Influencing factors and mechanism of water absorption process of iron ores during sintering

Abstract

The appropriate content and distribution of sinter moisture play an important role in the granulation of iron ores. In this study, the effects of porosity, size distribution, and particle shape on the water absorption rate (WAR) of four types of iron ores were analyzed by using the immersion method and capillary water absorption method. In addition, the mechanism underlying the water absorption process in iron ores was unraveled. It is found that the WARs of iron ores decrease quickly with the increase in water absorption time at the initial stages of water absorption. With further increase in absorption time, the WARs decrease gradually, until near 0. Iron ores with higher porosity, smaller particle size, and plate-like structure have the higher WARs. Compared with pores in the single-particle iron ore, voids among particles in the multi-particle iron oxide play an important role at the initial stages of water absorption. The water absorption mechanism of all single-particle and multi-particle iron ores analyzed in this study includes four steps, wherein the first three steps play a significant role in the sintering process.

Keywords

iron ores / sintering / water absorption / factor analysis

References

[1] Rath SS, Sahoo H, Das B. Optimization of flotation variables for the recovery of hematite particles from BHQ ore. Int. J. Miner. Metall. Mater., 2013, 20(7): 605.

[2] Wu SL, Oliveira D, Dai YM, Xu J. Ore-blending optimization model for sintering process based on characteristics of iron ores. Int. J. Miner. Metall. Mater., 2012, 19(3): 217.

[3] Newitt DM, Conway-jones JM. A contribution to the theory and practice of granulation. Chem. Eng. Res. Des., 1958, 36, 422

[4] Kapur PC. Balling and Granulation, 1978, Kanpur, Department of Metallurgical Engineering India Institure of Technology, 55

[5] Waters AG, Litster JD, Nicol SK. A mathematical model for the prediction of granule size distribution for multicomponent sinter feed. ISIJ Int., 1989, 29(4): 274.

[6] Maki T, Sekiguchi I. Study for evaluation and optimization of iron ore granulation with consideration of dynamics and particle conditions. ISIJ Int., 2009, 49(5): 631.

[7] Matsumura M, Kawaguchi T. Effect of moisture distribution of sinter mixture on granulation particles. Tetsu-to-Hagané, 2001, 87(5): 290

[8] Matsumura T, Miyagawa K, Yamagata Y. Influence of the nuclei particle properties on granulability of marra mamba iron ore by high speed agitating mixer. ISIJ Int., 2005, 45(4): 485.

[9] Matsumura T, Maki T, Amano S, Sakamoto M, Iwasaki N. Effect of moisture absorption behavior on optimal granulation moisture value of sinter raw material. ISIJ Int., 2009, 49(5): 618.

[10] Lv XW, Bai CG, Qiu GB, Zhang SF, Hu ML. Moisture capacity: definition, measurement, and application in determining the optimal water content in granulating. ISIJ Int., 2010, 50(5): 695.

[11] Maeda T, Nishioka K, Shimizu M. Effect of granulation condition and property of raw material on strength of granulated particle by tumbling granulation. ISIJ Int., 2009, 49(5): 625.

[12] Maeda T, Fukumoto C, Matsumura T, Nishioka K, Shimizu M. Effect of adding moisture and wettability on granulation of iron ore. ISIJ Int., 2005, 45(4): 477.

[13] Iveson SM, Holt S, Biggs S. Contact angle measurements of iron ore powders. Colloids Surf., 2000, 166(1-3): 203.

[14] Iveson SM, Holt S, Biggs S. Advancing contact angle of iron ores as a function of their hematite and goethite content: implications for pelletising and sintering. Int. J. Miner. Process., 2004, 74(1–4): 281.

[15] Iveson SM, Rutherford KF, Biggs SR. Liquid penetration rate into submerged porous particles: theory, experimental validation and implications for iron ore granulation and sintering. Miner. Process. Extr. Metall., 2001, 110(3): 133.