Mn–Zn soft magnetic ferrite nanoparticles synthesized from spent alkaline Zn–Mn batteries

Abstract: Using spent alkaline Zn–Mn batteries as raw material, Mn–Zn soft magnetic ferrite nanoparticles are prepared by multi-step processes including acid leaching, chemical treatment of battery iron shells and citrate-nitrate precursor auto-combustion. Acid leaching and chemical treatment mechanisms are investigated. Dried gels thermal decomposition process, auto-combustion, phase composition, morphological and magnetic properties of as-prepared Mn–Zn ferrite nanoparticles are characterized by thermogravimetric and differential thermal analysis, X-ray powder diffraction, transmission electron microscopy and vibrating sample magnetometer. Synthesized Mn–Zn ferrite nanoparticles (Mn0.5Zn0.5Fe2O4) have pure ferrite phase, larger saturation magnetization (M s =60.62emug−1) and lower coercivity (H c =30Oe) compared with the same composition ferrites prepared by other techniques due to better crystallinity. Mn–Zn ferrite nanoparticles synthesis method presents a viable alternative for alkaline Zn–Mn batteries recycling. [Copyright &y& Elsevier]