Evaluation of the Surface Tension of Ternary Silicate Melts Containing Al2O3, CaO, FeO, MgO or MnO

Abstract

A thermodynamic model for determining the surface tension of molten ionic mixtures derived by considering the ionic radii was extended to ternary silicate melts. The composition dependence of the surface tensions of molten silicates in ternary systems, was reproduced by the present model using surface tension information, the molar volumes of pure oxides, as well as the anionic and cationic radii of the component oxides in the system.

Evaluating Composition Dependence in Surface Tension of Si–Ca–Na–O–F Reciprocal Oxide–fluoride Melts

“…The experimental results of the slag surface tension were compared with the predicted values obtained using the semiempirical model proposed by Tanaka et al [8][9][10][11] This model requires ionic radii, molar volume, and surface tension data of pure components to calculate the surface tension of ionic melts including molten slag. In this study, these parameters were collected in the same way as in Ref.…”

“…In this study, these parameters were collected in the same way as in Ref. 11), where ionic radii data were from Shannon,19) molar volume data were from Mills and Keene, 20) and the recommended surface tension values of pure components were taken from Nakamoto et al 9,10) Figure 6 compares the experimental and predicted surface tension of SiO 2 -CaO-NaF slag (B1-B3 in Table 1) and demonstrates that good agreement is achieved when experimental uncertainties are taken into account. Figure 7 compares the experimental and predicted surface tension of the SiO 2 -CaO-CaF 2 -Na 2 O slag (A1-A3 in Table 1).…”

“…Using FactSage thermodynamic computation software and the latest thermodynamic databases, 13) the standard Gibbs energy change of the above reaction was found to be negative. Since pure NaF melt shows a very low surface tension compared with other molten pure components, 9,10,14,15) NaF formation according to the reciprocal reaction (1) may affect the composition dependence of the surface tension of the Si-Ca-Na-O-F melt.…”

“…[4][5][6][7] Recently, Tanaka et al derived a semi-empirical model to estimate the surface tension of molten ionic mixtures by taking into account the ionic radii ratios of cations and anions, 8) and this model was applied successfully to binary common alkali-halide systems and molten oxide slags. [8][9][10][11] However, uncertainties still exist regarding the surface tension of reciprocal ionic mixtures such as oxide-fluoride melts, in particular its composition dependence.…”

Surface Tension Measurements of Calcia-Alumina Slags: A Comparison of Dynamic Methods

“…[2] However, considerable amounts of experimental data have been collected for different systems at various compositions and temperatures; see for example the review by Mills and Keene. [3] From the analytical point of view, predictive models have been developed, [4][5][6][7] nevertheless, there often seem to be discrepancies between predicted values and experimental data which underline the need for a more reliable experimental database. In principle, a broad variety of surface tension measurement techniques is available.…”