Silicothermic self-reducing MoO_3 briquettes for direct alloying of Mo in molten steel

摘要

The use of molybdenum trioxide (MoO_3), which is cheap and relatively abundant MoO_3 has been evaluated as a potential alternative to expensive FeMo as a steel alloying method. Pure MoO_3 volatilises very significantly above its melting point (1068 K) and results in a poor alloy yield when added to steel. The volatilisation of MoO_3 in FeSi-MoO_3, MoO_3-CaO and MoO_3-MgO mixtures have been investigated by TG-DTA. Self-reducing experiments of industrial MoO_3 mixed with FeSi, CaO and CaF_2 have been performed in an electric resistance furnace. The results show that the volatilisation of industrial MoO_3 can be effectively inhibited when adding CaO and FeSi and addition of CaF_2 helps form a low melting point slag and results in good separation of metal and slag, The Mo quickly dissolves in the molten steel with 95% recovery.