The oxidation of UF4 in FLiNaK melt and its electrolysis

Evaporation behavior of 233Pa in FLiBeZr molten salt

“…LiF–BeF 2 –ZrF 4 salt (65–30–5 mol%) was prepared according to the procedures described in our previous work. 21 UF 4 , ThF 4 and LiF–BeF 2 –ZrF 4 salt with a mass ratio of 2 : 2 : 26 were mixed in the nickel crucible (purity ≥99.96%), which placed inside the furnace vessel, heated at 550 °C for 3 h, and then 20% F 2 /Ar mixture was injected for 2 h. Finally, UF 4 was oxidized into UF6 and then volatilized. The prepared carrier salt (FLiBeZr) containing 233 Pa was cooled and ground into powder for standby application.…”

Review—Fundamental Uranium Electrochemistry and Spectroscopy in Molten Salt Systems

“…It is known that U(IV) reduces to U(III) in fluoride molten salts with an applied current at a polarized electrode. 56,110 For pyroprocessing with chloride molten salts, the U(III) species is further reduced to U metal. In the FLiBe melt, the potential required to reduce U(III)/U metal competes with the Be(II)/ Be metal redox couple, thus hitting the solvent window, making it difficult to separate the uranium metal.…”

“…56 The fluoride melt, FLiNaK, was proposed to extend the solvent window and overcome this obstacle. 110 The basic electrochemical properties of the FLiBe melt were studied to help inform future molten salt separation process development in fluoride media. 56 56 The second figure in Straka et al 56 adds detail to the weak couple (1 a /1 c ) seen in the first figure of the manuscript with scan rates ranging from 25 mV s −1 to 250 mV s −1 .…”

“…111,112 In a molten salt reactor, oxygen is a potential contaminant. Han et al 110 studied the impact of the presence of oxygen on certain characteristics of uranium in the molten FLiNaK melt. The cyclic voltammograms in Han et al investigated UF 4 before and after oxidation in FLiNaK at 550 °C (825 K) with a scan rate of 100 mV s −1 vs K −1+ /K (see Fig.…”

The Electrochemical Behavior of Neodymium(III) in FLiNaK Molten Salt on Pt Cathode

“…25 In order to develop the electrochemical separation method for the pyroprocessing of spent fuel from molten salt reactor, we have been engaged in electrochemistry research of actinides and lanthanides in fluoride molten salts in recent years, especially in FLiNaK. [26][27][28][29][30] In this paper, the electrochemical behavior of Nd(III) on the Pt electrode in FLiNaK molten salt was investigated. Contrary to the results reported previously, 25 obvious peaks corresponding to Nd (III)/Nd(0) couple and Nd-Pt intermetallic compounds were observed in our experiment and the electrochemical separation of Nd (III) was demonstrated by the electro-deposition production on Pt electrode, indicating the possibility of Nd electrolysis extraction from FLiNaK.…”