Solubility Of Oxides In Molten Salts And The Preparation Of Carbide-derived Carbon By Fused Salt Electrolysis Process

In the temperature range of873-1173K, MgO, Al2O3and Fe2O3saturated molten salt CaCl2and CaCl2-NaCl were prepared. The acid-base titration method was used to study the solubility of the oxides in molten CaCl2and CaCl2-NaCl. In the temperature range, the solubility increases with increasing temperature, and there is a good linear relationship between solubility and temperature. The work provided basic data for the molten salt electrolysis of the oxides.A preliminary exploration of preparing carbide-derived carbon (CDC) by molten salt electrolysis method from TiC was conducted. Important parameters such as molding pressure, sintering temperature, and electrolysis temperature and voltage were studied. The optimized experimental conditions were obtained. TiC pellets shown the best electrochemical performance pressed at20MPa and sintered at950℃for4hours. The equimolar KCl-NaCl molten salt was used as electrolyte. The CDC was prepared in the following experimental conditions, electrolysis temperature is800℃and the electrolysis voltage is1.5V. The CDC was analysised by X-ray diffraction (XRD), Scanning electron microscope (SEM) and X-ray spectroscopy (EDS) and TG-DSC. The results show that the main composition of the product is the CDC. This indicates that the molten salt electrolysis method for the preparation of CDC is possibile.The adsorption process of the obtained CDC to methyl orange was studyed detailly. The results show that the adsorption of the CDC for different concentrations of methyl orange reached equilibrium within100min. Increasing initial concentration of methyl orange dye, both the force and the maximum adsorption capacity increases, and removal efficiency decreases. The maximum adsorption of the CDC to methyl orange decreases with increasing temperature. The adsorption process is exothermic. The adsorption thermodynamics and kinetics were discussed. It found that the Langmuir adsorption isotherm is better than Freundich adsorption isotherm to describe the adsorption process. The adsorption process is spontaneous. The study of adsorption kinetics shows that the second order equation fitted better than the first order equation.