Advertisement

Transactions of the Indian Institute of Metals

, Volume 72, Issue 2, pp 455–473 | Cite as

Steady-State Materials and Enthalpy Balance: Applications to Ferroalloy Production and Industrial-Scale Validation

  • Ankur Agnihotri
  • Prince K. Singh
  • Rishikesh Mishra
  • Dipak MazumdarEmail author
Technical Paper

Abstract

Steady-state material and enthalpy balance models for ferroalloy production in submerged arc furnace (SAF) have been developed. Two different types of ferroalloys, used commonly in the steel industry, namely high-carbon ferromanganese and high-carbon silicomanganese, were considered, and appropriate mass and energy conservation expressions were developed considering input, output and losses of various entities to/from two different 33 MVA SAFs. Several plant-specific parameters, such as material loss due to handling, off-gases, hot metal, slag and off-gas temperatures as well as heat losses from the SAFs, were incorporated in order to develop a predictive material and energy balance framework. Embodying types of feed materials, their composition and amount together with product composition along with relevant thermodynamic data, and amount of metal and slag produced in the two processes were estimated. Similarly, external power required to produce a given amount of ferroalloy was calculated by coupling material balance with an appropriate energy balance calculation scheme. It was demonstrated that estimates of hot metal production, slag generation and external electrical energy requirement were in reasonable agreement with industrial operating data. A graphical user interface was also developed to carry out material and energy balance calculations efficiently.

Keywords

Ferroalloy production Material and heat balance Industrial-scale validation 

List of symbols

[aMn]

Activity of manganese in the hot metal/ferroalloy (ferromanganese or silicomanganese)

(aMnO)

Activity of MnO in slag

D

Thermal demand per mole of product Mn (kJ/kg-mol Mn)

EExt.

External electrical energy supply per mole of Mn (kJ/kg-mol Mn)

H298

Enthalpy at 1 atm. pressure and 298 K

H298f

Heat of formation at 298 K

H1768, i

Enthalpy content of dissolved species ‘i’ in a ferroalloy at 1768 K

L

Cooling losses per mole of product Mn (kJ/kg-mol Mn)

Mi

Wt% Mn or wt% Si in an ore ‘i

nCOg

Number of kg-moles of CO in the off-gas per kg-mole of product Mn

nCOg

Number of kg-moles of CO2 in the off-gas per kg-mole of product Mn

nMgO

Number of kg-moles of MgO per kg-mole of product Mn

nCaO

Number of kg-moles of CaCO3 per kg-mole of product Mn

\(\mathop n\nolimits_{{{\text{SiO}}_{2} }}\)

Number of kg-moles of SiO2 per kg-mole of product Mn

nMnO

Number of kg-moles of MnO in slag per kg-mole of product Mn

nCA

Number of kg-moles of carbon (the active carbon) in the off-gas per kg-mole of product Mn

nCi

Number of kg-moles of carbon in the charge per kg-mole of Mn

p

Wt% Mn or wt% Si in hot metal

q

Wt% MnO or wt% SiO2 in slag

S

Supply of enthalpy per kg-mole of product Mn (kJ/kg-mol Mn)

S

Wt% MnO in high-MnO slag generated during HCFeMn production

Wore, i

Weight of ore i in the charge (kg)

WHMnO

Weight of high-MnO slag (kg)

Wslag

Weight of slag generated during FeMn or SiMn production (kg)

WFeMn

Weight of hot metal (ferromanganese) produced, kg

WSiMn

Weight of hot metal (silicomanganese) produced (kg)

(C/Mn)HM

Number of kg-moles of carbon per kg-mole of Mn in hot metal

(Fe/Mn)HM

Number of kg-moles of Fe per kg-mole of Mn in hot metal

(Si/Mn)HM

Number of kg-moles of silicon per kg-mole of Mn in hot metal

(P/Mn)HM

Number of kg-moles of phosphorous per kg-mole of Mn in hot metal

γMnO

Activity coefficient of MnO in slag during ferromanganese production

References

  1. 1.
    Pitts A, Iron and Steel Technology, 10 (2015) p 93.Google Scholar
  2. 2.
    Batra NK, Ironmaking and Steelmaking, 30 (2003) p 399.CrossRefGoogle Scholar
  3. 3.
    Pistorius PC, The Journal of the South African Institute of Mining and metallurgy, 2 (2002) p 33.Google Scholar
  4. 4.
    Sithole NA, Erwee MW and Steenkamp JD, 3rd Young Professionals conference, The South African Institute of Mining and Metallurgy, Pretoria (2017) p 481.Google Scholar
  5. 5.
    Olsen SE, Tansgstad M and Landstad T, Production of Manganese Ferroalloys, Academic Press (2007).Google Scholar
  6. 6.
    Ghosh A and Chatterjee A, Principles and Practices in Iron and Steelmaking, Prentice Hall, India (2008).Google Scholar
  7. 7.
    Engh TA, Principles of Metal Refining, Oxford Science Publication, Oxford University Press Inc., New York (1992).Google Scholar
  8. 8.
    Peacey JG and Davenport WG, Iron Blast Furnaces: theory and Practice, Pergamon Press (1978).Google Scholar
  9. 9.
    Mazumdar D, A First Course in Iron and Steelmaking, University Press, Hyderabad, India (2015).Google Scholar
  10. 10.
    Eom CH, Lee SH, Park JG, Park JH and Min DJ, ISIJ International, 56 (2016) p 37.Google Scholar
  11. 11.
    Engh TA, Principles of Metal Refining, Oxford Science Publications, Oxford University Press, New York (2002) p 417.Google Scholar

Copyright information

© The Indian Institute of Metals - IIM 2018

Authors and Affiliations

  • Ankur Agnihotri
    • 1
    • 2
  • Prince K. Singh
    • 1
  • Rishikesh Mishra
    • 1
  • Dipak Mazumdar
    • 1
    Email author
  1. 1.Department of Materials Science and EngineeringIndian Institute of TechnologyKanpurIndia
  2. 2.Vardhman Special Steels LimitedLudhianaIndia

Personalised recommendations