Electrochemical separation of Th from ThO2 and Eu2O3 assisted by AlCl3 in molten LiCl–KCl

Electroseparation of thorium from ThO2 and La2O3 by forming Th-Al alloys in LiCl-KCl eutectic

“…When Al 3+ was present in the melt, the deposition of La x Al y intermetallic compounds was favorable. However, in an Al 3+ poor system, electrochemical signals for the deposition of metals could be also observed [3,10]. One reasonable explanation for this phenomenon is that the W surface could not be completely covered by the deposited Al layer, or the deposited Al layer was too thin for the inner bulk directed diffusion of all deposited La metal to form La x Al y intermetallic compounds, in an Al 3+ poor system.…”

“…Similarly, peak I C belongs to the deposition of Al metal. Peaks I C1 at about À1.18 V and I C2 at À1.40 V are likely related to the formation of intermetallic compound Al 3 Th and AlTh by the co-reduction of Th 4+ and Al 3+ , according to our previous works [3,10].…”

“…Secondly, AlCl 3 might be exhausted during the separation process due to the consumption and volatilization, in this case, Al plates can serve as the active electrodes for the under potential deposition of Th. Actually, the under potential deposition of Th on the Al electrode had been described in our previous work [3].…”

“…In this work, AlCl 3 is used to chloridize ThO 2 and La 2 O 3 . In our previous works, AlCl 3 was successfully used to chlorinate ThO 2 , by the following reaction [3,10]:…”

“…In recent years, the new demand for the next generation nuclear cycles led to the renewed interest in thorium-based fuels and fuel cycles in the world [1]. ThO 2 with some advantages compared to the traditional UO 2 -based fuels, is an important nuclear fuel material for advanced reactors [1][2][3]. However, it is quite challenging to reprocess ThO 2 -based fuels by the traditional solvent extraction process due to the insolubility of ThO 2 in concentrated nitric acid.…”