Statistical analysis of the effect of operating parameters on acid mist generation in copper electrowinning

Acid mist is generated during the final stage of hydrometallurgical metal refining processes including the electrowinning of copper. In this study, the effect of five process parameters and their interactions on the amount of acid mist generated is analysed quantitatively. The amount of acid mist generated was measured under 32 different operating conditions. It was found that solution's temperature and mist suppressant chemical FC-1100 had significant effect on the amount of acid mist generated. More than 90% of the variations in the acid mist generation can be explained by changes in these two parameters and their interaction. To a lesser extent, electrical current density and solution acidity also affected the total amount of acid mist generated. The anode's age and most of the 3, 4, and 5-way parameter interactions were found to have negligible influence on the amount of acid mist. Overall, acid mist was found to increase with temperature and current density. In contrast, increasing the viscosity of the solutions tends to decrease the amount of acid mist.

Research highlights
► Temperature and FC-1100 are the most influential parameters in acid mist generation.
► Anode's age, current density and solution acidity have small effect on acid mist.
► FC-1100 reduces acid mist by increasing surface elasticity and surface viscosity.