锕系核素污染沙土的铝热剂SHS固化模拟实验

Simulating Experiments of Solidification of Sandy Soil Contaminated with Actinides by SHS Method of Thermite

为探索对锕系核素污染沙土进行玻璃或陶瓷固化的有效途径,采用了铝热剂自蔓延高温合成(SHS)固化的模拟实验。主要进行了铝热剂粉末SHS固化的原理分析、模拟物质的选择、单质铁中模拟物质的含量、固化体中模拟物质浸出率的实验等。结果表明,固化体中模拟元素铈、铒的浸出率为10-3～10-5g.m-2.d-1量级;X射线衍射分析、扫描电镜观察发现,固化体中含有模拟元素铈、铒的硅酸盐晶体,晶体周围分布着大量玻璃体;单质铁相中模拟元素含量极低。用铝热剂可以固化锕系核素污染的沙土。

Simulating experiments were conducted for solidification of sandy soils contaminated with actinides by SHS method of thermite. The main work consists of analysis of solidification mechanisms,selection of actinides analogs,test of concentration of the actinide analogs in the block of iron and leach rates of the actinide analogs in the solidification form. The results show that the leach rates of Ce and Er in the solidification form are on the order of 10-3-10-5 g·m-2·d-1. XRD and SEM indicate that Er and Ce in the solidification form exist in form of silicate crystal surrounded by glass. Concentrations of the actinide analogs in the iron block are extremely low.