ESTUDO DA INFLUÊNCIA DA HIDRATAÇÃO COMPLEMENTAR NAS PROPRIEDADES MECÂNICAS DE PELOTAS AUTORREDUTORAS
STUDY OF THE INFLUENCE OF COMPLEMENTARY HYDRATION ON THE MECHANICAL PROPERTIES OF SELF-REDUCING PELLETS
Sousa, Felippe de Oliveira; Araújo, Giselle de Mattos
http://dx.doi.org/10.4322/2176-1523.0741
Tecnol. Metal. Mater. Min., vol.12, n2, p.134-139, 2015
Resumo
No presente trabalho investigou-se como diferentes meios e tempos de hidratação complementares, ou seja, hidratações realizadas após a produção, em pelotas autorredutoras afetam suas propriedades mecânicas. Para tal, pelotas idênticas foram confeccionadas pela adição de pellet feed, finos de carvão não-coqueificado, cimento e cal, e então foram submetidas a hidratação por imersão em água ou em câmara úmida, por tempos distintos. As pelotas foram então caracterizadas por meio de ensaios mecânicos de compressão e tamboramento, além de medição de microdureza ao longo do raio. Pelotas não hidratadas serviram de base para comparação dos resultados, que comprovaram o aumento na resistência à compressão das pelotas quando hidratadas e definiram o meio de hidratação por câmara úmida como mais eficiente.
Palavras-chave
Pelotas autorredutoras, Hidratação, Cura a frio.
Abstract
This study has investigated how different methods and time of complementary hydration affects the cold strength of self-reducing pellets. Identical pellets had been made by the addition of pellet feed, coal, cement and lime and have been subjected to hydration by water immersion or in a moist chamber for different periods. A group of non-hydrated pellets was used as reference for evaluation the effect of hydration. The pellets were then characterized by mechanical tests of compression and tumbling strength. The results have shown an increase in the mechanical properties of pellets and have proved that the hydration by moist chamber was the most efficient method
Keywords
Self-reducing pellets, Hydration, Green strength.
Referências
1 D’Abreu JC, Mourão MB, Costa PHC, Noldi Júnior JH, Marcheze E. Curso de Auto redução carbo-metalotérmica. In: Anais do 7º Simpósio Brasil-Japão; 2008; São Paulo, Brasil. São Paulo: ABM; 2008.
2 Kasai A, Matsui Y. Lowering of thermal reserve zone temperature in blast furnace by adjoining carbonaceous material and iron ore. ISIJ International. 2004;44(12):2073-2078. http://dx.doi.org/10.2355/isijinternational.44.2073.
3 Matsui Y, Sawayama M, Kasai A, Yamagata Y, Noma F. Reduction behavior of carbon composite iron ore hot briquette in shaft furnace and scope on blast furnace performance reinforcement. ISIJ International. 2003;43(12):1904-1912. http://dx.doi.org/10.2355/isijinternational.43.1904.
4 Kasai A, Toyota H, Nozawa K, Kitayama S. Reduction of reducing agent rate in blast furnace operation by carbon composite iron ore hot briquette. ISIJ International. 2011;51(8):1333-1335. http://dx.doi.org/10.2355/isijinternational.51.1333.
5 Goksel MA. Fundamentals of cold bond agglomeration process. In: Proceedings of the 2nd International Symposium on Agglomeration, Agglomeration 77; 1977; Berkley, EUA. Atlanta: K.V.S. Sastry; 1977. p. 877-900.
6 Litster JD, Waters AG, Nicol SK. Coke degradation by surface breakage in a modified tumble drum. Transactions ISIJ. 1987;27(1):3-9. http://dx.doi.org/10.2355/isijinternational1966.27.3.
7 Takano C, Mourão MB. Self-reducing pellets for ironmaking: mechanical behavior. Mineral Processing and Extractive Metallurgy Review: An International Journal. 2003;24(3-4):233-252. http://dx.doi.org/10.1080/714856823.
2 Kasai A, Matsui Y. Lowering of thermal reserve zone temperature in blast furnace by adjoining carbonaceous material and iron ore. ISIJ International. 2004;44(12):2073-2078. http://dx.doi.org/10.2355/isijinternational.44.2073.
3 Matsui Y, Sawayama M, Kasai A, Yamagata Y, Noma F. Reduction behavior of carbon composite iron ore hot briquette in shaft furnace and scope on blast furnace performance reinforcement. ISIJ International. 2003;43(12):1904-1912. http://dx.doi.org/10.2355/isijinternational.43.1904.
4 Kasai A, Toyota H, Nozawa K, Kitayama S. Reduction of reducing agent rate in blast furnace operation by carbon composite iron ore hot briquette. ISIJ International. 2011;51(8):1333-1335. http://dx.doi.org/10.2355/isijinternational.51.1333.
5 Goksel MA. Fundamentals of cold bond agglomeration process. In: Proceedings of the 2nd International Symposium on Agglomeration, Agglomeration 77; 1977; Berkley, EUA. Atlanta: K.V.S. Sastry; 1977. p. 877-900.
6 Litster JD, Waters AG, Nicol SK. Coke degradation by surface breakage in a modified tumble drum. Transactions ISIJ. 1987;27(1):3-9. http://dx.doi.org/10.2355/isijinternational1966.27.3.
7 Takano C, Mourão MB. Self-reducing pellets for ironmaking: mechanical behavior. Mineral Processing and Extractive Metallurgy Review: An International Journal. 2003;24(3-4):233-252. http://dx.doi.org/10.1080/714856823.