A study on the preparation and characterization of maghemite (γ-Fe2O3) particles from iron-containing waste materials

The recovery and repurposing of valuable substances from iron-bearing wastes is challenging and vital from economic and environmental perspectives. Herein, maghemite (gamma-Fe2O3) particles were synthesized from different iron-containing waste materials by simple chemical precipitation method using HCl, NaOH, and Na2CO3, followed by calcination. Subsequently, the optimum pH value for the precipitation of iron from solution, and calcination temperature for getting gamma-Fe2O3 were found at 12 and 350 degrees C, respectively. The final products were characterized by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), particle size analysis (PSA), thermogravimetry/differential thermal analysis (TG/DTA), and vibrating sample magnetometry (VSM). The formation of gamma-Fe2O3 was anticipated from XRD and FT-IR studies, while TG/DTA data supported their excellent thermal permanence. SEM studies showed that the gamma-Fe2O3 particles were relatively irregular, mostly spherical structured with a particle size ranged around 0.2-0.35 mu m. PSA confirmed the high specific surface area of gamma-Fe2O3 particles, and the largest one was found from the iron dust. VSM measurement assured the existence of ferromagnetic properties in gamma-Fe2O3 particles at room temperature. The findings reveal that this procedure is a viable way to prepare gamma-Fe2O3 particles from iron-containing waste materials.