Characteristics of ferromanganese alloys produced via aluminothermic reduction of pre-reduced ores by hydrogen in comparison with conventional carbothermic process products

The development of sustainable metallurgical routes aimed at reducing CO 2 emissions has renewed interest in alternative reductants for alloy production. Secondary aluminium, due to its strong reducing potential and high reaction enthalpy, represents a promising candidate for aluminothermic processing. The choice of reductant plays a critical role in governing the microstructure and physicochemical properties of the resulting alloy. In this work, ultra-low carbon ferromanganese produced via aluminothermic reduction is systematically compared with conventionally produced ferromanganese in terms of phase constitution, microstructure, melting behaviour, and wettability against Al 2 O 3 refractory. Significant differences in phase evolution and thermophysical properties were observed between the two processing routes. The aluminothermic product predominantly consisted of the β-Mn phase, whereas the conventional alloy was characterized by the α-Mn phase. The aluminothermic ferromanganese exhibited a higher melting temperature range (1371–1601 °C) compared to the conventional material (1196–1234 °C). Wettability measurements revealed enhanced reactivity of the aluminothermic product toward Al 2 O 3 , with lower contact angles (59.92–98.76°) relative to the conventional alloy (97.39–123.28°). Furthermore, a clear correlation between carbon content and wetting angle was observed in conventionally produced ferromanganese, whereas no systematic dependence was identified for the aluminothermic product, indicating a distinct change in interfacial behaviour induced by the reduction route.