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

The coke reactivity is one of the major evaluation indexes of coke. But there is still no clear statement on the reaction temperature as well as the way of reaction. In order to have a further understanding on the process of coke solution loss reaction in the blast furnace, the present paper studied the coke reactivity at different temperatures and finally found out the reaction rules and constraints in different zones of the blast furnace.

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Degradation behaviors of coke under complex solution loss conditions

Metallurgical Research & Technology ◽

10.1051/metal/2020081 ◽

2020 ◽

Vol 118 (1) ◽

pp. 101

Author(s):

Jun Zhang ◽

Dongsheng Yu ◽

Rui Guo ◽

Jiaxiong Lin

Keyword(s):

Blast Furnace ◽

Alkali Metal ◽

Thickness Distribution ◽

Pore Wall ◽

Metal Enrichment ◽

Thermogravimetric Analyzer ◽

The Matrix ◽

Degradation Behaviors ◽

Gasification Reaction ◽

Solution Loss Reaction

Solution loss reaction of coke provides reducing agent for ironmaking, which is an important chemical reaction in blast furnace. The coke itself is also degraded by the loss of carbon. In this paper, the degradation behavior of coke under complex conditions including alkali metal enrichment, simulated blast furnace temperature and atmosphere was studied. The pore size and pore wall thickness distribution of coke were measured by a microscope to characterize the structure of coke. The gasification reaction rate of coke matrix was measured by a thermogravimetric analyzer to characterize the matrix reactivity of coke. The results show that a coke has high CRI and low CSR, but it has high matrix reactivity and thick pore wall, which may lead higher strength after solution loss under alkali metal enrichment and simulated blast furnace atmosphere and heating conditions.

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Investigation of the Effects of Coke Reactivity and Iron Ore Reducibility on the Gas Utilization Efficiency of Blast Furnace

Energies ◽

10.3390/en13195062 ◽

2020 ◽

Vol 13 (19) ◽

pp. 5062

Author(s):

Fanchao Meng ◽

Lei Shao ◽

Zongshu Zou

Keyword(s):

Blast Furnace ◽

Iron Ore ◽

High Reactivity ◽

Operating Conditions ◽

Utilization Efficiency ◽

Coke Reactivity ◽

Gas Utilization ◽

Actual Operation ◽

Solution Loss Reaction ◽

Reduction Region

The use of coke with high reactivity in the ironmaking blast furnace (BF) has yet to be explored, and a thorough understanding is still required to clarify the effect of coke reactivity on the BF gas utilization efficiency. In this paper, a one-dimensional kinetic model of the BF is presented and the accuracy of the model is verified. The model is then applied to analyze the effect of coke reactivity on the gas utilization efficiency of the BF. The results show that, under the operating conditions considered, the height of indirect reduction region and the starting temperature of coke solution loss reaction decrease with the increase of coke reactivity. Moreover, coke reactivity is first, directly proportional to gas utilization efficiency, and then, inversely proportional to it. In addition, high-reactivity coke may not improve gas utilization efficiency in case of high H2 content. Both, lowly and highly reactive coke need to be combined with highly reducible iron ore to maximize the gas utilization efficiency. Nevertheless, only appropriately reactive coke can combine with lowly reducible iron ore to obtain an optimal gas utilization efficiency. Hence, it is necessary to select coke with appropriate reactivity, in accordance with iron-ore reducibility, instead of blindly pursuing high-reactivity coke in actual operation.

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