A study on the effect of Na2O on the viscosity for ironmaking slags

H. Kim, W. H. Kim, J. H. Park, D. J. Min

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81 Citations (Scopus)


The viscosities of CaO-SiO2-10wt%MgO-20wt%Al2O 3-Na2O slags (CaO/SiO2=0.8-1.2, wt%Na 2O=0-10) were measured to estimate the effect of Na2O on the viscous behavior at elevated temperatures. The slag viscosity at 1773K decreased with increasing Na2Ocontents, which is observed in a basic oxide component. However, the FT-IR spectroscopic analysis of the slag structure seemed to verify that [AlO4]-tetrahedra depolymerized more readily than [SiO4]-tetrahedra due to ionic charge compensation which has a tendency to be more effective on [AlO4]-tetrahedra. Hence, for the present slag system, the viscosity decreased with additions of Na2O by providing network breaking O2- ions, and the charge balance by Na+ ions independently contributed to the depolymerization of the network structure of the molten slag. In addition, Na2O also lowered the critical temperature (TCR) resulting in a larger temperature difference between the operating temperature (TOP) and T CR, which can enhance operational stability.

Original languageEnglish
Pages (from-to)17-24
Number of pages8
JournalSteel Research International
Issue number1
Publication statusPublished - 2010 Jan

All Science Journal Classification (ASJC) codes

  • Condensed Matter Physics
  • Physical and Theoretical Chemistry
  • Metals and Alloys
  • Materials Chemistry


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