Ti/Ti4O7 Anodes for Efficient Electrodeposition of Manganese Metal and Anode Slime Generation Reduction

Abstract

Preventing lead-based anodes from causing high-energy consumption, lead pollution, and harmful anode slime emission is a major challenge for the current electrolytic manganese metal industry. In this work, a Ti4O7-coated titanium electrode was used as anode material (Ti/Ti4O7 anode) in manganese electrowinning process for the first time and compared with a lead-based anode (Pb anode). The Ti/Ti4O7 anode was used for galvanostatic electrolysis; the cathodic current efficiency improved by 3.22% and energy consumption decreased by 7.82%. During 8 h of electrolysis, it reduced 90.42% solution anode slime and 72.80% plate anode slime formation. Anode product characterization and electrochemical tests indicated that the Ti/Ti4O7 anode possesses good oxygen evolution activity, and γ-MnO2 has a positive catalytic effect on oxygen evolution reaction (OER), which inhibited anode Mn2+ oxidation reaction and reduced the formation of anode slime. In addition, the low charge-transfer resistance, high diffusion resistance, and dense MnO2 layer of the anode blocked the diffusion path of Mn3+ in the system and inhibited the formation of anode slime. The Ti/Ti4O7 anode exhibits excellent electrochemical performance, which provides a new idea for the selection of novel anodes, energy savings and emission reduction, and the establishment of a new mode of clean production in the electrolytic manganese metal industry.