On the reduction behavior, structural and mechanical features of iron ore-carbon briquettes

The utilization of Ferro-coke briquettes is increasingly being considered as a process to reduce CO2 emissions and energy consumption in blast furnace. The briquettes were prepared using iron ore, charcoal, lime, a binder and three different coals of poor coking properties. The coals have Gieseler maximum fluidity below 100 ddpm and are vitrinite-rich with inertinite content close to 30%. The briquettes were carbonized up to 1000 degrees C in a laboratory -scale oven and in a thermogravimetric analyzer which permitted a detailed evaluation of the weight loss at each stage of carbonization. Iron reduction, strength (both compression and drum tests) and optical properties of the carbon matrix were evaluated in the carbonized briquettes. The carbonization process caused significant differences in the optical textures of the carbonized materials, in particular in higher rank coals, where there was a greater range of optical texture sizes compared to the cokes from single coals. The best resistance to compression was observed in the briquettes with the larger optical texture, whereas the best resistance in a drum was that of the briquettes having larger proportion of mosaics. Furthermore, the Fe-coke briquettes produced by cold briquetting and carbonization show self-reducing properties of iron oxides. (C) 2016 Elsevier B.V. All rights reserved.