ESTUDO DA MORFOLOGIA DE PELOTAS DE MINÉRIO DE FERRO REDUZIDAS POR AGENTES GASOSOS
STUDY OF IRON ORE PELLETS MORPHOLOGY REDUCED BY GASEOUS AGENTS
Rodrigues, Girley Ferreira; Junca, Eduardo; Restivo, Thomaz Augusto Guisard; Oliveira, José Roberto de; Espinosa, Denise Crocce Romano
http://dx.doi.org/10.4322/2176-1523.0900
Tecnol. Metal. Mater. Min., vol.12, n4, p.274-280, 2015
Resumo
O estudo da morfologia de pelotas é uma importante ferramenta para compreender possíveis mecanismos envolvidos na redução. Assim, este trabalho tem por objetivo caracterizar três diferentes tipos de minérios e correlacionar a morfologia obtida na redução de pelotas fabricadas a partir destes minérios. A redução foi realizada em um forno tubular horizontal em 850°C em duas atmosferas redutoras. A primeira contendo hidrogênio e a segunda contendo hidrogênio + monóxido de carbono. Análise granulométrica, área superficial e difração de raios-X foram realizadas para a caracterização dos minérios. Microscópio eletrônico de varredura foi utilizado no estudo da morfologia das pelotas reduzidas. Os resultados mostraram que a diminuição da distribuição granulométrica do minério de pellet feed ocasiona um maior número de whisker. Além disso, foi observado que a presença de monóxido de carbono na mistura redutora proporcionou um menor número de poros e uma maior formação de whisker.
Palavras-chave
Caracterização mineralógica, Caracterização morfológica, Pellet feed, Minério de ferro.
Abstract
The study of pellets morphology is an important tool to understand possible mechanisms involved during its reduction reaction. Thus, the aim of this paper is characterize three different iron ores and correlate its morphology obtained after the complete reduction with its features. The reductions tests were accomplished in a horizontal tubular furnace at 850°C. Two reducing atmosphere were used. The first one contained hydrogen. The second one was a mixture between first gas + carbon monoxide. The iron ore characterization was carried out by size analysis, surface area and X-ray analysis. Scanning electron microscopy was used to obtain the morphology from the reduced pellets. The results showed a greater number of whisker were obtained with more fine ore. Furthermore, it was noted that carbon monoxide provided a lesser number of pores and greater number of whisker.
Keywords
Mineralogical characterization, Morphological characterization, Pellet feed, Iron ore.
Referências
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2 El-Geassy AA, Rajakumar V. Influence of particle size on the gaseous reduction of wustite at 900-1100°C. Transactions of the Iron and Steel Institute of Japan. 1985;25(12):1202-1211. http://dx.doi.org/10.2355/isijinternational1966.25.1202.
3 St John DH, Hayes PC. Microstructural features produced by the reduction of wustite in hydrogen/water gas mixtures. Metallurgical Transactions. B, Process Metallurgy. 1982;13B(1):117-124. http://dx.doi.org/10.1007/BF02666962.
4 St John DH, Mathews SP, Hayes PC. Establishment of product morphology during the initial stage of wustite reduction. Metallurgical Transactions. B, Process Metallurgy. 1984;15(4):709-717. http://dx.doi.org/10.1007/BF02657293.
5 Turkdogan ET, Vinters JV. Gaseous reduction of iron oxides: Parte III. Reduction-oxidation of porous and dense iron oxides and iron. Metallurgical Transactions. 1972;3(6):1561-1570. http://dx.doi.org/10.1007/BF02643047.
6 Gaballah I, Bert P, Dufour LC, Gleitzer C. Kinetics of the reduction of wustite by hydrogen and carbon monoxide + hydrogen mixtures. Les Memoires Scientifiques de la Revue de Metallurgie. 1972;69:523-530.
7 St John DH, Mathew SP, Hayes PC. The breakdown of dense iron layers on wustite in CO/CO2 and H2/H2O systems. Metallurgical Transactions. B, Process Metallurgy. 1984;15(4):701-708. http://dx.doi.org/10.1007/BF02657292.
8 Gransden JF, Sheasby JS. Sticking of iron-ore during reduction by hydrogen in a fluidized-bed. Canadian Metallurgical Quarterly. 1974;3(4):649-657. http://dx.doi.org/10.1179/cmq.1974.13.4.649.
9 Nicolle R, Rist A. The mechanism of whisker growth in the reduction of wustite. Metallurgical Transactions. B, Process Metallurgy. 1979;10B(3):429-438. http://dx.doi.org/10.1007/BF02652516.
10 El Moujahid S, Rist A. The nucleation of iron on dense wustite: a morphological study. Metallurgical Transactions. B, Process Metallurgy. 1988;19B(5):787-802. http://dx.doi.org/10.1007/BF02650198.
11 Chang M, De Jonghe LC. Whisker growth in reduction of oxides. Metallurgical Transactions. B, Process Metallurgy. 1984;15B(4):685-694. http://dx.doi.org/10.1007/BF02657290.
12 Zhang N, Lior N. Two novel oxy-fuel power cycles integrated with natural gas reforming and CO2 capture. Energy. 2008;33(2):340-351. http://dx.doi.org/10.1016/j.energy.2007.09.006.
13 Olivieri A, Vegliò F. Process simulation of natural gas steam reforming: fuel distribution optimisation in the furnace. Fuel Processing Technology. 2008;89(6):622-632. http://dx.doi.org/10.1016/j.fuproc.2007.12.001.
14 Yi L, Huang Z, Jiang T. Sticking of iron ore pellets during reduction with hydrogen and carbon monoxide mixtures: behavior and mechanism. Powder Technology. 2012;235:1001-1007. http://dx.doi.org/10.1016/j.powtec.2012.11.043.
15 Wang H, Sohn HY. Effects of reducing gas on swelling and iron whisker formation during the reduction of iron oxide compact. Steel Research International. 2012;83(9):903-907. http://dx.doi.org/10.1002/srin.201200054.
16 Komatina M, Gudenau H. The sticking problem during direct reduction of fine iron ore in the fluidized bed. Association of Metallurgical Engineers Serbia and Montenegro. 2004;309-328.
2 El-Geassy AA, Rajakumar V. Influence of particle size on the gaseous reduction of wustite at 900-1100°C. Transactions of the Iron and Steel Institute of Japan. 1985;25(12):1202-1211. http://dx.doi.org/10.2355/isijinternational1966.25.1202.
3 St John DH, Hayes PC. Microstructural features produced by the reduction of wustite in hydrogen/water gas mixtures. Metallurgical Transactions. B, Process Metallurgy. 1982;13B(1):117-124. http://dx.doi.org/10.1007/BF02666962.
4 St John DH, Mathews SP, Hayes PC. Establishment of product morphology during the initial stage of wustite reduction. Metallurgical Transactions. B, Process Metallurgy. 1984;15(4):709-717. http://dx.doi.org/10.1007/BF02657293.
5 Turkdogan ET, Vinters JV. Gaseous reduction of iron oxides: Parte III. Reduction-oxidation of porous and dense iron oxides and iron. Metallurgical Transactions. 1972;3(6):1561-1570. http://dx.doi.org/10.1007/BF02643047.
6 Gaballah I, Bert P, Dufour LC, Gleitzer C. Kinetics of the reduction of wustite by hydrogen and carbon monoxide + hydrogen mixtures. Les Memoires Scientifiques de la Revue de Metallurgie. 1972;69:523-530.
7 St John DH, Mathew SP, Hayes PC. The breakdown of dense iron layers on wustite in CO/CO2 and H2/H2O systems. Metallurgical Transactions. B, Process Metallurgy. 1984;15(4):701-708. http://dx.doi.org/10.1007/BF02657292.
8 Gransden JF, Sheasby JS. Sticking of iron-ore during reduction by hydrogen in a fluidized-bed. Canadian Metallurgical Quarterly. 1974;3(4):649-657. http://dx.doi.org/10.1179/cmq.1974.13.4.649.
9 Nicolle R, Rist A. The mechanism of whisker growth in the reduction of wustite. Metallurgical Transactions. B, Process Metallurgy. 1979;10B(3):429-438. http://dx.doi.org/10.1007/BF02652516.
10 El Moujahid S, Rist A. The nucleation of iron on dense wustite: a morphological study. Metallurgical Transactions. B, Process Metallurgy. 1988;19B(5):787-802. http://dx.doi.org/10.1007/BF02650198.
11 Chang M, De Jonghe LC. Whisker growth in reduction of oxides. Metallurgical Transactions. B, Process Metallurgy. 1984;15B(4):685-694. http://dx.doi.org/10.1007/BF02657290.
12 Zhang N, Lior N. Two novel oxy-fuel power cycles integrated with natural gas reforming and CO2 capture. Energy. 2008;33(2):340-351. http://dx.doi.org/10.1016/j.energy.2007.09.006.
13 Olivieri A, Vegliò F. Process simulation of natural gas steam reforming: fuel distribution optimisation in the furnace. Fuel Processing Technology. 2008;89(6):622-632. http://dx.doi.org/10.1016/j.fuproc.2007.12.001.
14 Yi L, Huang Z, Jiang T. Sticking of iron ore pellets during reduction with hydrogen and carbon monoxide mixtures: behavior and mechanism. Powder Technology. 2012;235:1001-1007. http://dx.doi.org/10.1016/j.powtec.2012.11.043.
15 Wang H, Sohn HY. Effects of reducing gas on swelling and iron whisker formation during the reduction of iron oxide compact. Steel Research International. 2012;83(9):903-907. http://dx.doi.org/10.1002/srin.201200054.
16 Komatina M, Gudenau H. The sticking problem during direct reduction of fine iron ore in the fluidized bed. Association of Metallurgical Engineers Serbia and Montenegro. 2004;309-328.
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