Electrochemical Reduction of Iron Oxides in Aqueous NaOH Electrolyte Including Iron Residue from Nickel and Zinc Electrowinning Processes

Abstract

Experiments were carried out in NaOH-H2O (50–50 wt%) electrolyte with a suspension of Fe2O3 particles at ~100 ℃. A rotating disk electrode of graphite or silver was used as the cathode. The current efficiency for iron deposition was consistently higher than 90%. Recent experiments were carried out by using iron-containing residue from industrial electrolysis processes for producing nickel and zinc. The challenge is to purify the residue before electrolysis.