Study on the processes and mechanism of the formation of Fe3O4 at low temperature

The removal of iron and various heavy-metal ions by their incorporation into stable ferrite-type precipitates at low temperature is a promising alternative to clean up large volumes of polluted effluents. As a first step, the present work investigated the formation of Fe3O4 by oxidation of Fe(OH)2 suspension at different conditions, including the initial Fe(OH)2 suspension concentration, pH value, and temperature. The various mechanisms of the formation of Fe3O4 at different conditions were given based on analysis of the curve in terms of disappearance of Fe(II) phase and the formation of Fe3O4 and the end products during the course of air oxidation. The effect of aging was also discussed.