摘要
压实纯膨润土的导热性能较差,常需添加石墨等导热性质好的材料制备混合型缓冲材料,以提高高放废物地质处置库中放射性废物衰变热的传导效率。使用Hot disk TPS2500s热常数分析仪测定不同温度条件下干燥膨润土-石墨混合材料的导热系数、热扩散系数和体积比热,分析石墨含量、温度与混合材料导热性能参数的关系。试验结果表明,石墨可有效提高膨润土的导热系数、热扩散系数,添加30%~35%的石墨可使干燥高庙子(GMZ)钠基膨润土(ρd=(1.75±0.5)g/cm3)的导热系数达到与北山花岗岩相当的水平;温度对膨润土及混合材料的导热系数影响不大,混合材料的热扩散系数随温度升高而降低,体积比热随温度升高而增大。
Due to the relatively low thermal property of bentonite even when highly-compacted,graphite was usually used to produce mixed buffer material to enhance the dissipation of decay heat generated by high-level radioactive waste in the repository.Hot disk TPS2500s thermal constants analyzer was employed to measure thermal conductivity,thermal diffusivity and volumetric heat capacity of bentonite/graphite mixtures under different temperature conditions,and the effect of mass fraction of graphite and temperature on the thermal property parameters of the mixtures were analyzed.Test results show that the thermal conductivity and thermal diffusivity of bentonite can be effectively enhanced by the addition of graphite.The thermal conductivity of dry GMZ sodium bentonite(ρd=(1.75±0.5)g/cm3)is equally high with Beishan granite by the addition of 30%-35%graphite powder.Temperature has a negligible influence on the thermal conductivity of bentonite and bentonite/graphite mixtures.The thermal diffusivity of the mixtures decreases with temperature while the volumetric specific heat of the mixtures increases with temperature.
作者
谢敬礼
佟强
鲁文玥
XIE Jingli;TONG Qiang;LU Wenyue(Beijing Research Institute of Uranium Geology, Beijing 100029, China)
出处
《硅酸盐通报》
CAS
北大核心
2020年第5期1689-1693,共5页
Bulletin of the Chinese Ceramic Society
关键词
缓冲材料
膨润土
石墨
导热系数
热扩散系数
buffer material
bentonite
graphite
thermal conductivity
thermal diffusivity
