A method for recovering thorium and rare earth elements from rare earth waste residues includes the steps of (1) mixing rare earth waste residues with an inorganic acid and heating to obtain a stock solution containing thorium and rare earth elements; (2) extracting thorium and rare earth elements from the stock solution with an organic phase containing an extractant; (3) washing the organic phase obtained after extraction in step (2) with a washing solution to move rare earth elements into the aqueous phase and leave thorium in the organic phase; (4) back-extracting the organic phase containing thorium obtained in step (3) with a back-extraction solution to extract move thorium in the organic phase into the aqueous phase. The extractant contains alkyl phosphonic acid monoalkyl ester and dialkylphosphinic acid.

A method for extracting a metal species from a solution is described, where the metal species comprises a rare earth element, Th, or U. The method involves the use of poly(caffeic acid) as a sorbent material. The poly(caffeic acid) may be crosslinked with a diamine crosslinker such as ethylenediamine.

A method for separating a rare earth metal. The method comprises contacting a solution comprising a rare earth metal with a first column to separate the rare earth metal into light, medium, and/or heavy rare earth metals; and contacting the light, medium, and/or heavy rare earth metals to with the second column to separate the light, medium, and/or heavy rare earth metals into individual rare earth metals. A method for extracting rare earth metals from a solution comprising contacting the rare earth metal with a plurality of resins. A method of extraction rare earth metal and lithium from a dynamic pad and permanent pad.

According to an embodiment, a nuclear fuel material recovery method of recovering a nuclear fuel material containing thorium metal by reprocessing an oxide of a nuclear fuel material containing thorium oxide in a spent fuel is provided. The method has: a first electrolytic reduction step of electrolytically reducing thorium oxide in a first molten salt of alkaline-earth metal halide; a first reduction product washing step of washing a reduction product; and a main electrolytic separation step of separating the reduction product. The first molten salt further contains alkali metal halide, and contains at least one out of a group consisting of calcium chloride, magnesium chloride, calcium fluoride and magnesium fluoride. The method may further has a second electrolytic reduction step of electrolytically reducing uranium oxide, plutonium oxide, and minor actinoid oxide in a second molten salt of alkali metal halide.

The present invention relates to a method for removing radioactive element thorium in a rare earth mineral, comprising: mixing the rare earth mineral with selenium dioxide in water, reacting radioactive element thorium with selenium dioxide by hydrothermal method, cooling to form a crystal, and separating the crystal to remove the radioactive element thorium. In the invention, tetravalent element thorium is selectively bound to inorganic ligand selenium dioxide in a hydrothermal environment to form a crystal, thereby achieving removal of radioactive element thorium. The method has high crystallization rate and high decontamination efficiency, and removes thorium from trivalent lanthanide element by crystallization solidification under a uniform reaction condition. Compared to a conventional industrial method for thorium separation, the method has low energy consumption and high separation ratio, enables one-step solidification separation, and effectively avoids the disadvantages of redundant separation operations and a large amount of organic and radioactive liquid wastes.

The present invention concerns a process for producing a daughter radionuclide from a parent radionuclide comprising the purification of the daughter radionuclide on a chromatography column, as well as the apparatus for carrying out such process.

Methods for the extraction of cerium and/or thorium from metal compounds and solutions. A single step or two-step extraction method may be applied to selectively precipitate thorium and/or cerium as hydroxides under controlled pH conditions such that a substantially thorium-free and/or cerium-free rare earth element (REE) solution may be formed, such as for the subsequent separation of individual rare earth elements.

A method for beneficiation of mineralogical materials that comprises using a one or more of a suite of processes including fluidized bed separation, plasma-based stimulation or enhancement of chemical reactions using a Reactive X-Ray Chemical Processor, field enhancement of chemical reactions and process and drying. All of the processes can be used singly, jointly, simultaneously or sequentially in multiple stages. The methods are nearly non-polluting and serve to replace polluting wet chemistry and other beneficiation techniques.

Disclosed herein are embodiments of methods for isolating rare earth elements (REEs) and radioisotopes from coal combustion products, such as fly ash. In particular embodiments, lanthanides, Al, Sc, Y, or compounds comprising lanthanides, AI, Sc, Y, or any combination thereof; or actinides can be isolated using the methods disclosed herein.

The present invention relates to use of an amino-containing neutral phosphine extractant of Formula I in extraction and separation of thorium, and a process of extracting and separating thorium using the amino-containing neutral phosphine extractant of Formula I, ##STR00001##
wherein, R.sub.1 and R.sub.2 are each independently selected from the group consisting of C.sub.1-C.sub.12 alkyl, R.sub.3 and R.sub.4 are each independently selected from the group consisting of C.sub.1-16 alkyl and hydrogen, and n is an integer of 1 to 8.