Preparation of highly uniform molybdenum powder by the short-process reduction of molybdenum trioxide with hydrogen

Abstract A novel short-process for preparing molybdenum powder is proposed in this paper in which the hydrogen flow direction is changed from traditional top diffusion to bottom blowing. The results showed that the short-process prevented sintering of the MoO2 reduction product in the first stage and permitted the continuous reduction of MoO3 by hydrogen without crushing or screening. Compared with top diffusion, when the hydrogen flow rates were 300 mL min−1 and 600 mL min−1 in the short-process, the time required for complete reduction in the second stage was shortened by 33.3% and 37.5%, respectively. In addition, the molybdenum powder obtained by the short-process was finer and more uniform, and the oxygen content was lower. The average particle size of molybdenum powder was only 1.89 μm, and the lowest oxygen content was only 1050 ppm at a hydrogen flow rate of 600 mL min−1. This novel process significantly improved the reduction efficiency and shows great potential for energy conservation and emission reduction.