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 and scanning electron microscopy-energy dispersive spectroscopy showed that the obtained granular alloys were mainly Al3U and Al4U, and inductive coupled plasma optical emission spectrometry 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.

Atomic spectrometry update: review of advances in the analysis of metals, chemicals and materials

“…166 Similar analyses were performed as the previous study by the same authors, with a maximum extraction rate of 99.39% quantified by ICP-AES. Separation of U from Ce, La and Sm in LiCl–KCl systems using porous Al electrodes was investigated by Wang et al 167 Almost no lanthanides were detected in the electrolysis products using ICP-AES, with a rapid and efficient separation and improved kinetic performance using an Al honeycomb electrode with regular pores compared with Al foam electrodes with irregular pores.…”

Potentiometric study of the interaction of Sm3+ and O2− ions: thermodynamic properties of samarium compounds in molten NaCl–2CsCl eutectic

“…Samarium (Sm) is a fission product that mainly exists in molten salts in oxidation form Sm 3+ and Sm 2+ , has neutron toxicity and is difficult to separate from actinide elements. 16,17 Many research groups have investigated the electrochemical properties and extraction of Sm 3+ in the molten salt chloride system using various types of reactive electrodes (Al, 18,19 Zn, 20 Bi, 21,22 Sn, 23 Ni, 24,25 ). Our research group has also explored Sm in NaCl-2CsCl molten salts on Mo, Ga, Pb and mixed Ga-Pb electrodes for a range of relevant parameters, such as electrochemical reduction processes, kinetic and thermodynamic properties, and the separation and purification of Sm under suitable conditions.…”

A Corundum Membrane Ni/Ni2+ Reference Electrode for High-Temperature Fluoride Molten Salt

“…Molten salts are attractive electrolytes, which are widely employed in various fields, such as heat transfer and storage medium in light of thermal power station, 1 silicon refining for solar cell, 2 refining and processing of metals, 3,4 and dry reprocessing of spent fuel in nuclear power plant. 5,6 In the processes of the separation and extraction of actinide elements and rare Earth, [7][8][9] electrodeposition of metal oxides, [10][11][12] and preparation of metals and their alloys [13][14][15] by molten salt electrolysis, it is necessary to precisely control the electrode potential, and the control of the electrode potential is usually regulated by the reference electrode. 16,17 Since molten salt has the characteristic of high temperature and corrosion, the reference electrode used in the molten salt must meet some requirements, i.e., when current flows, the electrode potential changes very little, and electrode has a good reusability, stability and reproducibility.…”