ENHANCEMENT OF OPERATING CURRENT-DENSITY IN A COPPER ELECTROWINNING CELL

Abstract

Efforts have been made to enhance the operating current density of an open channel cell to obtain high-quality cathode copper. Since increase of copper concentration and circulation rate did not improve the nature of the cathode deposit, the cell was modified to circulate the electrolyte through jets parallel to the cathode surface. With the modified cell it was possible to achieve quality deposits at a current density as high as 400 A m-2. The hydrodynamic conditions of the cell were studied in detail. The results show that high limiting current densities and high mass transfer coefficient values are possible due to increase in the linear velocity. It has also shown that there are four distinct regions of limiting current distribution on the cathode plate. Since there is no turbulence up to approximately 3.0 cm height from the bottom edge of the cathode plate (dead zone), the cell with a jetting system may be used as a high current density copper electrorefining cell.