Blasting Method for Improving the Secondary Combustion Efficiency in the Romelt Process Using CFD Analysis

Jong Thae Song; Oh Chung Hyok; Ri Kum Hyok; Ri Kwang; Phyon Kum Hyok

doi:doi:10.11648/j.ijmsa.20251406.12

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Blasting Method for Improving the Secondary Combustion Efficiency in the Romelt Process Using CFD Analysis

Jong Thae Song

, Oh Chung Hyok^*

, Ri Kum Hyok

, Ri Kwang

, Phyon Kum Hyok

Published in International Journal of Materials Science and Applications (Volume 14, Issue 6)

Received: 26 August 2025 Accepted: 30 October 2025 Published: 11 December 2025

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Abstract

The Romelt process is called liquid-phase smelting reduction process because in the metallurgical processes the reaction of coal and iron occurs in the liquid slag layer, which is boiling vigorously by oxygen-enriched air flow blown into the liquid slag. The bath of the furnace is charged with coal and iron ore, and an oxygen nozzle for secondary combustion is installed on both sides of the bath cavity to burn out the CO and H₂ gases generated in the bath. CO and H₂, rising from the boiling slag bath, are completely burned by oxygen blown into the secondary nozzle in the combustion chamber. The heat from this combustion reaction plays an important role in the Romelt process. 60-80% of the secondary combustion heat is transferred to the bath and becomes the heat source of the main process. At present, the Romelt process has a high CO content in the exhaust gas due to the low efficiency of combustion by oxygen blown into secondary nozzle and low oxidation of CO. This paper analyses the reason of the low efficiency of combustion by oxygen blown into conventional secondary nozzle using CFD, and based on it, suggests the blasting method to increase the secondary combustion efficiency by oxygen blown into the upper tuyere of the Romelt furnace. To improve the secondary combustion efficiency, a new type of catalyst for enhancing the oxidation of CO was investigated and more than 90% of efficiency of secondary combustion was achieved. At this time, oxygen concentration should be at least 95%.

Published in	International Journal of Materials Science and Applications (Volume 14, Issue 6)
DOI	10.11648/j.ijmsa.20251406.12
Page(s)	263-269
Creative Commons	This is an Open Access article, distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution and reproduction in any medium or format, provided the original work is properly cited.
Copyright	Copyright © The Author(s), 2025. Published by Science Publishing Group

Keywords

Romelt, Secondary Combustion Efficiency, Blasting Method, Oxidation Catalyst, Nozzle

References

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[2]	T. Kitagawa. Compact, economical, and ecological ironmaking process – DIOS. in: Commercializing New Hot Metal Processes Beyond the Blast Furnace: International Conf., Atlanta, Georgia, U.S., June, 2000, pp. 1–15.
[3]	P. Bates and A. Muir. Hlsmelt: low-cost ironmaking. in: Commercializing New Hot Metal Processes Beyond the Blast Furnace: International Conf., Atlanta, Georgia, U.S., June, 2000, pp. 1–12.
[4]	J. Fogarty, K. Hamilton, and J. Goldin. Ausiron – a new direct reduction technology for pig iron production. Skillings Mining Review, No. 5, 4–8 (1998).
[5]	V. A. Romenets. Romelt – a completely liquid-phase process for producing metal. Izv. Vyssh. Uchebn. Zaved. Chern. Metall.
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[7]	V. A. Romenets, V. S. Valavin, and Yu. V. Pokhvisnev. (2014). Technological Assessment of the ROMELT Process in the Classic and Two-Zone Variants. Metallurgist, 58, 1–2.
[8]	G. S. Sborshchikov, A. L. Petelin, and A. Yu. Terekhova. (2020). Increasing the Specific Performance of ROMELT Furnace. Metallurgist, 64, 3-4. https://doi.org/10.1007/s11015-020-00985-y
[9]	Yu. V. Pokhvisnev, V. S. Valavin, and S. A. Makeev. (2019). Effect of Ore and Coal Composition on ROMELT Furnace Performance. Metallurgist, 62, 11-12. https://doi.org/10.1007/s11015-019-00761-7
[10]	Zhou, G., Saxén, H., Mattila, O., Yu, Y. (2024). A Method for Image-Based Interpretation of the Pulverized Coal Cloud in the Blast Furnace Tuyeres. Process, 12, 529. https://doi.org/10.3390/pr12030529
[11]	Polis, M., Stolarczyk, A., Szydło K., Lisiecka, B., Procek, M., Sławski, S., Domagała, W., Iksal, J., Jarosz, T. (2024). Ti/CuO Nanothermite Doped with Secondary Energetic Materials: A Study of Combustion Parameters. Molecules, 29, 3664. https://doi.org/10.3390/molecules29153664
[12]	Shrivastava, A., Vivek Kumar Patel, V. (2019). Effect of injection angle of primary and secondary holes on the mixing and combustion in a can type combustor using CFD. SN Applied Sciences, 1, 786. https://doi.org/10.1007/s42452-019-0753-4
[13]	Hou, S., Chiang, C., Lin, T. (2020). Oxy-Fuel Combustion Characteristics of Pulverized Coal under O₂/Recirculated Flue Gas Atmospheres. Applied Sciences, 10, 1362. https://doi.org/10.3390/app10041362
[14]	Jiang, D., Wang, Z., Li, K., Zhang, J., Ju, L., Hao, L. (2022). Predictive Modeling of Blast Furnace Gas Utilization Rate Using Different Data Pre-Processing Methods. Metals, 12, 535. https://doi.org/10.3390/met12040535
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APA Style

Song, J. T., Hyok, O. C., Hyok, R. K., Kwang, R., Hyok, P. K. (2025). Blasting Method for Improving the Secondary Combustion Efficiency in the Romelt Process Using CFD Analysis. International Journal of Materials Science and Applications, 14(6), 263-269. https://doi.org/10.11648/j.ijmsa.20251406.12

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ACS Style

Song, J. T.; Hyok, O. C.; Hyok, R. K.; Kwang, R.; Hyok, P. K. Blasting Method for Improving the Secondary Combustion Efficiency in the Romelt Process Using CFD Analysis. Int. J. Mater. Sci. Appl. 2025, 14(6), 263-269. doi: 10.11648/j.ijmsa.20251406.12

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AMA Style

Song JT, Hyok OC, Hyok RK, Kwang R, Hyok PK. Blasting Method for Improving the Secondary Combustion Efficiency in the Romelt Process Using CFD Analysis. Int J Mater Sci Appl. 2025;14(6):263-269. doi: 10.11648/j.ijmsa.20251406.12

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@article{10.11648/j.ijmsa.20251406.12,
  author = {Jong Thae Song and Oh Chung Hyok and Ri Kum Hyok and Ri Kwang and Phyon Kum Hyok},
  title = {Blasting Method for Improving the Secondary Combustion Efficiency in the Romelt Process Using CFD Analysis},
  journal = {International Journal of Materials Science and Applications},
  volume = {14},
  number = {6},
  pages = {263-269},
  doi = {10.11648/j.ijmsa.20251406.12},
  url = {https://doi.org/10.11648/j.ijmsa.20251406.12},
  eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.ijmsa.20251406.12},
  abstract = {The Romelt process is called liquid-phase smelting reduction process because in the metallurgical processes the reaction of coal and iron occurs in the liquid slag layer, which is boiling vigorously by oxygen-enriched air flow blown into the liquid slag. The bath of the furnace is charged with coal and iron ore, and an oxygen nozzle for secondary combustion is installed on both sides of the bath cavity to burn out the CO and H2 gases generated in the bath. CO and H2, rising from the boiling slag bath, are completely burned by oxygen blown into the secondary nozzle in the combustion chamber. The heat from this combustion reaction plays an important role in the Romelt process. 60-80% of the secondary combustion heat is transferred to the bath and becomes the heat source of the main process. At present, the Romelt process has a high CO content in the exhaust gas due to the low efficiency of combustion by oxygen blown into secondary nozzle and low oxidation of CO. This paper analyses the reason of the low efficiency of combustion by oxygen blown into conventional secondary nozzle using CFD, and based on it, suggests the blasting method to increase the secondary combustion efficiency by oxygen blown into the upper tuyere of the Romelt furnace. To improve the secondary combustion efficiency, a new type of catalyst for enhancing the oxidation of CO was investigated and more than 90% of efficiency of secondary combustion was achieved. At this time, oxygen concentration should be at least 95%.},
 year = {2025}
}

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TY  - JOUR
T1  - Blasting Method for Improving the Secondary Combustion Efficiency in the Romelt Process Using CFD Analysis
AU  - Jong Thae Song
AU  - Oh Chung Hyok
AU  - Ri Kum Hyok
AU  - Ri Kwang
AU  - Phyon Kum Hyok
Y1  - 2025/12/11
PY  - 2025
N1  - https://doi.org/10.11648/j.ijmsa.20251406.12
DO  - 10.11648/j.ijmsa.20251406.12
T2  - International Journal of Materials Science and Applications
JF  - International Journal of Materials Science and Applications
JO  - International Journal of Materials Science and Applications
SP  - 263
EP  - 269
PB  - Science Publishing Group
SN  - 2327-2643
UR  - https://doi.org/10.11648/j.ijmsa.20251406.12
AB  - The Romelt process is called liquid-phase smelting reduction process because in the metallurgical processes the reaction of coal and iron occurs in the liquid slag layer, which is boiling vigorously by oxygen-enriched air flow blown into the liquid slag. The bath of the furnace is charged with coal and iron ore, and an oxygen nozzle for secondary combustion is installed on both sides of the bath cavity to burn out the CO and H2 gases generated in the bath. CO and H2, rising from the boiling slag bath, are completely burned by oxygen blown into the secondary nozzle in the combustion chamber. The heat from this combustion reaction plays an important role in the Romelt process. 60-80% of the secondary combustion heat is transferred to the bath and becomes the heat source of the main process. At present, the Romelt process has a high CO content in the exhaust gas due to the low efficiency of combustion by oxygen blown into secondary nozzle and low oxidation of CO. This paper analyses the reason of the low efficiency of combustion by oxygen blown into conventional secondary nozzle using CFD, and based on it, suggests the blasting method to increase the secondary combustion efficiency by oxygen blown into the upper tuyere of the Romelt furnace. To improve the secondary combustion efficiency, a new type of catalyst for enhancing the oxidation of CO was investigated and more than 90% of efficiency of secondary combustion was achieved. At this time, oxygen concentration should be at least 95%.
VL  - 14
IS  - 6
ER  -

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Author Information

Jong Thae Song

Faculty of Metallic Engineering, Kim Chaek University of Technology, Pyongyang, DPRK

http://orcid.org/0009-0002-4529-0171
Oh Chung Hyok

Faculty of Metallic Engineering, Kim Chaek University of Technology, Pyongyang, DPRK

Contact Email

http://orcid.org/0009-0009-7068-355X
Ri Kum Hyok

Faculty of Metallic Engineering, Kim Chaek University of Technology, Pyongyang, DPRK

http://orcid.org/0009-0007-5524-5020
Ri Kwang

Faculty of Metallic Engineering, Kim Chaek University of Technology, Pyongyang, DPRK

http://orcid.org/0009-0002-1504-6362
Phyon Kum Hyok

Faculty of Metallic Engineering, Kim Chaek University of Technology, Pyongyang, DPRK

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APA Style

Song, J. T., Hyok, O. C., Hyok, R. K., Kwang, R., Hyok, P. K. (2025). Blasting Method for Improving the Secondary Combustion Efficiency in the Romelt Process Using CFD Analysis. International Journal of Materials Science and Applications, 14(6), 263-269. https://doi.org/10.11648/j.ijmsa.20251406.12

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ACS Style

Song, J. T.; Hyok, O. C.; Hyok, R. K.; Kwang, R.; Hyok, P. K. Blasting Method for Improving the Secondary Combustion Efficiency in the Romelt Process Using CFD Analysis. Int. J. Mater. Sci. Appl. 2025, 14(6), 263-269. doi: 10.11648/j.ijmsa.20251406.12

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AMA Style

Song JT, Hyok OC, Hyok RK, Kwang R, Hyok PK. Blasting Method for Improving the Secondary Combustion Efficiency in the Romelt Process Using CFD Analysis. Int J Mater Sci Appl. 2025;14(6):263-269. doi: 10.11648/j.ijmsa.20251406.12

Copy | Download

@article{10.11648/j.ijmsa.20251406.12,
  author = {Jong Thae Song and Oh Chung Hyok and Ri Kum Hyok and Ri Kwang and Phyon Kum Hyok},
  title = {Blasting Method for Improving the Secondary Combustion Efficiency in the Romelt Process Using CFD Analysis},
  journal = {International Journal of Materials Science and Applications},
  volume = {14},
  number = {6},
  pages = {263-269},
  doi = {10.11648/j.ijmsa.20251406.12},
  url = {https://doi.org/10.11648/j.ijmsa.20251406.12},
  eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.ijmsa.20251406.12},
  abstract = {The Romelt process is called liquid-phase smelting reduction process because in the metallurgical processes the reaction of coal and iron occurs in the liquid slag layer, which is boiling vigorously by oxygen-enriched air flow blown into the liquid slag. The bath of the furnace is charged with coal and iron ore, and an oxygen nozzle for secondary combustion is installed on both sides of the bath cavity to burn out the CO and H2 gases generated in the bath. CO and H2, rising from the boiling slag bath, are completely burned by oxygen blown into the secondary nozzle in the combustion chamber. The heat from this combustion reaction plays an important role in the Romelt process. 60-80% of the secondary combustion heat is transferred to the bath and becomes the heat source of the main process. At present, the Romelt process has a high CO content in the exhaust gas due to the low efficiency of combustion by oxygen blown into secondary nozzle and low oxidation of CO. This paper analyses the reason of the low efficiency of combustion by oxygen blown into conventional secondary nozzle using CFD, and based on it, suggests the blasting method to increase the secondary combustion efficiency by oxygen blown into the upper tuyere of the Romelt furnace. To improve the secondary combustion efficiency, a new type of catalyst for enhancing the oxidation of CO was investigated and more than 90% of efficiency of secondary combustion was achieved. At this time, oxygen concentration should be at least 95%.},
 year = {2025}
}

Copy | Download

TY  - JOUR
T1  - Blasting Method for Improving the Secondary Combustion Efficiency in the Romelt Process Using CFD Analysis
AU  - Jong Thae Song
AU  - Oh Chung Hyok
AU  - Ri Kum Hyok
AU  - Ri Kwang
AU  - Phyon Kum Hyok
Y1  - 2025/12/11
PY  - 2025
N1  - https://doi.org/10.11648/j.ijmsa.20251406.12
DO  - 10.11648/j.ijmsa.20251406.12
T2  - International Journal of Materials Science and Applications
JF  - International Journal of Materials Science and Applications
JO  - International Journal of Materials Science and Applications
SP  - 263
EP  - 269
PB  - Science Publishing Group
SN  - 2327-2643
UR  - https://doi.org/10.11648/j.ijmsa.20251406.12
AB  - The Romelt process is called liquid-phase smelting reduction process because in the metallurgical processes the reaction of coal and iron occurs in the liquid slag layer, which is boiling vigorously by oxygen-enriched air flow blown into the liquid slag. The bath of the furnace is charged with coal and iron ore, and an oxygen nozzle for secondary combustion is installed on both sides of the bath cavity to burn out the CO and H2 gases generated in the bath. CO and H2, rising from the boiling slag bath, are completely burned by oxygen blown into the secondary nozzle in the combustion chamber. The heat from this combustion reaction plays an important role in the Romelt process. 60-80% of the secondary combustion heat is transferred to the bath and becomes the heat source of the main process. At present, the Romelt process has a high CO content in the exhaust gas due to the low efficiency of combustion by oxygen blown into secondary nozzle and low oxidation of CO. This paper analyses the reason of the low efficiency of combustion by oxygen blown into conventional secondary nozzle using CFD, and based on it, suggests the blasting method to increase the secondary combustion efficiency by oxygen blown into the upper tuyere of the Romelt furnace. To improve the secondary combustion efficiency, a new type of catalyst for enhancing the oxidation of CO was investigated and more than 90% of efficiency of secondary combustion was achieved. At this time, oxygen concentration should be at least 95%.
VL  - 14
IS  - 6
ER  -

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