Commercial Production of Agglomerates for Blast Furnace Burdens Using a Large Amount of High Grade Iron Ore Fines

Niwa, Yasuo; Sakamoto, Noboru; Komatsu, O.; Noda, Hidetoshi; Kumasaka, Akira

doi:10.2355/tetsutohagane1955.78.7_1029

Cited by 16 publications

(7 citation statements)

References 1 publication

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“…Presently, permeability in the sinter bed limits the productivity. It is derived from some advanced technologies, such as the method of fine coke coating on the surface of quasi-particles 4,5) and introduction of segregative charging system of fine coke in the depth direction of sinter bed. 6) These technologies have reduced the coke consumption remarkably in the sinter operation.…”

Section: Introductionmentioning

confidence: 99%

Iron Ore Granulation Model Supposing the Granulation Probability Estimated from Both Properties of the Ores and Their Size Distributions.

Sakamoto

2002

ISIJ International

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It is important to reduce fluctuation of the ore granulation for a stable operation of iron ore sinter plant, because the fluctuation affects directly productivity and productive yield of the operation. To clarify the granulation phenomena in a rotating granulator, an advanced mathematical model that is different from previously proposed ones was developed considering the probability theory. Mathematical characteristics of the model and granulation simulation by the model are summarized as follows:(1) Since it is difficult to analyze the phenomena by the models based on the motion of quasi-particles due to the complicated movement of large amounts of the quasi-particles, the present model treated it as a kind of probability phenomena.(2) This model is basically composed of matrix algebras defining following two granulation parameters, 1) overall granulation probability resulted from ore properties, and 2) granulation and disintegration probabilities at each size range of the ores.(3) This model is useful for evaluation of the granulation phenomena, because the simulation results using the appropriate granulation parameters agree with those from the granulation operation.(4) It is important to make clear the granulation conditions for defining the granulation parameters, because the parameters depend on the conditions of the granulation dynamics and the size of the granulator.KEY WORDS: granulation; simulation model; iron ore sinter; probability theory; Markov chain. granulation model in which fine particles coalesce mutually by both external and friction forces during rotating motion. Suzuki et al. 9) analyzed granulation phenomena formulating mass balance of iron ore fines in a drum mixer and discpelletizer. They concluded that size of quasi-particle is determined by total rotating distance in the granulators and granulation characteristics of a disc-pelletizer are superior to those by a drum mixer. Lister et al. 10) presented a population balance equation in which quasi-particles grow by the coating of fine ores on the surface of nuclei coarse ores. This equation made clear that it is important to control size of fine ores for size enlargement of the quasi-particles. Kanoh et al. 11) analyzed theoretically the granulation phenomena during rotating motion in a drum mixer, considering kinetic and colliding energy. They pointed out through the analysis that the granulation obtained in small-scaled tests does not agree with that in commercial plant operation. With recent advance of capacity of computers, analyses of granulation dynamics will progress remarkably introducing some advanced computational methods. 11) Proposal of Granulation Model Based on the Probability TheoryWhen fine ores are granulated in a disc pelletizer or drum mixer, it is necessary to obtain information of the granulated quasi-particles considering both the ore properties and granulation conditions in a granulation operation. Figure 1 shows a relation among raw material conditions, granulation parameters and quasi-particle conditions. I...

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Section: Introductionmentioning

confidence: 99%

Iron Ore Granulation Model Supposing the Granulation Probability Estimated from Both Properties of the Ores and Their Size Distributions.

Sakamoto

2002

ISIJ International

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“…The fracture load was measured in the same manner as with the green pellets, and the strength of the burned pellets was evaluated using Eq. (1).…”

Section: Evaluation Methods For Tensile Strength Of Burned Pelletmentioning

confidence: 99%

“…These include an granulation technology by using a pelletizer for pellet feed ore, 1) and the MEBIOS method, in which the large-sized particles made from low grade ore and arranged in the sintering bed. 2,3) In these processes, the void fraction of the sintering bed was increased by mixed use of pellets or coarse particles in the raw material mixture, made it possible to improve sintering bed permeability and increase productivity.…”

Section: Introductionmentioning

confidence: 99%

Influence of Coke Breeze Positioning on the Sintering Behavior of Pellets and Raw Material Bed with Embedded Pellets

Higuchi¹,

Iwami²,

Kuriki³

et al. 2013

ISIJ Int.

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The influence of coke breeze positioning on the sintering behavior of pellets and raw material bed with embedded pellets was investigated. With increasing the coke breeze ratio in the green pellet made from ore and coke mixture fine of -125 μm, the tensile strength of the green and dried pellets decreased.Based on the evaluations under the green and dried pellet equations concerning particle bond, it was presumed these results were caused by the decrease in the contact points between particles due to the reduction of mixture fine's specific surface area.With increasing the coke breeze ratio in the nucleus pellet, the tensile strength of the burned pellets also decreased. From the change in the porosity up to 900°C, sintering was predominant to the tensile strength. In the temperature from 900°C to 1 200°C, the increase of strength became small by adding coke breeze in the nucleus pellet. It was presumed this result was caused by remarkable increase of void after coke combustion.In the sintering of raw material bed with embedded the coke breeze coating pellet, the surrounding temperature of pellet increased and the large void was generated below the pellet. Based on the 2-dimensional numeric evaluation, it was found the heat amounts of the pellet and gas heated by coke combustion were transported to the region under the pellet where the gas flow rate was low. It was considered this heat concentration caused the remarkable melting and large void formation.

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“…Sinters (A)-(C) were produced by actual sintering machines with different operating conditions, and sinter (D) was prepared with a laboratory-scale experimental sintering machine simulating the Hybrid Pelletized Sinter (HPS) process 9,10) and contains 40 wt% of pellet feed with a high T.Fe content. Table 1 shows the chemical composition, JIS-RI, 11) and JIS-RDI 12) of sinters (A)-(D).…”

Section: Sinter Properties and Reducing Gas Conditionsmentioning

confidence: 99%

Evaluation of Sinter Quality for Improvement in Gas Permeability of Blast Furnace

Takeuchi

Iwami²,

Higuchi³

et al. 2014

ISIJ Int.

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In the recent operation of blast furnace, it is supposed that high gas permeability of burden is important for low RAR and high PCR operation. In this work, sinter quality for improvement in gas permeability of blast furnace was investigated with reduction degradation and under-load-reduction tests. As the results, the reduction degradation of sinter is deteriorated by increasing H2 concentration in the reduction gas under the condition of below 3.8 vol% H2. However, over 3.8 vol% H2, increase of H2 has no effect on the reduction degradation because the diffusion of reduction gas in the sinter is limited. On the other hand, from the under-load-reduction test, there is possibility that increase in H2 concentration of reduction gas and decrease in slag ratio in sinter are effective to improve gas permeability of lower part of blast furnace rather than reducibility of sinter. Due to adoption of these experimental results to a 2-dimentional mathematical simulation model, the precision of pressure drop calculation of blast furnace was improved. It is considered from the evaluation by this model calculation that the RDI, a slag ratio and the slag viscosity as the sinter properties are greatly influence on the permeability of blast furnace.

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Commercial Production of Agglomerates for Blast Furnace Burdens Using a Large Amount of High Grade Iron Ore Fines

Cited by 16 publications

References 1 publication

Iron Ore Granulation Model Supposing the Granulation Probability Estimated from Both Properties of the Ores and Their Size Distributions.

Iron Ore Granulation Model Supposing the Granulation Probability Estimated from Both Properties of the Ores and Their Size Distributions.

Influence of Coke Breeze Positioning on the Sintering Behavior of Pellets and Raw Material Bed with Embedded Pellets

Evaluation of Sinter Quality for Improvement in Gas Permeability of Blast Furnace

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