水滑石为前躯体合成尖晶石固化模拟^(90)Sr

Immobilization of Simulated ^(90)Sr in Spinel Synroc Synthesized From Hydratalcite Precursor

研究了以包容锶水滑石为前躯体合成尖晶石固化模拟90 Sr的方法,借助X射线衍射(XRD)、热重分析(TG)和浸出实验确定的包容锶尖晶石固化体制备的最佳条件为:煅烧温度为1 100℃、煅烧时间为4h、锶包容量为0.648%。测定固化体的物理性能,采用PCT和MCC-1法研究其化学稳定性,利用扫描电镜能谱(SEM/EDS)分析固化体的组成、微观结构等。结果表明,制备的包容锶固化体具有良好的物理性能,显气孔率为0.07%,密度为4.8g/cm3;固化体中的锶完全被尖晶石相所包容;PCT法浸出7d后的锶元素归一化浸出率为5.2×10-2 g/(m2.d),固化体的化学稳定性良好。

Spinel synroc in which Sr（ simulating 90 Sr） was embedded by using Sr-containing hydrotalcite as the precursor.The optimum conditions of spinel synthesis were determined by X-ray diffraction（X RD）, thermogravimetric analysis（T G） and leaching experiments as follows： the calcining temperature 1 100 ℃, calcining time 4hand maximum Sr loading 0.648%.The mine phase assemblages and micro-structure of spinel synroc were analyzed by XRD and scanning electron microscopy with energy dispersive spectrometer（S EM/ EDS）. The chemical stability tests were carried out by MCC-1 method and PCT method.The results indicate that the prepared spinel synroc has good physical properties with density of 4.8g /c m 3 and open porosity of 0.07%.Sr is embedded into the crystal lattice of spinel. Under these conditions, the elemental nominalized leach rate of Sr is 5.2×10-2 g/（m 2 ·d） by PCT method at 90℃, the 7th day.The spinel synroc has a good chemical stability.