Ferrosilicon alloy granules prepared through centrifugal granulation process

A novel granulation process that involved the use of a rotary multi-nozzles cup atomizer and water cooling was proposed for ferroalloy manufacturing. The effects of rotating speed and nozzle diameter on the properties of FeSi75 alloy (containing 75 wt.% Si) granules were investigated. Results indicated that median granule diameter decreased as rotating speed increased, and initially increased and then decreased as nozzle diameter increased. The optimal conditions for the granulation of FeSi75 alloy were a rotating speed of 150 r/min and nozzle diameter of 10 or 12 mm. The phase composition, micromorphology, and elemental distribution of the FeSi75 alloy granules were also studied by X-ray diffraction, scanning electron microscopy, and energy-dispersive X-ray spectrometry. In order to provide guidance for the layout and water depth of the tank, the solidification behavior of ferrosilicon alloy droplet was numerically studied. A simplified model was established to elucidate the traveling trajectory and heat transfer of alloy droplet in air and cooling water during the atomization process. The solidification time of droplet with different thicknesses of solidification layer increased with the increase in alloy droplet diameter.