熔融时间对模拟高放玻璃熔体中Ru析出物空间分布的影响  

Study on the Influence of Melting Time on the Spatial Distribution of Ru Precipitates in Simulated High-Level Waste Glass Melts

作　　者：徐立言 牛晨晨 徐凯[1,2] 胡开文[1] 贾子强 陈爱清 XU Liyan;NIU Chenchen;XU Kai;HU Kaiwen;JIA Ziqiang;CHEN Aiqing(State Key Laboratory of Silicate Materials for Architectures,Wuhan University of Technology,Wuhan 430070,China;CNPE-WHUT Joint Laboratory of Nuclear Waste Vitrification Technology,Beijing 100840,China;Analysis and Testing Center,China Three Gorges University,Yichang 443002,Hubei,China)

机构地区：[1]武汉理工大学硅酸盐建筑材料国家重点实验室,武汉430070 [2]中国核电工程有限公司,武汉理工大学玻璃固化技术联合实验室,北京100840 [3]三峡大学分析测试中心,湖北宜昌443002

出　　处：《硅酸盐学报》2024年第9期3019-3026,共8页Journal of The Chinese Ceramic Society

基　　金：国家自然科学基金(U2241290)。

摘　　要：陶瓷电熔炉技术是工业化应用最为广泛的高放废液玻璃固化处理技术,然而在其玻璃固化过程中低溶解度、高导电率的铂系金属(Ru、Rh及Pd)沉积问题是限制其发展的问题之一。本工作将1%(质量分数)RuO_(2)与模拟简化高放玻璃粉末在1200℃熔融制得铂系金属掺杂玻璃固化体样品,利用XRD与SEM表征Ru析出物的物相及微观形貌,并利用XRM分析Ru析出物在玻璃熔体中的分布特征及尺寸变化规律。结果表明Ru主要以RuO_(2)的物相析出,并伴随有少量Ru单质;样品中析出物颗粒体积分数随熔融时间延长而增加,而析出物团聚体平均尺寸随熔融时间呈现先增大后较小的趋势;此外,析出物在样品中的空间分布呈底层多、表层少的规律,底层析出物颗粒体积分数随熔融时间延长而增加,且其沉降速率随熔融时间延长而减小。Introduction Platinum group metals(PGM),including ruthenium(Ru),rhodium(Rh),and palladium(Pd)are enriched in high-level liquid waste(HLLW)during the reprocessing of spent nuclear fuels.Vitrification is currently the only practical technology to immobilize HLLW.However,the high density and low solubility of PGM in glass cause them to settle down during vitrification process,resulting in the increased viScosity and conductivity of the glass melt at the bottom of the melter.This would potentially lead to concerned issues such as blockages in the diScharge port and damage of electrodes.Therefore,understanding the deposition of PGM during vitrification is quite crucial in the management of HLLW.However,few research focused on the deposition process and the spatial distribution of PGM particles in glass melts.Thus,this work took Ru as the representative of PGM and investigated spatial distribution of Ru precipitates in glass melts.Methods A simplified simulated waste glass with the composition of 50.00%SiO_(2)-18.89%B_(2)O_(3)-2.79%Li_(2)O-5.00%CaO-13.30%Na_(2)O-6.68%Al_(2)O_(3)-3.34%ZrO_(2)(mass fraction)was formulated.Batches were thoroughly mixed and placed in corundum crucibles,and then melted at 1200℃for 1 h in a muffle furnace.The molten glass was quenched in air and then crushed to obtain the glass frits with the size smaller than 70μm.Subsequently,glass frits and additional 1.00%RuO_(2)(mass fraction)were then fully mixed.3 g of mixtures was placed in a corundum crucible with a lid to prevent Ru volatilization,and remelted at 1200℃for 0.5 h,1 h,2 h and 4 h,respectively,and then annealed at 500℃for 2 h to release the thermal stress.XRD was used to analyze the precipitated crystalline phases of the Ru-containing glasses.SEM-EDS was utilized to examine the morphology of Ru precipitates in glass samples and determine the distribution density of Ru precipitates particles in agglomerates.The glass samples were then cut into blocks with the size of 7 mm×7 mm×6 mm,and XRM was applied to detect the content of R

关 键 词：高放废液 玻璃固化 铂系金属 空间分布 沉积 

分 类 号：TQ171[化学工程—玻璃工业]