A facile and reliable route to prepare highly dispersive ammonium dimolybdate uniform crystals from commercial molybdenum oxide

Highly dispersive ammonium dimolybdate crystals with high purity have been prepared through reaction–evaporation–crystallization united route using commercial molybdenum oxide as starting material. The as-prepared ammonium dimolybdate uniform crystals were systematically characterized by X-ray powder diffraction, transmission-reflection optical microscope, Fourier transform infrared spectroscopy and TG-DSC thermal analysis. The Fsss grain diameter, loose packed density, and crystal-grain size distribution were also measured by the Malvern laser particle sizer. These collective characterization and analysis reveal that the ammonium dimolybdate grains are non-agglomerated uniform crystals with well normal distribution and geometric shape. The average Fsss diameter, d(0.5) and loose packed density are 433.316 μm, 470.981 μm and 1.592 g cm−3, respectively, which could well meet the quality requirements for the subsequent production of molybdenum powders.