Experimental determination of the factors affecting zinc electrowinning efficiency

Abstract

A series of experiments were conducted to investigate the factors affecting the efficiency of zinc electrowinning. The experiments were conducted in 10-1 cells using a high purity industrial zinc sulphate solution. The lowest specific energy consumption achieved in the cells was 2637 kWh t⁻¹ Zn under the following conditions:

$$\begin{gathered} 70 g1^{ - 1} Zn in cell solution \hfill \\ 180 g1^{ - 1} H_2 SO_4 in cell solution \hfill \\ 45^\circ C cell temperature \hfill \\ 400A m^{ - 2} current density \hfill \\ \end{gathered} $$

Further energy savings can be achieved by reducing the current density but this would also reduce the cellroom production capacity. Increasing the electrolyte temperature to 50° C also reduced the energy consumption, however additives capable of controlling deposit morphology at these high temperatures were required. The effects of zinc concentration, acid concentration, deposition time and additive levels are also reported.