ABOUT ELECTROCHEMICAL REACTIONS BETWEEN A BAO-RICH AND A PBO-RICH MELT, SHORT-CIRCUITED BY PLATINUM

The ''Reboiling'' effect is well known. If glass fragments with very d ifferent alkali oxide contents are remelted together in a platinum cru cible, there can take place a local generation of gas bubbles. Similar effects were observed in a study of the Ba/Pb interdiffusion kinetics between two melts with the same molar composition (MO)(33.3)(B2O3)(66 .7-s)(EO(2))(s) (M = Ba and Pb, resp.; E = Ge, s = 0.15 and Si, s = 0. 10, resp.). The thermodynamic potential of the melts and the electroch emical mobilities of the ions Ba2+ and Pb2+ will be discussed in conne ction with the above described phenomenon. At 700 degrees C the Ba/Pb ion-exchange in the ratio 1/1 shows a dominant viscosity-controlling. The formation of gas bubbles is caused by reactions, influenced by the experimental arrangement and by the melt compositions.