Solid biocarbon suitability quantification for iron ore pellet induration

Replacement of fossil carbon reductants utilisation by carbonaceous materials from renewable sources is one of the important approaches to reduce greenhouse gas (GHG) emissions of iron and steel production. Because of the wide variation in chemical and physical properties between biogenic carbon materials, selection of suitable materials for replacing fossil carbon to achieve the goal of GHG emissions reduction while maintaining process efficiency is challenging. This study focuses on technique development for evaluating the suitability of selected solid biocarbon to replace coke breeze in iron ore pellet induration. A laboratory analytical method based on thermogravimetry analysis (TGA) was developed to assist understanding the performance of solid biocarbon in the iron ore pellet induration process. Using this technique, a wide range of biocarbon samples were examined for developing the relationship between biocarbon production and processing conditions and its performance in iron ore pellet induration. Experimental results revealed that the combustion of biocarbon initiates at lower temperature than coke, which may negatively impact the induration process as well as quality of the resultant iron ore pellet. But the combustion initiation temperature is closely related to the pyrolysis severity employed in biocarbon materials production and post-processing of biocarbon by densification. Parameters that characterise the suitability of biocarbon candidates for replacement of coke breeze in iron ore pellet induration were defined to enable direct comparison between potential biocarbon candidates. It also serves as basis for biocarbon producers to further develop their products to meet the technical needs of end-users.