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Kinetics of Scrap Melting in Iron–Carbon Bath

  • Mengke Liu
  • Guojun MaEmail author
  • Xiang Zhang
Conference paper
  • 412 Downloads
Part of the The Minerals, Metals & Materials Series book series (MMMS)

Abstract

The melting kinetics of scrap is a limiting factor in controlling the temperature trajectory and scrap ratio of BOF process as well as the energy consumption and productivity of EAF steelmaking. Prediction of the melting rate of scrap, the mass transfer coefficient of carbon, and heat transfer coefficient between the melt and scrap can provide a theoretical basis for the process modeling of BOF and EAF. In this paper, the interface between melt and scrap in melting process is analyzed, and the moving boundary layer concept is optimized. Through Fick’s law and Fourier equation state, combined with the heat and mass balance of moving interface, the theoretical analysis model of scrap melting is established and programmed. The effects of bath temperature on the melting behavior of scrap in the liquid melt are studied. The results show that as the bath temperature increases, the formation time and maximum thickness of solidified layer decrease; furthermore, the time to reach the final stable melting rate and the initial heat transfer coefficient decreases. However, the final stable melting rate increases; moreover, the final stable heat transfer coefficient and mass transfer coefficient initially increase and then decrease.

Keywords

Scrap melting Kinetics Moving boundary layer Heat transfer Mass transfer 

Nomenclature

Cb

Carbon content of liquid melt (wt%)

Ci

Carbon concentration corresponding to the liquidus at Tm (wt%)

Csc

Carbon content of the parent scrap (wt%)

Cs

Carbon concentration corresponding to the solidus at Tm (wt%)

CP

The specific heat of the scrap (J/kg/K)

D

The diffusion coefficient for mass transfer inside the solid scrap (m2/s)

DC

The diffusion coefficient for mass transfer in the liquid melt (m2/s)

h

The heat transfer coefficient of the moving boundary (W/m2/K)

h0

The heat transfer coefficient for non-moving boundary (W/m2/K)

k

The thermal conductivity of liquid melt (W/m/K)

R

Scrap characteristic length (m)

v

The moving velocity of the interface/melting rate of scrap (m/s)

ρ

Mass density of the solid scrap (kg/m3)

Tb

Bath temperature (K)

Tm

Interface temperature (K)

T1

Center line temperature of scrap (K)

Hf

The latent heat of melting (J/kg)

β

The mass transfer coefficient for the moving boundary (m/s)

β0

The mass transfer coefficient for non-moving boundary (m/s)

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Copyright information

© The Minerals, Metals & Materials Society 2020

Authors and Affiliations

  1. 1.Key Laboratory for Ferrous Metallurgy and Resources Utilization of Ministry of EducationWuhan University of Science and TechnologyHubei WuhanPeople’s Republic of China
  2. 2.Hubei Provincial Key Laboratory of New Processes of Ironmaking and SteelmakingWuhan University of Science and TechnologyHubei WuhanPeople’s Republic of China
  3. 3.State Key Laboratory of Refractories and MetallurgyWuhan University of Science and TechnologyHubei WuhanPeople’s Republic of China

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