High Temperature behaviour of Directly Reduced Iron Fines

The objective of this work was to characterize the high temperature behaviour of direct reduced iron (DRI) fines because they could potentially be injected into liquid steel to reduce the nitrogen content of the steel. Physical and chemical analysis of samples of DRI fines were conducted including size analysis, chemical analysis, X-Ray Diffraction and simultaneous thermogravimetric and differential thermal analysis. The chemical changes during heating were also simulated using FACT thermodynamic analysis. It was found that the carbon and oxygen in the iron oxides reacted above 500 °C and were generally completed by 700 °C if the carbon-to-oxygen ratio was balanced. Samples with lower oxygen contents continued to react above this temperature due to the reduction of gangue oxides in the DRI.