8th International Congress on Science and Technology of Ironmaking - ICSTI 2018

In recent years, substituting a part of coke breeze with a biomass fuel in the sintering of iron ores has became an attractive research topic, which should help with the minimization of CO2 released from fossil fuels as well as searching for an alternative for coke in ironmaking. Besides the common process analyses, characterization of sinter properties through the mineralogical composition represents a new challenge. In this study, the mineralogy of iron ore sinters produced with partial fuel substitution with charcoal, milled walnut shells and oak sawdust are described and the basic technical parameters such as the tumble index and temperature are compared. When the fuel substitution is based on the equivalent fixed carbon content, the overall fuel amount in the sintering mixture by using non-pyrolysed biomass increases. Because this is caused by the volatile matter, which cannot be fully utilised, no dramatic increase of the temperature of FeO/magnetite content was observed. On the other hand, energy brought due the non-pyrolysed biomass is distributed much more uniformly and the ore particle assimilation is then more advanced. Also, higher porosity during the cooling of the hot sinter mass supported the formation of the calcium ferrites. Finally, the tumble index shows that the substitution of the coke breeze in the sintering process generates quality sinters but is limited by pyrolised or non-pyrolised biomass.