On the covalency of U(III)–Cl, U(IV)–Cl bonding in a LiCl–KCl eutectic melt at 450°C: Spectroscopic evidences from their 5f–6d and 5f–5f electronic transitions

Chlorination of Pu and U Metal Using GaCl3

“…An analysis of the crystalline material by UV–vis–NIR spectroscopy was performed in both the solution and solid state, where both spectra contained bands that are consistent with those typically observed for f – f transitions in 5 f 5 Pu 3+ species (Figure ; Figures S2 and S3); notably, the spectra lacked features attributable to simple ions of Pu 4+ . − [PuCl 2 (dme) 3 ]­[GaCl 4 ] displayed poor solubility in DME once crystallized, and only approximate concentrations for solution UV–vis–NIR were obtained.…”

Electrochemical Behaviors and Extraction of Ln(III) (Ln = La, Ce, Nd) Ions in LiCl–KCl–CsCl Eutectic Salts at Low Temperatures

“…It is well known that the binary chloride system is highly soluble and stable for lanthanide (Ln) fission products and actinides (An), and therefore it has been widely used in the pyrochemical process. − Previously, the electrochemical behaviors of Ln/An elements on Al, Ga, Zn, Bi, and other electrode materials have been studied extensively in order to improve the separation efficiency of Ln/An in binary chloride salts. − Additionally, chemical properties of Ln and An ions such as the diffusion coefficients, exchange current densities, activity coefficients, and Gibbs free energy changes corresponding to the formation of intermetallic compounds can be obtained. − …”

In Situ Spectroscopic Identification and DFT-Assisted Prediction of the Valence and Structure of Tungsten Ions in a Cationic/Anionic Molten Salt System

“…Molten salts have become attractive reaction media in many fields. − The electrolytic process technique using molten salts is considered to be one candidate for the future extraction technique of metals. − A metal extraction process based on molten salt electrolysis has been proposed as a new option for the secondary metal resource recovery, such as magnet scrap, nuclear waste, and metal/alloy waste. − Among them, studies of cemented carbide scrap have received growing attention recently because of their implications in the long-term safety of metal waste treatment and the metal extraction process. − However, the solubility of cemented carbide is weak, especially for tungsten carbide (WC) in cemented carbide, which limits its industrialization process. All of the above-mentioned electrolytic reactions take place in the chloride molten salt system, which is usually promoted by using additives or changing the molten salt system. − Thus, to accelerate the dissolution of WC, the development of efficient and robust electrolytic environment is critical, which in turn relies on an in-depth understanding of reaction mechanisms and intermediate processes, especially at the molecular or atomic level.…”

“…Several studies have been reported on the electronic absorption spectra of metal ions in molten salt. Cho et al reported the visible range electronic absorption spectra of [U III Cl 6 ] 3– and [U IV Cl 6 ] 2– species in a LiCl–KCl eutectic melt at 450 °C . Liu et al observed the effect of substitution of Cl – by F – ions on the crystal field splitting energy of the U­(III) complex by using in situ UV–vis spectroscopy .…”

“…Cho et al reported the visible range electronic absorption spectra of [U III Cl 6 ] 3− and [U IV Cl 6 ] 2− species in a LiCl−KCl eutectic melt at 450 °C. 1 Liu et al observed the effect of substitution of Cl − by F − ions on the crystal field splitting energy of the U(III) complex by using in situ UV−vis spectroscopy. 39 You et al investigated the microstructure of solid and molten A 2 W 2 O 7 (A = Li, Na, and K) by adopting in situ high-temperature Raman spectroscopic technique in combination with density functional theory (DFT) analysis.…”