Accelerated Separation of Uranium from Lanthanides (La, Ce, Sm) in LiCl-KCl Eutectic by Porous Aluminum Electrodes

Abstract

In order to optimize the application of Al electrodes in pyrochemical reprocessing of spent nuclear fuel, the feasibility of porous Al electrodes to separate actinides-lanthanides (An-Ln) in LiCl-KCl eutectic melt was explored. The separation efficiencies and rates of U and lanthanides (La, Ce, Sm) on Al electrodes with regular and irregular and without pores were compared. U was selectively recovered in the form of U-Al alloys by controlling the potential (−1.2 V) on both Al rod and porous Al electrodes. X-ray diffraction (XRD) and scanning electron microscopy (SEM)-energy dispersive spectroscopy (EDS) showed that the obtained granular alloys were mainly Al3U and Al4U, and inductive coupled plasma optical emission spectrometry (ICP-OES) indicated that there was almost no Ln in the electrolysis products. Positively, the required separation time was greatly shortened, and the separation rate was effectively improved when porous Al electrodes were used. In addition, the Al honeycomb electrode with regular pores has better kinetic performance compared with Al foam electrodes with irregular pores. The results indicate that the specially designed porous Al electrodes may have a good application prospect for the separation of An-Ln in the pyrochemical reprocessing of spent nuclear fuel.