Uses of cyclic amine monoamides for extracting uranium(VI) and/or plutonium(IV) from an acidic aqueous solution, as well as for totally or partially separating uranium(VI) from plutonium(IV) from an acidic aqueous solution. A method for treating an aqueous solution resulting from the dissolution of spent nuclear fuel in nitric acid to extract, separate and decontaminate uranium(VI) and plutonium(IV) in a single cycle and without resorting to any operation of reducing plutonium(IV), and wherein a cyclic amine monoamide or a mixture of cyclic amine monoamides is used as extractant. The cyclic amine monoamides have formula (I):

##STR00001##

Uses of cyclic amine monoamides for extracting uranium(VI) and/or plutonium(IV) from an acidic aqueous solution, as well as for totally or partially separating uranium(VI) from plutonium(IV) from an acidic aqueous solution. A method for treating an aqueous solution resulting from the dissolution of spent nuclear fuel in nitric acid to extract, separate and decontaminate uranium(VI) and plutonium(IV) in a single cycle and without resorting to any operation of reducing plutonium(IV), and wherein a cyclic amine monoamide or a mixture of cyclic amine monoamides is used as extractant. The cyclic amine monoamides have formula (I):

##STR00001##

A molecule enabling the selective recovery of gold, platinum, and palladium from an oxidative organic solution that also contains contaminants such as base metals, polymers, or other gangue material. The disclosed formula simultaneously eliminates multiple costly and hazardous steps of recovering such metals by using a single chemical comminution and solvent extraction process using dual organic phases. The resulting gold, platinum, and/or palladium-containing solution can be stripped to recover these elements and to regenerate the extractant for subsequent use.

A method for purifying lutetium includes providing a solid composition comprising ytterbium and lutetium and subliming or distilling ytterbium from the solid composition at a temperature of about 1196 C. to about 3000 C. to leave a lutetium composition comprising a higher weight percentage of lutetium than was present in the solid composition.

A method for purifying lutetium includes providing a solid composition comprising ytterbium and lutetium and subliming or distilling ytterbium from the solid composition at a temperature of about 1196 C. to about 3000 C. to leave a lutetium composition comprising a higher weight percentage of lutetium than was present in the solid composition.

A method for purifying lutetium includes providing a solid composition comprising ytterbium and lutetium and subliming or distilling ytterbium from the solid composition at a temperature of about 1196 C. to about 3000 C. to leave a lutetium composition comprising a higher weight percentage of lutetium than was present in the solid composition.

A method for purifying lutetium includes providing a solid composition comprising ytterbium and lutetium and subliming or distilling ytterbium from the solid composition at a temperature of about 1196 C. to about 3000 C. to leave a lutetium composition comprising a higher weight percentage of lutetium than was present in the solid composition.