Abstract
The present study investigates the possibility of selective iron reduction from the Keregetas iron–manganese ore deposit (Kazakhstan) using hydrogen, followed by the separation of iron- and manganese-containing phases. The relevance of the research is associated with the need to develop environmentally sustainable processing technologies for low-grade iron–manganese ores under the conditions of metallurgical industry decarbonization. Experimental studies were carried out at temperatures of 800–900 °C in a high-purity hydrogen atmosphere, followed by magnetic separation and liquid-phase separation of the reduction products. The phase and chemical compositions of the samples were analyzed using X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive spectroscopy (EDS). It was established that during the reduction process, iron oxides were predominantly transformed into the metallic state with the formation of α-Fe, whereas manganese oxides were mainly reduced to MnO and Mn3O4. Magnetic separation demonstrated limited selectivity due to the simultaneous transfer of iron-containing and manganese-containing phases into the magnetic fraction. At the same time, liquid-phase separation of the pre-reduced material at 1650 °C ensured effective separation of metallic and slag phases, with manganese concentrated in the slag and minimal losses in the metallic product. A technological flowsheet for the processing of iron–manganese ores is proposed, including hydrogen reduction, magnetic separation, and subsequent high-temperature phase separation. The obtained results demonstrate the prospects of hydrogen metallurgy for the development of low-carbon technologies for the integrated processing of iron–manganese raw materials.