Preparations of Mo2C or Mixture of Mo2C and Mo by Silicon/Carbon Synergistic Reduction of Molybdenum Concentrate

Molybdenum is one of the most widely used refractory metals, and about 80 pct of molybdenum is used in the iron and steel industries in the form of molybdenum additives. This work proposed a novel green strategy to prepare molybdenum additives with low S and Si contents through Si/C synergistic reduction of molybdenum concentrate, with the assistance of desulfurizer composed of CaO and C. The reaction mechanism as well as the effects of C and Si additions on reduction of molybdenum concentrate (which is one of the most important minerals for Mo extraction) with the main component of MoS2 was studied in detail. After the sample was reacted at 1600 °C for 4 hours, a core–shell-structured product with molybdenum additive wrapped by the desulfurizer layer was obtained. For the raw material with a MoS2:C:Si molar ratio of 6:6:4 reacted at 1600 °C for 4 h, Mo2C with S and Si contents of 0.04 and 0.35 wt pct can be prepared. When the MoS2:C:Si molar ratio was changed to 6:4:3.2, a mixture of Mo and Mo2C can be prepared with C, S, and Si contents of 2.19, 0.13, and 0.23 wt pct, respectively. This work provides a sulfur-free emission method for the industrial production of carbon-containing molybdenum additives directly from molybdenum concentrate.