Electrochemical Deposition of Zero-Valent Iron from Alkaline Ceramic Suspensions of Fe2−xAlxO3 for Iron Valorisation. Issue 10 (15th June 2020)

• Record Type: Journal Article
• Authors: Lopes, Daniela V.; Kovalevsky, Andrei V.; Quina, Margarida J.; Frade, Jorge R.
• Is Part Of: Journal of the Electrochemical Society. Volume 167:Issue 10(2020)
• Publication Date: 2020-06-15
• Subjects: Cathodic reduction -- cellular ceramics -- hematite -- red mud -- iron recovery; Electrochemistry -- Periodicals; 541.3705
• DOI: 10.1149/1945-7111/ab9a2b
• Languages: English
• ISSNs: 0013-4651

Abstract

Abstract : Electrochemical reduction of iron oxides into zero-valent iron (ZVI, Fe 0 ) is a promising alternative to the traditional methods used for iron production. The electrochemical deposition of Fe 0 from hematite and hematite-based Fe2−x Alx O3 ceramic in alkaline suspensions (10 M of NaOH) was assessed at relatively low temperature (90 °C). Ceramic compositions aimed to mimic the main components of red mud waste from the alumina refining industry for iron valorisation purposes. The impact of aluminium content on the electroreduction and microstructure of the deposited Fe 0 films was demonstrated and discussed. Trapping and following the leaching of the aluminium species during deposition causes drastic morphological changes and induces significant porosity. Faradaic efficiencies of the reduction to Fe 0 were found to decrease from 70% to 32% for Fe2 O3 and Fe1.4 Al0.6 O3, respectively. The results highlight possible effects imposed by aluminium presence during Fe 0 electrodeposition for future iron recycling from, for example, red mud or other aluminium containing wastes by electrowinning in alkaline conditions.