Removal of Zirconium From High-Level Liquid Waste by Silica Gel Absorption

The static and dynamic adsorption behaviors of zirconium and plutonium(Ⅳ) on silica gel were studied. In 1.0-4.0 mol/L HNO₃ solution, the static capacity of Zr on silica gel is about 20 mg/g, and the adsorption distribution coefficient of Pu(Ⅳ) is 0.7-1.4 mL/g. The adsorption of Zr and Pu increases with the decrease of aqueous acidity. The results of dynamic adsorption show that the effective capacity of dynamic adsorption for silica gel column is 3.5 times of bed volume. Zr and Pu absorbed in column can be partly eluted by 2 mol/L HNO₃. 0.2 mol/L H₂C₂O4 can be used to elute Zr and Pu completely. The silica gel column eluted by 0.2 mol/L H₂C₂O₄ can be reused six times and the position of dynamic adsorption curve of each time is the same.