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

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 = 60.62 emug(-1)) and lower coercivity (H-c = 30 Oe) 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. (C) 2011 Elsevier B.V. All rights reserved.