Research into resource-saving molybdenum-containing alloying additive, obtained by the metallization of oxide concentrate

We established that the phase composition of oxide molybdenum concentrate is re presented mainly by MoO3, as well as МоО2, WO3, Mo2C and associated ore impurities of Al2O3, CaO, SiO2 and MgO. We found non-uniform microstructure in the form of plates, granules of round shape, and thread-like formations. It was determined that phase composition of metallized molybdenum concentrate, obtained by carbon-thermal technique, is mostly composed of metal Mo with the presence of MoC and Mo2C. Unrestored component is represented by the oxy-carbide compound (Mo, O, C) and the lower molybdenum oxide MoO2. We noted fragmented presence of Mo8O23. Spongy microstructure revealed areas where the molybdenum oxide restoration products dominate. The presence of residual oxygen confirms the existence, along with metal Mo, of unrestored oxide or oxy-carbide compounds. The residual oxygen could also be contained in the oxide compounds of Si, Al, Ca, Mg, K, Na as associated ore impurities. This is confirmed by discovery of the specified elements in the examined areas. The detected phases and compounds do not display significant susceptibility to sublimation. High restorative ability, due to the excess of carbon in the form of carbides, provides the post-restoration of oxide component in the liquid metal in the process of alloying, as well as protection against secondary oxidation