Current Efficiency Comparison of Two Types of Rare Earth Electrolytic Cells: Flow Field Numerical Simulation Analysis and Experimental Investigation

To achieve the scale development of rare earth electrolytic cells and to improve their current efficiency and life cycle, a bottom cathode rare earth electrolytic cell was put forward. The flow fields of a conventional vertical cathode rare earth electrolytic cell (CVCEC) and a bottom cathode rare earth electrolytic cell (BCEC) were simulated by a multiphase flow model. The VOF model was used to simulating the flow fields of the two types of cells. The simulation results indicate a strong fluid circulation flow between the cathode and anode in the CVCEC, which enhances the convective mass transfer and also affects the trajectory of rare earth metals. The fluid flow between the cathode and anode is relatively gentle for the BCEC, and the possibility of secondary oxidation of rare earth metals is very low. It is speculated that the electrolytic current efficiency of the BCEC is higher. To prove the speculation based on the flow field simulation results, electrolysis experiments were carried out on two types of electrolytic cells. The results show that the current efficiency of the BCEC is about 10 pct higher than that of the CVCEC, which confirms that the BCEC can significantly improve the current efficiency.