Utilization of multiphase fluxes for the dephosphorization of hot metal

Kimihisa Ito, Masahiro Terasawa

    Research output: Contribution to journalArticle

    1 Citation (Scopus)

    Abstract

    Although steelmaking slags have been usually treated and studied as homogeneous liquids, they are actually mixtures of a liquid and solids in practical processes. CaO-based refining flux that does not contain fluxing agents such as CaF2 inevitably forms a heterogeneous slag in normal cases, and hence, it is defined as a "multiphase flux." Efficient utilization of this type of flux would decrease the consumption of resources and the emission of CO2, and thus, would reduce the load on the environment. Metallurgical studies on multiphase fluxes are limited, however, the physical chemistry and reaction kinetics of the same are important for the development of advanced refining processes. The reaction mechanism of dephosphorization using a multiphase flux at hot metal temperatures was investigated in this study. The reaction of a P2O5- containing slag with solid CaO was studied by immersing a CaO disc in the slag. A CaO-FeO layer was formed near the interface, and a solid solution of Ca 2SiO4-Ca3P2O8 was observed in this layer. The Fe-P-Si alloy reacted with calcium ferrites at 1673 K, and the samples were analysed by XMA. The same solid solution (Ca 2SiO4-Ca3P2O8) was observed near the slag-metal interface, which suggests that the phosphorus removed from the metal gets concentrated in the solid phase. The experimental results were reproduced with a kinetic simulation model. The simulation program was also applied to the reaction of the CaO-FeO droplet in a hot-metal bath.

    Original languageEnglish
    Pages (from-to)733-736
    Number of pages4
    JournalSteel Research International
    Volume80
    Issue number10
    Publication statusPublished - 2009

    Fingerprint

    slags
    Slags
    Metals
    Fluxes
    phosphorus pentoxide
    metals
    refining
    Refining
    Solid solutions
    solid solutions
    Physical chemistry
    physical chemistry
    Ferrites
    Steelmaking
    kinetics
    Liquids
    liquids
    Polysilicon
    Reaction kinetics
    Phosphorus

    Keywords

    • Dephosphorization
    • Hot metal
    • Multi-phase flux
    • Slag

    ASJC Scopus subject areas

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

    Cite this

    Utilization of multiphase fluxes for the dephosphorization of hot metal. / Ito, Kimihisa; Terasawa, Masahiro.

    In: Steel Research International, Vol. 80, No. 10, 2009, p. 733-736.

    Research output: Contribution to journalArticle

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