Collect. Czech. Chem. Commun. 1981, 46, 3049-3056

Oxidation of ferrous sulphate in neutral and weakly alkaline solutions

Alexandra Šolcová, Jan Šubrt, Jaroslav Vinš, František Hanousek, Vladimír Zapletal and Jaroslav Tláskal

Institute of Inorganic Chemistry, Czechoslovak Academy of Sciences, 250 68 Řež


Oxidation of FeSO4 by air oxygen has been studied in aqueous solutions of constant acidity. The effect of various reaction conditions (of acidity, temperature, concentration of FeSO4, and of the air flow through the suspension) on the yield of various modifications of ferric oxide-hydroxides in the product mixture is described and the mechanism of the process is discussed. Reaction products prepared in the neutral and weakly alkaline solutions contain predominantly lepidocrocite (γ-FeOOH), amorphous Fe2O3.n H2O (ferrihydrite), at higher pH values also goethite (α-FeOOH) is formed. Their mutual ratios depend strongly on the solution acidity.