Measured and modelled air flow rates during the iron ore sintering process: green and sintered beds

In the iron ore sintering process, air flow rate is a major factor in determining the flame front speed which in turn influences the sinter quality and productivity. In the present work, sintering characteristics of an Asia Pacific blend of Australian and Brazilian iron ores were extensively studied in an experimental sinter pot test system to determine this parameter for two limiting cases namely green bed (no sintering) and sintered bed (complete sintering). Detailed experiments were conducted to measure the air flow rate for a range of fuel rates and basicities. Different theoretical pressure drop models were utilised to predict this parameter in each case. For the green bed, operating at a pressure drop of 16 kPa used in industry, the air flow rate was successfully modelled (within ±15 percent) using the Ergun Equation, with modified coefficient values of 260 and 2.48, respectively. Similarly, for the sintered bed operating at 16 kPa pressure drop, the air flow rate was able to be predicted by the Sugiyama orifice model, where a flow fraction parameter, a, of 0.7 was used instead of the 0.8 value determined previously from softening and melting tests. Interestingly, the revised a was also successful in predicting air flow rate across the range of fuel rates and basicities for the pressure drop range of 4-21 kPa.