The density of molten zinc-bismuth alloys was measured at the temperature range of 723 to 903 K by using a modified picnometric method and then their surface tension by the capillary depression and maximum bubble pressure methods. Values of the density obtained showed a similar trend to slightly deviate positively from the additivity in all cases. The composition dependence of the surface tension was irregular and resembled the body activity curves to a large extent.

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By means of the TIE method, the activities for silver-antimony, silver-lead and silver-tin binary molten alloys were measurements except for some cases. Comparing the activities measured for the more noble component of the silver-lead system with the values estimated from its phase diagram, it was confirmed that the TIE method is capable of yielding accurate results.From the activities of both components for the silver-tin system, the modified equation of Gibbs-Duhem relation was found to be reliable.It was also found that the activity curves for the silver-base alloy systems took wavy forms which changed in a series.

Synopsis:Measurements have been done on the rates of carbon and oxygen transfer between CO-CO2 mixtures and levitated iron droplet. Supposing that the mass transfers between two phases determine the total reaction rate, the kinetics of this reaction has been considered. Results obtained here are as follows: Type of reaction at the initial period is different from that at the later period. At the initial, a simple absorption of gas takes place independently of the composition of gas mixture. The rate is controlled by the mass transfer at the melt side. At the later period, decarburization or carburization proceeds and the countercurrent flow of CO and CO2 in gas phase controls the total rate. It is concluded that whether iron is melted by the levitation technique or in usual crucibles, there is no essential differences in the mechanism of reaction, and that one or both of the mass transfers at gas and melt determines the total rate of reaction according to the experimental conditions such as the flow rate and composition of gas, mass and violency of stirring of melt. Re-examinations have been done for the previous investigations which proposed the interfacial chemical reaction mechanism as the rate determining step.

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