In-situ Observation of Bubble Through Each Interface of a KCl Aqueous Solution / Hg and a Molten Salt / Sn by Controlling Applied Potential

Abstract

In-situ observation of Ar bubble through each interface of a KCl aqueous solution / Hg and a molten salt / liquid Sn were conducted by controlling applied potential in order to simulate the behavior of bubble at interface of slag / metal. In a KCl aqueous solution, the rate of Ar bubble through each interface of a KCl aqueous solution / Hg became slow with applying −2.0 V at 298 K. This behavior caused by the stabilization of interface with deceasing the interfacial tension, and a lot of Hg droplet formed by rupture of bubble was drawn into Hg phase under the interface in seconds. In a LiCl-KCl eutectic melt, the interfacial tension of the molten salt / liquid Sn were measured by the in-site observation of contact angle with applying −2.0~0 V(vs. Ag⁺/Ag) at 793 K. The behavior of interfacial tension corresponded to typical electrocapillary curve. The interfacial tension at −0.75 V became highest, 310 (dyn/cm = mN/m), and the interfacial tension at −2.0, 0 V became lowest, 210 (dyn/cm = mN/m), and the Ar bubble through the interface became slowest with applying at −2.0 V. This behavior was same as that through the interface of KCl aqueous solution / Hg.