Abstract: A method for the recovery of a desired metal (e.g., copper) from its sulfide ore by reaction with process metal (e.g., aluminum) capable of forming at least a high sulfide and subsulfide compound. The aluminum subsulfide compound is reacted with the copper sulfide at a first temperature to reduce the copper to metal form and to convert the aluminum to the high sulfide form. Then, the copper metal is separated and the aluminum high sulfide may be reconverted to the subsulfide form by heating to a second higher temperature at which the low sulfide is stable. After separation of the reduced sulfur, the aluminum subsulfide is recycled to reduce additional copper metal without consumption of process metal. The procedure may also be used to reduce and separate two or more metal sulfides (e.g., CuFeS.sub.2) by selective reduction with controlled amounts of processed metal.

Abstract: An actinide nitride-fueled nuclear reactor and a method of operation therefor, including continuous in situ removal of fission products and optional addition of fuel-forming actinide material as the reaction proceeds. The reactor employed has a fuel system comprising a critical mass of a nitride of an actinide metal in contact with a non-critical solution of the actinide metal in a molten metal solvent of low neutron adsorption cross section such as tin, said fuel system being maintained under a nitrogen atmosphere in an inert, refractory vessel such as graphite which is non-conducive to the formation of actinide oxides. Fission products formed are continuously exchanged with the actinide metal dissolved in the molten metal solvent as the nuclear reaction proceeds, with equivalent amounts of actinide nitride being formed and precipitated into the critical mass as fission products are dissolved in the molten metal solution.

Abstract: A method for the separation of a light reactive metal (e.g., zirconium) from a heavy reactive metal (e.g., hafnium) by forming insoluble nitrides of the metals in a molten metal solvent (e.g., copper) inert to nitrogen and having a suitable density for the light metal nitride to form a separate phase in the upper portion of the solvent and for the heavy metal nitride to form a separate phase in the lower portion of the solvent. Nitriding is performed by maintaining a nitrogen-containing atmosphere over the bath. The light and heavy metals may be an oxide mixture and carbothermically reduced to metal form in the same bath used for nitriding. The nitrides are then separately removed and decomposed to form the desired separate metals.