Effect of carbon solution-loss reaction on properties of coke in blast furnace

Liu, Qihang; Yang, Shuangping; Wang, Chen; Ji, Yuexia

doi:10.1007/s42243-020-00399-9

Cited by 7 publications

(6 citation statements)

References 19 publications

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“…In the lower part of the blast furnace, after the iron ore is reduced and dripped, coke becomes the only lumpy material. It is not only affected by factors such as temperature, CO 2 , slag, molten iron, and gas flow, but also needs to ensure its stability, support the upper charge of the blast furnace, ensure that the blast-furnace column does not collapse, and produce smoothly [ 11 , 12 ]. Therefore, the quality of metallurgical coke is closely related to the technical and economic indicators of blast furnaces.…”

Section: Introductionmentioning

confidence: 99%

Metallurgical Coke Combustion with Different Reactivity under Nonisothermal Conditions: A Kinetic Study

Qin

Ling

et al. 2022

Materials

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The combustion characteristics and kinetics of high- and low-reactivity metallurgical cokes in an air atmosphere were studied by thermogravimetric instrument. The Coats–Redfern, FWO, and Vyazovkin integral methods were used to analyze the kinetics of the cokes, and the kinetic parameters of high- and low-reactivity metallurgical cokes were compared. The results show that the heating rate affected the comprehensive combustion index and combustion reaction temperature range of the cokes. The ignition temperature, burnout temperature, combustion characteristics, and maximum weight-loss rate of low-reactivity coke (L-Coke) were better than high-reactivity coke (H-Coke). Low-reactivity coke had better thermal stability and combustion characteristics. At the same time, it was calculated via three kinetic analysis methods that the combustion activation energy gradually decreased with the progress of the reaction. The coke combustion activation energy calculated by the Coats–Redfern method was larger than the coke combustion activation energy calculated by the FWO and Vyazovkin methods, but the laws were consistent. The activation energy of L-Coke was about 4~8 kJ/mol more than that of H-Coke.

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Section: Introductionmentioning

confidence: 99%

Metallurgical Coke Combustion with Different Reactivity under Nonisothermal Conditions: A Kinetic Study

Qin

Ling

et al. 2022

Materials

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“…Sinter reduction was simulated in the presence of coke in the heat reserve lump zone of a hanging hightemperature blast furnace under reducing atmosphere conditions. Simultaneously, FeO reduction (FeO + C = Fe + CO) occurred when CO 2 in the off-gas reacted with carbon in the coke to form CO [20][21][22][23]. The sinter and coke were first dried in a drying oven for 2 h at 100 • C. Afterward, a hanging basket made of iron wire containing the coke and sinter mixed in certain proportions was placed inside the high-temperature furnace, which was heated to 1000 • C at a suitable heating rate.…”

Section: Methodsmentioning

confidence: 99%

Investigation of the Reaction Kinetics of a Sinter-Reduction Process in the Thermal Reserve Zone of a Blast Furnace Using a Modified Sectioning Method

Zhu

Wenlong

et al. 2022

Metals

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With the development of large-scale and high-performing blast furnaces, it is necessary to extensively study the reaction characteristics and related kinetic parameters of sinters in their heat reserve area. Under reducing atmosphere conditions, the reduction of iron oxide in sinter is closely related to the gasification reaction of coke. Based on a simulation experiment, the transition point from chemical reactions to diffusion and the related kinetic parameters were determined through a sectioning method. The results showed that increasing the proportion of low-grade coke increased the chemical-reaction rate, but it slightly decreased the mass-transfer and diffusion rates. An increase in the coke particle size increased the chemical-reaction, mass-transfer, and diffusion rates. However, an increase in the CO2 volume fraction in gas reduced the chemical-reaction, diffusion, and mass-transfer rates. The mixing ratio of coke and sinters increased the chemical-reaction rate, but it decreased the mass-transfer and diffusion rates. The rate constant of the chemical reactions in the early stage was three orders of magnitude higher than that of the diffusion and mass-transfer coefficients, and the fitting degree was obviously better than that of the molecular diffusion in the later stage. Based on the thermodynamics of irreversible processes, the interference of the chemical reactions with the diffusion and mass transfer in the near-equilibrium region was tentatively established, the method of controlling coke diffusion and mass transfer in the later reaction stage was given and related kinetic parameters were corrected, and further improvement of the modified sectioning method was completed.

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“…The dissected blast furnace [ 5 ] showed that the coke solution loss reaction influenced the gas permeability of the upper part of BF [ 6 , 7 , 8 ], and there are many references available in this field [ 9 , 10 ]. In addition, the thickness of the coke layer is also an important factor affecting the distribution of gas flow.…”

Section: Introductionmentioning

confidence: 99%

Study on the High-Temperature Interaction between Coke and Iron Ores with Different Layer Thicknesses

Wang,

Du,

Diao

et al. 2024

Materials

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Coke plays a key role as the skeleton of the charge column in BF. The gas path formed by the coke layer in the BF has a decisive influence on gas permeability. At high temperatures, the interface between coke and ore undergoes a melting reaction of coke and a reduction reaction of ore. The better the reducibility of the ore, the more conducive it is to the coupling reaction of ore and coke. The melting loss reaction of coke becomes more intense, and the corresponding strength of coke will decrease, which will affect the permeability of the blast furnace and is not conducive to the smooth operation of the blast furnace. Especially with a deterioration in iron ore quality, BF operation faces severe challenges, which makes it necessary to find an effective way to strengthen BF operation. In this study, a melting-dropping furnace was used to develop and clarify the high-temperature interaction between coke and iron ores with different layer thicknesses. The influencing factors were studied by establishing a gas permeability mathematical model and observing the metallographic microscope images of samples after the coke solution loss reaction. The relationships between coke layer thickness, distribution of gas flow, and pressure drop were obtained. The results showed that, under certain conditions, the gas permeability property of a furnace burden has been improved after the coke layer thickness increased. Upon observing the size of coke particles at the interface reaction site, the degree of melting loss reaction can be determined. A smaller particle size indicates more melting loss reaction. A dripping eigenvalue for molten metal was introduced to evaluate the dynamic changes in the comprehensive dripping properties of molten metal of furnace burden, which showed that the dripping eigenvalue for the molten metal could deteriorate because of the unruly thickness and the coke layer thickness should be limited through considering the operational indicators of the blast furnace.

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Effect of carbon solution-loss reaction on properties of coke in blast furnace

Cited by 7 publications

References 19 publications

Metallurgical Coke Combustion with Different Reactivity under Nonisothermal Conditions: A Kinetic Study

Metallurgical Coke Combustion with Different Reactivity under Nonisothermal Conditions: A Kinetic Study

Investigation of the Reaction Kinetics of a Sinter-Reduction Process in the Thermal Reserve Zone of a Blast Furnace Using a Modified Sectioning Method

Study on the High-Temperature Interaction between Coke and Iron Ores with Different Layer Thicknesses

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