Preparation of α-Fe2O3 (hematite) by oxidation precipitation of aqueous solutions of iron(II) sulphate

Abstract

The oxidation precipitation of aqueous solutions of iron(II) sulphate by oxygen gas was studied; the effect of pH, temperature, and presence of α-FeOOH and α-Fe₂O₃ crystal nuclei was examined and the conditions for the preparation of phase-pure α-Fe₂O₃ (hematite) were sought. The hematite prepared contained 3-5% structurally bonded water. The effect of the bonded water on the properties of the product is described and the way of the bonding in the structure is discussed.