动力堆高放废液煅烧产物与玻璃基体熔融反应过程研究  

Phase Evolution in Dissolution Reactions between Power Reactor High Level Liquid Waste Calcines and Basic Glass

作　　者：谭盛恒 常煚 王佳腾 贺诚 李扬[1] 王长福 张华[1] 龙浩骑[1] TAN Shengheng;CHANG Jiong;WANG Jiateng;HE Cheng;LI Yang;WANG Changfu;ZHANG Hua;LONG Haoqi(Department of Radiochemistry,China Institute of Atomic Energy,Beijing 102413,China;School of Nuclear Science and Engineering,East China University of Technology,Nanchang 330013,China)

机构地区：[1]中国原子能科学研究院放射化学研究所,北京102413 [2]东华理工大学核科学与工程学院,江西南昌330013

出　　处：《原子能科学技术》2025年第1期46-56,共11页Atomic Energy Science and Technology

基　　金：乏燃料后处理科研专项(BG202312100403)。

摘　　要：在冷坩埚玻璃固化技术中,高放废液煅烧产物与玻璃基体在高温下的熔融反应是实现高放废液玻璃固化的关键步骤。为掌握高放废液煅烧产物与基础玻璃在高温下的反应机理,获得合适的玻璃固化体熔制工艺条件,本文以动力堆高放废液煅烧产物和基础玻璃为研究对象,探究了它们在不同熔制温度和熔制时间下熔融反应的物相变化特征。根据XRD、拉曼光谱和SEM结果,煅烧产物与基础玻璃在650℃以上可发生熔融反应,并且在15~30 min内反应即趋近平衡。煅烧产物中的钼酸钠在650℃以上熔融于玻璃MoO_(4)^(2-)完全熔融于玻璃;煅烧产物中的镧系锆酸盐(Ln_(2)Zr_(2)O_(7))在700℃以上与玻璃基体发生化学反应,生成镧系硅氧化物(Ca_(2)Ln_8(SiO_(4))6O_(2))和二氧化锆(ZrO_(2)),生成物相在700~950℃时可稳定存在,950℃上完全熔解。为实现基础玻璃与煅烧产物的完全熔融,冷坩埚熔炉内熔融温度应不低于1050℃,熔制时间应不短于60 min。The dissolution reactions between high level liquid waste(HLLW)calcines and molten basic glass are key to the HLLW vitrification by two-step cold crucible induction melter(CCIM)technology.The phase evolution occurring in the melts of glass and calcines at different melting temperatures and periods was investigated.A mixture of basic glass powders and calcine powders in Pt-Au disks was isothermally heated for 15-90 min at 650-1100℃.The HLLW calcines are mainly composed of Na_(2)MoO_(4),Ln_(2)Zr_(2)O_(7),ZrO_(2),CsNO_(3)and(Sr,Ba)MoO4.Based on X-ray diffraction,Raman spectroscopy and scanning electron microscopy results,dissolution reactions began to take place at temperatures above 650℃,and the resultant phases reached stability within 30 min.Specifically,the platelike Na_(2)MoO_(4)particles from HLLW calcines were initially dissolved in glass melts to form regional melts that were oversaturated with MoO_(4)^(2-)ions,which subsequently gave rise to crystallization of powellite CaMoO_(4)in the samples.The formed CaMoO_(4)particles were partially dissolved in glass melts at temperatures below 1000℃and completely dissolved at 1050℃or above.It is also found that a small amount of Sr^(2+)joins the crystallization process,leading to slight shifts in X-ray diffraction angles and Raman shift of formed CaMoO_(4)crystals.Results of Raman spectra also suggest that the structure of MoO2-4 in glass network changes with dissolution reactions.Amorphous MoO2-4ν1 band moves to higher frequencies for samples heated at higher temperatures and longer time,which is probably attributable to the incorporation of high strength cation Ln^(3+)into glass network interstices.Ln_(2)Zr_(2)O_(7)phases from calcines are reacted with basic glass to form oxyapatite(Ca_(2)Ln_8(SiO_(4))6O_(2))and ZrO_(2)crystals.This reaction starts from 700℃and almost completes at 850℃.The formed oxyapatite are stable at 700-800℃,partially dissolves again into glass at 850 and 900℃,and completely dissolves at950℃in the melts.The residual ZrO_(2)p

关 键 词：高放废液 煅烧产物 玻璃固化 熔融反应 钼酸盐 

分 类 号：TL941.33[核科学技术—辐射防护及环境保护]