硅胶对锆钚(Ⅳ)吸附的研究

Adsorption of Zirconium and Plutonium(Ⅳ) From Acid Solution on Silica Gel

为了去除乏燃料溶解液和高放废液中的Zr,研究了酸性条件下硅胶对Zr的静态吸附和对Zr,Pu的动态吸附。研究结果表明,在25℃和1 mol/L HNO3时,硅胶对Zr的静态吸附容量约为0.225 mmol/g,随着料液酸度的降低、硅胶粒度的减小、Zr浓度及固液比的升高,硅胶吸附Zr的能力增大;在4 mol/L HNO3溶液中,硅胶吸附Zr而几乎不吸附Pu(Ⅳ),因此可用硅胶吸附法使Zr与Pu(Ⅳ)分离。用2个柱体积的0.2 mol/L H2C2O4可将吸附在硅胶上的Zr解吸下来,洗脱率可达99.2%。硅胶再次吸附Zr时,吸附性能曲线和吸附容量均无明显变化,硅胶可重复使用。

The static adsorption of Zr and dynamic adsorption of Zr and Pu（Ⅳ） on silica gel in HNO3 solution were studied. The study results show that adsorptive capacity of Zr is about 0. 225 mmol/g. Adsorption of Zr increase with decrease of HNO3 concentration and silica gel size, likewise with increase of the rate of liquid to solid and Zr concentration. Zr is adsorbed but Pu（Ⅳ） is not adsorbed on silica gel column in 4 mol/L HNO3 solution so it is possible to separate Zr and Pu（IV） from acid solution by adsorption on silica gel. The adsorbed Zr on the silica gel can be efficiently eluted with 2 column volume of 0.2 mol/L oxalic acid, the elutriation reaches to 99.2 %, and the silica gel can be used repeatedly.