발간논문

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Tensile properties of aluminum which were corroded in H₂O during reactor irradiation or without irradiation were investigated. Through corrosion the yield strength σ_0.2 was increased and σ_0.8 was more increased than σ_0.2. The higher the treated annealing temperature before the corrosion, the greater was the effect. Tensile strength σB was increased only a little after the corrosion. After the corrosion (σB-σ_0.2)/σB and percentage elongation δwas decreased. All these effects were greater by the not irradiated corrosion samples than the irradiated.

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In a stationary reducing atmosphere, H₂or CO, fifteen Korean iron ores were reduced at the temperatures ranging from 500℃ to 1050℃ to find out the effect of temperature on the reduction degree of iron ores. Generally an initial reduction rate is accelerated at the higher temperature. Most of the Korean magnetite, however, reach to the critical reduction degree at the range between 650℃ and 900℃. Temperature, on the other hand, has a minor effect on the critical reduction degree of hematite and siderite. It is found that reduction rate of H₂gas is 3∼4 times higher than that of CO at the magnetite reduction, and that initial reduction rate is reciprocal to the size of ore. Two types of reduction equation are available in accordance with the degree of reduction rate. At higher reduction rate, namely at an initial stage of reduction, for example. and at lower reduction rate, As a result of this investigation, the following formula is presented for the representation of reducibility in terms of "reducibility index."

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Crude bismuth from a smelter was electrolyzed in fluosilicate and chloride baths in order to assure 99.99% purity. Both processes can be utilized for commercial application with adherent cathode deposit and almost theoretical current efficiency for this purpose, with the exception of the problem of separation of silver, for which the fluosilicate bath was, preferable. With high grade of anode bismuth, high purity cathode deposits was obtained in addition to which, the electrolysis can be carried out free of operational troubles with longer life of electrolyte. The effect of addition agents, e.g. glue, was observed favorably in fluosilicate bath, but not in chloride solution. The typical operating data are summerized as follows;

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