Fine Generation Ratio of Iron Ore at the Cyclone in a Gas-Solid Circulating Fluidized Bed

Fine generation ratio of iron ore at the cyclone was modeled with time. The variables were cyclone inlet velocity (20.6 - 30.9 m / s), solid loading (0.5-1) and elapsed time (0.5 - 13 hour) and experiments were conducted in a circulating fluidized bed (0.076 m ID x 3.7 m height) reactor. Fine generation ratio was divided into sifting effect and attrition ratio. The sifting effect was rapidly decreased with increasing cyclone inlet velocity and solid loading. The attrition ratio was positively correlated with cyclone inlet velocity and negative with solid loading as mentioned in the previous study. Since the sifting effect decreases with time, as the elapsed time increased, the contribution of sifting effect to fine generation was decreased. Thus, when the elapsed time was 0.5 h, contribution of sifting effect was 86-93 % and when elapsed time was 5 h, contribution of sifting effect was 57 %.