Advances on separation of lanthanides and actinides from high-level waste liquids using N-containing solid phase adsorption material

This paper aims to review on the synthesis and Lanthanides/Actinides separation performance of N-containing solid-phase adsorption materials in treatment of high-level waste liquids. The main technology of separating lanthanides and actinides in the spent fuel processing are solvent extraction and solid phase extraction. Compared with solvent extraction, solid phase extraction has some unique advantages such as no possibility of third phase formation, more compact equipment, less organic solvent utilization and less secondary waste generation. N- containing solid phase adsorption materials, synthesized by physical impregnation or chemical modification with SiO₂ and resin as solid carriers, respectively, were taken as research object. In physical impregnation method, N-containing extractant was loaded into the micropores of SiO₂ or resin, and the content of extractant was as high as 30% ∼ 40% after filling whilst the chemical modification method was to graft the ligand functional groups onto the matrix through chemical reaction to obtain solid-phase adsorption materials. The preparation methods and the adsorption conditions of these N-containing solid phase adsorption materials are reviewed in this paper, as well as the adsorption mechanisms and the separation efficiency of lanthanides and actinides. Compared with the separation of lanthanide and actinide by liquid-liquid extraction, N-containing solid-phase adsorption material with resin and SiO₂ as carrier has the advantages of low cost, almost no organic waste liquid and suitable for dilute solution. (authors)