Process Mineralogical Characterisation of Magnetite Ores in the Shilu Iron Mine, Hainan Province, South China

The Shilu Iron Mine is one of China's largest high‐grade haematite deposits. Intense regional magmatism has also generated significant reformed magnetite ores. However, the underutilisation of these resources has led to resource waste. This study analyses representative magnetite ore samples to characterise process mineralogical attributes, including chemical composition, mineral species, content, dissemination, grain size, and the occurrence states of Fe and associated Co and Ni, to provide new insights into process optimisation and comprehensive resource utilisation. Results suggest that Fe predominantly occurs in magnetite, with concentrations ranging from approximately 69.81% to 71.46%. Magnetite and pyrite contain Co in favourable occurrence states, even at subeconomic grades. Ni is present in native iron, although in minimal amounts and difficult to separate. Magnetite mainly exhibits euhedral to subhedral equigranular textures, with dispersed features and well‐defined boundaries with gangue minerals. Pyrite occurs in banded or disseminated aggregates. With an estimated 5%–10% gangue entrainment, the iron ore concentrate grade can reach 65.0%–68.5%. Due to the heterogeneous medium‐to‐fine dissemination of magnetite, a staged grinding–separation strategy is recommended: an initial grind to 74 μm (200 mesh) for low‐intensity magnetic separation at the roughing stage, followed by regrinding of the middlings to 44 μm (325 mesh) before flotation, thereby improving magnetite liberation and recovery while limiting over‐grinding and flocculation‐related losses. In summary, reformed magnetite ores show considerable Fe recovery potential. Co can be partially utilised, whereas Ni offers limited value for comprehensive utilisation.