Abstract: A process for preparing powder of high temperature oxide superconductors of Bi-Pb-Sr-Ca-Cu-O type. In an aqueous solution of nitrate salts of Bi, Pb, Sr, Ca, and Cu metals, an appropriate ratio of triethylamine/oxalic acid was added to form a coprecipitate. Through the process of calcination at a temperature in the range of 750.degree. C. to 800.degree. C. and sintering at a temperature of 860.degree. C., a uniform and fine powder superconductive metal oxide having a critical temperature of 110K is obtained as the final product.

Abstract: An oxalate route coprecipitation process for preparing a superconducting YBaCuO system precursor powder comprises preparing an aqueous solution of nitrates of yttrium, barium and copper, which is then mixed with an organic solution containing a dibasic oxalate ester, an organic base and acetone. An ultrasound vibration is applied to the mixture to coprecipitate oxalates of yttrium, barium and copper. The decomposition of the oxalate ester is enhanced to an optimum rate as the result of the homogeneous phase contributed by acetone which is miscible with both water and the oxalate ester. The ultrasound vibration segregates the precipitate particles thereby preventing the coagulation of the particles and assuring fine and uniform particle size.

Abstract: A homogenous coprecipitation method by which superconducting oxides having perovskite-like structure, such as YBa2Cu307-x, can be produced in mass, in which urea is used as solvent to adjust and control the PH value of an aqueous nitrate solution. The coprecipitation method of this invention comprises following steps: (a) preparing an aqueous mixture containing Y, Ba and Cu salts with molar ratio of 1:2:3 wherein Y being 0.068M; (b) adding 5-10 moles of oxalic acid per one mole of Y and 20-250 moles of urea per moles of Y into the aqueous mixture; (c) heating the aqueous mixture to a temperature range of 80.degree. to 100.degree. C. to proceed a hydrolysis of the urea such that PH value of the aqueous mixture will be gradually elevated by NH.sub.3 gas evoluted from the urea hydrolysis; and (d) cooling the temperature of the aqueous mixture to room temperature at which time a desired uniform PH value is reached. After cooling, pale blue homogeneous coprecipitates of the superconducting oxides can be obtained.

Abstract: The preparation of nuclear fuels such as uranium dioxide, carbide and nitride employing the ammonium urante, (NH.sub.4).sub.2 U.sub.2 O.sub.7, as starting material usually must undergo a series of chemical and metallurgical processes at relatively high temperature and under strictly controlled working condition.A simple method for the preparation of these nuclear fuels has evolved with respect to the electrolytic amalgamation of uranium ion directly from an aqueous solution. The thereby obtained uranium amalgam maybe thermally decomposed into a fine metallic powder which reacts readily with water vapor, methane and nitrogen gas to bring forth uranium dioxide, carbide and nitride, respectively.

Abstract: Metal amalgams are prepared electrolytically by using an ion exchange membrane for the purpose of adjusting pH during the course of electrolysis. The subsequent thermal decomposition of the thereby obtained amalgam under reduced pressure brings forth metallic powder and solid metal.