Iron ore reduction using sawdust: Experimental analysis and kinetic modelling

Iron and steel making are two of the largest energy intensive industries with the highest growth rate in energy consumption of all energy utilisation sectors. In order to meet the growing greenhouse challenges, incorporation of renewable energy sources to the existing and emerging metallurgical operations is desirable. In this respect, biomass can potentially be applied as fuel for minerals processing to stabilise the greenhouse gas emissions as it is renewable and CO₂ neutral. The work presented here investigates the fundamental mechanisms of iron ore reduction with biomass wood waste. Several mixtures with different ratios of biomass and iron ore were subjected to thermal, gaseous and X-ray Diffraction analysis. The iron ore was successfully reduced to predominantly metallic iron phase when up to 30% by weight of biomass was introduced into the mixture. Reduction commenced at approximately 670 °C and was almost completed at 1200 °C. Thermal analysis data identified the individual thermal reaction regions associated with developments of individual iron phases during the heating and were used to calculate the corresponding kinetics of the reduction process.