Mitsubishi Kinzoku Kabushiki Kaisha

Yutaka Nishiyama

Etsuji Kimura

Nozomu Hasegawa

Takeyoshi Shibasaki

A process for preparing compound metal oxides, superconductive compound oxides, is disclosed. The process comprises preparing an aqueous solution containing a predetermined content ratio of chloride, nitrate or acetate of a rare earth metal, an alkaline earth metal and copper, said content ration corresponding to the composition of the object compound metal oxide, adjusting the pH of the solution to 1.5-2.0, adding oxalic acid in an amount such that the concentration of the residual oxalic acid becomes 0.05 M/l-0.1 M/l, collecting the thus formed precipitate and firing it.

Process for preparing compound metal oxides of yttrium, barium and copper

Gallium-containing waste is chlorinated in the presence of gallium trichloride from the beginning. By this procedure, gallium is more efficiently chlorinated and gallium trichloride is more easily separated from other chlorides and recovered.

Process for recovering gallium trichloride from gallium-containing waste

A process for preparing compound metal oxides, a superconductive compound oxides for instance, is disclosed. The process comprises preparing an aqueous solution containing a predetermined content ratio of chloride, nitrate or acetate of a rare earth metal, an alkaline earth metal and copper, slightly basifying the solution to form hydroxides of the rare earth metal and copper and then introducing carbon dioxide to form carbonate of the alkaline earth metal, collecting the thus formed mixed precipitate of hydroxides and carbonate and firing it.

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Yono, Japan

Yutaka Nishiyama