Manganese consumption during zinc electrowinning using a dynamic process simulation

•We develop a process simulation of a zinc cell house, validating dynamic water and zinc mass balances over multiple weeks.•We examine the movement of manganese in the cell house including its deposition as manganese dioxide•Previous Mn consumption values were found to overestimate the Mn consumption rate for this cell house.•The deposition rate of manganese dioxide was found to increase with lower manganese to chloride ion concentrations ratios.•The rate of manganese consumption was found to be in the range of 19.5–38.0 g m− 2 day− 1.

The consumption of manganese in a zinc electrowinning cell house is examined using a process simulation coupled with industrial cell house data. A cell house of a major industrial producer of zinc was simulated using process simulation software. Process data was input in to the simulation on a simulated hourly basis to provide a simulation which appropriately represented the dynamic process. A small amount of dissolved manganese is desired in a zinc electrowinning electrolyte in order to reduce corrosion of the anodes by the formation of a thin layer of manganese dioxide. The manganese consumption was followed through a major change in the Mn concentration. The consumption rate of manganese ions from solution was found to vary between 8 × 10− 7 and 4 × 10− 7 mol s− 1 m− 2 on PbAg anodes. During shut downs, aqueous manganese concentration was not reduced. Larger rates of manganese consumption were found to be associated with lower concentration ratios of manganese ions to chloride ions in the electrolyte.