LAUSR

Dissolution of iron oxides such as hematite (α-Fe2O3), magnetite (Fe3O4), and goethite (α-FeOOH) is an important chemical process in industries to improve properties of industrial minerals (e.g., ore, clay, quartz, soil, and ceramic). During this process, the iron oxides, as impurity metals, are removed by acids.1–5) Inorganic (HCl and HNO3) and organic acids (oxalic, acetic, L-ascorbic, and citric acids) have been studied for the iron oxide dissolution.1–8) Among them, oxalic acid has been suggested to be the most promising acid due to its high acid strength, complexing ability, and reducing property.8–12) Moreover, since it can be easily decomposed by calcination, there is no risk of contaminating the treated materials.5,11) The dissolution of iron oxides in oxalic acid aqueous solution is generally explained by three different mechanisms: (1) adsorption of oxalate anions on the surface of iron oxide Dissolution of Iron Oxides Highly Loaded in Oxalic Acid Aqueous Solution for a Potential Application in Iron-Making