Methods for the extraction of metals such as rare earth metals and thorium from metal compounds and solutions. The methods may include the selective precipitation of rare earth elements from pregnant liquor solutions as rare earth oxalates. The rare earth oxalates are converted to rare earth carbonates in a metathesis reaction before being digested in an acid and treated for the extraction of thorium. A two-step extraction method may be applied to precipitate thorium as thorium hydroxide under controlled pH conditions such that pure thorium precipitate is recovered from a first step and a thorium-free rare earth solution is recovered at the subsequent step. The resulting rare earth solutions are of extremely high purity and may be processed directly in a solvent extraction circuit for the separation of rare earth elements, or may be processed for the direct production of a 99.9% bulk rare earth hydroxide/oxide concentrate.

The invention pertains to a method for separating uranium and/or thorium from an aqueous suspension, said method comprising: a) Contacting said suspension with at least a polymer having formula (I), wherein n is an integer which is not 0 and is no more than 50, R1 is H or CH.sub.3, R2 is H or a C1-C20-alkyl, R3 and R4 arc independently H or a C1-C20-alkyl, X, Y arc O or NH, said polymer being soluble in said aqueous suspension, and wherein when R3 and R4 are H, p is an integer which is 1 or more and 10 at the most, and said polymer is a flocculating polymer, and when at least one of R3 and R4 is not H, p is an integer which is 3 or more and 10 at the most, and said polymer is a thermosensitive polymer and has a LCST in said suspension, b) Carrying out at least one of the following steps b1) and b2) b1) If said suspension contains uranium, separating the aggregates resulting from flocculation of said polymer, from said mixture, b2) If said suspension contains thorium, modifying the mixture until the LCST of the polymer in the mixture is reached or exceeded and separating the resulting aggregates from said mixture; and c) Recovering at least one of uranium and/or thorium-free mixture, aggregates bearing uranium and aggregates bearing thorium.

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An apparatus is for the automated production of a daughter radionuclide from a parent radionuclide using a generator comprising a solid medium onto which the parent nuclide is fixed and whereby the daughter nuclide is formed by radioactive decay of the parent nuclide. The apparatus includes a fluid circuit including a chromatography column having a head port and a tail port, at least one connection port for connecting the generator to the fluid circuit, at least one inlet port for connecting fluid sources to the fluid circuit and at least one valve controlled by an electronic control unit for selectively connecting the chromatography column, the connection port and the at least one inlet port in various configurations. The various configurations include a first elution configuration for circulating an A1 solution exiting the generator and containing the daughter radionuclide, through the chromatography column from the head port to the tail port for loading the chromatography column with the daughter radionuclide; a first washing configuration for circulating an A2 washing solution from a solution inlet through the chromatography column from the head port to the tail port; and a second washing configuration for circulating an A2 washing solution from a solution inlet through the chromatography column from the tail port to the head port.

A method of separating actinium and/or radium from proton-irradiated thorium metal. The thorium metal is irradiated to produce isotopes including thorium, actinium and/or radium. The resultant product is dissolved in solution and a selective precipitant is used to precipitate a bulk portion of the thorium. The precipitated thorium can be recovered. Chromatography is carried out on the remaining solution to remove residual thorium and to separate the actinium from the radium.

Described is a process for the refinement of a quartz powder, comprising the step of separating microparticles of refractory minerals, in particular minerals containing rare earth metal compounds, from the quartz powder by an elutriation step.

A process for producing a daughter radionuclide from a parent radionuclide includes a) loading the parent radionuclide on a first solid medium contained in a generator and onto which the parent radionuclide is retained and whereby the daughter radionuclide is formed by radioactive decay of the parent radionuclide; b) eluting this medium with a A0 solution so as to recover a A1 solution comprising the daughter radionuclide; c) optionally adjusting the pH of the A1 solution so as to obtain a A1 solution, d) loading this A1 or A1 solution onto the head of a second solid medium contained in a chromatography column; e) first washing said second solid medium with a A2 solution; f) second washing said second solid medium with a A2 solution; g) eluting the daughter radionuclide with a A3 solution. The first washing step is conducted from head to tail of the column and the second washing step and the second eluting step are conducted from tail to head of the column.

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.

A method includes contacting a coal feedstock with an acidic solution to form residual coal and a leachate. The method further includes separating the residual coal from the leachate where the leachate contains rare earth elements and where the residual coal has preserved organic content and reduced inorganic content. Another method includes contacting a coal feedstock with a basic solution to form residual coal and a leachate. The method further includes separating the residual coal from the leachate where the leachate contains rare earth elements.

Described is a process for the refinement of a quartz powder, comprising the step of separating microparticles of refractory minerals, in particular minerals containing rare earth metal compounds, from the quartz powder by an elutriation step.

Provided are a method and a system for processing a rare earth concentrate ore. The method comprises (1) mixing the rare earth concentrate ore and concentrated sulfuric acid, thereby obtaining a mixed slurry and a first fluorine-containing gas; (2) mixing the mixed slurry and an initiator liquid for acidolysis, thereby obtaining a clinker and a second fluorine-containing gas; (3) subjecting the clinker to leaching with water, thereby obtaining a leached slurry; (4) subjecting the leached slurry to a solid-liquid separation, thereby obtaining a filtrate and a leached slag, and recycling the leached slag to step (2) for acidolysis again.