Thermodynamic analysis for the refining ability of salt flux for aluminum recycling

Takehito Hiraki, Takahiro Miki, Kenichi Nakajima, Kazuyo Matsubae, Shinichiro Nakamura, Tetsuya Nagasaka

    Research output: Contribution to journalArticle

    12 Citations (Scopus)


    The removability of impurities during the aluminum remelting process by oxidation was previously investigated by our research group. In the present work, alternative impurity removal with chlorination has been evaluated by thermodynamic analysis. For 43 different elements, equilibrium distribution ratios among metal, chloride flux and oxide slag phases in the aluminum remelting process were calculated by assuming the binary systems of aluminum and an impurity element. It was found that the removability of impurities isn't significantly affected by process parameters such as chloride partial pressure, temperature and flux composition. It was shown that Ho, Dy, Li, La, Mg, Gd, Ce, Yb, Ca and Sr can be potentially eliminated into flux by chlorination from the remelted aluminum. Chlorination and oxidation are not effective to remove other impurities from the melting aluminum, due to the limited parameters which can be controlled during the remelting process. It follows that a proper management of aluminum scrap such as sorting based on the composition of the products is important for sustainable aluminum recycling.

    Original languageEnglish
    Pages (from-to)5543-5553
    Number of pages11
    Issue number8
    Publication statusPublished - 2014



    • Impurity removal
    • Recycling of aluminum
    • Refining ability
    • Salt flux
    • Thermodynamic analysis

    ASJC Scopus subject areas

    • Materials Science(all)

    Cite this

    Hiraki, T., Miki, T., Nakajima, K., Matsubae, K., Nakamura, S., & Nagasaka, T. (2014). Thermodynamic analysis for the refining ability of salt flux for aluminum recycling. Materials, 7(8), 5543-5553.