A new method for the calculation of the theoretical flame temperature has been proposed to reflect the impact of coal combustion efficiency. Investigations of the influence of operational and raw materials conditions on Tf and maximum PCI rate has been carried out by applying this new method and by assuming that the furnace production rate is governed by the flooding phenomenon based on the high PCI practices in the Bao Steel blast furnaces. It has been found that maximum coal rate is not limited by Tf and that the primary effect of blast oxygen enrichment lies in the improvement of the flooding condition of the furnace. The future of ironmaking technology has also been discussed.