Abstract:To achieve the appropriate utilization of complex ferromanganese ore associated with medium and low grade, the paper employed chemical composition analysis, X-ray diffraction analysis, field emission scanning electron microscope and other testing methods to investigate the mineralogy and separation experiments of the complex ferromanganese ore associated with medium and low grade in Gabon, Africa. The research indicated that the TMn grade of this ferromanganese ore was 34.20%, and manganese minerals mainly in the form of pyrolusite, accounting for 54.21%. the TFe grade was 35.76%, and iron minerals mainly in the form of limonite, accounting for 35.76%. And the gangue minerals with low content mainly consist of quartz, biotite and muscovite. Pyrolusite was mainly generated in the form of irregular granular aggregates, with internal porosity, which was usually associated with limonite. Limonite is irregularly grained, concentric ring-banded aggregate grains with developed internal pores/holes. Based on the process mineralogy characteristics, the ferromanganese ore resources have complex mineral composition and similar ferromanganese mineral properties, with dense co-associated relationship and little difference in selectivity between minerals, making efficient separation of minerals with conventional beneficiation process difficult to be achieved. By hydrogen-based mineral phase transformation-magnetic separation process, the high-quality manganese concentrate with the TMn grade of 58.30% and the manganese recovery of 85.15% and the iron concentrate with the TFe grade of 53.76% and an iron recovery of 79.00% can be obtained, which can provide a theoretical basis for the development and utilization of a complex ferromanganese ore associated with medium and low grade.