Efficiency of injection of natural gas and pulverized coal at ironmaking

The method for calculating indicators of blast furnace smelting with replacement of part of coke with additional fuels has been developed on the basis of full and complex compensation and compensating measures. Efficiency of the use of natural gas and pulverized coal in the blast furnace conditions of the Enakievo Metallurgical Plant was calculated and it has been confirmed as rather high. Increase in the consumption of natural gas from the baseline (71.8 m³/t of iron) to 110 m³/t ensures a corresponding increase in productivity of the blast furnace to 107.6 % and a decrease in the consumption of coke to 417.3 kg/t of iron (–38.4 kg/t, –8.42 %). Replacing natural gas with pulverized coal in the amount of 160 kg/t of iron made it possible to completely remove it from the blast. At the same time, coke consumption decreased to 354.59 kg/t of iron (–101.1 kg/t; –22.18 %). Increasing the consumption of pulverized coal fuel up to 200 kg/t of iron with compensation of the blast temperature of1200 °Cand oxygen of the blast of 25 % provides an increase in the productivity of the blast furnace to 105.8 % and reduction of coke consumption to 303.8 kg/t of iron (–151.9 kg/t, –33.33 %). High efficiency of the use of pulverized coal in conditions of the Enakievo Metallurgical Plant is explained by its lower cost compared to natural gas, high carbon content in coal and a significantly lower effecton the theoretical combustion temperature and other technological parameters.

1. Kurunov I.F. Blast-furnace smelting in China, Japan, North Ameri- ca, Western Europe, and Russia. Metallurgist. 2010, vol. 54, no. 1-2, pp. 114–126.

2. Shen F., Yang Т., Gao B. Technology progress and strategy in blast furnace ironmaking in China. Steel Research International. 2005, vol. 76, no.10, pp. 676–682.

3. Zhang S., Yin H. The trends of ironmaking industry and challenges to Chinese blast furnace ironmaking in the 21st century. In: Pro- ceedings of the 5th Int. Congress on the Science and Technology of Ironmaking (ICSTI`99) on October 20 - 22, 2009, Shanghai, China. Beijing: Chinese Society for Metals, 2009, pp. 2–15.

4. Production and technology of iron and steel in Japan during 2018.ISIJ International. 2019, vol. 59, no. 6, pp. 939–955.

5. Naito M., Tekeda K., Matsui Y. Ironmaking technology for the last years: deployment to advanced technologies from introduction of technological know-how, and evolution to next-generation pro- cess. ISIJ International. 2015, vol. 55, no. 1, pp. 7–35.

6. Dauwels G., Clairay S., Hess E. etc. Stable and efficient blast fur- nace operation with high PCI and low coke rate at Arcelor Mittal Flat Carbon West Europe. Rev. Met. Paris. 2007, vol. 104, no. 5, pp. 221–230.

7. Lacroix Ph., Dauwels G., Dufresne P. etc. High blast furnaces pro- ductivity operations with low coke rates in the European Union. Rev. Met. Paris. 2001, vol. 98, no. 3, pp. 259–268.

8. Tovarovskii I.G. Domennaya plavka. Evolyutsiya, khod protsessov, problemy i perspektivy [Blast furnace smelting. Evolution, progress of processes, problems and prospects]. Dnepropetrovsk: Porogi, 2003, 597 p. (In Russ.).

9. Vegman E.F. Metallurgiya chuguna [Iron-making]. Moscow: Akademkniga, 2004, 774 p. (In Russ.).

10. Yaroshevskii S.L. Vyplavka chuguna s primeneniem pyleugol’nogo topliva [Ironmaking with pulverized coal]. Moscow: Metallurgiya, 1988, 176 p. (In Russ.).

11. Ramm A.N. Sovremennyi domennyi protsess [Modern blast furnace process]. Moscow: Metallurgiya, 1980, 303 p. (In Russ.).

12. Kitaev B.I., Yaroshenko Yu.G., Lazarev B.L. Teploobmen v domen- noi pechi [Heat exchange in a blast furnace]. Moscow: Metallurgiya, 1966, 355 p. (In Russ.).

13. Babii V.I., Kuvaev V.F. Gorenie ugol’noi pyli i raschet pyleugol’nogo fakela [Combustion of coal dust and calculation of pulverized coal torch]. Moscow: Energoatomizdat, 1986, 208 p. (In Russ.).

14. Yaroshevskii S.L., Afanas’eva Z.K., Kuzin A.V. Main principles of calculation and organization of blast furnace technology with re- placing of 30 – 60 % of coke by additional fuels (domestic and for- eign experience) In.: Tvorcheskoe nasledie B.I. Kitaeva. Trudy Mezhdunarodnoi nauchno-prakticheskoi konferentsii 11-14 fev- ralya 2009 g. Ekaterinburg [Creative Heritage of B.I. Kitaev: Proceedings of the Int. Sci. and Pract. Conf. on February 11-14, 2009, Ekaterinburg]. Ekaterinburg: USTU-UPI, 2009, pp. 138–148. (In Russ.).

15. Filatov Yu.V., Kovalev E.T., Shul’ga I.V. etc. Teoriya i prak- tika proizvodstva i primeneniya domennogo koksa uluchshennogo kachestva [Theory and practice of production and use of coke of improved quality]. Kiev: Naukova dumka, 2011, 128 p. (In Russ.).

16. Gusak V.G., Kuznetsov A.M., Emchenko A.V. etc. Teoriya i prak- tika podgotovki metallurgicheskogo koksa k domennoi plavke [The- ory and practice of preparing metallurgical coke for blast furnace smelting]. Kiev: Naukova dumka, 2011, 216 p. (In Russ.).

17. Langer K. Injection of pulverized coal at ThyssenKrupp Steel. Stahl and Eisen. 2005, no. 11, pp. 591–594.

18. Majeski A., Runstedtler A., D’alessio J., Macfadyen N. Injection of pulverized coal and natural gas into blast furnaces for iron-ma- king: lance positioning and design. ISIJ International. 2015, vol. 55, no. 7, pp. 1377–1383.

19. Chai Y., Zhang J., Shao Q. etc. Experiment research on pulverized coal combustion in the tuyere of oxygen blast furnace. High Temp. Mater. Proc. 2019, no. 38, pp. 42–49.

20. Ueki Y., Yoshiie R., Naruse I. Combustion behavior of pulverized coal and ash particle properties during combustion. ISIJ Interna- tional. 2015, vol. 55, no. 6, pp. 1305–1312.

21. Babich A., Senk D., Born S. Interaction between co-injected sub- stances with pulverized coal into the blast furnace. ISIJ Internatio- nal. 2014, vol. 54, no. 12, pp. 2704–2712.

22. Nozawa K., Kasai A., Matsui Y. etc. Combustion behaviors of fine coal and its impact on gas permeability at lower part of blast furnace under high pulverized coal rate operation. ISIJ International. 2011, vol. 51, no. 8, pp. 1336–1343.

23. Nomura S., Callcott T. Maximum rates of pulverized coal injec- tion in ironmaking blast furnaces. ISIJ International. 2011, vol. 51, no. 7, pp. 1033–1043.