Synthesis of nanomagnetite using natural iron ores exposed in Buttala, Sri Lanka: A cost-effective approach for possible application in electrophotographic toners

Magnetite nanoparticles (MNPs) are a key component in electrophotographic toner powders, where they contribute to triboelectric charge generation and magnetic control during the printing process. This study introduces a novel and cost-effective method for synthesizing MNPs from naturally occurring magnetite-rich iron ore found in the Buttala region of Sri Lanka, an underutilized resource with high potential for industrial applications. Magnetite was initially separated from crushed ore using magnetic screening, followed by high-energy ball milling with varied feed sizes and milling durations to optimize nanoparticle synthesis. Comprehensive material characterization was performed using X-ray diffraction, Inductively Coupled Plasma Mass Spectrometry, Fourier Transform Infrared Spectroscopy, and Scanning Electron Microscopy. The mineralogy, coupled with geochemical results, revealed that the magnetic fraction of the ore contains 97.2 wt.% magnetite with a total iron content of 95.97 wt.%, indicating its suitability as a high-grade raw material. The synthesized MNPs consisted primarily of magnetite (Fe₃O₄) and maghemite (γ-Fe₂O₃), with minor hematite (α-Fe₂O₃). Also, the MNPs exhibited a nearly spherical morphology with moderate flake-like agglomeration and an average particle size of approximately 51 nm. These findings demonstrate the feasibility of using Buttala iron ore as a low-cost, natural source for producing MNPs suitable for potential application in electrophotographic toner powders.