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.

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.

Complexing or chelating agents that offer strong, selective bonding with uranium as well as a broad pH range of effectiveness, specifically including the pH range around 8.2, together with the acrylic double bonds required for radiation-induced grafting on polymers to remove uranium from a solution such as seawater. The novel adsorbing species are phosphorus-containing molecules, in particular organic phosphates, phosphonates and phosphoric acids. Organic phosphorus compounds, for example, organic phosphates, phosphonates, and phosphoric acids, are attached to polymer fibers to form fibers, fiber fabrics or membranes that are effective, or show activity, in uranium adsorption.

In alternative embodiments, the invention provides processes and methods for the recovery, removal or extracting of, and subsequent purification of uranium from a wet-process phosphoric acid using a continuous ion exchange processing approach, where the uranium is recovered from a phosphoric acid, or a phos-acid feedstock using either a dual or a single stage extraction methodology. In both cases an intermediate ammonium uranyl-tricarbonate solution is formed. In alternative embodiments, in the dual cycle approach, this solution is contacted in a second continuous ion exchange system with a strong anion exchange resin then subsequently recovered as an acidic uranyl solution that is further treated to produce an intermediate uranyl peroxide compound which is ultimately calcined to produce the final uranium oxide product. In alternative embodiments, in the single cycle case, the intermediate ammonium uranyl-tricarbonate solution is evaporated to decompose the ammonium carbonate and produce an intermediate uranium carbonate/oxide solid material. These solids are digested in an acid medium, and then processed in the same manner as the secondary regeneration solution from the dual cycle process to produce an intermediate uranyl peroxide that is calcined to produce a final uranium oxide product.

A method for separating radionuclides from ores, ore concentrates, and tailings or mixtures of two or more thereof comprising the steps of (a) providing an ore, ore concentrate, or tailings, or a mixture of two or more thereof in which radionuclides have been liberated onto surfaces of particles of the ore, ore concentrate or tailings or mixtures of two or more thereof, (b) forming a pulp or slurry comprising the ore, ore concentrate or tailings or a mixture or two or more thereof from step (a), water or an aqueous solution, and an ion exchange resin to cause the radionuclides to load onto the resin, and (c) separating the resin from other solids present in the pulp or slurry.

A method for extracting uranium (VI) from an aqueous solution including phosphoric acid, which includes placing the aqueous solution 5 in contact with an organic material, followed by separating the aqueous solution and the organic material. The organic material includes a solid polymer substrate impregnated with a compound having the following general formula (I):

##STR00001##

The invention also relates to a method for retrieving uranium (VI) from an aqueous solution including phosphoric acid.

An organic material which includes a solid polymer substrate onto which molecules having the following general formula (I) are grafted:

##STR00001##

The invention also relates to the use of the organic material to extract the uranium (VI) from an aqueous acid solution, to associated methods for extracting and retrieving uranium (VI) as well as to a molecule which is a precursor of the organic material. The disclosure also relates to the use of the organic material to extract the uranium (VI) from an aqueous acid solution, to associated methods for extracting and retrieving uranium (VI) as well as to a molecule which is a precursor of the organic material.

In alternative embodiments, the invention provides processes and methods for the recovery, removal or extracting of, and subsequent purification of uranium from a wet-process phosphoric acid using a continuous ion exchange processing approach, where the uranium is recovered from a phosphoric acid, or a phos-acid feedstock using either a dual or a single stage extraction methodology. In both cases an intermediate ammonium uranyl-tricarbonate solution is formed. In alternative embodiments, in the dual cycle approach, this solution is contacted in a second continuous ion exchange system with a strong anion exchange resin then subsequently recovered as an acidic uranyl solution that is further treated to produce an intermediate uranyl peroxide compound which is ultimately calcined to produce the final uranium oxide product. In alternative embodiments, in the single cycle case, the intermediate ammonium uranyl-tricarbonate solution is evaporated to decompose the ammonium carbonate and produce an intermediate uranium carbonate/oxide solid material. These solids are digested in an acid medium, and then processed in the same manner as the secondary regeneration solution from the dual cycle process to produce an intermediate uranyl peroxide that is calcined to produce a final uranium oxide product.

A system for extracting uranium from wet-process phosphoric acid (WPA), includes an ion exchange resin or solvent extractor for separating uranium from WPA to produce a loaded uranium solution stream and a uranium depleted WPA stream. An ion exchange resin is positioned to receive the loaded uranium solution stream and bind uranium species thereto. An anion solution stream is positioned to feed a solution comprising anions onto the ion exchange resin to form a loaded uranium eluant stream. The loaded uranium eluant stream may then be treated to provide a uranium containing product.