The present invention relates to a process for recovering metals from metal-bearing material, said process comprising the step of contacting the metal-bearing material with condensed phosphoric acid at a temperature of greater than 215° C. and less than 300° C. for a period of time sufficient to at least partially dissolve the metal-bearing material; to provide a leaching solution containing metal ions. The invention is applicable to a range of metals including the rare earth elements, as well as thorium and uranium. The invention is applicable to a range of metal-bearing materials, particularly phosphate minerals such as monazite and xenotime.

The present disclosure describes a method of recovering uranium including a continuous ion exchange (CIX) process including a single cycle or a dual cycle CIX process and at least a gradient elution or resin crowding process. The present disclosure also describes an apparatus including a single cycle or dual cycle CIX system and a gradient elution and/or resin crowding system.

A fiber useful in the absorption of metal ions from aqueous solutions, the fiber comprising a polyolefin backbone having a diameter of at least 1 micron and having covalently appended on its surface halogen atoms and vinyl-addition polymeric grafts functionalized with metal-binding groups, such as at least one functional group selected from carboxylate, keto, aldo, amino, imino, nitrile, amido, oxime, amidoxime, imide dioxime, and hydroxamate groups. The vinyl-addition polymeric grafts may also be further functionalized with hydrophilic groups different from the metal-binding groups, wherein the hydrophilic groups may be selected from carboxylate, sulfone, sulfonate, phosphonate, alkylammonium, iminium, amide, pyrrolidone, and polyalkyleneglycol groups. Also described are methods for producing the functionalized fibers, and methods for using the functionalized fiber, particularly in extracting metal ions from metal-containing solutions.

A mesoporous organic material which makes it possible to extract, using the liquid-solid extraction technique, the uranium(VI) contained in an aqueous medium including phosphoric acid, with high efficiency and high selectivity for the iron that the medium can likewise contain. The material is likely to be obtained by cross-linking polymerisation of a monomer of formula (I) below, wherein: R.sup.1, R.sup.2 and R.sup.3 are, independently from one another, H, a C.sub.1 to C.sub.12 saturated or unsaturated, linear or branched hydrocarbon group, or a polymerisable group, with the condition that at least one of R.sup.1, R.sup.2 and R.sup.3 is a polymerisable group; R.sup.4 and R.sup.5 are, independently from one another, H or a C.sub.1 to C.sub.8 saturated or unsaturated, linear or branched hydrocarbon group; the cross-linking polymerisation being carried out in the presence of a cross-linking agent and one or more pore-forming agents.

Methods and systems for separation of thorium from uranium and their decay products are provided. The method comprises combining a nuclear fuel feedstock comprising thorium and uranium with a first acid to form a first solution. The first solution is contacted an ion exchange resin that is selective for thorium or uranium. The thorium or uranium is at least partially removed from the first solution by binding the thorium or uranium to the ion exchange resin thereby forming a second solution. The second solution is combined with oxalic acid to precipitate uranium or thorium from the second solution to form a precipitate. The precipitate is separated from the second solution.

A high flux antibacterial polyacrylonitrile-based uranium-extraction-from-seawater-seawater desalination cogeneration membrane and a preparation method thereof are disclosed. To satisfy demand of uranium-extraction-from-seawater-seawater desalination cogeneration application, polyacrylonitrile, chitosan and amidoxime modified polyacrylonitrile are taken as raw materials and a proportion of raw materials of a casting membrane are optimized in a membrane forming process. The conversion rate of polyacrylonitrile is adjusted so that formation of an amidoxime modified polyacrylonitrile powder in a casting membrane liquid mixing system is regulated and controlled, thereby significantly improving the mechanical properties, the flux, the hydrophilicity, the antibacterial property and the uranium adsorptive property. A compound cogeneration membrane composed of a top membrane, a clipping membrane and a bottom membrane are also prepared according to actual function characteristics of seawater and the membrane material, and the uranium-extraction-from-seawater-seawater desalination performance of the membrane material is integrally improved.

A high flux antibacterial polyacrylonitrile-based uranium-extraction-from-seawater-seawater desalination cogeneration membrane and a preparation method thereof are disclosed. To satisfy demand of uranium-extraction-from-seawater-seawater desalination cogeneration application, polyacrylonitrile, chitosan and amidoxime modified polyacrylonitrile are taken as raw materials and a proportion of raw materials of a casting membrane are optimized in a membrane forming process. The conversion rate of polyacrylonitrile is adjusted so that formation of an amidoxime modified polyacrylonitrile powder in a casting membrane liquid mixing system is regulated and controlled, thereby significantly improving the mechanical properties, the flux, the hydrophilicity, the antibacterial property and the uranium adsorptive property. A compound cogeneration membrane composed of a top membrane, a clipping membrane and a bottom membrane are also prepared according to actual function characteristics of seawater and the membrane material, and the uranium-extraction-from-seawater-seawater desalination performance of the membrane material is integrally improved.

A process is provided for recovering uranium comprising (A) bringing a solution (A) into contact with a resin (A) to produce a mixture of solution (B) and resin (B), wherein the solution (A) is an aqueous solution comprising dissolved sodium carbonate, sodium bicarbonate, or a mixture thereof, and wherein the resin (A) is a strong acid cation exchange resin that comprises one or more cationic moiety that comprises uranium and one or more cationic moiety that comprises iron, and (B) separating the solution (B) from the resin (B).

The present disclosure provides a method for numerical simulation of reactive transport during CO.sub.2+O.sub.2 in-situ leaching of uranium at a sandstone-type uranium deposit. Unlike the traditional method for numerical simulation of solute transport during in-situ leaching of uranium with consideration of only convection and diffusion, the method permits establishment of a multi-field coupled reactive solute transport model to simulate the dynamic leaching process of a sandstone-type uranium deposit in Northern China. The method provided in the present disclosure includes: creating a thermodynamic database suitable for CO.sub.2+O.sub.2 leaching of a sandstone-type uranium deposit in Northern China, and with consideration of the dynamic reaction process of uranium dissolution under combined action of oxygen O.sub.2 (aq) and bicarbonate HCO.sub.3.sup.−, performing numerical simulation of reactive transport during CO.sub.2+O.sub.2 in-situ leaching of uranium using a TOUGHREACT simulation technology framework.

Disclosed are novel polymers that contain monomer units derived from 4-vinylpyridine and monomer units derived from a co-monomer. The polymers may be complexed with a metal, and linear or crosslinked. Also disclosed are methods for preparing these polymers by radical polymerization, as well as to their use for metal capture in aqueous media, particularly uranium capture in seawater or in final nuclear waste from nuclear power plants.