Print Email Facebook Twitter Effect of nut coke addition on physicochemical behaviour of pellet bed in ironmaking blast furnace Title Effect of nut coke addition on physicochemical behaviour of pellet bed in ironmaking blast furnace Author Gavel, D.J. (TU Delft (OLD) MSE-3) Adema, A.T. (TU Delft (OLD) MSE-3; Tata Steel) Stel, Jan Van Der (Tata Steel) Sietsma, J. (TU Delft Materials Science and Engineering; TU Delft (OLD) MSE-3) Boom, R. (TU Delft (OLD) MSE-1) Yang, Y. (TU Delft (OLD) MSE-3) Department Materials Science and Engineering Date 2019 Abstract One of the primary causes that limit the blast furnace productivity is the resistance exerted to the gas flow in the cohesive zone by the ferrous burden. Use of nut coke (10–40 mm) together with ferrous burden proves beneficial for decreasing this resistance. In present study, effect of nut coke addition on the olivine fluxed iron ore pellet bed is investigated under simulated blast furnace conditions. Nut coke mixing degree (replacement ratio of regular coke) was varied from 0 to 40 wt% to investigate the physicochemical characteristics of the pellet bed. Three distinct stages of bed contraction are observed and the principal phenomena governing these stages are indirect reduction, softening and melting. It is observed that nut coke mixing enhances the reduction kinetics, lowers softening, limits sintering and promotes iron carburisation to affects all three stages. In the second stage, the temperature and displacement range is reduced by 60°C and 24%, respectively upon 40 wt% nut coke mixing. Addition of nut coke exponentially increases the gas permeability (represented by pressure drop and S-value). A higher degree of carburisation achieved on the pellet shell (iron) is suggested to be the principal reason for decrease in the pellet melting temperature. The pellets softening temperature increases by approximately 4°C, melting and dripping temperature drops by 11°C and 12°C, respectively, for every 10 wt% nut coke addition. Consequently, the nut coke addition shortens the softening, melting and dripping temperature ranges, which shows improved properties of the cohesive zone. Subject Blast furnaceCarburisationIronmaking, nut cokeMeltingOlivine pelletsPermeabilitySoftening To reference this document use: http://resolver.tudelft.nl/uuid:c6745be1-30cb-4116-a13b-478464283cea DOI https://doi.org/10.2355/isijinternational.ISIJINT-2018-580 ISSN 0915-1559 Source ISIJ International, 59 (5), 778-786 Part of collection Institutional Repository Document type journal article Rights © 2019 D.J. Gavel, A.T. Adema, Jan Van Der Stel, J. Sietsma, R. Boom, Y. Yang Files PDF 59_ISIJINT_2018_580.pdf 1.67 MB Close viewer /islandora/object/uuid:c6745be1-30cb-4116-a13b-478464283cea/datastream/OBJ/view