Heterogeneous electron transfer as a pathway in the dissolution of magnetite in oxalic acid solutions

Journal Article · Wed Aug 03 04:00:00 EDT 1983 · Inorg. Chem.; (United States)

DOI:https://doi.org/10.1021/ic00158a002· OSTI ID:5251063

Baumgartner, E; Blesa, M A; Marinovich, H A; Maroto, A J.G.

The dissolution of metal oxides is a process of importance in several fields such as hydrometallurgy, passivity of metals, and cleaning of boilers and metal surfaces in general. Oxalic acid is one of the most effective reagents for dissolution of magnetite under mild acid conditions. Magnetite is the oxide that confers passivity to steel surfaces. In the present communication, the more salient features of the mechanism of dissolution of magnetite by oxalic acid solutions are discussed with special focus on the role played by ferrous ions in the process. Oxalate plays an unique role among complexing carboxylic ligands in the dissolution of magnetite; it not only facilitates the electron-transfer reaction but also mediates in a relatively fast dissolution during the initial induction period (the induction period is much shorter than in the case of the dissolution of magnetite by ethylenediaminetetraacetic or nitrilotriacetic acid). This unique role has been used in the development of a very efficient scale removal formulation used in the decontamination of nuclear power plants.

• Research Organization: Comision Nacional de Energia Atomica, Buenos Aires, Argentina
• OSTI ID: 5251063
• Journal Information: Inorg. Chem.; (United States), Journal Name: Inorg. Chem.; (United States) Vol. 22:16; ISSN INOCA
• Country of Publication: United States
• Language: English

Related Subjects

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY
400201* -- Chemical & Physicochemical Properties
CARBOXYLIC ACIDS
CHALCOGENIDES
CHEMICAL REACTION KINETICS
DICARBOXYLIC ACIDS
DISSOLUTION
IRON COMPOUNDS
IRON ORES
IRON OXIDES
KINETICS
MAGNETITE
MINERALS
ORES
ORGANIC ACIDS
ORGANIC COMPOUNDS
OXALIC ACID
OXIDE MINERALS
OXIDES
OXYGEN COMPOUNDS
REACTION KINETICS
SOLVENT PROPERTIES
TRANSITION ELEMENT COMPOUNDS
USES