An Alternative Method for Reducing Hematite to Magnetite Using Starch

Starch was found to be suitable organic reducing agent for hematite in the solid state at elevated temperature in air. Samples were analyzed using x-ray diffraction, Fourier transform infrared spectroscopy and Moessbauer spectroscopy. After heating the starting mixture for 0.5 hr and 2 hr at 300 degree,magnetite and small fraction of hematite were found with XRD. With prolonged time of heating up to 24 hr, magnetite re oxidized to hematite. Magnetite formed at 580 degree was nonstoichiometric and probably of poor crystallinity. FT-IR spectra showed the presence of organic intermediaries formed during the thermal decomposition of starch. The characteristic IR bands of organic components were assigned. Moessbauer spectra showed that the stoichiometry of magnetite was very dependent on the thermal treatment of the samples. The reduction of hematite with starch into alpha-Fe was not observed in any sample