Synthesis and study of TiMn2 intermetallic compound anode materials with different structures for zinc electrowinning

Abstract

In the zinc electrowinning process, lead anodes have been the main cause of lead pollution, resulting in environmental and ecological imbalances. To address this issue, this study prepared high purity bulk and porous TiMn2 intermetallic compound lead-free anodes through elemental reaction synthesis and investigated their electrochemical properties and electrolytic performance. The Tafel slopes of the bulk and porous TiMn2 anodes were found to be 351.85 and 741.9 mV·dec−1, respectively, with oxygen evolution overpotentials of 0.952 and 0.704 V in 160 g L−1 H2SO4 solutions. Both bulk and porous TiMn2 anodes exhibited long-time stability of 4210 and 960 h, respectively, during simulated electrolysis at 500 A m−2. Additionally, porous TiMn2 anodes exhibited lower potential than lead in simulated electrowinning experiments, while maintaining the quality of the deposited Zn conforming to the Zn-1 standard according to ISO 752–2004, with higher electrowinning efficiency than lead anode. Therefore, this study proposes a new intermetallic compound anode system that shows great potential and application in electrowinning, while reducing lead pollution and promoting environmental and ecological balance.