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Basicity Separation of Th, U and Ce from their nitrate solution was investigated under ultrasonic effect. The intensity of the field and wave frequency employed were respectively 2.0-8.2W/㎠ and 400, 1200KC. It was found from the investigation that ultrasonic field considerably improved the separation of Th from U over conventional mechanical stirring. The effect of ultrasonic field intensity on the precipitation curve was such that the precipitation pH shifted as the intensity increased. Hence, a broader precipitation pH range between Th and U was observed when ultrasonic field was applied, i.e. from 0.4 pH unit (mechanical stirring) to 1.3 pH unit (at 4.1W/㎠ of ultrasonic intensity). The effect of wave frequency on the precipitation pH was small but tendency of flocculating the precipitated particles was observed to be noticeable at the high frequency.

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The effect of heating rate and oxide film on copper surface on the dimensional change during sintering Cu-10% Sn compact and possible mechanism for the abnormal expansion near the peritectic temperature (798℃) are suggested. Two kinds of copper powders, reduced powder and oxidized powder, are used in this experiment in order to investigate the effect of oxide film on copper surface on the dimensional change of Cu-Sn transient liquid phase sintering. According to these experimental observation, the dimensional change is strongly depended upon the amount of localized tin-rich liquid phase during sintering. The more localized tin-rich liquid phase result in more dimensional expansion. In the case of specimen which is prepared with oxidized copper powder, the dimensional expansion is smaller than that of specimen prepared with reduced copper powders. It is apparent that the thin film of copper oxide on copper powder makes easy the flowing of tin-rich liquid through the interparticles of copper which may reduce the amount of localized tin-rich phase and resulted smaller dimensional expansion subsequently.

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Autovacuum cleaning and hot rolling processes were applied to produce stainless clad steel. The effects of manufacturing variables on the bonding shear strength were investigated. The principal factor that controls the bonding shear strength was known to be the rolling reduction ratio and good bonding strength over 30㎏f/㎟ was obtained at over 40% rolling reductions. Thickness of the nickel layer or annealing time showed little effects on the bonding strength. The effect of surface roughness was greatly reduced at over 50% rolling reductions. Rearrangement of mild steel-nickel interface was observed after annealing process but the rearrangement did not affect the bonding strength when the rolling reduction is over 50%. Porosities were observed after up to 40% rolling reductions but were barely noticed after 60% rolling reduction. Carbon diffusion was not significant right after hot rolling but occurred very rapidly during annealing process.

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Simple methods for the relationship between the crystallographic texture and planar anisotropy in the plastic strain ratio and the yield strength have been developed on the basis of ideal sheet textures. Calculation of the R value and the yield strength has been made using the methods as a function of tensile directions for various textures in fcc and bcc metals. The agreement between calculated and measured values was satisfactory.

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A mathematical model for the precipitation of spherical particles has been developed for the growth stage of particles where no further nucleation is accounted for. The applicability of the model has been tested by measuring the rate of precipitation of hydronium jarosite from ferric sulfate solution at elevated temperatures, and the agreement was found to be satisfactory. At the initial period of reaction the rate of hydrolysis is limited by a surface controlled process (activation energy, 8.5 ㎉/㏖), whereas at the latter period that of hydrolysis is controlled by a diffusion process(activation energy, 2.2 ㎉/㏖) in the interfacial layer. The criterion of the operating mechanism is apparently the size of the precipitate particle. It is also interesting to note that the lower the initial concentration of ferric sulfate and also the higher the basicity of solutions, the higher the yield was obtained.

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Co^(2+) ion in zinc electrolyte is deterious to the electrowinning of zinc. for it lowers the current efficiency of the electrolyte; therefore it should be removed until it`s concentration becomes tower than 1㎎/ℓ. In this experiment, a study on the precipitation of Co^(2+) ion in zinc electrolyte was carried out by using Zn-Pb alloy dust and Sb₂O₃as additives. Co^(2+) ion is precipitated by electrochemical reaction mechanism; Sb₂O₃plays an important role by acting as anodes after it is precipitated as Sb on the surface of Zn-Pb alloy dust while Zn acts as cathodes, and Pb lowers the resolving-rate of the precipitated Co. In these experiments the optimum condition of the reaction is as follows ; stirring speed : 250 rpm. temperature : 95℃, Pb content in Zn-Pb alloy dust : 1.35%, amount of Zn-Pb alloy dust : 3g/ℓ, amount of Sb₂O₃: 5㎎/ℓ, pH ; 4, and at the optimum condition, Co^(2+) ion concentration is lowered from 30㎎/ℓ to 0.2㎎/ℓ after two hours of reaction.

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