Electrowinning of Iron in Aqueous Alkaline Solution Using a Rotating Cathode

Electrowinning of iron by electrodecomposition of iron oxide ore in aqueous alkaline electrolytes is an alternative method to reduce emissions in steelmaking. Laboratory experiments were carried out in a suspension of hematite in concentrated NaOH at . particles were reduced to metallic iron upon contact with the rotating cathode, while oxygen gas was evolved on the nickel mesh anode. Iron deposits generally adhered well to the carbon cathode substrate. The current efficiency for iron was consistently above 90%, hydrogen evolution on the cathode being the main reason for the inefficiency. The influence of cathode rotation rate, cathodic current density, content of particles, and concentration of NaOH on the current efficiency and the morphology of the deposit was studied.