Graphitization of Coke and Its Interaction with Slag in the Hearth of a Blast Furnace

Li, Kejiang; Zhang, Jianliang; Liu, Yanxiang; Barati, Mansoor; Liu, Zhengjian; Zhong, Jianbo; Su, Buxin; Wei, Mengfang; Wang, Guangwei; Yang, Tianjun

doi:10.1007/s11663-015-0574-9

Cited by 39 publications

(27 citation statements)

References 23 publications

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“…9 show that there is an obvious shift of the carbon peak positions of the deadman cokes towards the right side compared with the feed coke, indicating that graphite crystals of the deadman coke possess a lower interlayer spacing d 002 than the feed coke. The d 002 value of all deadman coke fines is estimated to be about 0.339 nm which is very close to the interlayer spacing of pure graphite (0.338 nm 10) ). The crystallite height of the carbons of deadman coke fines is larger and increases from 24.31 to 44.35 nm from DM1.8-F to DM > 5.0-F, which is about 5-10 times the value of the crystallite height of the feed coke.…”

Section: The Analysis Of the Carbon Structure Of The Deadman Cokessupporting

confidence: 51%

“…The cokes were crushed to passing less than 74 μm and then were ashed by heating in air at 1 088 K (815°C) to remove carbon similar to the previous studies. 10,13) The samples for carbon structure identification were not treated by ashing process. XRD spectra were obtained using a Bruker diffractometer (D8 ADVANCE, Germany) as well as Cu (Kα) radiation.…”

Section: The Analysis Methods and Sample Preparationmentioning

confidence: 99%

“…This implies that the most ordered carbon structure occurs in deadman coke fines, followed by deadman coke lumps and the feed coke. Gupta 19) and Li 10) found that the graphitization of coke in the high temperature zone starts from the coke surface and the graphitization process leads to the formation of coke fines. The previous studies 21,22) proposed that the carbon in highly ordered coke would be easier to dissociate and this leads to higher dissolution rates.…”

Section: The Analysis Of the Carbon Structure Of The Deadman Cokesmentioning

confidence: 99%

“…However, a limited number of papers have studied on the coke samples extracted from the deadman below the tuyere level. [10][11][12] B.van der Velden et al 11) studied the microstructure of coke taken from different heights of the hearth after blowdown. They found that the slag partly drips into the coke pores at tuyere level, a large quantity of slag fills pores of coke at the liquid slag level, and liquid iron and slag permeate the coke pores at the liquid iron level, however, they did not study the mineralogy and graphitization of the deadman coke.…”

Section: Introductionmentioning

confidence: 99%

“…They found that the slag partly drips into the coke pores at tuyere level, a large quantity of slag fills pores of coke at the liquid slag level, and liquid iron and slag permeate the coke pores at the liquid iron level, however, they did not study the mineralogy and graphitization of the deadman coke. Li et al 10) studied the graphitization of deadman coke and its interactions with slag with samples obtained from blast furnace center at the taphole level during its overhaul period. They found that hearth coke samples from fines to lumps were highly graphitized and slag phase filled up with all the macro coke pores, but they did not study the coke soaked in iron layer.…”

Section: Introductionmentioning

confidence: 99%

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Changes in Microstructure and Chemical Composition of Deadman Coke of a 2800 m<sup>3</sup> Industrial Blast Furnace

Niu

Cheng

et al. 2018

ISIJ Int.

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The paper examined the changes in microstructure and inorganic elements in their true mineral forms of the coke samples from various hearth locations using X-ray diffraction (XRD) and scanning electron microscopy-energy dispersive spectroscopy (SEM-EDS) after the blow out and cool down of a 2 800 m 3 industrial blast furnace. The results illustrate that all deadman coke samples from fines to lumps were confirmed to be highly graphitized. Furthermore, the deadman coke was filled up with the accumulated KAlSiO 4 during its descent process and the blast furnace slag which consisted of Ca 2 MgSi 2 O 7 -Ca 2 Al 2 SiO 7 system and Ca 2 ZnSi 2 O 7 phases. Besides the slag phases, the iron was also observed in the deadman coke soaked in the iron layer. Those cause that the mass of the deadman coke is about 1.62-2.82 times larger than that of the feed coke under the same conditions. Thus it may make the deadman which was designed to float sit on the hearth bottom as the permeation of the slag and the liquid iron into the deadman coke was not taken into consideration during the design process. We concluded that the slag phase below the taphole level is primarily derived from the blast furnace slag. Moreover, the deadman coke carrying final slag may come in contact with the hearth bottom and react with ceramic pad or carbon brick with a sitting deadman, thereby it results in degrading the hearth lining. Meanwhile, the slag phases below the taphole level can provide the material for the formation of skull to protect the hearth lining.

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Section: The Analysis Of the Carbon Structure Of The Deadman Cokessupporting

confidence: 51%

Section: The Analysis Methods and Sample Preparationmentioning

confidence: 99%

Section: The Analysis Of the Carbon Structure Of The Deadman Cokesmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Changes in Microstructure and Chemical Composition of Deadman Coke of a 2800 m<sup>3</sup> Industrial Blast Furnace

Niu

Cheng

et al. 2018

ISIJ Int.

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Deadman Behavior and Slag–Iron–Coke Interaction of Low Carbon and Safety Blast Furnace: A Review

Zong,

Guo,

Zhang

et al. 2024

steel research int.

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The elucidation of the deadman's behavior and the interaction between slag–iron–coke within the blast furnace hearth are essential for the realization of low‐carbon and safe production. In this review, the macrostate of the deadman, the interactions between slag–iron–coke, carburizing behaviors, and renewal mechanisms are comprehensively examined. First, the formation and state of the deadman, voidage, and the distribution of coke sizes within the blast furnace hearth are characterized. The average coke particle size ranges from 20 to 30 mm, and the deadman void fraction of 30–50%. Second, the interaction between slag–iron–coke as well as the occurrence state of the mineral layer at the interface within the deadman is elucidated. The ash composition and content of coke are the key factors affecting the slag–iron–coke interaction and interface phase composition. Third, the influence exerted by critical factors such as the physical properties of the carbon source, molten iron, and temperature on the carburizing behavior are analyzed, with the renewal mechanisms of the deadman also being disclosed. Finally, three future focal areas are proposed: characterization and intelligent monitoring of deadman permeability, analysis of slag–iron–coke properties and interface mineral layers control, and in‐depth analysis of deadman renewal and carbon carburization in molten iron. It is anticipated that the studies will enhance the comprehension of deadman behavior and the interactions between slag–iron–coke, thereby fostering the blast furnace's sustainable development.

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Coke Reactivity in Simulated Blast Furnace Shaft Conditions

Haapakangas

Suopajärvi

Iljana

et al. 2016

Metall Mater Trans B

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Graphitization of Coke and Its Interaction with Slag in the Hearth of a Blast Furnace

Cited by 39 publications

References 23 publications

Changes in Microstructure and Chemical Composition of Deadman Coke of a 2800 m<sup>3</sup> Industrial Blast Furnace

Changes in Microstructure and Chemical Composition of Deadman Coke of a 2800 m<sup>3</sup> Industrial Blast Furnace

Deadman Behavior and Slag–Iron–Coke Interaction of Low Carbon and Safety Blast Furnace: A Review

Coke Reactivity in Simulated Blast Furnace Shaft Conditions

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