Activation of Deadman State in the Blast Furnace Using Serpentine Injection through Tuyere

Ichida, Morimasa; Orimoto, Takashi; Sakatani, Masatoshi; Nakamura, Katsumi; Kumaoka, Hisashi; Ueno, Hideki

doi:10.2355/isijinternational.44.2134

Cited by 7 publications

(4 citation statements)

References 11 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…One may therefore conclude that fundamental changes in the deadman state can often be predicted by the hot metal chemistry. A possible reason for the observed behavior is that a gradual revival of an inactive deadman, where coke fines and slag of high melting point are dissolved, [9,20] eventually leads to a hot metal flow through the core of the deadman, which consumes the bottom skull and improves the utilization of the hearth volume. However, it seems that this deadman activation within a month leads to a return to the inactive state characterized by bottom skull and high hot metal sulfur content.…”

Section: Hot Metal Compositionmentioning

confidence: 99%

Wear-Model-Based Analysis of the State of Blast Furnace Hearth

Helle

Saxén

Graaff

et al. 2022

Metall Mater Trans B

View full text Add to dashboard Cite

The condition and state of the hearth of the blast furnace is of considerable importance since the life length of the refractories governs the campaign length of the furnace, but it is also of significance as it affects the drainage of iron and slag and the hot metal temperature and composition. The paper analyses the hearth of a blast furnace using a model of the lining wear based on the solution of an inverse heat conduction problem, studying the changes in the lining state throughout the campaign. Different operation states are detected, characterized by smooth and efficient hot metal production and by erratic behavior with large disturbances in the hearth state. During the periods of poor performance, the hearth exhibits a cycling state with stages of excessive skull growth on the unworn refractory, followed by periods of dissolution of the skull and lining erosion. An explanation of the transitions is sought by a stating and solving a force balance for the deadman with the aim to clarify whether it is floating or sitting. A connection between the thermal cycles in the hearth and the hot metal sulfur content is finally demonstrated.

show abstract

Section: Hot Metal Compositionmentioning

confidence: 99%

Wear-Model-Based Analysis of the State of Blast Furnace Hearth

Helle

Saxén

Graaff

et al. 2022

Metall Mater Trans B

View full text Add to dashboard Cite

show abstract

“…12,13) Many phenomena in hearth are related to the iron-carbon interface, such as the erosion of carbon brick, the deterioration of coke, the state of deadman, molten iron circulation, and hearth activity. [14][15][16] Moreover, the carburization will occur at iron-carbon interface due to the carbon content of molten iron in hearth is undersaturated. 17,18) The changes of element content and properties of molten iron are mainly reflected at the iron-carbon interface.…”

Section: Introductionmentioning

confidence: 99%

Iron-Carbon Interface Phenomenon and Reaction Behavior Analysis in Blast Furnace Hearth

et al. 2023

View full text Add to dashboard Cite

The iron-carbon interface plays an important role in hearth, the dissection investigation of BFs was carried out to clarify the iron-carbon interface phenomenon and reaction behavior. The results show that the iron-coke interface can be divided into two types: partial coverage and overall coverage. The molten iron penetration from the interface to the center of coke is found. The hot face of residual carbon brick has obvious embrittlement layers, the pulverization phenomenon of carbon brick is observed, cracks appear in the carbon brick near the iron-carbon brick interface. Many holes in coke are filled with iron and slag, the filling rate increases as the coke moves towards the lower part of hearth. The graphitization degree of coke increases through dissolution precipitation and carbide transformation mechanism, the high graphitization of coke caused by carburization at iron-coke interface is the essential cause of coke deterioration. The flexural strength of carbon brick decreases under the alternate process of penetration and dissolution, effect of Zn. The critical temperature difference for crack generation decreases from 286 ℃ to 208 ℃ after the reaction, which makes it easier for the carbon brick to produce cracks. These cracks produce brittle embrittlement layers, which accelerates the erosion of carbon brick. The carburization of coke and the dissolution carburization of carbon brick are carried out simultaneously in hearth, there is a competitive carburization between iron-coke interface and iron-carbon brick interface. The methods of controlling competitive carburization are put forward to delay the erosion of carbon brick.

show abstract

“…The state of deadman is related to the smooth discharge of slag and iron, the hearth activity, and even plays a key role in the stable running of BF. [7][8][9] The slag and iron will react with the coke in deadman, which will affect the slag composition and molten iron composition. 10) In addition, the state of deadman affects the flow of molten iron and has a significant impact on the sidewall erosion in hearth.…”

Section: Introductionmentioning

confidence: 99%

State of Deadman in Blast Furnace Hearth and Its Internal Phase Distribution Characteristics

Deng

Liu

Wang³

et al. 2023

ISIJ Int.

View full text Add to dashboard Cite

The state of deadman in hearth is important for the long campaign life of blast furnace (BF). In order to clarify the influence of deadman on sidewall erosion, the corresponding relationship between the shape of deadman and sidewall erosion was studied, the fundamental reason for the difference of sidewall erosion was analyzed, the influence mechanism of slag-coke interface and iron-coke interface on the coke in deadman was explored based on the phase distribution in deadman. The results show that: The shape of circumferential bulge at the root of deadman is a common feature of BFs, this feature is the main reason for the serious erosion of sidewall, and the serious erosion area of sidewall corresponds to the root position of deadman. The deadman shows a dynamic evolution law of sinking and floating under the action of force in the smelting process of BF, the depth of slag and iron level in hearth has the greatest influence on the deadman. The difference of central voidage of deadman is the fundamental reason for the difference of sidewall erosion for BFs in which the deadman is in the same floating state. Slag-coke interface and iron-coke interface commonly exist in hearth. The dissolution reaction at iron-coke interface makes carbon in coke continuously migrate into molten iron, which makes the graphitization degree of coke increase, the coke is easy to pulverize, this is the main mechanism of coke deterioration and renewal in deadman. The enrichment of harmful element K at slag-coke interface makes the coke expand and crack, the coke matrix is easier to peel off, which accelerates the deterioration process of coke.

show abstract

Activation of Deadman State in the Blast Furnace Using Serpentine Injection through Tuyere

Cited by 7 publications

References 11 publications

Wear-Model-Based Analysis of the State of Blast Furnace Hearth

Wear-Model-Based Analysis of the State of Blast Furnace Hearth

Iron-Carbon Interface Phenomenon and Reaction Behavior Analysis in Blast Furnace Hearth

State of Deadman in Blast Furnace Hearth and Its Internal Phase Distribution Characteristics

Contact Info

Product

Resources

About