LIQUID-LIQUID INTERFACIAL-TENSION MEASUREMENTS APPLIED TO MOLTEN AL-HALIDE SYSTEMS

After a brief review of the theory concerning the formation of a meniscus by a flat, vertical blade, the equipment and testing procedure used are described. The value of the interfacial tension between molten aluminium and flux (made of the equimolar mixture, NaCl-KCl) at 740° C is γ=792 dyn cm-1. The influence of the addition of various fluorides (NaF, KF, LiF, Na3AlF6) to the NaCl-KCl flux on the interfacial tension value between aluminium and flux was then studied. For a given molar fraction of salt addition, the interfacial tension decreases when the resulting effect increases in the following order: Na3AlF6<LiF<NaF<KF. The results obtained with the addition of Na3AlF6 and NaF match those obtained previously by Kurdyumov et al. © 1979 Chapman and Hall Ltd.