Abstract: The composite seal includes a metal member arranged on a first substrate side and an elastic member arranged on a second device side and capable of elastic deformation. The composite seal having a structure capable of suppressing degradation even with ultraviolet radiation is thus provided.

Abstract: The composite seal includes a metal member arranged on a first substrate side and an elastic member arranged on a second device side and capable of elastic deformation. The composite seal having a structure capable of suppressing degradation even with ultraviolet radiation is thus provided.

Abstract: Separation of hafnium tetrachloride from zirconium tetrachloride by introducing zirconium tetrachloride containing about 2-4 wt percent of hafnium tetrachloride into an electrolytic cell filled with a molten salt and dissolving it to make an electrolytic bath. Running first phase electrolysis which produces zirconium trichloride containing a lower hafnium content than the dissolved zirconium tetrachloride at the cathode. Running second phase electrolysis using the first cathode, but switching the first cathode to become an anode and using a second cathode. Producing zirconium trichloride of a lower hafnium content than the dissolved zirconium tetrachloride at the second cathode. Evolving a gaseous zirconium trichloride at the anode by electrolytic oxidation of the zirconium trichloride produced in the first phase electrolysis. Recovering this evolved zirconium tetrachloride which has a lower hafnium content than the dissolved zirconium tetrachloride and the zirconium trichloride produced at the cathodes.

Abstract: A process for separation of hafnium tetrachloride from zirconium tetrachloride and electrode is disclosed. Zirconium tetrachloride containing hafnium tetrachloride in natural ratio dissolved in a molten salt is reduced in the first phase electrolysis using an anode composed of a substance formed by firing a mixture of more than one kind of compound selected from the group consisting of silica, silicate containing zirconium or zirconium oxide and carbon with a binder under maintenance of an initial concentration of the zirconium tetrachloride in order to produce zirconium trichloride containing a hafnium content lower than that of the zirconium tetrachloride at a cathode.

Abstract: Minute spherical bismuth (III) oxide particles are produced by adding a monocarboxylic acid to an aqueous solution containing trivalent bismuth ions thereby inducing formation of a bismuth-monocarboxylic acid complex in the aqueous solution, further adding an alkali to the aqueous solution thereby inducing precipitation of the complex, separating the precipitated complex from the solution, and firing the separated complex.

Abstract: A process of separation of hafnium from zirconium by molten salt electrolysis in which zirconium tetrachloride with ordinary hafnium tetrachloride content is dissolved in a molten salt and the zirconium tetrachloride is electrolytically reduced to zirconium trichloride with lower hafnium content at a cathode in the molten salt and hafnium tetrachloride is remained. Next, the cathode on which the zirconium trichloride is formed by the cathode reaction is used as an anode. The electrolytic reduction of zirconium tetrachloride at another cathode in the molten salt is carried out and at the same time the zirconium trichloride formed on the anode is oxidized to zirconium tetrachloride with a low hafnium content and the zirconium tetrachloride is evaporated for separation. The obtained zirconium tetrachloride containing a low hafnium content is suitable for production of reactor grade zirconium containing about 100 ppm of hafnium.