Kinetics of Reduction of Composite Pellets Containing Iron Ore and Carbon

Carvalho, Roberto José de; Netto, Pedro Gutemberg Quariguasi; D'Abreu, José Carlos

doi:10.1179/cmq.1994.33.3.217

Cited by 30 publications

(7 citation statements)

References 6 publications

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“…Literature data (De Carvalho et al , 1994) have been used for validation of the model estimations. Experimental conditions are shown in Table 2.…”

Section: Resultsmentioning

confidence: 99%

“…Exit gas samples were taken at certain time intervals, and the extent of reduction was obtained by off-gas analysis. More detailed information on this experiment can be found in the paper (De Carvalho et al , 1994). The degree of reduction f of pellets was calculated using the equation …”

Section: Resultsmentioning

confidence: 99%

“…The main reduction reactions may be represented as follows Many papers have been published to understand the direct reduction process of iron ore–carbon composite pellet/mixtures. The effects of temperature ranging from 1173 to 1473 K, pellet type, external gas flowrate, and external atmosphere on the direct reduction of iron ore–carbon composite pellets were investigated through experiments (De Carvalho et al , 1994). It was observed that the reaction rate increased with the increase of temperature, decrease of N 2 flowrate and utilisation of CO atmospheres.…”

Section: Introductionmentioning

confidence: 99%

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Numerical simulation and parameters optimisation of direct reduction process of iron ore–carbon composite pellet

Liu

Wen

et al. 2014

Mineral Processing and Extractive Metallurgy

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A mathematical model considering heat transfer, mass transfer, porosity change, stepwise reductions of iron oxides and carbon gasification has been developed to investigate the direct reduction process of iron ore-carbon composite pellet. The governing equations were discretised in fully implicit form based on control volume method and numerically solved using tri-diagonal matrix algorithm. The model has been validated by comparison with experimental data from the literature. The effects of some operational parameters have been investigated, and the optimal combination of these parameters is determined by orthogonal test. The results show that the reduction rate increases with the decrease of pellet diameter initially. However, the final degree of reduction increases with the increase of pellet diameter ranging from 5 to 15 mm. Chemical reaction rates increase significantly with the increase of furnace temperature. The degree of reduction for pellet with C/O ratio of 0?8 is lower than pellets with C/O ratio of 1?0 and 1?2 after reduction for 900 s. The degree of reduction is 95?84%, which is high enough in engineering, when furnace temperature, reduction time, C/O mole ratio, and pellet diameter are 1473 K, 10 min, 1?2, and 20 mm, respectively.

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“…Literature data (De Carvalho et al , 1994) have been used for validation of the model estimations. Experimental conditions are shown in Table 2.…”

Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Numerical simulation and parameters optimisation of direct reduction process of iron ore–carbon composite pellet

Liu

Wen

et al. 2014

Mineral Processing and Extractive Metallurgy

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“…In reducing the off gas of the CBB and CBBC samples throughout the reduction process, the off gas type and change trend of the CO/CO 2 ratio may be consistent, indicating that the off gases present include CO, CO 2 , and N 2 ; the CO/CO 2 ratio increases steadily during the reduction process. [38][39][40] 3.2. Reduction Kinetics Analysis…”

Section: Reduction Degree and Rvimentioning

confidence: 99%

Reduction Kinetics of Cold‐Bonded Briquette Prepared from Return Fines of Sinter with Carbon Monoxide and Coke

Ren

Han

et al. 2023

steel research int.

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Return fines of sinter is now being utilized in blast furnaces straight after cold briquetting, a novel method of return fines utilization. [1][2][3][4] This technique can prevent return fines from being repeatedly sintered at high temperatures. On the one hand, it can lower the amount of energy used by the sinter plant, and on the other, it can increase the output of the sintering process. The compressive strength, reduction degradation index, and reducibility index of coldbonded briquette prepared from return fines are close to those of the sinter, which is acceptable for use in a large blast furnace. Cold-bonded briquette prepared from return fines has successfully substituted 5-10% of the sinter in a 2800 m 3 blast furnace in Gansu Province, China. [1,4] However, the lack of knowledge regarding the cold-bonded briquette prepared from return fines' reduction kinetics in the blast furnace prevents further advancements in the cold-bonded briquette prepared from return fines' utilization ratio.Numerous studies have investigated the reduction kinetics of sinter under varying conditions. The sinter's porosity, particle size, and chemical composition affect its reduction kinetics. [5] For instance, sinter with greater porosity or with a large number of microscopic pores is usually reduced more quickly because the pores enable the reducing gas to reach the reaction's interface. However, macropores (>0.125 mm) are more crucial than micropores for the increased reduction rate of sinter because the reduction front of fine pores (<0.125 mm) is complex and irregular. [6] The reduction rate usually increases with the decreasing particle size of the sinter, and varied iron

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“…The studies on the assessment of the kinetics and iron metallisation mechanisms of self-reducing agglomerates, [4][5][6][7][8][9][10][11][12][13][14][15][16][17] confirmed the importance of heat transfer for the process, and that the dominant mechanism is the Boudouard reaction in the temperature range circa 1200uC. Additionally, for higher temperatures, a mixed mechanism, involving the wu ¨stite reduction and the Boudouard reaction, is considered to define the rate determinant step for the overall process.…”

Section: Introductionmentioning

confidence: 99%

Mathematical model for descending self-reducing agglomerates in lumpy zone of Tecnored furnace

D'Abreu¹,

Kohler²,

Noldin³

2008

Ironmaking & Steelmaking

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This work presents a comprehensive mathematical modelling generated by a cooperative research programme implying Pontifı ´cia Universidade Cato ´lica do Rio de Janeiro -PUC/Rio and Tecnored, Tecnologia de Auto-Reduc ¸a ˜o Ltda, designed and utilised in the early pilot plant development of the Tecnored process. It aimed to predict the heating and reduction behaviour of descending agglomerates in the upper zone of a packed bed type shaft furnace, e.g. the Tecnored reactor. In a very effective way, based on the results of the Tecnored pilot plant development, the mathematical modelling had been calibrated and has proved to be extremely important in the understanding of the various physical chemical phenomena occurring in this zone of the furnace, as well as a powerful tool to plan and implement new improvements into the process. Two case studies are presented in this paper, where the effects of different reactivities of the reductant and solid fuel, are simulated by the model for the upper zone of the furnace.

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Kinetics of Reduction of Composite Pellets Containing Iron Ore and Carbon

Cited by 30 publications

References 6 publications

Numerical simulation and parameters optimisation of direct reduction process of iron ore–carbon composite pellet

Numerical simulation and parameters optimisation of direct reduction process of iron ore–carbon composite pellet

Reduction Kinetics of Cold‐Bonded Briquette Prepared from Return Fines of Sinter with Carbon Monoxide and Coke

Mathematical model for descending self-reducing agglomerates in lumpy zone of Tecnored furnace

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