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Metallurgical and Materials Transactions B

, Volume 50, Issue 5, pp 2377–2388 | Cite as

Improving the Modeling of Slag and Steel Bath Chemistry in an Electric Arc Furnace Process Model

  • Thomas HayEmail author
  • Alexander Reimann
  • Thomas Echterhof
Article
  • 218 Downloads

Abstract

An improvement to the thermochemical module of the electric arc furnace (EAF) process model developed by Meier based on the work of Logar, Dovžan, and Škrjanc is presented. Different models for the calculation of activities in melt and slag are implemented, and separate reaction zones are defined for the interaction of slag and melt, the injection of oxygen, and the injection of carbon. For each zone, equilibrium compositions and reaction rates are calculated. Furthermore, diffusion of species is considered as a rate-limiting factor in reactions between slag and melt, and diffusion rates are calculated from the bulk melt to the reaction zone where reactions with the slag take place. Oxygen and sulfur dissolved in the melt and CaS in the slag are added as new species not previously considered in the EAF model. The treatment of carbon is revised to reduce model complexity and improve accuracy. The improved model is validated using extensive data from an industrial EAF, and results are compared to measured data as well as results obtained with the unmodified model. The different models for the determination of thermodynamic activities and their impacts on the duration of the simulation as well as its results are evaluated.

Abbreviations

EAF

Electric arc furnace

RSM

Regular solution model

UIP

Unified interaction parameter formalism

lSc

Melt zone

lSl

Slag zone

sSc

Solid scrap zone

sSl

Solid slag (charged slag formers) zone

wall

Furnace walls

roof

Furnace roof

gas

Gas zone

arc

Electric arc(s)

el

Electrode(s)

pks

Palm kernel shells

WIPF

Wagner interaction parameter formalism

Greek Letters

α

Interaction parameter RSM

ε

Interaction parameter UIP/WIPF (molar)

ν

Stoichiometric coefficient

ɣ

Activity coefficient (molar)

Φ

Stoichiometric oxygen mass per mass of reacting element

Latin Letters

a

Activity

eij

Interaction parameter UIP/WIPF (mass pct)

f

Activity coefficient (mass pct)

ΔG0

Free enthalpy of reaction

HEAF

Height of furnace

HScrap

Height of scrap inside furnace (at the wall)

I

Conversion factor RSM

Keq

Equilibrium constant

k

Equilibrium correction factor

kddiff/react

Ratio of diffusion to reaction rates

kd

Reaction parameter

kconv-gas

Fraction of lanced carbon oxidized by carrier gas (air)

kloss

Fraction of injected carbon not reacting (lost with off-gas)

\( k_{{\text{C-inj-CO}}_{2}}\)

Fraction of injected carbon reacting further to CO2

\( k_{{{\text{FeO-O}}_{2} }} \)

Reaction parameter for oxidation of scrap with O2 from atmosphere

\( k_{{{\text{O-inj-diss}}}} \)

Fraction of injected oxygen dissolving in melt

m

Mass

\( \dot{m}_{{{\text{C-res-inj}}}} \)

Mass flow Carbon from reservoir becoming available for slag reactions

\( \dot{m}_{{{\text{C-inj-temp}}}} \)

Mass injected Carbon from input data

\( \dot{m}_{{{\text{C-inj}}}} \)

Mass flow of carbon for slag reactions at carbon injection site

\( \dot{m}_{i}^{j} \)

Mass flow of element i in reaction zone j from chemical reaction

\( \dot{m}_{\Delta } \)

Mass flow to maintain mass of melt in interface zone

\( \dot{m}_{\text{FeO}}^{\text{atm}} \)

Mass flow of FeO from oxidation of scrap with O2 from atmosphere

pCO

CO partial pressure

R

Gas constant

T

Temperature

w

Mass fraction (pct)

X

Molar fraction

X

Cation fraction

Subscripts and Superscripts

Slag

Slag zone

Diffusion

Mass flows resulting from diffusion

bulk

Bulk melt zone

interface

Interface zone

total

sum of all mass flows in interface zone

oxide

Oxide in slag zone

eq

At equilibrium

C-inj

Carbon injection zone

O-inj

Oxygen injection zone

Slagformer

Charged slag formers (chalk, dolomite)

Notes

References

  1. 1.
    P. Nyssen, G. Monfort, J. L. Junque, M. Brimmeyer, P. Hubsch, J. C. Baumert: STEELSIM Conference, Graz/Seggau, Austria, 2007Google Scholar
  2. 2.
    A. Cameron: Steel Times, 1999, vol. 227, pp. 7-10Google Scholar
  3. 3.
    M. Hofer, P. L. Steger, J. Lehner, W. Gebert: Iron Steel Eng., 1997, vol. 40, pp. 35-42Google Scholar
  4. 4.
    A. Linninger, M. Hofer, A. Patuzzi: Iron Steel Eng., 1995, vol. 72, pp. 43-53Google Scholar
  5. 5.
    S. Matson, W. F. Ramirez: Electric Furnace Conference, 57, Warrendale (Pennsylvania, USA), 1999Google Scholar
  6. 6.
    S. A. Matson, W. F. Ramirez: Electric Furnace Conference, 55, Chicago (Illinois, USA), 1997Google Scholar
  7. 7.
    S. A. Matson, W. F. Ramirez, P. Safe: Electric Furnace Conference, 56, New Orleans (Louisiana, USA), 1998Google Scholar
  8. 8.
    J.G. Bekker: Master Thesis, University of Pretoria, Pretoria, South Africa, 1998Google Scholar
  9. 9.
    J. G. Bekker, I. K. Craig, P. C. Pistorius: ISIJ Int., 1999, vol. 39, pp. 23-32CrossRefGoogle Scholar
  10. 10.
    M. Modigell, A. Traebert, P. Monheim: AISE Annual Convention & Mini-Expo, 2001Google Scholar
  11. 11.
    A. Traebert, M. Modigell, P. Monheim, K. Hack: Scand. J. Metall., 1999, vol. 28, pp. 285-290Google Scholar
  12. 12.
    R. D. Morales, A. N. Conejo, H. H. Rodriguez: Metall. Mater. Trans. B, 2002, vol. 33, pp. 187-199CrossRefGoogle Scholar
  13. 13.
    R. D. Morales, H. Rodríguez-Hernández, A. N. Conejo: ISIJ Int., 2001, vol. 41, pp. 426-436CrossRefGoogle Scholar
  14. 14.
    R. D. M. MacRosty, C. L. E. Swartz: Ind. Eng. Chem. Res., 2005, vol. 44, pp. 8067-8083CrossRefGoogle Scholar
  15. 15.
    R. D. M. MacRosty, C. L. E. Swartz: AIChE J., 2007, vol. 53, pp. 640-653CrossRefGoogle Scholar
  16. 16.
    A. Fathi, Y. Saboohi, I. Škrjanc, V. Logar: Steel Res. Int., 2017, vol. 83, p. 1600083CrossRefGoogle Scholar
  17. 17.
    T. Meier, K. Gandt, T. Hay, T. Echterhof: Steel Res. Int., 2018, vol. 89, p. 1700487CrossRefGoogle Scholar
  18. 18.
    V. Logar, D. Dovžan, I. Škrjanc: ISIJ Int., 2012, vol. 52, pp. 402-412CrossRefGoogle Scholar
  19. 19.
    V. Logar, D. Dovžan, I. Škrjanc: ISIJ Int., 2012, vol. 52, pp. 413-423CrossRefGoogle Scholar
  20. 20.
    V. Logar, D. Dovžan, I. Škrjanc: ISIJ Int., 2011, vol. 51, pp. 382-391CrossRefGoogle Scholar
  21. 21.
    V. Logar, I. Škrjanc: ISIJ Int., 2012, vol. 52, pp. 1225-1232CrossRefGoogle Scholar
  22. 22.
    T. Meier: Modellierung und Simulation des Elektrolichtbogenofens, Mainz, Aachen, Germany, 2016Google Scholar
  23. 23.
    T. Meier, K. Gandt, T. Echterhof, H. Pfeifer: Metall. Mater. Trans. B, 2017, vol. 48, pp. 3329-3344CrossRefGoogle Scholar
  24. 24.
    T. Meier, T. Hay, T. Echterhof, H. Pfeifer, T. Rekersdrees, L. Schlinge, S. Elsabagh, H. Schliephake: Steel Res. Int., 2017, vol. 88, p. 1600458CrossRefGoogle Scholar
  25. 25.
    T. Meier, V. Logar, T. Echterhof, Š. Igor, H. Pfeifer: Steel Res. Int., 2015, vol. 86Google Scholar
  26. 26.
    A. Fathi, Y. Saboohi, I. Škrjanc, V. Logar: ISIJ Int., 2015, vol. 55, pp. 1353-1360CrossRefGoogle Scholar
  27. 27.
    J. In-Ho, Calphad, 2010, vol. 34, pp. 332-362CrossRefGoogle Scholar
  28. 28.
    C. W. Bale, A. D. Pelton: Metall. Trans. A, 1990, vol. 21, pp. 1997-2002CrossRefGoogle Scholar
  29. 29.
    J. F. Elliot, M. Gleiser, V. Ramakrishna (1963) Thermochemistry for Steelmaking. Addison-Wesley,Google Scholar
  30. 30.
    S. Ban-Ya: ISIJ Int., 1993, vol. 33, pp. 2-11CrossRefGoogle Scholar
  31. 31.
    H. Gaye, J. Lehmann: 5th International Conference on Molten Slags, Fluxes and Salts, Sidney, Australia, 1997Google Scholar
  32. 32.
    L.C. Oertel, A. Costa e Silva: Calphad, 1999, vol. 23, pp. 379–91Google Scholar
  33. 33.
    K.J. Graham: Doctor of Philosophy Thesis, McMaster University, 2008Google Scholar
  34. 34.
    H. Gaye, J. Lehmann, T. Matsumiya, W. Yamada: 4th International Conference on Molten Slags and Fluxes, Sendai, Japan, 1992Google Scholar
  35. 35.
    E. T. Turkdogan: Fundamentals of steelmaking, Manay, Leeds, GB, 2010Google Scholar
  36. 36.
    A.N. Conejo, F.R. Lara, M. Macias-Hernandez, R.D. Morales: Steel Res. Int., 2007, vol. 78,Google Scholar
  37. 37.
    R. Ding, B. Blanpain, P. T. Jones, P. Wollants: Metall. Mater. Trans. B, 2000, vol. 31B, pp. 197-206CrossRefGoogle Scholar
  38. 38.
    Y. Xiao, L. Holappa: INFACON 7, Trondheim, Norway, 1995Google Scholar
  39. 39.
    B. Deo, R. Boom: Fundamentals of Steelmaking Metallurgy, Prentice Hall International, 1993Google Scholar
  40. 40.
    S. Basu, A. K. Lahiri, S. Seetharaman: ISIJ Int., 2007, vol. 47, pp. 1236-1238CrossRefGoogle Scholar
  41. 41.
    S.K. Choudhary: Ironmak. Steelmak. 2007, vol. 34Google Scholar
  42. 42.
    M.A. Tayeb, R.J. Fruehan, S. Sridhar: Proceedings of the 2013 International Symposouim on Liquid Metal Processing & Casting 2013Google Scholar
  43. 43.
    S. Ueno, Y. Waseda, K. T. Jacob, S. Tamaki: Steel Res., 1988, vol. 59, pp. 474-483CrossRefGoogle Scholar
  44. 44.
    A.V. Alpatov, S.N. Paderin: Russ. Metall. (Engl. Transl.), 2009, vol. 2010, pp. 557–64Google Scholar
  45. 45.
    I.-H. Jung: Metall. Mater. Trans. B, 2004, vol. 35B, pp. 493-507CrossRefGoogle Scholar

Copyright information

© The Minerals, Metals & Materials Society and ASM International 2019

Authors and Affiliations

  • Thomas Hay
    • 1
    Email author
  • Alexander Reimann
    • 1
  • Thomas Echterhof
    • 1
  1. 1.Department of Industrial Furnaces and Heat EngineeringRheinisch-Westfälische Technische Hochschule (RWTH) Aachen UniversityAachenGermany

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