ANALYSIS OF ENERGY EFFICIENCY INCREASE OF CAST IRON SMELTING IN NLMK BLAST FURNACES

The analysis of effects and risks of the main measures aimed at  reducing energy costs has shown that the change in any one parameter  is ineffective. The greatest effect can be achieved by the joint change of  several variables. Theoretical analysis made it possible to identify the  main combinations of changes in the regime parameters, which provide the greatest effect on the particular activity factor. The influence  of the granulometric composition of the agglomerate on the efficiency  of blast furnace smelting was examined through the influence of average diameter of the pieces, both on the rate of recovery and on the gas  dynamics of furnace upper zone. It is shown that the variations in heat  costs are largely determined by the fluctuations in recovery work of  gas flow, which, in turn, depends on granulometric composition of the  agglomerate. It was established that when the FeO  +  CO  =  Fe  +  CO2  reaction is approached to balance, the heat loss reduction for cast iron  smelting is achieved by increasing the melting intensity. The specific  ways of reducing the heat costs for cast iron smelting in blast furnaces were analyzed on the example of PAO NLMK. It is shown that  the main activities providing the reduction of heat losses in the plant  conditions are: quality optimization of the iron ore materials due to  the fraction decrease of +45  mm; increasing the intensity of the blastfurnace operation to relative production of 75  –  90  tons per day from  square meter of the blast-furnace hearth; blast-furnace operation at the  alarm pressure (according to the design of charging equipment); increasing the coke strength reactivity up to 60  –  62  %; pulverized coal  injection up to 140  kg per ton of cast iron and optimization of the ore  load distribution on the furnace’s radius. As a result of these measures  implementation in 2013  –  2016, the coke rate reduction by more than  10  kg per ton of cast iron was achieved. In this case, not only the specific consumption of coke, but also the consumption of total carbon of  fuel is reduced.

 blast-furnace,  coke consumption,  carbon total consumption,   melting intensity,  high-top pressure,  reduction ratio of carbon oxides,   energy consumption,  heat losses,  quality of the raw materials,  heat  balance

1. Rammer B., Millner R., Boehm C. Comparing the CO2 emission of  different ironmaking rout. Proceedings of the 7th European Coke and Ironmaking Congress – ECIC. 2016, pp. 284–291.

2. Schmole P. The blast furnace – fit for future. Proceeding of the 7th Europeaen Coke and Ironmaking Congress – ECIC. 2016, pp. 3–12.

3. Tovarovskii I.G. Protsessy domennoi plavki. Tom 2. Problemy i perspektivy: monografiya [Blast furnace processes. Vol.2. Problems  and perspectives: Monograph]. Izdatel’skii dom LAP LAMBERT  Akademic Publishing, 2012, 406 p. (In Russ.).

4. Tovarovskii I.G. Domennaya plavka: monografiya [Blast furnace  smelting: Monograph]. Dnepropetrovsk: Porogi, 2009, 768 p. (In  Russ.). 

5. Spirin N.A., Lavrov V.V., Rybolovlev V.Yu. etc. Matematicheskoe modelirovanie metallurgicheskikh protsessov v ASU TP [Mathematical modeling of metallurgical processes in automated process  control system]. Spirin N.A. ed. Ekaterinburg: OOO “UIPTs”, 2014,  558 p. (In Russ.).

6. Zagainov S.A., Onorin O.P., Gileva L.Yu. Volkov D.N., Tleugobulov B.S. Software for flexible blast-furnace operation. Steel in Translation. 2000, vol. 30, no. 9, pp. 9–11. 

7. Spirin  N.A.,  Lavrov V.V.,  Rybolovlev V.Yu.,  Krasnobaev A.V.,  Ono rin O.P. Model’nye sistemy podderzhki prinyatiya reshenii v ASU TP domennoi plavki [Model decision support systems in the  automated process control system of blast furnace smelting]. Ekaterinburg: UrFU, 2011, 462 p. (In Russ.).

8. Filatov S.V., Zagainov S.A., Gileva L.Yu., Pykhteeva K.B. Development of the analysis of iron oxide reduction processes. Izvestiya VUZov. Chernaya metallurgiya = Izvestiya. Ferrous Metallurgy.  2015, no. 9, pp. 658–661. (In Russ.).

9. Shvartsman A.A., Zhukhovitskii A.A Nachala fizicheskoi khimii dlya metallurgov [Fundamentals of physical chemistry for metallurgists]. Moscow: Metallurgiya, 1991, 208 p. (In Russ.).

10. Shavrin S.V . Regularities of reduction of iron oxides and modeling  of metallurgical processes. In: Fizicheskaya khimiya i tekhnologii v metallurgii: sbornik nauchnykh trudov [Physical chemistry and  technologies in metallurgy: Coll. of sci. papers]. Ekaterinburg: UrO  RAN, 1966, pp. 239-248. (In Russ.).

11. Frolov Yu.A., Ptichnikov A.G., Barinov V.Kh., Gorshkov N.N.  Method of calculating and analyzing the factors that affect the  coke consumption and productivity of blast furnaces at the Chelyabinsk Metallurgical Combine. Metallurgist. 2013, vol. 57, no. 3-4,  pp.  183–193.

12. Tir’on K., Suvorov M., Shmit L. On integrated approach for pulverized coal fuel blowing into blast furnaces. In: Domennoe proiz vodstvo – XXI vek: trudy mezhdunarodnogo kongressa domenshchikov [Blast  furnace production – 21th century: Papers of Int. Congress of Blast  Furnacemen]. Moscow: 2014, pp. 80–91. (In Russ.).

13. Lyalyuk V.P., Tovarovskii I.G., Demchuk D.A. etc. Koksozameshchayushchie tekhnologii v domennoi plavke [Coke-substituting  technologies in blast furnace smelting]. Dnepropetrovsk: Porogi,  2006, 276 p. (In Russ.).

14. Gotlib A.D. Domennyi protsess [Blast furnace process]. Moscow:  Metallurgiya, 1966, 503 p. (In Russ.). 

15. Filatov S.V., Zagainov S.A., Gileva L.Yu., Kurunov I.F., Titov V.N.  Influence of elevated pressure on blast-furnace performance. Steel in Traslation. 2015, vol. 45, no. 4, pp. 275–278.

16. Mishchenko I.M., Kuzin A.V . Quality of coke and other important  factors for ensuring effective smelting of cast iron using pulverized  coal. Chernaya metallurgiya. Byul. in­ta “Chermetinformatsiya”. 2014, no. 5, pp. 26–32. (In Russ.).

17. Kitaev B.I., Yaroshenko Yu.G., Lazarev B.D. Teploobmen v domennoi pechi [Heat transfer in blast furnace]. Moscow: Metallurgiya,  1966, 355 p. (In Russ.).

18. Kitaev B.I., Timofeev V.N., Bokovikov B.A. etc. Teplo­ i massoobmen v plotnom sloe [Heat and mass transfer in a dense layer]. Moscow: Metallurgiya, 1972, 432 p. (In Russ.). (In Russ.).

19. Kitaev B.I., Yaroshenko Yu.G., Sukhanov E.L. etc. Teplotekhnika domennogo protsessa [Thermal engineering of blast furnace process]. Moscow: Metallurgiya, 1978, 248 p. (In Russ.).

20. Spirin N.A., Shvydkii V.S., Lobanov V.I., Lavrov V.V. Vvedenie v sistemnyi analiz teplofizicheskikh protsessov metallurgii [Introduction to the system analysis of thermophysical processes of metallurgy]. Ekaterinburg: UGTU, 1999, 205 p. (In Russ.).

21. Katunin V.V., Petrakova T.M., Ivanova I.M. Main performance indicators of the Russian ferrous metallurgy in 2015. Chernaya metallurgiya. Byul. in­ta “Chermetinformatsiya”. 2016, no. 3, pp. 3–24.  (In Russ.).