Tecnologia em Metalurgia, Materiais e Mineração
https://tecnologiammm.com.br/article/doi/10.4322/tmm.2013.050
Tecnologia em Metalurgia, Materiais e Mineração
Artigo Original

STUDY ON REDUCING AND MELTING BEHAVIOR OF MILL SCALE/PETROLEUM COKE BLEND

ESTUDO DO COMPORTAMENTO DE REDUÇÃO E FUSÃO DE MISTURAS DE CAREPA/COQUE DE PETRÓLEO

Flores, Bruno Deves; Flores, Ismael Vemdrame; Bagatini, Mauricio Covcevich; Osório, Eduardo; Vilela, Antônio Cezar F.

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Abstract

Self-reducing tests were carried out under isothermal and non-isothermal condition in a muffle furnace, aiming to assess the reduction and melting of a self-reducing blend of mill scale and petroleum coke (85-15% in weight).The products obtained were analyzed by mass loss and wet analysis. Further investigations for the products from the non-isothermal condition were done by X-ray diffraction, nude eye inspection and carbon analyzer. It was observed that mass loss fraction and metallization degree are directly related and both increase with time and temperature. In the non-isothermal maximum mass loss was achieved in 8 minutes, reaching metallization degrees above 90%. It was observed that the reduction of iron oxide occurs mainly in solid state and the smelting of the samples is directly related to the iron carburization process. Thus, the use of self-reducing mixtures shows a possible way to recycle mill scale.

Keywords

Mill scale, Self-reduction, Iron carburization

Resumo

Testes de autorredução em condições isotérmicas e não isotérmicas em forno mufla, foram propostos para avaliar a redução e fusão de uma mistura autorredutora de carepa e coque de petróleo (85-15% em massa). Os produtos obtidos foram analisados através de análises de perda de massa e via úmida. Para os produtos obtidos nas condições não isotérmicas também foram realizadas análises de difração de raios-X, inspeção a olho nu e análise de carbono. Observou-se que a fração reagida e o grau de metalização obtidos estão diretamente relacionados e ambos aumentam com o tempo e temperatura. Os ensaios não isotérmicos levaram 8 minutos para atingir a perda de massa máxima da mistura, alcançando graus de metalização superiores a 90%. Verificou-se que a redução dos óxidos de ferro ocorre principalmente no estado sólido e que a fusão das amostras está diretamente relacionada com o processo de carburação do ferro. Desta forma, o uso de misturas autorredutoras indica uma possibilidade de reciclagem de carepa.

Palavras-chave

Carepa, Autorredução, Carburação do ferro

Referências



1. Umadevi T, Sampath Kumar MG, Mahapatra PC, Mohan Babu T, Ranjan M. Recycling of steel plant mill scale via iron ore pelletisation process. Ironmaking & Steelmaking. 2009;36:409-415. http://dx.doi. org/10.1179/174328108X393795

2. Krzyzanowski M, Beynon JH, Farrugia DCJ. Oxide scale behavior in high temperature metal processing. Weinheinm: Wiley - VCH; 2010. http://dx.doi.org/10.1002/9783527630318

3. Bagatini MC, Zymla V, Osorio E, Vilela ACF. Characterization and reduction behavior of mill scale. ISIJ International. 2011;51:1072-79. http://dx.doi.org/10.2355/isijinternational.51.1072

4. Balajee SR, Callaway PE Jr, Keilman LM. Production and BOF recycling of waste oxide briquettes containing steelmaking sludges. Steelmaking Conference Proceedings. 1995;78:51- 65.

5. Nascimento RC, Lenz G, Martins D, Takano C, Mourão MB. Carbothermic reduction of self-reducing briquettes containing wastes from blast furnace and BOF sludges. In: ABM. Proceedings of th 5th Japan-Brazil Symposium on Dust Processing-Energy-Environment in Metallurgical Industries; 2004; Vitória, Brasil. São Paulo: ABM; 2004. p. 507-516.

6. Dukelow DA, Werner JP, Smith NH. Use of Waste Oxides in the Great Lakes BOP Steelmaking. In: Iron and Steel Society. Proceedings of the Steelmaking Conference; Nashville, EUA; 1995. Ann Arbor: ISS; 1995. p. 67-72.

7. Godinski NA, Kushnarev NN, Yakhshuk DS, Kotenev VI, Yu Barsukova E. Use of iron-carbon bearing briquettes in electric steelmaking, Metallurgist. 2003;47:16-19. http://dx.doi.org/10.1023/A:1023818126564

8. El-Hussiny NA, Shalabi MEH. A self-reduced intermediate product from iron and steel plants waste materials using a briquetting process. Powder Technology. 2001;205:217-23. http://dx.doi.org/10.1016/j.powtec.2010.09.017

9. Donskoi E, McElwain DLS, Wibberley LJ. Estimation and modeling of parameters for direct reduction in Iron ore/coal composites: Part II - Kinetic parameters. Metallurgical and Materials Transactions B. 2003;34B:255-66.

10. Fortini OM, Fruehan RJ. Rate of reduction of ore-carbon composites: Part II - Modeling of reduction in extended composites. Metallurgical and Materials Transactions B. 2005;36B:709-17.

11. Coetsee T, Pistorius PC, Villiers EE. Rate-determining steps for reduction in magnetite-coal pellets. Mining Engineering. 2002;15:919-29. http://dx.doi.org/10.1016/S0892-6875(02)00120-6

12. Sun K, Lu W-K. Mathematical modeling of the kinetics of carbothermic reduction of iron oxides in ore-coal composite pellet. Metallurgical and Materials Transactions B. 2009;40B:91-103.

13. Ohno K, Miki T, Hino M. Kinetic Analysis of iron carburization during smelting reduction. ISIJ International. 2004;44(12):2033-39. http://dx.doi.org/10.2355/isijinternational.44.2033

14. Ohno K, Miki T, Sasaki Y, Hino M. Carburization degree of iron nugget produced by rapid heating of powdery iron, iron oxide in slag and carbon mixture. ISIJ International. 2004;48(10):1368-72. http://dx.doi.org/10.2355/isijinternational.48.1368

15. Kim SH, Lee SH, Sasaki Y. Enhancement of iron rate the co-existence of graphite and Wüstite. ISIJ International. 2007;50(1):71-80. http://dx.doi.org/10.2355/isijinternational.50.71

16. Sasaki Y, Asano R, Ishii K. The effect of the liquid Fe-C phase on the kinetics in the carburization of iron by CO at 1523K. ISIJ International. 2001;41(3):209-15. http://dx.doi.org/10.2355/isijinternational.41.209

17. Murakami T, Fukuyama H, Nagata K. Mechanisms of carburization and melting of iron by CO gas. ISIJ International. 2001;41(5):416-21. http://dx.doi.org/10.2355/isijinternational.41.416

18. Fruehan RJ. The rate of carburization of iron in CO-H2 atmospheres: Part I - Effect of temperature and CO and H2-pressures. Metallurgical Transactions. 1973;4:2123-27. http://dx.doi.org/10.1007/BF02643276

19. Iguchi Y, Endo S. Carburized carbon content of reduced iron and direct carburization in carbon composite iron ore pellets heated at elevated temperature. ISIJ International. 2004;44(12):1991-98. http://dx.doi.org/10.2355/isijinternational.44.1991

20. Hughe H, Davey J, Summerhill BD. The determination of metallic iron oxides pre-reduced ores. Londres: British Steel Corporation; 1976.

21. American Society for Testing and Materials - ASTM. E1019-11: Standard Test Methods for Determination of Carbon, Sulfur, Nitrogen, and Oxygen in Steel, Iron, Nickel, and Cobalt Alloys by Various Combustion and Fusion Techniques. ASTM; 2011.

22. Murakami T, Fukuyama H, Nagata K. Mechanisms of carburization and melting of iron by CO gas. ISIJ International. 2001;41(5):416-21. http://dx.doi.org/10.2355/isijinternational.41.416
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