Synthesis of magnetite nanoparticles from iron ore tailings using a novel reduction-precipitation method

Magnetite nanoparticles successfully produced from a pregnant leach solution (PLS) of iron ore tailings via a simple reduction-precipitation method using Na2S2O3·5H2O reducing agent while the ratio of [Fe3+] to [S2O32−] were 3 and 2 in the presence and absence of nitrogen gas respectively. The produced nanoparticles were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), scanning and transmission electron microscopy (SEM, TEM), Brunauer-Emmett-Teller (BET), and vibrating sample magnetometry (VSM). The achieved XRD and FTIR results confirmed the presence of Fe3O4 nanoparticles while SEM and TEM images displayed that the formed nanoparticles were spherical with an average diameter of 19 ± 3 nm. The average surface area and the pore volume of produced nanoparticles were calculated to be 64.04 m2 g−1 and 0.079 cm3/g, respectively using the BET method. By performing VSM analysis and estimation of the low magnetic remanence (Mr) and coercive field (Hc), it was concluded that the produced nanoparticles are highly ferromagnetic at the room temperature.