Fluorination reaction of UO3 and electrochemical preparation of UO2

Preparation and Electrochemical Dissolution of a Soluble Uranium Oxycarbide Anode

“…Subsequently, three new pairs of oxidation/reduction signals C/C′, E/E′, and F/F′ appeared; in addition, separate oxidation signal D was observed. According to refs , , , it could be inferred that C/C′ reflected the transformation of UO 2 and U, oxidation signal D corresponded to the oxidation of U to U­(III), and E/E′ and F/F′ could be attributed to the oxidation/reduction process of UO 2 2+ and UO 2 . The oxidation/reduction reactions involved in each oxidation/reduction signal in Figure a are shown in Table .…”

“…According to eq , the transfer electron numbers for E′ and F′ were calculated to be 0.81 and 0.82, respectively, both of which were close to 1. Therefore, it could be inferred that the corresponding reactions of E′ and F′ were the transformation of UO 2 + to UO 2 and UO 2 2+ to UO 2 + , respectively, which was consistent with the results in refs , . In addition, the oxidation/reduction reactions involved in each oxidation/reduction signal in Figure a are shown in Table .…”

“…Ogata et al 14 studied the fluorination of UO 2 using F 2 to generate UO 2 F 2 but faced similar problems as chlorination with chlorine gas. Liu et al 15 fluorinated UO 3 with NH 4 HF 2 in an air atmosphere to generate UO 2 2+ . Therefore, it is essential to study other methods for dissolving insoluble uranium oxide in molten salts.…”

Impact of Ag on Electrochemical Recovery of UO2 in Molten LiCl-KCl Salt

“…Uranyl chloride (UO Cl 2 2 ) was prepared by the chlorination reaction of UO 3 (purchased from CNNC North nuclear fuel element Co., Ltd.) with ammonium chloride, which was described in detail in the previously published literature. 11 Then, to remove impurities in LiCl-KCl eutectic, pre-electrolysis was performed at −2.2 V (vs Ag/AgCl) for 4 h. The temperature was maintained at 773 K and measured with a type-K thermocouple sheathed by an alumina tube. All experiments were carried out in a glove box (O 2 and H 2 O contents ⩽5 ppm).…”

“…[4][5][6][7][8][9] Among them, the oxide electrowinning process is considered as one of the candidates for the future recycling process of uranium. 10 Therefore, some investigators explore the electro-reduction of + UO 2 2 and recycling UO 2 in various molten salt systems, such as LiCl-KCl, [11][12][13][14][15][16][17] NaCl-CsCl, 18,19 NaCl-KCl, [20][21][22] NaCl-KCl-CsCl, 10 FLiNaK 23 and FLiBe 24 melts, respectively. Meanwhile, the coordination chemical and chemical species of uranium were also investigated in molten chlorides.…”