Large-scale production of Fe3O4 nanopowder using ferrous ions in a rotating packed bed with precipitation

Abstract

This study concerns the use of the rotating packed bed (RPB) in the large-scale production of Fe3O4 nanopowder using ferrous ions and precipitation. Fe3O4 nanopowder was produced at 25 °C with an FeCl2 concentration of 0.15 mol/L, an NaOH concentration of 0.3 mol/L, a rotational speed of 1800 rpm, and flow rates of aqueous FeCl2 and NaOH of 0.5 L/min. The rate of large-scale production of Fe3O4 nanopowder using ferrous ions in the RPB with precipitation was 7.6 kg/day. The produced Fe3O4 nanopowder had a mean crystallite size of 28.4 nm, an average particle size of 34.5 nm, and a BET specific surface area of 32.5 m2/g. The produced Fe3O4 nanopowder displayed ferromagnetic behavior with a saturation magnetization of 37 emu/g. The adsorption of Orange G (OG) in water was utilized to assess the adsorption capacity of the produced Fe3O4 nanopowder. The maximum adsorption capacity (17.5 mg/g) of the produced Fe3O4 nanopowder greatly exceeded that (2.4 mg/g) of Fe3O4 nanopowder that was purchased from Alfa Aesar.