassy Wasteforms for nuclear waste immobilization[J]. Metallurgical and Materials Transactions A, 2011, 42(4): 837-851. doi: 10.1007/s11661-010-0525-7 [4] WEBER W J, NAVROTSKY A, STEFANOVSKY S, et al. Materials science of high-level nuclear waste immobilization[J]. MRS Bulletin, 2009, 34(1): 46-53. doi: 10.1557/mrs2009.12 [5] 耿安东,朱永昌,崔竹,等. 高放废料固化用硼硅酸盐材料研究进展[J]. 玻璃,2018, 45(2): 5-10. [6] 柳伟平,高振,范承蓉,等. 法国高放废液玻璃固化技术最新进展[J]. 辐射防护,2014, 34(6): 404-406. [7] 古雨鑫. 含Mo硼硅酸盐玻璃及玻璃陶瓷固化体的研究[D]. 绵阳: 西南科技大学,2022. [8] 凡思军,钱敏,薛天锋. Joule加热陶瓷炉玻璃固化技术研究进展[J]. 硅酸盐学报,2021, 49(12): 2736-2750. [9] 陈金方. 钼电极与玻璃电熔炉中各组份作用的热力学计算[J]. 玻璃与搪瓷,1999, 27(6): 46-48,55. [10] 关志峰. 钼电极表面玻璃基防氧化涂层的制备及性能研究[D]. 上海: 东华大学,2009. [11] NATH M, SONG S Q, GARBERS-CRAIG A M, et al. Phase evolution with temperature in chromium-containing refractory castables used for waste melting furnaces and Cr(VI) leachability[J]. Ceramics International, 2018, 44(16): 20391-20398. doi: 10.1016/j.ceramint.2018.08.032 [12] 谭盛恒,HAND R J. 钼酸盐在硼硅酸盐玻璃体系中的溶解[J]. 中国材料进展,2016, 35(7): 496-503. [13] WU K M, WANG F, LIAO Q L, et al. Synthesis of pyrochlore-borosilicate glass-ceramics for immobilization of high-level nuclear waste[J]. Ceramics International, 2020, 46(5): 6085-6094. doi: 10.1016/j.ceramint.2019.11.071 [14] 王长福,刘丽君,张生栋. 玻璃固化过程中Mo的化学行为研究进展[J]. 核化学与放射化学,2019, 41(6): 509-515. [15] KIERFELD J, VINOKUR V. Crack propagation, arrest and statistics in heterogeneous materials[J]. Journal of Statistical Mechanics: Theory and Experiment, 2008, 2008: P04011. [16] PIRES R A, ABRAHAMS I, NUNES T G, et al. Multinuclear magnetic resonance studies of borosilicate glasses for use in glass ionomer cements: incorporation of CaO and Al2O3[J]. Journal of Materials Chemistry, 2006, 16(24): 2364-2373. doi: 10.1039/b601593j -
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