Lopes Daniela V, Lisenkov Aleksey D, Ruivo Luís C M, Yaremchenko Aleksey A, Frade Jorge R, Kovalevsky Andrei V
Department of Materials and Ceramic Engineering, CICECO-Aveiro Institute of Materials, University of Aveiro, 3810-193 Aveiro, Portugal.
Department of Environment and Planning & Centre for Environmental and Marine Studies (CESAM), University of Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro, Portugal.
Materials (Basel). 2022 Feb 15;15(4):1440. doi: 10.3390/ma15041440.
The alkaline electrolytic production of iron is gaining interest due to the absence of CO emissions and significantly lower electrical energy consumption when compared with traditional steelmaking. The possibility of using an iron-bearing pseudobrookite mineral, FeTiO, is explored for the first time as an alternative feedstock for the electrochemical reduction process. To assess relevant impacts of the presence of titanium, similar electroreduction processes were also performed for FeTiO·FeO and FeO. The electroreduction was attempted using dense and porous ceramic cathodes. Potentiostatic studies at the cathodic potentials of -1.15--1.30 V vs. an Hg|HgO|NaOH reference electrode and a galvanostatic approach at 1 A/cm were used together with electroreduction from ceramic suspensions, obtained by grinding the porous ceramics. The complete electroreduction to Fe was only possible at high cathodic polarizations (-1.30 V), compromising the current efficiencies of the electrochemical process due to the hydrogen evolution reaction impact. Microstructural evolution and phase composition studies are discussed, providing trends on the role of titanium and corresponding electrochemical mechanisms. Although the obtained results suggest that pseudobrookite is not a feasible material to be used alone as feedstock for the electrolytic iron production, it can be considered with other iron oxide materials and/or ores to promote electroreduction.
由于与传统炼钢相比不存在一氧化碳排放且电能消耗显著降低，碱性电解法生产铁越来越受到关注。首次探索了使用含铁假板钛矿矿物FeTiO作为电化学还原过程的替代原料的可能性。为了评估钛存在的相关影响，还对FeTiO·FeO和FeO进行了类似的电还原过程。尝试使用致密和多孔陶瓷阴极进行电还原。采用相对于Hg|HgO|NaOH参比电极在-1.15--1.30 V的阴极电位下进行恒电位研究以及在1 A/cm²下进行恒电流方法，同时从通过研磨多孔陶瓷获得的陶瓷悬浮液中进行电还原。只有在高阴极极化（-1.30 V）下才能将铁完全电还原，但由于析氢反应的影响，这会损害电化学过程的电流效率。讨论了微观结构演变和相组成研究，提供了关于钛的作用和相应电化学机制的趋势。尽管所得结果表明假板钛矿不是单独用作电解铁生产原料的可行材料，但可以与其他氧化铁材料和/或矿石一起考虑以促进电还原。
