Communication—On the Possibility of Fe Electrowinning from Hematite Suspensions in Mixed-Acid Electrolytes

Abstract

Iron electrowinning offers a greener path for steel production. While alkaline media has received the most significant attention, the acidic media declined due to low Faradaic efficiency and difficulties imposed by fragile deposits. This study proposes, for the first time, prospects for acidic Fe electrowinning using a mixed-acid electrolyte (H 2 SO 4 +C 2 H 2 O 4 ), comparing the deposition from hematite suspensions and soluble Fe 2+ salts (FeSO 4 .7H 2 O). Oxalic acid emerges as a key factor, facilitating Fe electrodeposition by forming iron complexes in solution, addressing the challenge associated with slow Fe 2 O 3 dissolution in H 2 SO 4 .