Synthesis of nanocrystalline metallic iron from secondary iron oxide resources

Abstract

The reduction of mill scale into nanocrystallites metallic iron was studied. The powder samples of iron oxides (mill scale) were mixed with different ratios of space holder material (3, 6 and 9% starch) and then pelletised before being fired at 1000°C for 1 h in a muffle furnace. The fired pellets were reduced in hydrogen atmosphere at 800°C using thermogravimetric techniques. The reduced products were characterised using X-ray diffraction analysis technique, scanning electron microscope and vibration sample magnetometer. The presence of starch has a great effect on the physicochemical properties of produced metallic iron during reduction of the fired mixed pellets. Nanocrystalline size of the produced metallic iron was found to be gradually decreased from 114˙1 to 66˙1 nm with increasing pellets starch content from 0 to 9% respectively. Soft magnetic nano-iron metal was formed with H_c ranged from 18˙4 to 30˙98 Oe, B_r from 4˙3 to 6˙7 emu g^–1 and B_s from 60˙8 to 101 emu g^–1.