摘要
采用碱矿渣-粘土复合胶凝材料(AASCM)和普通硅酸盐水泥(OPC)固化模拟放射性泥浆,对固化体中Cs+、U(Ⅵ)的浸出性能进行了研究。根据Fick第二定律建立并优化了预测核素浸出行为的二维衰变浸出模型。通过MATLAB软件编程计算,以非恒定表观扩散系数的二维衰变模型对Cs+、U(Ⅵ)的浸出行为进行了预测。结果表明:AASCM固化Cs+、U(Ⅵ)的能力大于OPC,浸出28d后,AASCM中Cs+、U(Ⅵ)的累积浸出分数分别低于OPC的1/5和1/2;Cs+、U(Ⅵ)浸出的表观扩散系数呈衰减趋势,当考虑表观扩散系数衰减时,二维衰变浸出模型对OPC固化Cs+、U(Ⅵ)及AASCM固化U(Ⅵ)的浸出行为预测较好,但对离子交换吸附作用较强的AASCM固化体中Cs+浸出行为预测较差。
Alkali-activated slag-clay minerals composite cement（AASCM） and ordinary portland cement（OPC） were used to immobilize the simulated radioactive slurry.The leachabilities of Cs＋,U（Ⅵ） were studied.A two-dimension decay leaching model（T-DLM） applied to predict the leaching behavior of radionuclides was established and optimized,according to Fick＇s second law.The leaching behaviors of Cs＋,U（Ⅵ） were predicted by the T-DLM with non-constant apparent diffusion coefficient,via programmed calculation with MATLAB software.The results indicate that the capacity of AASCM immobilizing Cs＋,U（Ⅵ） is better than OPC.The cumulative leaching fractions of Cs＋,from AASCM are less than 1/5 and 1/2 of that from OPC,separately,after leaching for 28 d.The apparent diffusion coefficients of Cs＋,U（Ⅵ） register as the attenuation trend.While considering the attenuation of apparent diffusion coefficient,the leaching behaviors of Cs＋,U（Ⅵ） immobilized in OPC and U（Ⅵ） immobilized in AASCM can be predicted well by the T-DLM,but the leaching behavior of Cs＋ immobilized in AASCM which has stronger ion-exchange and adsorption capacity can not be predicted well.
出处
《原子能科学技术》
EI
CAS
CSCD
北大核心
2011年第1期7-13,共7页
Atomic Energy Science and Technology
基金
国防基础科研项目资助(A3120080126)
西南科技大学国防重点学科实验室重点培育项目资助(07JGZB01)
关键词
水泥固化体
浸出行为
扩散
浸出模型
cement-solidified waste form
leaching behavior
diffusion
leaching model
