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ABSTRACTThe oxidation characteristics of anionic exchange resins (AERs) during molten salt oxidation (MSO) were investigated in carbonate melt. The residue after MSO of AERs were carbon, which was confirmed by the X-ray diffraction (XRD) and Raman spectra. The remaining amount of salt-free residue after MSO was evaluated by destruction and removal efficiency (DRE), which indicates that 2 hours is a suitable oxidation time. The morphologies of the AERs after MSO were observed by scanning electron microscopy (SEM). The oxidation process of AERs in MSO was investigated by thermogravimetric analysis (TG) and Fourier Transform Infrared Spectrometer (FT-IR), which revealed that initial AERs, experienced four reaction stages in MSO: dehydration, thermal decomposition of functional groups, carbonization of styrene-divinylbenzene copolymer (ST-DVB), and gasification of carbon. The TG data proved that the presence of carbonate promotes the carbonization process of ST-DVB in AERs. The reason why salt catalyzes this stage had been proved to be that the carbonate captures the nitrogen-containing exhaust gas generated by the oxidation of the anion resin, and produces nitrate with catalytic oxidation ability, which catalyzes the oxidation of the resins effectively. This means that MSO will be an environmentally friendly and efficient method for catalytic oxidation of AERs.

Studying the electrodeposition mechanism of La3+in LiCl-KCl salt is extremely important for understanding the main characteristics of the deposition of An/Ln in the pyrochemical reprocessing of spent nuclear fuels. In this work, cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and Tafel methods were employed to investigate the electrodeposition mechanism and kinetic processes of La3+on Al, Ga and Al-Ga alloy cathodes in LiCl-KCl eutectic salt at the temperature range of 723?873 K. The EIS spectra were measured by applying a minimum overpotential near the equilibrium potential, and the suitable equivalent circuits were fitted. The values of exchange current density (i0) calculated by EIS ranged from 0.078 to 0.42 A cm?2. Finally, Al2Ga2La ternary and Al3La, Ga6La binary alloys were obtained by the potentiostatic electrolysis, which were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM) equipped with energy dispersive spectroscopy (EDS).

This work presented the electrochemical synthesis of Sm-Ni alloy magnetic materials by co-reduction of Sm(III) and Ni(II) ions on a Mo electrode or a nickel coated Mo electrode in molten LiCl-KCl-SmCl3-NiCl2at 873 K. The electrochemical behaviors of Sm(III), Ni(II) ions and alloy formation in the melt were investigated by cyclic voltammetry (CV), square wave voltammetry (SWV) and open-circuit chronopotentionmetry (OCP) techniques. The Sm-Ni alloys were obtained on Mo electrode by potentiostatic electrolysis with the varied potential at −0.8 V, −1.5 V, −1.8 V and −2.2 V (vs. Ag+/Ag), respectively. Afterwards, all the Sm-Ni alloys were characterized by X-ray diffraction (XRD), the results indicated that the SmxNiyalloys (SmNi5, SmNi2and SmNi) were prepared on Mo electrode successfully. The microstructure and micro-zone chemical analysis of Sm-Ni alloys were characterized by scanning electron microscopy (SEM) with energy dispersive spectrometry (EDS). The X-ray photoelectron spectroscopy (XPS) was performed to investigate the surface composition. The results showed that valence states of Sm and Ni on the surface were zero, which were consistent with the peak of the Sm and Ni standard spectra of metals. Vibrating sample magnetometer (VSM) tests illustrated that the magnetization intensity reached the saturated state along magnetic domain direction.