Blast Furnace Flue Dust as a Potential Carbon Additive in Hematite Ore Pellet
Ammasi Ayyandurai, J Pal
Abstract
Coke or anthracite coal is traditionally used as the carbon source in the hematite ore pellet for providing in-situ heat and enhancing diffusion bonding and slag bonding. Blast furnace flue dust (BFD) is a waste material, which contains a significant quantity of carbon may be another possible option of carbon source. However, the feasibility of using this material for the preparation of blast furnace quality pellet from hematite ore needs to be studied. In the present study, the burning characteristics of BFD in pellet have been studied and compared with that of coke fines. The characteristics of the pellets prepared with the above two carbon sources have been compared to assess the feasibility of using BFD as a carbon source in the hematite pellet. While 1% C level in BFD-added pellet shows the optimum result, 1.5% C level in coke-added pellet shows that. All properties of pellets improve significantly by the addition of carbon in form of either BFD or coke both in acidic and basic conditions. Induration temperature could be reduced by 50–75 K in both cases. However, better pellet properties in terms of cold crushing strength (277 kg/pellet) and reducibility index (81%) have been observed in using BFD. This study optimizes the process parameters to utilize the BFD as a carbon additive in hematite pellet both in acidic and basic condition replacing coke fines and establishes that BFD is a potential carbon source to achieve better pellet properties without any adverse effect.