Surface coating of group B iron powders in a spouted bed

Group B iron powders with the size range of 44 μm - 88 μm are coated in a spouted bed fitted with a draft tube using polyethylene aqueous solutions. Group B iron powders are coated in a spouted bed coater using draft tubes of 4 different diameters and 2 different positions (i.e., entrainment length). The surface coating of Group B powders was qualitatively confirmed by SEM-EDS and quantitatively evaluated by TGA. The effects of the draft tube diameter and the entrainment height on the coating efficiency are investigated. The results show that the amount of coating increases with the increasing of the entrainment length and is less affected by the draft tube diameter. The maximum coating mass fraction achieved in our system is approximately 0.78 wt%.