Effect of CaO/SiO2 ratio on surface tension of CaO-SiO2-Al2O3-MgO melts

Sohei Sukenaga, Tomoyuki Higo, Hiroyuki Shibata, Noritaka Saito, Kunihiko Nakashima

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    14 Citations (Scopus)


    The effect of the CaO/SiO2 molar ratio on the surface tension of calcium aluminosilicate melts containing magnesia (CaO-SiO2-Al2O3-MgO) has been explored using a ring method at 1 723-1 823 K; the Al2O3 and MgO contents were approximately 12 and 8 mol%, respectively. The CaO/SiO2 molar ratio of the samples was varied in the range of 1.1-1.7. The surface tension of the CaO-SiO2-Al2O3-MgO system simultaneously increased upon increasing the CaO/SiO2 molar ratio. The present data were compared with the surface tension of the binary calcium silicate (CaO-SiO2) and the ternary calcium aluminosilicate (CaO-SiO2-Al2O3) melts reported in the literatures. The surface tension of the present CaO-SiO2-Al2O3-MgO melts was higher than those of the binary calcium silicate melts and slightly lower than those of the ternary calcium aluminosilicate melts when the polymerization degrees of the melts were comparable. The change in the surface tension was considered from the viewpoint of the local structure of oxygen atoms at the melt surface. Oxygen atoms, which require higher coordination by cations in the bulk, may tend to lose their neighbors at the surface of the melts, which can result in the formation of unsatisfied bonds at the surface. An increase in the number of unsatisfied bonds can yield an increase in the surface tension.

    Original languageEnglish
    Pages (from-to)1299-1304
    Number of pages6
    JournalIsij International
    Issue number6
    Publication statusPublished - 2015


    • Blast-furnace-type slag
    • Mg-Ca aluminosilicate melts
    • Negative charge on oxygen atoms
    • Polymerization degree
    • Surface tension

    ASJC Scopus subject areas

    • Mechanics of Materials
    • Mechanical Engineering
    • Metals and Alloys
    • Materials Chemistry

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