Mrutyunjay Panigrahi

Predictive model for ionic liquid extraction solvents for rare earth elements

The purpose of our study was to select the most effective ionic liquid extraction solvents for dysprosium (III) fluoride using a theoretical approach. Conductor-like Screening Model for Real Solvents (COSMO-RS), based on quantum chemistry and the statistical thermodynamics of predefined DyF3-ionic liquid systems, was applied to reach the target. Chemical potentials of the salt were predicted in 4,400 different ionic liquids. On the base of these predictions set of ionic liquids’ ions, manifesting significant decrease of the chemical potentials, were selected. Considering the calculated physicochemical properties (hydrophobicity, viscosity) of the ionic liquids containing these specific ions, the most effective extraction solvents for liquid-liquid extraction of DyF3 were proposed. The obtained results indicate that the COSMO-RS approach can be applied to quickly screen the affinity of any rare earth element for a large number of ionic liquid systems, before extensive experimental tests.

Fe‐Ti Alloy Production from Mixed Ilmenite and Titanium Dioxide by Direct Electrolytic Reduction in Molten Calcium Chloride Electrolyte

The electrolytic reduction process of mixed ilmenite (FeTiO3) and titanium dioxide (TiO2) to Fe-Ti intermetallic alloy in molten calcium chloride (CaCl2) electrolyte was studied. FeTiO3 and TiO2 powders were taken, which was then mixed, milled and pressed into 2.2 g of pellet and heat treated at 1000 °C for 2 h. The pellet was reduced electrochemically in a molten CaCl2 electrolyte at 950 °C and at a constant voltage of 3.0 V. The electrolyzed samples formed by the electrolytic reduction of the mixed FeTiO3 and TiO2 pellets were analyzed using X-ray diffraction, scanning electron microscopy/energy-dispersive X-ray spectroscopy, electron-probe microanalysis. From this analysis, it was confirmed that the mixed FeTiO3 and TiO2 pellets were successfully reduced to a dense Fe-Ti intermetallic alloy consisting of β-Ti (FeTi4) and FeTi phases.