Agglomeration during reduction of MoO3

► Very few studies have been reported in literature focusing on the first stage reduction of molybdenum powders. ► The agglomeration of the powders occurs during reduction of MoO3. ► The agglomeration of the oxides reduced at 650 °C was larger compared to the oxides reduced at 550 °C and 750 °C. ► The shape of the reduced oxide powder showed a dependency on the starting shape of MoO3. ► Agglomeration of reduced oxides is due to melting of eutectic formed between MoO3 and Mo4O11 and due to melting of MoO3.