Browsing by Author "Lim, Sung-Ki"

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    Physico-chemical investigation of the behavior of sodium in the float glass process Part 1. Distribution of sodium and tin between the glass melt and the bath of molten tin
    (Offenbach : Verlag der Deutschen Glastechnischen Gesellschaft, 1989) Müller, Franz; Lim, Sung-Ki; Gebhardt, Franz; Küstner, Dieter
    The chemical equilibrium between a soda-lime-silica melt typifying float glass melts and molten tin is considered for the conditions prevailing in the float glass process. A consideration of the thermodynamic stability of the relevant oxides of the glass melt reveals that CaO, MgO, AI2O3, and SiO2 are not involved in the heterogeneous reactions occurring in the molten glass/liquid tin system, whereas sodium may be transferred from the glass melt to the metal phase, and tin may be oxidized and dissolved as SnO and SnO2 in the glass melt. Thermochemical information pertaining to the reaction of sodium and tin in the molten glass/liquid tin system has been compiled from the literature. From this data basis, the equilibrium distribution of sodium and tin between the glass melt and the liquid tin is calculated. The results are presented in the form of equilibrium diagrams. Additionally, it is shown that the exchange reactions Na2O(glass melt) + Sn(metal bath) = SnO(glass melt) + 2 Na(metal bath) and 2 Na2O(glass melt) + Sn(metal bath) = SnO2(glass melt) + 4 Na(metal bath) may be considered as electrochemical processes occurring simultaneously and statistically disordered with respect to time and reaction site at the molten glass/liquid tin interface. Certain indications suggest that the rate of these reactions is controlled essentially by the transport of the reaction partners.
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    Physico-chemical investigation of the behavior of sodium in the float glass process Part 2. Reactions of sodium and oxygen dissolved in the bath of molten tin
    (Offenbach : Verlag der Deutschen Glastechnischen Gesellschaft, 1989) Müller, Franz; Lim, Sung-Ki; Gebhardt, Franz; Küstner, Dieter
    The chemical reactions which may be evoked by the Joint action of sodium and oxygen dissolved in the molten tin of the float bath are discussed from a thermodynamic point of view. It is shown that the prevalent thermodynamic conditions preclude precipitation of Na2O from the tin melt at decreasing temperatures, but admit chemical reactions of sodium and oxygen with the refractory material (burnt fire clay). The thermodynamic conditions for the sodium and oxygen transfer from the tin bath to the refractory lining are specified, and the reactions occurring in the lining by the incorporation of Na2O are considered. The results indicate that large amounts of Na2O can be incorporated in the refractory material. Since under the prevailing conditions the sodium and oxygen contents of the tin melt are very small, however, the transport of large amounts of Na2O from the glass melt to the refractory lining can only take place over a long time period.