Studies on Some Aspects of Deterioration of Coke in Blast Furnace

Haraguchi, Hiroshi; Nishi, Tetsu; Miura, Yoshiaki; Ushikubo, Miyoshi; Noda, Tamio

doi:10.2355/tetsutohagane1955.70.16_2216

Cited by 26 publications

(9 citation statements)

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“…It has not been shown that Ca-rich coke starts to react at a lower temperature range than conventional coke does when the mixture of Ca-rich coke and conventional coke are charged in a blast furnace. Although it is known that coke reactivity is promoted by condensed alkali vapor in an actual blast furnace, 21) there have been no studies on the behavior of Caloaded highly reactive coke in the presence of alkali and the interaction of the catalytic activity of Ca and alkali is unclear.…”

Section: Introductionmentioning

confidence: 99%

Reaction Behavior of Ca-loaded Highly Reactive Coke

Nomura

2014

ISIJ Int.

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Usage of highly reactive coke in order to decrease the thermal reserve zone temperature in a blast furnace is considered promising to increase the reaction efficiency in the blast furnace and to decrease the reducing agent rate. In order to develop a new method to produce highly reactive coke by adding a Ca catalyst other than Ca-rich coal, in this paper, firstly the effects of Ca compounds pre-addition to coal on coke qualities were investigated. It was shown that carbonizing the mixture of coal and Ca compounds (CaO, CaCO3) greatly increased coke reactivity and that it was possible to produce Ca-loaded highly reactive coke with high coke strength by adding 3% of Ca compounds under such conditions as high strength coke was produced. Furthermore, the reaction behavior of Ca-loaded highly reactive coke when mixed with conventional coke in the presence of an alkali was investigated. It was shown that when a mixture of Ca-loaded highly reactive coke and conventional coke was heated in a reaction gas, Ca-loaded coke selectively and preferentially reacted. It was also confirmed that Ca acted as catalyst in the existence of K. This shows that the reactivity of Ca-loaded coke is higher than that of conventional coke in an actual blast furnace whereby coke reactivity is promoted by condensed alkali vapor.

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Section: Introductionmentioning

confidence: 99%

Reaction Behavior of Ca-loaded Highly Reactive Coke

Nomura

2014

ISIJ Int.

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“…It was reported that a sudden decrease of coke diameter was observed at the cohesive zone's temperature range (1 473 K-1 723 K), which was thought to be introduced the solution loss reaction as well as the some amount of volume breakage. 5) One of the possible reasons of the volume breakage is that coke particles undergo sudden impacts by collapsing into the voids below the coke layer which is introduced when ore particles disappear by melting.…”

Section: Introductionmentioning

confidence: 99%

Numerical Study Using Discrete Element Method about Coke Particle Behavior in Cohesive Zone

Kim

Sasaki

2013

ISIJ Int.

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The simulation of cohesive zone in the blast furnaces is conducted using 2-dimensional discrete element method. The simulation is divided into two parts; (1) the group simulation of the flow of coke and ore particles in the cohesive zone when the reduced ore particles start to shrink and disappear with melting, and (2) the biaxial compression test simulations of breakable single coke particle with receiving x and y directional stresses which is evaluated from the group simulation. In addition, a gasification model is developed and combined with the coke model for the biaxial compression test simulation. The gasification process is simulated by removing element particles for a fixed amount.In the group simulation, coke particles have been found to move actively not only the axial (horizontal) direction but also the radial (vertical) direction due to the elimination of ore particles in the melting zone. Due to these movements, the coke layers are severely distorted and the coke layer thickness is much decreased. The developed stresses on particles in the group simulation are recorded and this stress information is applied to a non-gasified and the gasified coke model to simulate the coke breakage behaviors. In the non-gasified case, both of the volume breakage and the surface abrasion are not observed. In the gasified case, the surface abrasion and fragmentation occur, but the volume breakage is not observed under the present simulation condition.

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“…10,11) On the other hand, it is necessary to prove that formed iron coke starts to react in a lower temperature range than conventional coke does in the BIS test in order to ascribe the decrease in the thermal reserve zone temperature to the decrease in the reaction beginning temperature of iron coke. Furthermore, since coke reactivity is promoted by condensed alkali vapor in an actual blast furnace, 12) it is necessary to prove that the use of formed iron coke can decrease the thermal reserve zone temperature in the presence of alkali.…”

Section: Introductionmentioning

confidence: 99%

Reaction behavior of Formed Iron Coke and Its Effect on Decreasing Thermal Reserve Zone Temperature in Blast Furnace

et al. 2010

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Usage of highly reactive coke in order to decrease the thermal reserve zone temperature in blast furnaces is promising to increase reaction efficiency in blast furnaces and to decrease the reducing agent rate. We focused on the catalytic effect of iron and succeeded in producing highly reactive formed iron coke with high iron content. In this paper the reaction behavior of formed iron coke when mixed with conventional coke and in the presence of alkali was investigated and the following results were obtained. When the mixture of iron coke and conventional coke is heated in a reaction gas, iron coke selectively and preferentially reacts near the thermal reserve zone temperature (900°C), which causes a decrease in the thermal reserve zone temperature, while conventional coke barely reacts and is protected from degradation. It was also confirmed that the catalytic activity of Fe and that of K is independent of each other and that in the presence of alkali, the reaction beginning temperature of iron coke is lower than that of conventional coke. These results show that the use of formed iron coke could decrease the thermal reserve zone temperature in an actual blast furnace where coke reactivity is promoted by condensed alkali vapor.

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Studies on Some Aspects of Deterioration of Coke in Blast Furnace

Cited by 26 publications

References 0 publications

Reaction Behavior of Ca-loaded Highly Reactive Coke

Reaction Behavior of Ca-loaded Highly Reactive Coke

Numerical Study Using Discrete Element Method about Coke Particle Behavior in Cohesive Zone

Reaction behavior of Formed Iron Coke and Its Effect on Decreasing Thermal Reserve Zone Temperature in Blast Furnace

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