Abstract
Considerable effort has been directed towards understanding the carbothermic reduction mechanisms of self-reducing, fluxing dried green balls to produce pig iron nuggets. Given the geometry of the situation, some investigators believed that the shrinking core model was applicable. Hence, this study involved investigation of the applicability of the shrinking core model to pig iron nugget production. The experiments involved heat treatment of dried green balls utilizing either a laboratory-scale resistance box furnace or a gas-fired muffle furnace at various furnace temperatures and residence times. The products were analyzed for the following: (i) preferred reaction pattern, (ii) distribution of the metallized areas, (iii) % iron content variation in the pig iron nuggets from surface to center, (iv) carburization pattern and (v) physical and chemical properties of the pig iron nuggets. It was determined that the reduction of iron oxide occurred simultaneously throughout the sample and not beginning at the surface and propagating inward; thus the shrinking-core model was not applicable. Heat transfer and gas diffusion from surface to center were not the rate-limiting steps for reduction and carburization reactions.
This is a preview of subscription content, access via your institution.
References
Anameric, B., and Kawatra, S.K., 2006a, “Laboratory study related to the production and properties of pig iron nuggets,” Minerals and Metallurgical Processing, Vol. 23, No 1, pp. 52–56.
Anameric, B., and Kawatra, S.K., 2006b, “Pig iron nuggets versus blast furnace pig iron,” Proceedings of the Sohn International Symposium, San Diego, California, Vol.5, pp.136–156.
Anameric, B., and Kawatra, S.K., 2007a, “Microstructural investigation of the pig iron nuggets produced at laboratory conditions,” ISIJ International, No. 1.
Anameric, B., and Kawatra, S.K., 2007b, “Transformation mechanisms of self reducing fluxing dried green balls into pig iron nuggets,” presented at the SME Annual Meeting, Denver, CO.
Anameric, B., Rundman, K.B., and Kawatra, S.K., 2006, “Carburization effects on pig iron nugget making,” Minerals and Metallurgical Processing, Vol. 23, No. 3, pp. 139–151.
ASTM E 92-82, 1997, “Standard test method for vickers hardness of metallic materials,” Annual Book of ASTM Standards, Volume 03.01 (Metals Test Methods and Analytical Procedures, Metals, Mechanical testing, elevated and Low-temperature Tests, Metallography), pp. 229–237.
ASTM E 384, 1999, “Standard test method for microindentation hardness of materials,” Annual Book of ASTM Standards, Volume 03.01 (Metals Test Methods and Analytical Procedures, Metals, Mechanical testing, elevated and Low-temperature Tests, Metallography), pp. 418–427.
ASTM E 407, 1999, “Standard practice for microetching metals and alloys,” Annual Book of ASTM Standards, Vol. 03.01 (Metals Test Methods and Analytical Procedures, Metals, Mechanical Testing, Elevated and Low-temperature Tests, Metallography), pp. 474–493.
ASTM E 3, 2001, “Standard guide for preparation of metallographic specimens,” Annual Book of ASTM Standards, Vol. 03.01 (Metals Test Methods and Analytical Procedures, Metals, Mechanical testing, elevated and Low-temperature Tests, Metallograhpy), pp. 1–11.
ASTM B 311-93, 2002, “Density determination for power metallurgy (p/m) materials containing less than two percent porosity,” Annual Book of ASTM Standards, Volume 02.05 (Nonferrous Metal Products, Metallic and Inorganic Coatings, Metal Powders, Sintered P/M Structural Parts), pp. 86–89.
ASTM E 1508-98, 2003, “Standard guide for quantitative analysis by energy dispersive spectroscopy,” Annual Book of ASTM Standards, Volume 03.01, Metals Test Methods and Analytical Procedures, Metals, Mechanical Testing, Elevated and Low-Temperature Tests, Metallography, pp. 975–979.
ASTM E 2141-01, 2003, “Standard test methods for rating and classifying inclusions in steel using the scanning electron microscope,” Annual Book of ASTM Standards, Volume 03.01, Metals Test Methods and Analytical Procedures, Metals, Mechanical Testing, Elevated and Low-Temperature Tests, Metallography, pp. 1221–1236.
ASTM E 246 -01, 2005, “Standard test methods for determination of iron in iron ores and related materials by dichromate titration,” Annual Book of ASTM Standards, Volume 03.05.
Gou, H., Lu, W.K., and Bryk, C., 1992, “Bench scale test of a new ironmaking process with mixture of iron ore concentrate and pulverized coal,” ISIJ International, Vol. 32, No. 6, pp. 733–740.
Huang, B.H., and Lu, W.K., 1993, “Kinetics and mechanisms of reactions in iron ore/coal composites,” ISIJ International, Vol. 33, No. 10, pp. 1055–1061.
Kobayashi, I., Tanigahi, Y., and Uragami, A., 2001, “A new process to produce iron directly from fine ore and coal,” Iron and Steelmaker, Vol. 28, No. 9, pp. 19–22.
Lu, W.K., and Huang, D., 2001, “The evaluation of ironmaking processes based on coal–containing iron ore agglomerates,” ISIJ International, Vol. 41, No. 8, pp. 807–812.
Lu, W.K., and Huang, D., 2003, “Mechanisms of reduction of iron ore/coal agglomerates and scientific issues in RHF operations,” Mineral Processing and Extractive Metallurgy Review, Vol 24, pp. 293–324.
Matsumura, T., Takenaka, Y., Shimizu, M., Negami, T., Kobayashi, I. and Uragami, A., 1998, “The reduction and melting behaviour of carbon composite iron ore pellet on high temperature,” Tetsu to Hagane, Vol. 84, No. 6.
Matsumura, T., Takenaka, Y., and Shimizu, M., 1999, “Effect of the carbon content on reduction and melting behavior of carbon composite iron ore pellet,” Tetsu to Hagane, Vol. 85, No. 9, pp. 14–19.
Meissner, S., Kobayashi, I., Tanigaki, Y. and Tacke, K.H., 2003, “Reduction and melting model of carbon composite ore pellets,” Ironmaking and Steelmaking, Vol. 30, No. 2, pp. 170.
Mourao, M.B., and Takano, C., 2003, “Self-reducing pellets for ironmaking: reaction rate and processing,” Mineral Processing and Extractive Metallurgy Review, Vol. 24, pp. 183–202.
Nagata, K., Kojima, R., Murakami, T., Susa, M. and Fukuyama, H., 2001, “Mechanics of pig iron making from magnetite ore pellets containing coal at low temperature,” ISIJ International, Vol. 41, No. 11, pp. 1316–1323.
Sun, S.S., 1997, A Study of Kinetics and Mechanisms of Iron Ore Reduction in Ore/Coal Composites, PhD dissertation, McMaster University.
Sun, S., and Lu, W.K., 1993, “Mathematical modelling of reactions in iron ore/coal composites,” ISIJ International, Vol. 33, No. 10, pp. 1062–1069.
Sun, S., and Lu, W.K., 1999a, “Building of a mathematical model for the reduction of iron ore in ore/coal composites,” ISIJ International, Vol. 39, No. 2, pp. 130–138.
Sun, S., and Lu, W.K., 1999b, “A theoretical investigation of kinetics and mechanisms of iron ore reduction in an ore/coal composite,” ISIJ International, Vol. 39, No. 2, pp.123–129.
Tsuge, O., Kikukuchi, S., and Tokuda, K., 2002, “Successful iron nugget production at itmk3 pilot plant,” 61st Ironmaking Proceedings, Nashville, Tennessee.
Author information
Authors and Affiliations
Corresponding author
Additional information
Paper number MMP-07-016.
Discussion of this peer-reviewed and approved paper is invited and must be submitted to SME Publications Dept. prior to August 31, 2011.
Rights and permissions
About this article
Cite this article
Anameric, B., Kawatra, S.K. Shrinking-core model for pig iron nugget production. Mining, Metallurgy & Exploration 28, 24–32 (2011). https://doi.org/10.1007/BF03402321
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1007/BF03402321
Key words
- Pig iron nuggets
- Reduction
- Self-reducing
- fluxing dried green balls
- Shrinking core