DOI: 10.52150/2522-9117-2025-39-01

R. M. Rudenko^1,*, Ph. D. Student, ORCID 0009-0008-6207-0107
Ye. M. Sigarev¹,D. Sc. (Tech.), Professor, Head of the Department of Metallurgy, ORCID 0000-0002-8229-7877
M. R. Rudenko¹, Ph. D. (Tech.), Assoc. Prof., ORCID 0000-0002-8016-5221
M. A. Kashcheev¹, Ph. D. (Tech.), Assoc. Prof., ORCID 0000-0002-0938-4384

¹Dniprovsky State Technical University, Dniprobudivska St., 2, Kamianske, 51918, Ukraine

^*Corresponding author: 18rudenko@gmail.com

IMPACT OF CAPILLARY MOISTURE UPTAKE ON THE FORMATION OF IRON ORE SINTER MIX GRANULES

Abstract. The research focuses on determining main factors that affect quality granulation of iron ore sinter mix. Granulation is a crucial stage in sintering technology, since strength, size distribution, and gas permeability of granules directly influence bed resistance, flame front stability, and overall productivity the sintering machine. Based on both experimental studies and theoretical analysis, role of moisture content, drum operating parameters, and pore structure characteristics has been clarified. It has been demonstrated that preliminary granulation of fine fractions (dust, sludges, lime, and other secondary raw materials) significantly improves the uniformity granule structure. Capillary absorption tests showed that concentrates, ores, and waste products differ considerably in water uptake, which is mainly due to variations in pore radius. According to the Washburn equation, smaller pores limit penetration depth and reduce moisture distribution, whereas larger pores accelerate water movement and ensure better wetting of the charge. Calculated data indicate that at pore sizes of 5 μm the penetration depth does not exceed 2 mm within 10 s, while at 20 – 40 μm moisture spreads several millimeters during the same period. These results confirm the necessity of pre-granulating fine wastes with poor wettability in order to stabilize the structure of the sinter mix. Optimization of granulation parameters has been carried out. The most favorable regime corresponds to a moisture content of 7.5 – 9.0 %, drum speed of 12 – 14 rpm, and fill degree of 22 – 26 %. Under these conditions, strong and uniform granules with a dominant fraction of 3 – 6 mm are formed. The fraction below 1 mm decreases from more than 40 % to approximately 24 %, which considerably lowers dust generation during sintering. The obtained results also prove that the use of preliminary granulation makes it possible to introduce up to 25 – 30 % of secondary materials without deterioration of granule stability. At the same time, dust emissions are reduced by 5 – 10 % and the environmental performance of sintering is improved. The novelty of this work consists in establishing the relationship between moisture absorption mechanisms and the stability of granules, and in proving the possibility of increasing the share of secondary raw materials in the charge while simultaneously reducing the ecological footprint of agglomeration.

Key words: sinter mix; granulation; moisture content; capillary absorption; particle size distribution; bed permeability.

For citation: Rudenko, R. M., Sigarev, Ye. M., Rudenko, M. R., & Kashcheev, M. A. (2025). Impact of capillary moisture uptake on the formation of iron ore sinter mix granules. Fundamental and applied problems of ferrous metallurgy, 39, 4-19. https://doi.org/10.52150/2522-9117-2025-39-01

References

Ting, J.-M., & Lin, R.-Y. (1994). Effect of particle-size distribution on sintering – Part I: Modelling. Journal of Materials Science, 29 (7), 1867–1872. https://doi.org/10.1007/BF00351306
An, X., Yang, R., Zou, R., & Yu, A. (2008). Effect of vibration condition and inter-particle frictions on the packing of uniform spheres. Powder Technology, 188, 102–109. https://doi.org/10.1016/j.powtec.2008.04.056
Umadevi, T., Bandopadhyay, U. K., Mahapatra, P. C., Prabhu, M., & Ranjan, M. (2010). Influence of limestone particle size on iron ore sinter properties and productivity. Steel Research International, 81(6), 425–433. https://doi.org/10.1002/srin.201000020
Zhang, H., Bai, K., Liu, W., Zhang, Z., & Kou, M. (2022). Effect of magnetite concentrate particle size on pellet oxidation roasting process and compressive strength. ISIJ International, 62(6), 1207–1216. https://doi.org/10.2355/isijinternational.ISIJINT-2021-628
Bjørk, R., Tikare, V., Frandsen, H. L., & Pryds, N. (2013). The effect of particle size distributions on the microstructural evolution during sintering. Journal of the American Ceramic Society, 96 (1), 103–110. https://doi.org/10.1111/jace.12100
Aladejebi, O. A., Mitra, S., Singh, T., Pinson, D. J., Chew, S., & Honeyands, T. (2025). Effect of ultrafine iron ore addition on green bed properties and sinter productivity. ISIJ International, 65 (7), 937–947. https://doi.org/10.2355/isijinternational.ISIJINT-2024-374
Kawatra, S. K., & Claremboux, V. (2020). Granulation fundamentals and applications in iron ore sintering. Minerals Engineering, 146, 106136. https://doi.org/10.1016/j.mineng.2019.106136
Oliveira, V. de M., Domingues, A. L. A., Bagatini, M. C., & Resende, V. G. de. (2020). Granulation behavior of an iron ore sintering mixture containing high-grade pellet feed with different specific surface. ISIJ International, 60 (11), 2376–2384. https://doi.org/10.2355/isijinternational.ISIJINT-2020-023
You, Y., Guo, J., Zheng, Z., Li, G., Li, Y., Lv, X., & Yang, R. (2022). Comparisons of iron ore granulation and sintering performance between horizontal high-shear granulators and drum granulators. Powder Technology, 409, 117367. https://doi.org/10.1016/j.powtec.2022.117367

Received 29.07.2025
Accepted 21.10.2025
Published online 01.12.2025