Numerical heat transfer analysis for the design of the engineering-scale electrowinning cell in pyroprocessing

Abstract

A heat transfer analysis of the electrowinning cell was conducted to develop a basic tool for designing of the engineering-scale electrowinner. For calculating the heat transfer properties of argon gas and LiCl–KCl eutectic salt in the electrowinning cell, the ANSYS CFX commercial code was adapted. The simulation model was prepared, and the temperature profiles of the argon gas and the salt were compared with those in the lab-scale electrowinning cell. Using the simulation model, temperature distributions of the engineering-scale electrowinning cell were analyzed. When the heating zone length was 2.5 times longer than the height of the LiCl–KCl salt, the salt temperature was maintained at about 500 °C and its temperature gradient became less than 5 °C. The cooling zone length had an influence on both temperatures of the argon gas under the cell cover as well as the salt. When the cooling zone length was about 0.16–0.19 of the heating zone length, the temperature of the salt was maintained at 500 °C and the argon gas temperature under the cover decreased below 200 °C. The number of the heat shield plates and size mainly affected the temperature gradient of the salt and argon gas under the cover. More than 3 heat shield plates had to be placed in the cooling zone and their diameters should be extended over 410 mm that is over 0.95 of the cell diameter.