Numerical simulation and experimental verification of the influence of non-uniform pole pitch to rare earth electrolysis process

For the purpose of investigating the effect of polar distance inhomogeneity on electric, thermal and flow field, a function D was introduced to establish the mathematical model of polar distance inhomogeneity to represent it, which simulated the distribution of the electric and thermal field, and calculated the distribution of the flow field, bubble and metal liquid. Studying four different pole pitch inhomogeneity D showed that: when D increased in the range of 1 to 1.48, the distribution of current on both sides of the cathode was not symmetrical gradually, the heat generation decreased, and the bubble content and turbulence intensity were changed. When the metal liquid from cathode was dripping, the deviation angle from the centerline of the cell was 0°~30°, which could fall within the bottom of the crucible; but when D=1.73, the deviation angle was 43°, and the cell condition was so deteriorate that the liquid of rare earth metal would not fall into the crucible, which means the anode needs to be replaced to ensure proper electrolysis. When equidistant drawdown method was used to measure the anode current distribution, it was found that the calculation error was 2.7% ~ 5.6%, compared with the actual current value and the measured value of the analog current. This indicated that numerical simulation can be used to find out the effect of the inhomogeneity of anode current distribution, which could optimize the process operation in actual production, improve the electrolysis efficiency, and provide protection for reducing energy consumption.