稀土湿法冶炼废渣中氡的放射性及其测定方法  

Radioactivity of Radon in Rare Earth Hydrometallurgical Residue and Its Measuring Method

作　　者：苏峻[1] 陈祖义[1] 朱旭东[1] 杨宏伟[1] 

机构地区：[1]南京农业大学理学院,江苏南京210095

出　　处：《中国稀土学报》2008年第6期748-752,共5页Journal of the Chinese Society of Rare Earths

基　　金：江苏省科学技术厅社会发展计划项目(BS2006057)

摘　　要：基于稀土矿石中伴生的钍(Th)、铀(U)、镭(Ra)等天然放射性核素在湿法冶炼过程中富集于废渣,它们衰变可释放出氡(Rn)。以活性炭吸附、二甲苯闪烁液静态和动态吸收3种方法捕集Rn,应用液闪系统测定了两种稀土湿法冶炼废渣中Rn的放射性活度。测量结果表明,废渣中Rn的放射性比活度(Bq.kg-1)表现出较高水平,且在不同废渣中具有明显差异,为综合评估稀土厂"三废"的放射性及其危害性提供了依据;从3种方法的比较分析,提出了以二甲苯闪烁液静态吸收后用液闪法测定Rn的程序。In this paper, radon in two kinds of residue were captured by three methods： acticarbon absorption, static and dynamic xylene scintillation liquid absorption, and their radiation activity were determined by a liquid scintillation counter. The results showed that the specific activity （Bq· kg^- 1 ） of radon in these residues were at a high level, also visibly different in different residues. These provide the basis for the comprehensive evaluation on radioactivity and harmfulness of ＂three wastes＂ from rare earth factory. Meanwhile, based on the comparison of the three methods, a procedure of measuring radon by using static xylene scintillation liquid absorption followed by liquid scintillation counting was investigated.

关 键 词：氡 稀土湿法冶炼废渣 放射性 放射性比活度 液闪法 稀土 

分 类 号：X591[环境科学与工程—环境工程]