Process for uranium recovery

Abstract

The present disclosure describes a method for recovering uranium, including a continuous ion exchange (CIX) process, including a single-cycle or 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. The present disclosure describes an apparatus and process for recovering uranium from a source that involves a combination of one or more CIX processes and at least a gradient elution or resin crowding process to increase the purity of the obtained uranium. In embodiments, the apparatus and process for recovering uranium described herein include a CIX apparatus and a gradient elution and / or resin crowding system.

Description

Technical Field

[0001] The present disclosure relates to processes and methods for the recovery of uranium.

Background Art

[0002] Uranium is an important heavy metal that is used in many ways in our daily lives. As an example, uranium provides nuclear fuel for generating electricity in nuclear power plants. It is also used industrially as a radioactive isotope in medicine for diagnostic purposes, in food preservation, and in crop cultivation and livestock breeding. Uranium is found in the earth's crust, in rocks, and in seawater and can be recovered from the sea. However, it is not sufficiently concentrated in seawater to be economically recoverable.

[0003] Uranium is also found in phosphate ores, and different processes have been developed for the recovery of uranium from phosphoric acid produced from phosphate ores. Three of these processes are the DEPA-Topo process developed at Oak Ridge National Laboratory, which uses di(2-ethylhexyl)phosphoric acid and trioctylphosphine oxide as extractants; the OPAP process, also developed at Oak Ridge National Laboratory, which uses octylphenyl acidic phosphate ester as an extractant; and the OPPA process developed by Dow, which uses octylpyrophosphate as an extractant. However, these processes are based on solvent extraction (SX) technology, where the extractant is dissolved in a certain diluent, such as a high purity kerosene-like solution, and then used in this diluted form for the recovery process. To eliminate the operational problems associated with these solvent extraction systems, particularly the potential for trace amounts of solvent to enter the phosphoric acid process after the U extraction process and cause significant problems in rubber-lined equipment, the development of non-solvent extraction systems has been the focus.

[0004] Phosphate serves as an alternative uranium source, depending on the uranium content of the phosphate rock. The presence of uranium in wet-process phosphate is well established, and uranium recovery from wet-process phosphate is also commercially practiced. Ion exchange systems are also used to recover uranium, and fixed-bed ion exchange systems are used in practice to recover uranium from various conventional sulfate and carbonate solutions (non-phosphate rock sources). Typically, these solutions are produced from leaching of various ores, or from so-called "in-situ" leaching, where the leaching solution is injected into the ground to leach the uranium-supported material, and then recovered in pumping well systems.

[0005] U.S. Patent No. 9,702,026 discloses a process for recovering uranium from wet process phosphate using a single or double-cycle continuous ion exchange (CIX) system. While prior art CIX systems simplify the recovery of uranium from wet process phosphate, improvements are still needed to increase the purity of the recovered uranium. [Overview of the Initiative] [Means for solving the problem]

[0006] This disclosure describes an improved method for recovering uranium, involving gradient elution and / or resin crowding processes. In embodiments, gradient elution and resin crowding are used in combination with one or more CIX processes. In embodiments, the method includes a single CIX process (single-cycle CIX process) comprising a gradient elution or resin crowding process. In embodiments, the method includes two CIX processes (dual-cycle CIX processes), each comprising a gradient elution or resin crowding process, or only one of the CIX processes comprises a gradient elution or resin crowding process.

[0007] The disclosure also describes a CIX apparatus that includes a single or dual-cycle CIX system and at least a gradient elution or resin crowding system for recovering uranium. [Brief explanation of the drawing]

[0008] [Figure 1] Figure 1 shows an exemplary single-cycle CIX apparatus and process for uranium recovery. The basic process block is shown along with the main material inputs and outputs. Flow numbers for explanatory purposes are indicated in the figure as (flow #). A gradient elution system or a resin crowding system may be included within the primary CIX system.

[0009] [Figure 2] Figure 2 shows an exemplary dual-cycle CIX apparatus and process for uranium recovery. The basic process block is shown along with the main material inputs and outputs. Flow numbers for explanatory purposes are indicated in the figure as (flow #). A gradient elution system or resin crowding system may be included within the primary CIX system and / or secondary CIX system.

[0010] [Figure 3] Figure 3 shows an exemplary gradient elution system and process that may be part of the single or dual-cycle CIX process shown in Figures 1 and 2. In this exemplary gradient elution process, the gradient elution process is included as part of the secondary CIX process of a dual-cycle CIX process, which includes an AE (i.e., anion exchange) resin medium. The AE medium (1) is loaded with uranyl carbonate complexes from the primary regeneration solution. As the resin moves from region X to region X-1, exemplary acids (2)-(4), i.e., sulfuric acid, of increasing strength are added to the resin to remove contaminants loaded onto the AE medium with uranyl carbonate. In region X-2, a uranium-loaded secondary regeneration solution is generated. The AE medium is finally regenerated with the strongest acid (6) and washed with water before re-entering the secondary CIX process.

[0011] [Figure 4] Figure 4 shows an exemplary resin crowding process, which may be part of the single or dual-cycle CIX process shown in Figures 1 and 2. This exemplary resin crowding process is part of the secondary CIX process of a dual-cycle CIX process, which includes an AE resin. The AE medium (1) is loaded with uranyl carbonate complexes from the primary regeneration solution. A portion of the uranium-loaded secondary regeneration solution is adjusted with a weak base (3) such as ammonia and applied to the AE medium. As the medium moves from area X to area X-2, uranium in the secondary regeneration solution, converted to anionic form for pH adjustment, is loaded onto the AE medium and displaces contaminants on the AE resin. In area X-2, a uranium-loaded secondary regeneration solution is generated. The AE resin is finally regenerated with the strongest acid (4) and washed before re-entering the CIX process.

[0012] In both Figures 3 and 4, depending on how the secondary CIX system is configured, area X can be any area, such as area 27 in a system with a total of 30 areas. Because there is a considerable degree of flexibility inherent in the possible configurations that can be used for optimized operation, "X" is used to represent a specific area of ​​the secondary CIX system. Area X-4 is part of a gradient elution or resin crowding system. [Modes for carrying out the invention]

[0013] Detailed explanation This disclosure describes apparatus and processes for recovering uranium from a source, involving a combination of one or more CIX processes and at least a gradient elution or resin crowding process to increase the purity of the recovered uranium. In embodiments, the apparatus and processes for recovering uranium described herein include a CIX apparatus and a gradient elution and / or resin crowding system. The CIX apparatus (and processes) described herein include a single-cycle or dual-cycle CIX apparatus (and processes) and a gradient elution and / or resin crowding system (and processes). In embodiments, a single-cycle CIX apparatus has a single CIX (primary CIX) system, and a dual-cycle CIX apparatus has two CIX systems, namely a primary CIX system and a secondary CIX system. In embodiments, the gradient elution process and / or resin crowding process may be used in one or both cycles of a dual-cycle CIX apparatus.

[0014] The terms “recovery,” “isolation,” “removal,” “extraction,” and “purification” are used synonymously to refer to obtaining products such as uranium from a source. In embodiments, recovering uranium includes obtaining uranium in various chemical forms, including uranyl ammonium compounds, uranyl oxide, uranyl carbonate, uranyl hydroxide, uranyl ammonium tricarbonate, and equivalents. Recovering uranium also includes obtaining uranyl ions. The terms “uranium” or “U” as used herein refer to uranium in various chemical forms.

[0015] The source of uranium can be any source containing uranium. The sources of uranium used in the methods described herein include sources of phosphoric acid containing uranium, such as phosphoric acid (P2O5) or phosphoric acid raw materials. In embodiments, the source of phosphoric acid is from wet process (WP) phosphoric acid. WP phosphoric acid is obtained by decomposing recovered phosphate rock with sulfuric acid and filtering the resulting slurry. Depending on the properties of the phosphate rock, most of the uranium that may be present in the ore is dissolved and carried into the phosphoric acid stream. WP phosphoric acid is used to produce more than 90% of the world's phosphoric acid. The electric furnace process (EFP) is used to produce the remaining phosphoric acid. The majority of the phosphoric acid produced by WP is used for fertilizer production. WP phosphoric acid is less pure, less concentrated, and much cheaper to produce than EFP phosphoric acid. A small percentage of WP phosphoric acid is typically processed in different solvent extraction processes to produce higher quality phosphoric acid, i.e., industrial grade or even food grade phosphoric acid. The phosphoric acid produced by EFP (95-100%) is used for various industrial and food applications. EFP phosphate is far purer, more concentrated, and far more expensive to produce than WP phosphate. Furthermore, EFP-produced phosphate contains no uranium because all the uranium in the raw phosphate ore is transported to the slag industrial waste during the process.

[0016] In the embodiment, any phosphate rock that can be treated to produce WP phosphate and contains a certain level of uranium is suitable as a source for uranium recovery.

[0017] In the embodiments, the uranium source includes uranium in any chemical and oxidized state or form. "Uranium in any chemical and oxidized state" refers to uranium dissolved in the source. An example is uranium dissolved in phosphoric acid during the preparation of phosphoric acid from the reaction of phosphate ore and sulfuric acid in a phosphate plant. Uranium can be in either an oxidized state of +4 or +6 and is most likely to exist as a cationic complex that can be extracted by an ion exchange medium.

[0018] CIX systems and processes were developed in the early 1980s. With technological advancements, second and third-generation CIX systems have been developed, which use less water, consume less chemicals, and therefore reduce operating costs. Continuous ion exchangers have multiple resin chambers, which can be configured to allow for numerous processing steps. For example, there may be several chambers configured for extraction steps in the process. This may be followed by configurations of chambers to allow for resin washing, resin regeneration, and the equivalent. Ion exchange for the extraction of one or more components from the feed solution is generally performed first, which transfers the desired ions onto the column. This is generally followed by a water washing step to remove the feed solution contaminated with the resin. This is followed by column regeneration and removal of the extracted ions from the column. After regeneration, another water washing step is used to minimize the loss of any regenerated solution. The advantages of the CIX system include the washing and regeneration of the resin medium without interrupting the ion exchange process. In addition, there is an inherent flexibility in the approach that allows additional process steps, such as multiple regeneration solutions, post-loading and pre-water washing resin treatments, and equivalents, to be incorporated into the CIX system configuration. These additional process configurations are not practical in other ion exchange contact systems, such as fixed-bed units. Furthermore, this flexibility allows for an entirely different approach to assessing ion exchange applications for processes that were previously considered impractical (in previous contact systems).

[0019] The main difference between the CIX devices and processes described herein and prior art methodologies, such as solvent extraction methods, is that in the CIX devices and processes described herein, solids, polymers, functionalized materials are used to extract uranium from a source. No liquid extractants and diluent solvents such as high purity kerosene are used. Thus, problems associated with emulsion formation and fire / explosion risks are essentially eliminated. Elimination of the need for organic diluents such as kerosene also eliminates the potential for downstream damage in existing operations that would result from entrained solvent materials.

[0020] The processes and systems for both chelation or complexation cation exchange (CE) and anion exchange (AE) described below are carried out in a continuous ion exchange (CIX) equipment system. The system used is a continuous operation with a plurality of solid media chambers and a plurality of feed and discharge ports to / from the system that allow for continuous solution feeding and discharging. The system is such that the ports can be configured in various ways and once operating, the solid media chambers are transferred from one port or area section to another without any interruption of the process flow.

[0021] In embodiments, examples of types of CIX systems include the Calgon ISEP system (U.S. Patent No.4,522,726), developed in the early 1980s. In this system, there is a fixed inlet and discharge distributor arrangement that directs fluid to / from the system. There are a plurality of resin chambers mounted on a rotating table that moves the chambers from one section to the next. Another example would be an IONEX unit with a modified inlet / outlet fluid distribution arrangement that provides a sample response, as in a system that allows the resin chambers to remain stationary and uses a rotating platform to move fluid from one chamber to the next via a modified distribution system. These types of systems are essential for carrying out the multiple steps required to execute the process.

[0022] More conventional types of ion exchange systems, such as fixed bed units, which utilize a manifold for fluid distribution, are not sufficiently flexible and are limited in terms of the number of process steps that can be carried out from a practical perspective. Similarly, so-called semi - continuous ion exchange systems, such as "pulse bed" units, in which the resin is periodically pulsed from one section of the unit to another, do not allow truly continuous fluid flow and operational response. The nature of the process is such that multiple steps need to be carried out without interruption and the overall complexity of the ion exchange equipment system needs to be minimized. A truly continuous system, such as those referred to, meets this requirement.

[0023] Also, in the apparatus and process described herein, a source of uranium, for example a phosphoric acid source, can be returned to a phosphoric acid facility. The apparatus and process described herein include the regeneration of media using a regenerant chemical or combination of chemicals.

[0024] Furthermore, in the case of CIX, the solid medium (i.e., resin or equivalent material) has no solubility in the source of uranium, so there is no need for any additional post - treatment of the solid medium used in the ion exchange column. In addition, the uranium contained in the solid medium is subsequently removed in the regeneration stage of the process described herein. (Single - cycle continuous ion exchange (CIX) apparatus and process)

[0025] The process for recovering uranium described herein includes a single - cycle CIX apparatus and process. In a single - cycle CIX process, a solid contact medium is used to extract uranium from a source of uranium in a single CIX cycle. Exemplary embodiments of the single - cycle CIX apparatus and process are shown in FIG. 1.

[0026] In an embodiment, the single - cycle CIX apparatus includes the following main systems (ports). A pretreatment system that may include cooling of the uranium source and filtering and / or purifying the uranium source. A primary continuous contact (or primary CIX) system containing a primary CIX system, along with the systems and peripheral equipment typically associated with the primary CIX system, such as a surge tank, ammonia water preparation, ammonium carbonate preparation (which is the primary regeneration solution), water washing and supply system, and equivalents. ○ A gradient elution and / or resin crowding system (subport or subsystem), which may be part of a primary continuous contact system, for further removal of contaminants from the uranium source. A primary regeneration solution evaporation system is required to concentrate the primary regeneration solution and reduce the pH by decomposing excess ammonium carbonate. A uranyl precipitate filtration, washing, and digestion system in which the precipitated uranyl material is filtered, washed, and then digested with an acidic solution to decompose the uranyl compound and produce an acidified uranyl salt solution. • An acidified uranyl salt solution precipitation (uranium precipitation) system in which soluble uranium is precipitated as an insoluble uranyl compound when the pH of the acidified uranyl salt solution is adjusted. A uranium precipitation washing and calcination system in which an insoluble uranyl compound is washed, and subsequently the uranyl compound is dried and calcined to produce a form of uranium, such as uranium oxide.

[0027] The single-cycle CIX process may also include uranium storage and automated packaging systems and steps, which are standard operation and will not be described in detail here. The single-cycle CIX process uses a single-cycle CIX apparatus to recover uranium. The single-cycle CIX process is described below.

[0028] Pretreatment System and Process: A pretreatment system (and process) is not required, but may be used to remove suspended solids from the uranium source to minimize solid accumulation within the system. If the uranium source does not contain suspended solids, a pretreatment system (process) is not necessary. When phosphoric acid is used as the uranium source, a pretreatment system is used in the CIX process to remove suspended solids from the phosphoric acid. The uranium source is treated in a purification system to remove suspended solids in the source to a specific target level or less than approximately 1,000 ppm. The purified source is then treated in a polishing filtration system to reduce trace amounts of solids to a level of less than 100 ppm. It is important to note that, unlike fixed-bed ion exchange or solvent extraction systems, a certain level of solids is acceptable in the CIX process because there is a routine, sometimes frequent, "purification" step within the CIX operation itself. The incoming uranium source (1) is cooled and may subsequently be treated for the removal of suspended solids and trace amounts of chromophores. The solids can be returned to the original source. For example, solids from a phosphate source (a source of uranium) can be returned to the phosphate facility. The cooling system is optional and may be site-specific.

[0029] In embodiments, pretreatment of the uranium source in a pretreatment system involves adding activated clay to the phosphoric acid from a gypsum / phosphate separation filter, followed by the addition of a coagulation material to solidify the solid, and the resulting mixture is sent to a purification (sedimentation) system. The purified acid is then treated in an abrasive filter to remove any remaining trace amounts of solid. Typically, activated clay can be used, but other coagulation materials such as activated silica, activated carbon powder, and equivalents may also be used instead of activated clay. Organic coagulants are added to enhance the purification of the solid. The primary function of the addition at this stage is to enhance the solidification of the suspended solid in the feed source and to provide assistance in enhancing the final sedimentation of the solid from the liquid.

[0030] In the embodiment, the pretreatment system (process) includes a system (process or step) for clay addition, coagulant addition, and purification, followed by a system (process or step) for polishing and filtration. All of these systems (processes) are for the removal of solids from the uranium source.

[0031] Primary continuous contact (or primary CIX) system: The primary CIX system (and process) performs two steps: an ion exchange extraction step to remove the target species, i.e., uranium in this case, and the regeneration of the solid medium. The uranium source (4), optionally a pre-treated uranium source, first enters the primary CIX system, where it is brought into contact with a continuous system containing a suitable primary solid medium. As the uranium source passes through the primary solid medium, soluble uranium is transferred from the source to the solid medium. The mechanism may be ion exchange transfer, and the uranium may be in cation form when it is extracted from the source and transferred to the solid medium. Herein, the uranium source (5) can then be returned to the plant. As an example, the uranium source may be a phosphoric acid source, which is returned to the phosphoric acid plant after the transfer of uranium to the primary solid medium. Note that some dilution of the source material may exist, and therefore an evaporation unit may be included for the removal of small amounts of water from the source material. The uranium-loaded primary solid medium is first washed with process water (7) to remove any source solution mixed in from the resin. It is then regenerated by treatment with an alkaline carbonate solution (6), which converts the uranium into an anionic uranyl carbonate complex, which migrates from the solid medium to the solution phase. The treatment then yields the regenerated primary solid medium and a uranium-loaded primary regeneration solution (9) containing the anionic uranyl carbonate complex. In the embodiment, the solid medium in the primary CIX system is an ion exchange medium.

[0032] The gradient elution or resin crowding systems (and processes), described in detail below, are subsystems (subprocesses) of the primary CIX system.

[0033] The primary solid medium for extracting uranium from a source can be any material that chelates or complexes the uranium from the source. The primary solid medium includes a chelate or complexing cation exchange (CE) medium. As described above, the primary solid medium removes uranium from the source in cationic form. The primary solid medium can be a primary CIX resin. Examples of useful resins and / or equivalent materials for the primary solid medium include: -LEWATIT(registered trademark) TP 260 TM A weakly acidic CE resin with chelating aminomethylphosphonic acid groups for the selective recovery of transition heavy metals such as those found in Lanxess, Maharashtra, India. - AMBERLITE IRC-747 TM Aminophosphonose chelate resins such as (Dow; Rohm & Haas, Philadelphia, PA), -S-930 TM A macroporous polystyrene chelating resin with iminodiacetic acid groups, designed for the selective recovery of heavy metal cations such as (Purolite resin, Bala Cynwyd, PA), - A composition or material comprising a chemical having a chelating group, functionality, or moiety that binds uranium, such as an iminodiacetic acid group, an aminomethylphosphonic acid group, an aminophosphonic group, or a similar chelating functionality or moiety. Optionally, the composition or material comprises beads, wires, meshes, nanobeads, nanotubes, nanowires, or other nanostructures, or hydrogels. The chemical may also be a non-resin solid or semi-solid material.

[0034] In embodiments, the primary solid medium may be any resin or equivalent material containing one or more chelating groups, functional groups, or moieties that bind uranium from the source. In embodiments, the chelating groups, functional groups, or moieties bind uranium using their high affinity for phosphoric acid. Examples of one or more such groups or moieties include iminodiacetate groups, aminomethylphosphonic acid groups, and aminophosphonic groups.

[0035] Prior to regeneration, the primary solid medium is pre-treated. The uranium-loaded primary solid medium from the primary contact step is washed with a small amount of water (7) and then transferred to the regeneration pre-treatment step of the primary CIX process. During this part of the primary CIX process, the uranium-loaded primary solid medium is brought into contact with a small amount of alkali carbonate solution (8) that exits the regeneration subsystem (of the primary CIX system) to prepare the primary solid medium for regeneration. The alkali carbonate solution (8) is part of the uranium-loaded regeneration solution that is to be recycled. The spent pre-treatment solution is combined with the uranium-loaded primary regeneration solution (9) that exits the system.

[0036] The pretreatment of the primary solid media can also utilize a portion of the uranium-loaded primary regeneration solution that is initially exited from the regeneration system. This initial solution has a low uranium content and effectively neutralizes any residual acids in the primary solid media. This is important so that when the primary solid media enters the regeneration stage, there are no residual acids that could react with the alkaline carbonate solution and lower its pH.

[0037] Furthermore, if any uranium is present in the pretreatment solution, it will be reloaded onto a solid medium prior to its entry into the regeneration system. This has the additional effect of enabling a certain level of uranium separation from the contaminants by crowding the ion exchange site with uranium.

[0038] Furthermore, it has been discovered that by operating part of the pretreatment steps of the primary CIX process in an upward flow mode, the primary solid medium can expand between each cycle. This expansion allows for periodic cleaning of the solid medium and enables the CIX apparatus to handle much higher levels of solid than either a fixed-bed system or an alternative solvent extraction system. Any solid accumulated in the system is then washed out of the system and transferred to a spent pretreatment solution storage area, and the solid is then discarded. In embodiments, the initial pretreatment solution exiting the upward flow section of the CIX may contain solid and is transferred to a spent pretreatment solution storage area. The solid can be discarded as is, or the spent pretreatment solution is filtered to discard the solid and retain any uranium in the spent pretreatment solution.

[0039] After the regeneration pretreatment step, the pretreated primary solid medium is brought into contact with an alkaline carbonate solution (6) to remove uranium and return the primary solid medium to its extract form. In this step, the alkaline carbonate solution converts the uranium to anionic (extract form), i.e., an anionic uranyl carbonate complex, which has no affinity for the primary solid medium. The uranium then migrates from the primary solid medium in its extract form to the alkaline solution phase that forms the uranium-loaded primary regeneration solution (9). The resulting regeneration solution (9) is then transferred to an evaporation system (primary regeneration solution evaporation system) for concentration of the anionic uranyl carbonate solution. The concentration of uranium in the primary regeneration solution (9) is significantly increased because the resulting volume of the primary regeneration solution is considerably less than the source of uranium loaded onto the solid medium.

[0040] The recycled primary solid media is washed with water before being returned to the primary CIX process.

[0041] In embodiments, suitable alkali carbonate solutions include ammonium carbonate, sodium carbonate, potassium carbonate, and equivalents. The selection of a suitable solution is based on its compatibility with the plant and the overall process. In embodiments, ammonium carbonate is used as the alkali carbonate because it decomposes in the downstream evaporation / decomposition process to produce uranylammonium tricarbonate (AUT), which will reduce the pH of the regeneration solution to be loaded and thus enable uranium precipitation. It is important that the pH during the regeneration stage is above a minimum value. In embodiments, the pH of the uranium-loaded primary regeneration solution is above about pH 9.0. If the pH is below a minimum value, the uranium in the uranium-loaded primary regeneration solution may be reloaded onto the primary solid medium. The minimum value depends on the selected alkali carbonate solution. As an example, an ammonium carbonate solution has a pH in the range of about pH 9.8 to about pH 10.5 due to the addition of ammonium, which is acceptable for this process.

[0042] In the embodiment, if the alkali carbonate solution (6) used to remove uranium from the primary solid medium and form an anionic uranyl complex is ammonium carbonate, the anionic uranyl complex formed is uranyl ammonium tricarbonate, and the resulting uranium-loaded primary regeneration (9) solution contains the uranyl ammonium tricarbonate solution.

[0043] Primary regeneration solution evaporation system and process: In this system (and process), an anionic uranyl carbonate solution is concentrated by evaporation. In embodiments, the uranium-loaded primary regeneration solution (9) is heated in the evaporation system using indirect vapor (10) to concentrate the AUT, decompose excess alkali carbonate, and reduce the pH of the solution. In embodiments, the alkali carbonate solution is ammonium carbonate, and therefore the primary regeneration solution (9) containing the AUT is heated in the evaporation system using indirect vapor to concentrate the AUT, decompose excess ammonium carbonate, and reduce the pH of the solution through the release of ammonia from the solution. As the pH is reduced, the solubility of uranium is reduced, which leads to the formation of uranyl precipitates. The alkaline components resulting from the decomposition, e.g., ammonia (11B), are recovered and recycled, and the resulting solution is combined with a dilute alkali carbonate stream (11A). This allows for a high degree of recycling within the system and minimization of the spent solution resulting either way. Other alkali carbonates can also be used, but ammonium carbonate is preferred because, upon heating, the ammonia component decomposes and is released from the solution, leading to a decrease in pH and a reduction in the solubility of uranium in the solution. This is an important factor because, when using the AUT system, heating and evaporation will decompose the AUT. Other alkali carbonate systems, such as sodium carbonate and potassium carbonate, can also be used in conjunction with reducing the pH of the uranium-loaded primary regeneration solution (9), which requires the use of a certain form of acid to result in uranyl precipitation.

[0044] The primary regeneration solution evaporation system also includes a condenser for recovering compounds decomposed from the regeneration solution, such as ammonia, and enabling the recycling of the compounds.

[0045] Uranyl Precipitate Filtration / Washing / Digestion System and Process: In this system (and process), the uranyl precipitate (11) is first filtered and then washed with a small amount of water (12) to form a filtration cake. The washed filtration cake is then digested with an acid (13) to dissolve the uranium and produce an acidified uranyl salt solution. Acids that can be used to digest the filtration cake include sulfuric acid, nitric acid, hydrochloric acid, and equivalents. Organic acids such as acetic acid, glycolic acid, and equivalents can also be used, but in the context of general recovery, these organic acids are impractical and expensive. An important aspect of the process described herein is that, in order to minimize the introduction of new materials into the entire plant, it is possible to use the acid that is most likely to be present in other operations of the phosphoric acid production process. As an example, sulfuric acid is used when the phosphoric acid source facility uses H2SO4. In terms of production volume, the majority of phosphoric acid plants in the world use H2SO4 as the digesting medium for phosphate ore. The resulting acidified uranyl salt solution (14) is then transferred to a precipitation system (acidified uranyl salt solution precipitation system) for uranium precipitation. Dilute solutions containing alkali carbonate at a lower pH can be recycled into the primary CIX system (11A) and reused in combination with recovered alkali or anionic components (11B).

[0046] This system includes a filtration subsystem for filtering out the uranyl precipitate, a washing system for washing the uranyl precipitate and forming a filtration cake, and a digestion system for digesting the filtration cake with acid to dissolve the uranium and produce an acidified uranyl salt solution.

[0047] Acidified Uranyl Salt Solution Precipitation System and Process: In this uranium precipitation system (and process), an acidified uranyl salt solution (14) is combined with an alkaline solution (15) such as ammonium hydroxide to increase the pH of the solution from approximately 2.5 to approximately 7.0 or from approximately 3.5 to approximately 6. After pH adjustment, a uranium precipitating agent (16) such as hydrogen peroxide is added to form a uranyl peroxide precipitate or slurry (17). The uranyl precipitate or slurry is then transferred to a washing and calcination operation (Uranium Precipitation Washing and Calcination System).

[0048] Other alkaline solutions that may be used include sodium hydroxide, potassium hydroxide, and sodium carbonate or potassium carbonate.

[0049] Hydrogen peroxide is a preferred precipitant for producing high-quality uranium oxide, but other precipitants can also be used. For example, ammonium hydroxide, ammonium carbonate, sodium hydroxide, sodium carbonate, or potassium hydroxide can be used as precipitants. These precipitants can be used by increasing the pH of the solution to 7 or above. As an example, the use of ammonium hydroxide will result in the formation of an ammonium diuranate compound at a higher pH, which may contain higher levels of impurities that need to be removed. Another preferred uranium compound is uranium oxide, which is formed using hydrogen peroxide as a precipitant. Other forms of uranium formed using other precipitates have limited uses other than for power and defense.

[0050] Precipitated Uranium Washing / Castration System and Process: In this system (and process), when the uranyl precipitate (17) enters the process step, a small amount of pH adjusting reagent (18) is added to adjust the pH of the precipitate. If the pH of the precipitate is low, for example below pH 2, an alkaline solution may be used for adjustment. If the pH is too high, for example above pH 5, a small amount of acidic solution may be added. Examples of alkaline solutions for increasing pH include ammonium hydroxide, and examples of acidic solutions for decreasing pH include sulfuric acid.

[0051] The mixture is then purified, and the thickened uranyl precipitate is washed with a small amount of water (19). The uranyl solid is then centrifuged, and the recovered uranyl solid is transferred to a dryer / calcinerator system, where the uranyl solid is decomposed to produce uranium oxide products (21). Optionally, the process as described herein may further include the step of separating the uranyl precipitate from the solution phase by sedimentation, filtration, centrifugation, or similar procedures, and then washing the uranyl precipitate with water. Washing may include the step of washing the uranyl precipitate on a filter, or the step of repulping the uranyl precipitate with water, followed by sedimentation, filtration, centrifugation, or similar procedures, and optionally further includes additional washing of the uranyl precipitate with water to remove most of any contaminated secondary solution (uranium-free) via additional filter washing, washing in a centrifuge, or optional additional repulping with water, followed by sedimentation.

[0052] In the embodiments, the precipitating agent used is hydrogen peroxide, and therefore the uranyl precipitate formed is uranyl peroxide (UO42H2O). The process described herein optionally includes the step of separating the uranyl peroxide from the solution phase by sedimentation, filtration, centrifugation, or equivalent, and then washing the uranyl peroxide with water. The process described herein further includes the step of drying the uranyl peroxide in a dryer / calcinerator system to form a dry solid material. In the dryer / calcinerator system, the uranyl peroxide is heated to a temperature sufficient to decompose or calcine the uranyl peroxide and form a uranium oxide compound, such as U3O8.

[0053] It should be noted that the precipitated uranium at this stage is a uranyl peroxide compound, which, if desired, can be washed and dried without calcination to produce a dried U peroxide material. However, typically, the material is calcined to produce uranium oxide (U3O8) to produce a standard product for commercial use.

[0054] The spent solution from washing the uranyl precipitate is collected and filtered. In the embodiment, the spent solution is recycled to an upstream process to minimize the total amount of aqueous spent solution (20) in the plant.

[0055] In the embodiment, the calcined oxide product (U3O8) is lightly crushed and then placed into drums for storage and shipment. The drum loading system can be used to minimize the potential for dust generation. Dual-cycle continuous ion exchange (CIX) systems and processes

[0056] The uranium recovery processes described herein also include dual-cycle CIX apparatus and processes. In a dual-cycle CIX process, two separate solid contact media are used to extract uranium from a uranium source. Exemplary embodiments of dual-cycle CIX apparatus and processes are shown in Figure 2.

[0057] In this embodiment, the dual-cycle CIX apparatus for uranium recovery can be divided into the following main systems (ports): A pretreatment system that may include acid cooling of the uranium source and filtration and / or purification of the uranium source. A primary continuous contact (or primary CIX) system containing a primary CIX system, along with the systems and peripheral equipment typically associated with the primary CIX system, such as a surge tank, regeneration solution preparation (e.g., ammonium carbonate), regeneration pretreatment solution preparation (e.g., ammonium hydroxide), and equivalents. A gradient elution and / or resin crowding system (subport or subsystem), which may be part of a primary continuous contact system, for further removal of contaminants from the uranium source. A secondary continuous contact (or secondary CIX) system containing a secondary CIX system, along with the system required for the preparation of the secondary pretreatment regeneration solution (of the secondary CIX system) and the peripheral equipment typically associated with it as discussed above. A gradient elution and / or resin crowding system (subport or subsystem), which may be part of a secondary continuous contact system for further removal of contaminants from a uranium source, A secondary uranium loading and regeneration solution is pH-adjusted, and soluble uranium compounds are precipitated as insoluble uranyl compounds in a secondary regeneration solution precipitation system. A uranium precipitation washing and calcination system in which insoluble uranyl compounds are washed, and subsequently the uranyl compounds are dried and calcined to produce a form of uranium such as uranium oxide.

[0058] The dual-cycle CIX process may also include uranium storage and automated packaging systems and steps, which are standard operation and will not be described in detail here. The dual-cycle CIX process uses a dual-cycle CIX apparatus to recover uranium. The dual-cycle process is described below.

[0059] In the embodiment, at least one of the primary CIX system or the secondary CIX system includes a gradient elution or resin crowding system. In the embodiment, both the primary CIX system and the secondary CIX system include a gradient elution or resin crowding system.

[0060] Pre-processing system and process: The pre-processing process is described above for a single-cycle CIX and is therefore not repeated here.

[0061] Primary continuous contact (or primary CIX) system: Similar to the primary CIX system (process) of a single-cycle CIX, the primary CIX system (and process) of a dual-cycle CIX performs two steps: an ion exchange step and a solid medium regeneration step. A uranium source (4), optionally a pre-treated uranium source, first enters the primary CIX system, where it is contacted in a continuous system containing a suitable primary solid medium. As the uranium source passes through the primary solid medium, soluble uranium is transferred from the source to the solid medium. The mechanism can be ion exchange transfer, and the uranium may be in cation form when it is extracted from the source and transferred to the solid medium. Herein, the uranium source (5) can then be returned to the plant. As an example, the uranium source may be a phosphoric acid source, which is returned to the phosphoric acid plant after the transfer of uranium to the solid medium. The uranium-loaded primary solid medium is then regenerated using an alkaline carbonate solution (9) to convert the uranium into an anionic uranyl carbonate complex, thereby producing a uranium-loaded primary regeneration solution containing the regenerated primary solid medium and the anionic uranyl carbonate complex.

[0062] The gradient elution or resin crowding systems (and processes), described in detail below, may be included as subsystems (subprocesses) of the primary CIX system.

[0063] The primary solid medium for extracting uranium from the source can be any material that chelates or complexes the uranium from the source, as described above under the single cycle CIX. Therefore, the information is not repeated here.

[0064] Prior to regeneration, the primary solid medium is pre-treated. The uranium-loaded primary solid medium is washed with a small amount of water (6) contained within it and then transferred to the regeneration pre-treatment step of the primary CIX process. During this part of the primary CIX process, the uranium-loaded primary solid medium is brought into contact with an alkaline pre-treatment solution (7) to prepare the medium for regeneration. The alkaline pre-treatment solution used during the regeneration pre-treatment step is a weak alkaline solution such as ammonium hydroxide, which neutralizes any residual free acids in the solid medium. The spent alkaline pre-treatment solution (8) can be sent to a wastewater system or recycled for other use. Other weak alkaline solutions that may be used include weak sodium hydroxide, weak potassium hydroxide, and equivalents. However, weak ammonium hydroxide is preferred due to its compatibility with the CIX process and, in particular, its common use in many phosphate complex facilities where ammonium fertilizers are produced.

[0065] Following the pretreatment of the primary solid medium, the uranium-loaded primary solid medium is regenerated using an alkaline carbonate solution (9) to convert the uranium into an anionic uranyl carbonate complex that has no affinity for the primary solid medium, and this is added to the regenerated primary solid medium to produce a uranium-loaded primary regeneration solution (10). Examples of alkaline carbonate solutions include ammonium carbonate, sodium carbonate, and potassium carbonate. The selection of an appropriate alkaline solution is based on its compatibility with the plant and the overall process. In the embodiment, the anionic uranyl carbonate complex is an ammonium uranyl tricarbonate complex when the alkaline carbonate solution is ammonium carbonate. As shown, the steps performed in the primary stage of the dual-cycle CIX process are essentially identical to the CIX operation in the single-cycle approach.

[0066] Uranium, therefore, migrates from the primary solid medium to the alkali carbonate solution phase. The resulting uranium-loaded primary regeneration solution has a smaller volume compared to the volume of the uranium source used and contains a higher concentration of uranium in the solution. The resulting uranium-loaded primary regeneration solution (10) is then transferred to the secondary CIX system. The concentration of uranium in the primary regeneration solution (10) is significantly increased because the resulting volume of the primary regeneration solution is considerably less than the uranium source loaded onto the solid medium.

[0067] The recycled primary solid media is washed with water before being returned to the primary CIX process.

[0068] As mentioned in the single-cycle CIX process, if the pH falls below a certain level, uranium in the primary regeneration solution can be reloaded onto the primary solid medium; therefore, it is important that the pH during the regeneration phase is above a minimum value. Information regarding the importance of pH during the regeneration phase will not be repeated here.

[0069] Furthermore, similar to a single-cycle CIX process, by operating part of the pretreatment in an upward flow mode, the primary solid medium can be expanded between each cycle, which allows for periodic cleaning of the solid medium and enables the CIX process to handle much higher levels of solid than either a fixed-bed system or an alternative solvent extraction system. Any solid accumulated in the system is then washed out of the system and transferred to a spent pretreatment solution storage area, and finally, the solid is discarded. In embodiments, the initial pretreatment solution exiting the upward flow section of the CIX may contain solid and is transferred to a spent pretreatment solution storage area. The solid can be discarded as is, or the spent pretreatment solution is filtered to discard the solid and retain any uranium in the spent pretreatment solution.

[0070] Secondary continuous contact (or secondary CIX) system and process: In this system (and process), the uranium-loaded primary regeneration solution (10) is brought into contact with a secondary CIX solid medium (second ion exchange system), and uranium is extracted from the primary regeneration solution using a strong anionic resin and loaded onto the strong anionic resin. The secondary regeneration solution is an acid other than phosphoric acid, and may be an inorganic acid such as sulfuric acid (H2SO4), nitric acid (HNO3), hydrochloric acid (HCl), and equivalents. H2SO4 is preferred in this case because it is used in most (but not all) phosphoric acid facilities as an acid source for digesting phosphate rock to produce so-called wet process phosphoric acid. The secondary CIX system may be considerably smaller than the primary CIX system, and different solid media may be used. However, the principle of operation is similar to that used in the primary CIX system.

[0071] The uranium (anionic uranyl carbonate) contained in the primary regeneration solution (10) is transferred to a secondary solid medium. The secondary solid medium comprises a strongly anionic ion exchange resin (AE) medium or an equivalent material. Therefore, the secondary solid medium has a high affinity for the anionic uranyl carbonate complex in the primary regeneration solution (10). In the embodiment, a dilute primary regeneration solution (11) from the secondary system is recycled to the greatest extent possible.

[0072] Strong anion exchange resins are commercially used for processing conventional uranium-supported solution sources, such as those produced in some of the popular in-situ uranium leaching processes. In this disclosure, the use of AEs is incorporated into a novel process for the recovery of uranium from phosphoric acid. The AEs are used after the uranium has been removed from the phosphoric acid and transferred to another solution phase, such as ammonium carbonate. The "conventional" ion exchange approach, i.e., the direct use of conventional cationic or anionic resins with phosphoric acid, is impractical due to the highly complex nature of uranium in the phosphoric acid medium. Therefore, stronger techniques, such as complexing or chelate ion exchange resins, are required to remove uranium from phosphoric acid. Once the uranium has been transferred to a more "conventional" solution phase, such as ammonium carbonate, approaches based on some modifications of current techniques, such as anion exchange, can be used. Some of the chemistry for the second CIX of a dual-cycle CIX system is similar to conventional methods, but necessary adaptations still exist, such as methods in which secondary extraction and subsequent regeneration are incorporated into the overall processing system in order to have an integrated process approach.

[0073] The gradient elution or resin crowding systems (and processes), described in detail below, may be included as subsystems (subprocesses) of the secondary CIX system.

[0074] The secondary solid medium can be any strong anionic ion exchange material that extracts anionic uranium from the primary loading and regeneration solution (10) by using corresponding ion exchange between an anionic uranium complex in the primary loading and regeneration solution (10), such as uranyl carbonate anion, and an anion on the regenerated anionic resin, such as sulfate (SO4) anion. The secondary solid medium should be a strong anionic ion exchange material. Examples of resins or equivalent materials relating to the secondary solid medium include the following: -LEWATIT(registered trademark) K 6267 TMA strongly basic anion exchange resin with type II quaternary ammonium functional groups for the selective recovery of anionic heavy metal complexes such as those from Lanxess, Maharashtra, India. -Dow-Rohm / Haas 21K and other established strong anionic resins in the conventional uranium recovery industry, -PUROLITE A-600 TM A strongly basic anion exchange resin with type I quaternary ammonium functional groups for the selective recovery of anions such as (Purolite, Bala Cynwyd, PA), - A composition or material comprising a chemical having one or more chelating groups, functionalities, or moieties that bond an anionic uranyl complex. For example, the chelating groups, functionalities, or moieties comprise type I or type II quaternary ammonium functional groups. Optionally, the composition or material comprises beads, wires, meshes, nanobeads, nanotubes, nanowires, or other nanostructures, or hydrogels. The chemical may also be a non-resin solid or semi-solid material.

[0075] In the embodiment, the secondary solid medium may be any resin or equivalent material containing type I or type II quaternary ammonium functional groups.

[0076] In this embodiment, the secondary solid medium is sulfuric acid (SO4). -2 It contains strongly anionic anionic groups such as (SO4), which, in exchange for the anionic uranyl carbonate species originally present in the primary loading and regeneration solution from the primary CIX system, transfer strongly anionic anions, such as (SO4), through the migration of the anionic groups from the resin (solid) phase to the liquid phase. -2 Uranium extraction is carried out via anion exchange. It should be noted that other strong anionic groups, such as nitrates (NO3) or chlorides (Cl), may also be used. However, the preferred material is H2SO4, as this is generally the most common acid solution used in the phosphoric acid industry.

[0077] The loaded secondary solid medium is then pre-treated for regeneration by washing with water (12). The washed medium is then regenerated by contact with a secondary regeneration solution (13), which is a strong acid such as H2SO4, but is diluted with water to produce a lower concentration acidic solution for use as a regeneration material. Herein, the uranium-loaded secondary regeneration solution (14), which contains a high concentration of uranium, is then transferred to the uranium-loaded secondary regeneration solution precipitation system. The regenerated secondary solid medium is washed with water before returning to the secondary CIX process. After washing with water, the solid medium is washed with a small amount of weak ammonium hydroxide (not shown) to neutralize any trace amounts of H2SO4 that may remain in the medium. This is done so that the pH of the resin medium entering the secondary loading or extraction section of the CIX is within the same range as that of the loading regeneration solution obtained from the primary CIX system. In this way, uranyl carbonate is maintained as a strong anion in the primary solution (10) fed into the secondary cycle.

[0078] In the initial startup, the uranium-loaded secondary regeneration solution (14) may not be of sufficient purity. The initial uranium-loaded secondary regeneration solution (14) can be recycled and / or stored. Under normal conditions, even if the plant is shut down, once the process has progressed, a purified solution will be available for storage and use in restarting the plant.

[0079] The use of an acidic secondary regeneration solution enhances secondary regeneration by ensuring that all uranium is converted back into a cationic form that has no affinity for the anionic secondary solid medium. In embodiments, the secondary regeneration solution (13) may be dilute sulfuric acid, dilute nitric acid, dilute hydrochloric acid, or an equivalent solution. The acid selected for the secondary regeneration solution depends on the acid source used for the production of phosphoric acid and whether there are any unique circumstances associated with the particular uranium recovery operation. In embodiments, sulfuric acid is used due to its compatibility with the existing phosphoric acid operation when the uranium source is a phosphoric acid source. In this system, an acidic material is used for regeneration. However, other regeneration solutions are also used in other applications. Typically, these would be neutral salts of strong acid materials. These would include salts of ammonium sulfate, ammonium nitrate, ammonium chloride, sodium chloride, sodium nitrate, sodium sulfate, potassium salts, and equivalents. With regard to uranium recovery from a phosphoric acid system, H2SO4 is a preferred regeneration solution for secondary CIX anion exchange.

[0080] In the embodiment, when ammonium carbonate is used as the primary regeneration solution in the primary CIX process and sulfuric acid is used as the secondary regeneration solution in the secondary CIX process, the cation form of uranium in the uranium-loaded secondary regeneration solution is an acidic uranylammonium sulfate solution.

[0081] In the past, concerns arose regarding the use of low-pH solutions for the regeneration of anionic media because residual carbonate solutions remaining in the media after secondary loading would react with acids, decompose, form salts, and release carbon dioxide into the media bed. However, by implementing the CIX approach as described herein, a portion of the regeneration system can be operated in an upward flow mode, and by operating the initial regeneration contact in this mode, a certain level of decomposition occurs, and the released carbon dioxide actually helps to expand the media bed, enabling a certain level of media cleanup at the start of the secondary regeneration stage.

[0082] The use of the upward flow mode is discussed above in relation to the pretreatment regeneration of the primary CIX process. In embodiments, the CIX process described herein may be operated with or without air assistance to assist the upward-flowing liquid so that it can be washed away from the solid medium as it expands the medium bed and relaxes the accumulated solids. In the case of the secondary CIX process, the release of carbon dioxide in the medium bed enables "in-situ" gas formation and subsequent solid medium refining.

[0083] The regenerated secondary solid medium can be treated with water to remove any contaminating acidic regeneration solution. The secondary solid medium can further be post-treated with an alkaline solution (not shown) to neutralize any residual acid in the medium before re-entering the secondary CIX process. Typically, this alkaline solution would consist of weak ammonium hydroxide, similar to that used in the primary CIX system following a post-loading water wash to remove trace amounts of phosphoric acid from the loaded resin prior to the ammonium carbonate regeneration step.

[0084] Secondary regeneration solution precipitation system and process: In this precipitation system (and process), the uranium-loaded secondary regeneration solution (14) is combined with an alkaline solution to increase the pH of the uranium-loaded secondary regeneration solution to approximately pH 2.5 to approximately pH 7.0 or approximately pH 3.5 to approximately pH 6. After pH adjustment, a precipitant (16) is added to form a uranyl precipitate or slurry. The uranyl precipitate or slurry is then transferred to a uranium precipitation washing and calcination system for decantation, washing, and calcination.

[0085] Examples of alkaline solutions that can be used to increase the pH of the uranium loading secondary regeneration solution include ammonium hydroxide, potassium hydroxide, and sodium hydroxide. Ammonium hydroxide is the preferred alkali because it is generally used elsewhere in the process and can therefore be composed at a single point for use throughout the entire process. The alkaline solution can have a concentration of 10% to 30%. Optionally, the alkaline solution has a pH greater than 10 in its solution form.

[0086] The precipitating agent in this example is hydrogen peroxide. In this example, when hydrogen peroxide is added to a pH-adjusted uranium-loaded secondary regeneration solution, the uranyl precipitate formed is uranyl peroxide. Hydrogen peroxide is added in sufficient quantities to form uranyl peroxide, allowing excess peroxide to be present in the solution and ensuring complete uranyl peroxide precipitation. It is important to note that H2O2 is used as a precipitating agent because uranyl peroxide will precipitate from the uranium-loaded solution at a slightly acidic pH. For example, with pH adjustment of the loading secondary solution to pH 3-4, the peroxide material will precipitate. Equally important is that many of the other impurities that may be present in the secondary loading solution will not precipitate under acidic conditions and therefore may remain in the solution phase. Thus, a higher degree of uranium purity is achieved.

[0087] Other methods exist for precipitating uranium from a secondary charging solution by adding an alkaline solution such as ammonium hydroxide, raising the pH of the solution to a level above 7, and forming a weakly alkaline solution. In such cases, uranium can be precipitated as uranylammonium diuranate. Sodium hydroxide or potassium hydroxide can also be used for alkaline precipitation. These precipitants can be used to increase the pH of the solution to 7 or above. As an example, the use of ammonium hydroxide will result in the formation of an ammonium diuranate compound at a higher pH, which may contain higher levels of impurities that would need to be removed.

[0088] Furthermore, a preferred product is uranium oxide, formed using hydrogen peroxide as a precipitating agent. Therefore, the use of hydrogen peroxide precipitation is a preferred method for introducing minimal impurities, as the precipitation occurs under weakly acidic conditions.

[0089] Precipitated Uranium Washing / Castration System and Process: In this system (and process), for example, pH adjustment, washing, and calcination of uranyl precipitates for forming uranium oxide compounds or uranium are discussed under a single-cycle CIX process. Therefore, the information is not repeated here.

[0090] The final product will likely be uranium oxide. This product will be similar to U3O8, which is produced from conventional uranium recovery operations using various uranium ores (not phosphoric acid) as raw materials.

[0091] Many parts of the dual-cycle and single-cycle CIX procedures, such as acid sweeping, most of the primary extraction, and the precipitation and drying portions to the final product, can be the same. One major difference between the two processes is that in the dual-cycle, a second CIX system is present, while in the single-cycle, a single CIX system is present. In the single-cycle CIX process, the second CIX system is essentially replaced by a primary regeneration solution evaporation system and a different treatment of the concentrated primary regeneration solution (in each figure (14)) for preparing the acidified uranyl solution, which is common to both processes. From there, the processes are substantially identical. Gradient elution (GE) and resin clogging (RC) systems and processes

[0092] It has been found that some contaminants, when loaded onto a solid medium with uranium and a regeneration solution is applied during the regeneration stage, are eluted and removed along with the uranium. Therefore, uranium-loaded primary and secondary regeneration solutions often contain contaminants in addition to uranium. As an example, the source of uranium, such as phosphoric acid, may contain dissolved iron. A small portion of the iron can be co-extracted with the uranium onto the primary CIX chelate resin. Although the proportion of dissolved iron in the acid co-extracted is small, the starting amount of iron can be high, and therefore, a good portion of iron still exists to be loaded onto the primary resin with the uranium for uranium recovery.

[0093] This disclosure describes processes for further removal of contaminants to increase the purity of recovered uranium obtained from single and dual-cycle CIX processes. These processes include gradient elution (GE) and resin clogging (RC). The GE and RC processes remove contaminants before the removal of uranium from the solid medium, which reduces the amount of contaminants in the final uranium product and results in a higher quality uranium product. Both of these processes utilize the strong affinity of uranium for the CIX medium compared to contaminants, which results in the selective removal of contaminants from the uranium.

[0094] Gradient Elution (GE) Systems and Processes: In GE systems (and processes), in the case of primary CIX systems, a weak solution of alkaline carbonate regeneration solution or a diluted solution of acidic regeneration solution, which will be used in secondary CIX systems, is applied to the solid medium during pretreatment. The appropriate choice of acid or base solution depends on whether the solid medium is a chelate or complexed cationic ion exchange (CE) medium or an anionic ion exchange (AE) medium. In the case of AE media, which are in secondary CIX systems, a diluted acidic solution is used for the removal of anions, which are non-uranium anions, from the medium. The concentration of the acidic solution will be started at a value of less than 1 / 3 of that of the actual solution that will be used for resin regeneration and uranium removal. The pH will be slightly higher, by about 1 pH point, than that of the actual regeneration solution. Non-uranium anions have a lower affinity for the AE medium than the uranyl complexes that bind to the AE medium. Therefore, even with a diluted regeneration solution, many of the non-uranium ions can be removed from strongly anionic resins. Regarding the uranium recovery process, it has been found that in this system, uranium has some of the highest affinity for the resin compared to other ions present. Therefore, some of the non-uranium ions can be removed by first treating the resin with a solution weaker than that required to remove the uranium. After the initial treatment with the weakest acidic solution, the process continues by applying increasingly strong diluted acidic solutions to the AE medium, continuously removing non-uranium anions from the AE medium until a practical point is reached where the additional acid treatment will begin to remove uranium along with any remaining impurities. The maximum allowable strength for the gradient solution material will depend on the actual operating conditions, but in approximate terms, the maximum strength will be estimated to be 40% of the actual strength of the acid that will be used for recovery and uranium removal. These values ​​may vary but can be determined and controlled empirically.

[0095] Various known methods exist for producing dilute acid gradient solutions of varying strengths. Examples of dilute acid solutions that can be used in combination with AE media in GE include dilute sulfuric acid, dilute hydrochloric acid, and dilute nitric acid. The acid selected depends on its compatibility with the rest of the process. In some embodiments, when the uranium source is the phosphoric acid source, sulfuric acid is the most suitable acid for the entire process and system.

[0096] In the case of complexing or chelate cation exchange (CE) media (in the primary CIX system), a diluted base solution is used. In this case, the solution is prepared by diluting a portion of the primary alkaline regeneration solution (ammonium carbonate). The same process as described above is used for the diluted base solution, including increasing the strength of the diluted base solution to remove non-uranium cations that have a lower affinity for the CE medium. Examples of diluted base solutions that may be used in combination with the CE medium include diluted ammonium carbonate, diluted sodium carbonate, and diluted potassium carbonate. The base selected depends on its compatibility with the rest of the process. In the embodiment, the alkaline solution is ammonium carbonate, since this is the solution that will be used for the primary regeneration step.

[0097] The single and double-cycle CIX processes described herein may include a GE process in the primary and / or secondary CIX processes. In a single-cycle CIX process, the solid medium in the primary CIX process is a CE medium. Therefore, a diluted base solution is a suitable solution to be used for gradient elution. Similarly, in a double-cycle CIX, the solid medium in the primary CIX process is a CE medium, and therefore, a suitable solution is also a diluted base solution. However, in a double-cycle CIX, the solid medium in the secondary CIX process is an AE medium. Therefore, in the GE process, a suitable solution to be used in conjunction with the AE medium is a diluted acidic solution.

[0098] The GE process is performed during the regeneration pretreatment step of the primary or secondary CIX medium, after uranium has been loaded onto the primary or secondary CIX medium and before the regeneration of the primary or secondary CIX medium. In embodiments, GE is performed during the primary regeneration pretreatment step of the primary CIX process in both single and dual-cycle CIX processes. GE is initiated after the uranium-loaded CE medium, i.e., the primary CIX medium, has been washed with a small amount of water. In embodiments, during the GE of the primary CIX process, an increased-strength diluted base solution, such as a diluted carbonate solution, is used to remove non-uranium cations. The strength of the diluted base solution is increased until most of the contaminants have been removed from the CE medium, but uranium is left on the resin to be removed in the primary regeneration step. The diluted base solution includes a diluted ammonium carbonate solution, a diluted sodium carbonate solution, or a diluted potassium carbonate solution. In embodiments, the diluted base solution is a diluted ammonium carbonate solution.

[0099] After the removal of most of the contaminants, the CE medium is in a regenerative state, which involves the step of converting the uranium on the CE medium to anionic uranyl carbonate using alkali carbonate (primary regeneration solution), as discussed above.

[0100] The GE process can also be performed during the secondary regeneration pretreatment step of the secondary CIX process in a dual-cycle CIX process. Similar to the primary CIX process, GE can be initiated after the AE medium, i.e., the secondary CIX medium, loaded with uranyl carbonate complexes, has been washed with a small amount of water. In embodiments, during the GE of the secondary CIX process, an increased-intensity weak sulfuric acid solution is used to remove non-uranium anions. The intensity of the dilute sulfuric acid solution is increased until most of the contaminants are removed, but uranium is not removed at this stage and is left for removal in the regeneration step.

[0101] After the removal of most of the contaminants, the AE medium is in a state where it can be regenerated, as described herein, by a secondary regeneration solution, i.e., a weak acid, which is used to convert the uranium on the AE medium into a cation form.

[0102] In the embodiment, when ammonium carbonate is used as the primary regeneration solution in the primary CIX process and sulfuric acid is used as the secondary regeneration solution in the secondary CIX process, the cation form of uranium in the uranium-loaded secondary regeneration solution is an acidic uranylammonium sulfate solution.

[0103] In the embodiments, the GE process is carried out in the primary or secondary CIX process of a dual-cycle CIX process. In the embodiments, the GE process is carried out in both the primary and secondary CIX processes of a dual-cycle CIX process. The use of this technique in both cycles of a dual-cycle system provides further assurance of contamination control.

[0104] In the embodiment, the GE system carrying out the GE process includes several zones within the CIX system itself. In each zone, acids or bases of different strengths can be applied to the CE or AE medium to remove some of the contaminants. The GE system will be run before the actual regeneration step. Following the GE portion of the process, the solid medium will enter the actual regeneration zone within the CIX system for the removal of uranium from the solid medium, which involves treatment of the solid medium with an alkaline or acidic regeneration solution and subsequent conversion of the solid medium to the form required to be returned to the loading portion of the process. The GE system may include 1 to 50 zones. The GE system may include 1, 2, 3, 4, or 5 zones. The GE system may include 1 to 50 zones, 5 to 45 zones, 10 to 40 zones, 15 to 35 zones, 20 to 34 zones, 22 to 33 zones, or 24 to 32 zones. The number of zones used for GE will depend on the specific system and the required scope of contamination control.

[0105] Figure 3 shows an example of a GE system and process, including a zone, used in conjunction with a secondary CIX process to remove anionic contaminants. A chamber containing an AE medium (1) loaded with a uranyl carbonate complex (from the primary regeneration solution) enters zone X of the GE process. Note that the zones are referred to as X, X-1, etc. This convention was chosen to allow focus on the GE step, regardless of the actual zones that may exist in a commercial system. Depending on the process, there may be several zones, e.g., 24 to 32, for a given commercial unit. Therefore, a general method was used rather than selecting zone numbers for explanatory purposes. In some processes, zone X may be the actual zone 24 in specific cases. In this case, zone X-1 would be zone 23. In other processes, the zone numbers may differ. Therefore, the use of X, X-1, etc. eliminates the need for specific numbering. An important point to recognize is that the resin chamber moves from right to left in this embodiment, i.e., from zone X to zone X-1, etc. The AE medium (1) is brought into contact with a sulfuric acid solution (2) that is considerably weaker than the acid strength used for the actual removal of uranium from the resin. The weakest sulfuric acid solution passes through the resin and removes anions that have a lower affinity for the resin than uranyl carbonate complexes. The used weakest solution (3) is then discharged from the system.

[0106] The chamber containing the solid medium is then transferred to area X-1. In area X-1, the resin is brought into contact with a medium-strength sulfuric acid solution (4). The strength of the solution is controlled so that additional contamination is removed from the resin, but again, the acid in this area is weaker than what is required to remove uranium from the resin. The spent medium-strength sulfuric acid (5) is also discharged from the system.

[0107] Depending on how the uranium recovery unit is integrated into the phosphate complex, opportunities may arise to utilize these spent solutions in other operations within the overall phosphate production facility. These are advantageous factors that can be employed to enhance the economic attractiveness of the process for specific phosphate operations.

[0108] After treatment with moderate-intensity sulfuric acid, the chamber containing the solid medium is then transferred to area X-2. In this area, the regeneration solution used for countercurrent contact with the solid medium chambers in areas X-4 and X-3 is collected from area X-3 and fed to area X-2 for final regeneration contact. The uranium-loaded secondary regeneration solution exiting area X-2 is transferred to the uranium-loaded secondary regeneration solution precipitation system (8). In areas X-2-X-4, the AE medium is brought into countercurrent contact with the strongest sulfuric acid (6), which is fed from area X-4 to area X-3 and then to area X-2. This countercurrent contact approach is used to maximize the potential concentration of uranium in the uranium-loaded secondary regeneration solution (8) exiting the CIX system and to provide efficient regeneration of the medium with minimal amounts of fresh regeneration solution.

[0109] The regenerated AE medium (7) is then transferred to a post-regeneration water washing step and finally returned to the secondary CIX system, where it is again brought into contact with fresh primary regenerated solution obtained from the primary CIX system.

[0110] The GE process allows for the treatment of primary or secondary media for the selective removal of anions from resins. For example, by utilizing the affinity of various anions to AE resins in a secondary CIX system, sulfuric acid of varying strengths can be used to separate contaminants from the AE resin before U is removed. As shown, the same process concept can be applied to a primary CIX system, except that in this case, an alkaline carbonate solution, e.g., ammonium carbonate, is used instead of an H2SO4 solution. The operating concept is identical. The only difference is that in the primary system, an alkaline carbonate gradient is used.

[0111] Resin Crowding (RC) Systems and Processes: The RC process may be performed during the regeneration pretreatment step of the primary or secondary CIX medium, after uranium has been loaded onto the primary or secondary CIX medium and before the regeneration of the primary or secondary CIX medium. The single-cycle or dual-cycle CIX processes described herein may also include an RC system (and process). In a single-cycle CIX process, RC may be performed during the regeneration pretreatment step of the primary CIX process. In a dual-cycle CIX, RC may be performed during one or both of the primary and secondary regeneration pretreatment steps of the primary and secondary CIX processes.

[0112] In both single and dual-cycle CIX systems (and processes), the RC can be initiated after the uranium-loaded CE medium (primary CIX medium) has been washed with a small amount of water. A portion of the uranium-loaded primary regeneration solution, either recycled / stored or (low-purity) initial starting uranium-loaded regeneration solution, is pH-adjusted using a dilute sulfuric acid solution. pH adjustment converts the anionic composite uranium in the solution into a cation form so that it has affinity for the CE medium and can be reloaded onto it. The pH-adjusted solution (cloud solution) is applied to the CE medium. Due to the affinity of uranium in the CE medium for other ions present, the uranium in the cloud solution displaces non-uranium contaminants, resulting in the CE medium being more completely loaded with uranium before regeneration. It is important to note that even a relatively small pH reduction in the loaded primary regeneration solution will cause the uranium component to be reloaded onto the primary CE medium. This sensitivity was discovered during regeneration tests of primary CE medium using an ammonium carbonate solution. If a pH reduction in the regeneration solution were present, for some reason, the uranium would not be removed from the CE medium; rather, the uranium that was in the regeneration solution would be loaded back onto the CE medium. This was a clear adverse effect on regeneration efficiency, but it showed the potential for slight pH adjustments to a portion of the primary loading regeneration solution to allow for reloading onto the resin before complete regeneration and "clouding" of non-uranium ions on the CE medium.

[0113] Examples of dilute acids used to reduce the pH of a portion of the primary charge-regenerate solution (uranylammonium carbonate) to produce a small amount of clouding solution for RC in the primary CIX process include sulfuric acid, nitric acid, and hydrochloric acid. In the embodiments, sulfuric acid is used because it is most compatible with process systems that use phosphoric acid as the source of uranium. In accordance with the addition of the dilute acid to a portion of the primary charge-regenerate solution (uranylammonium carbonate), the pH of the solution is reduced to a target value. Typically, the charge-regenerate solution has a pH in the range of 10.0 to 10.5. With slight acidification, the pH of the portion that will be used for clouding is reduced to about 8.0 to 8.5. Under these conditions, the uranium contained is in a non-anionic form.

[0114] After crowding, most of the non-uranium contaminants were removed, and additional uranium was reloaded onto the resin. The CE medium was then made regenerative, as described herein, with the step of converting the uranium on the CE medium to anionic uranyl carbonate using alkali carbonate (primary regeneration solution).

[0115] RC can also be performed during the secondary regeneration pretreatment step of the secondary CIX process in a dual-cycle CIX process. Similar to the primary CIX process, RC can be initiated after the ureanyl carbonate-loaded AE medium (secondary CIX medium) has been washed with a small amount of water. A portion of the uranium-loaded secondary regeneration solution (e.g., uranyl sulfate solution) from storage / regeneration of a previous cycle or from the initial start is pH-adjusted using a diluted base solution and applied to the AE medium. pH adjustment converts the uranium in the solution into anionic form so that it has affinity for the AE medium and can be reloaded onto it. Due to the affinity of uranium for the medium to other ions present, the uranium in the cloud solution displaces non-uranium contaminants, resulting in the AE medium being more completely loaded with uranium before regeneration.

[0116] Examples of bases that may be used in the secondary CIX process include ammonium hydroxide, sodium hydroxide, and potassium hydroxide. In the embodiment, ammonium hydroxide is used because it is compatible with the overall process system.

[0117] After "crowding" of impurities from the resin and substitution with uranyl anion complexes, the AE medium is in a state where it can be regenerated, which involves a secondary regeneration solution, i.e., dilute sulfuric acid, to convert the uranium on the AE medium into a cation form.

[0118] In the embodiment, the RC system carrying out the RC process includes one or more sections. In each section, a pH-adjusted loaded regeneration solution from either a primary or secondary CIX system is pH-adjusted according to the CIX on which the RC is being performed, and then applied to either a CE or AE medium to remove contaminants. The pH-adjusted primary or secondary regeneration solution may be obtained from another section, such as a later section in the sequence of sections, through which a chamber containing the CE or AE medium passes during the regeneration process. Following the RC section of the CIX system before regeneration, the solid medium chamber moves through the regeneration section following the RC. The RC section for each CIX system, either CE or AE, can consist of any number of ion exchange sections, but typically, the RC section will have 1 to 5 sections. The number of sections depends on the specific operating characteristics of the CIX, either CE or AE. Following the RC section of the CIX, the "crowded" resin is processed in the regeneration section of the CIX, where it is brought into contact with a selected regeneration solution. In this system, an ammonium carbonate solution will be used for CE, and dilute sulfuric acid will be used for AE.

[0119] Figure 4 shows an example of an RC system and process, including an area, used in conjunction with a secondary CIX process to remove anionic contaminants. The secondary CIX (AE) medium is sulfuric acid (SO4). -2Uranium extraction is performed via anion exchange with . After washing, AE medium (1) loaded with uranyl carbonate complex (from the primary regeneration solution) enters area X of the RC process. AE medium (1) is brought into contact with the solution exiting area X-1, which is fed forward to area X. This provides countercurrent contact as mentioned above and provides increased efficiency with minimal amount of solution used. The spent RC solution exiting area X(2) contains the majority of impurities.

[0120] The crowding solution, i.e., the solution exiting from area X-1, can be prepared by taking a portion of the uranium-loaded secondary regeneration solution exiting from area X-2(6), adjusting it with base(3) to increase its pH, and then moving this solution forward to area X-1. In this embodiment, the base used is a diluted ammonia solution because the material is compatible with the overall uranium regeneration operation. Other bases such as sodium hydroxide, potassium hydroxide, and equivalents can also be used, but ammonia is selected for its convenience and ease of handling.

[0121] Due to the properties of uranium in the sulfate solution (initial uranium-loaded secondary regeneration solution), when the pH is slightly increased, the uranium again becomes anionic, and this again has a higher affinity for the AE medium than other anions (contaminants). As the AE medium moves from area X to area X-2, the pH adjustment solution comes into contact with the AE medium containing uranium and contaminants, and the anionic uranium in the pH adjustment solution displaces the non-uranium anions (contaminants) on the AE medium because anionic uranium has a higher affinity for the AE medium than non-uranium anions. The non-uranium anions are transferred to the solution phase. The pH adjustment solution that has left area X-1 is transferred to area X, creating countercurrent contact.

[0122] The displacement or extrusion of non-uranium anions by uranium anions with higher affinity provides a "crowding" effect, as the AE medium loading becomes fully loaded with different anions, the anions with the highest affinity for the AE medium will displace or crowd the anions with lower affinity. These lower affinity anions then move into the solution phase. Since uranium has the highest affinity for AE, the crowding step can be very efficient.

[0123] The used RC solution (2) exiting from area X is discharged from the secondary CIX system.

[0124] The uranium-loaded secondary regeneration solution (6) from area X-2 is transferred to the secondary regeneration precipitation system.

[0125] As the AE medium moves from area X-2 to area X-4, it is regenerated using a strong acid such as sulfuric acid. The regenerated AE medium (5) is then transferred to a post-regeneration water washing step and finally returned to the secondary CIX system, where it is again brought into contact with fresh primary regeneration solution obtained from the primary CIX system.

[0126] In some embodiments, the dual-cycle CIX apparatus (and process) includes a GE or RC system within a primary or secondary CIX system. In some embodiments, the dual-cycle CIX apparatus (and process) includes a GE system and an RC system, one of which is located within the primary CIX system and the other within the secondary CIX system.

[0127] Examples of contaminants that can be removed by the GE and RC processes include iron and phosphorus ions. While trace amounts of other anionic complexes may also be present and can be removed within the AE system, iron and phosphorus are the primary items to consider. With respect to the CE primary CIX system, the operating concept is similar, except that in the case of CE, a portion of the loading primary regeneration solution (uranylammonium carbonate) is treated with a small amount of acid, e.g., H2SO4, and then used to cloud the CE resin before the regeneration step. Again, under these conditions, uranium in the lowered pH solution is loaded back onto the resin, displacing contaminants that have a lower affinity for the resin compared to uranium.

[0128] The uranium obtained from the process described above will typically be recovered as a uranium oxide (U3O8) product. This material will be prepared in a hydrogen peroxide precipitation system as discussed above, with subsequent calcination of uranyl peroxide precipitate to produce U3O8. Uranium can also be recovered as a diuranic acid compound.

[0129] The terms “region,” “port,” or “system” can be used synonymously to refer to a specific system used to carry out a part of an overall process. The terms “sub-region,” “sub-port,” or “subsystem” refer to a part of a system that carries out a sub-part of a specific part of an overall process. In relation to GE and RC systems, the terms “system” and “subsystem” are used synonymously.

[0130] In embodiments, each of the systems (units) described herein, such as a single-cycle CIX system, a primary CIX system and a secondary CIX system of a dual-cycle CIX system, a GE system, and an RC system, may contain several zones, for example, 1 to 50 zones. Each system may contain 1, 2, 3, 4, or 5 zones. A system may contain 1 to 10 zones, 1 to 50 zones, 5 to 45 zones, 10 to 40 zones, 15 to 35 zones, 20 to 35 zones, 25 to 30 zones, or 24 to 32 zones. A zone is a stationary, fixed feeding and discharge point related to the system.

[0131] In embodiments, each system described herein may have several resin chambers, for example, 1 to 50 resin chambers. Each system may include 1, 2, 3, 4, or 5 zones. The system may include 1 to 10 zones, 1 to 50 zones, 5 to 45 zones, 10 to 40 zones, 15 to 35 zones, 20 to 35 zones, 25 to 30 zones, or 24 to 32 zones. In embodiments, the resin remains within the chambers, and the resin chambers move from zone to zone, providing a continuous process without any interruption. Each resin chamber remains within each CIX system or unit. For example, the resin chambers of the primary system do not move to the secondary system in a dual cycle.

[0132] As will be understood by those skilled in the art, each embodiment disclosed herein comprises, essentially consists of, or may consist of, its particular described element, step, component, or constituent. Accordingly, the terms “include” or “including” should be interpreted as enumerating “comprises, comprises, or essentially consists of.” The transitional terms “comprises” or “comprises” mean “includes, but not limited to,” allowing for the inclusion of elements, steps, components, or constituents not specified, even in a major quantity. The transitional clause “consists of” excludes any elements, steps, components, or constituents not specified. The transitional clause “essentially consists of” limits the scope of the embodiment to the specified elements, steps, components, or constituents, and those that do not substantially affect the embodiment.

[0133] All numerical values ​​used in this specification and in the claims, representing quantities of components, properties of reagents, reaction conditions, etc., are understood to be modified in all cases by the term “approximately,” unless otherwise indicated. Therefore, the numerical parameters described herein and in the appended claims are approximations, which may vary depending on the desired properties to be sought. At a minimum, each numerical parameter should be interpreted by applying common rounding techniques, at least in light of the reported number of significant figures. Where further clarification is required, the term “approximately,” when used in conjunction with a stated numerical value or range, has a meaning reasonably attributable to those skilled in the art, i.e., a range slightly greater or slightly less than the stated value or range, within ±20%, ±15%, ±10%, ±5%, ±4%, ±3%, ±2%, ±1%, or any percentage range from ±1% to 20% of the stated value.

[0134] Although the numerical ranges or parameters describing the broad scope of the present invention are approximations, the numerical values ​​described in the specific examples are reported as precisely as possible. However, any numerical value inherently contains some error, which is necessarily derived from the standard deviation found in those individual test measurements.

[0135] In the context describing the present invention (in particular in the context of the following claims), the terms “a,” “an,” “the,” and similar references are to be interpreted as encompassing both singular and plural unless otherwise indicated herein or explicitly contradicted by the context. The enumeration of value ranges herein is intended merely as abbreviation for each distinct value that falls within the range. Unless otherwise indicated herein, each individual value is incorporated herein to the same extent as if it were individually enumerated herein. All methods described herein may be carried out in any preferred order unless otherwise indicated herein or explicitly contradicted by the context. Any use of any examples or illustrative language provided herein (e.g., “etc.”) is intended merely to better illustrate the present invention and does not raise any limitation to the scope of the invention as otherwise claimed. No language herein should be interpreted as indicating any non-claimed element essential to the practice of the present invention.

[0136] The grouping of alternative elements or embodiments of the Invention disclosed herein shall not be construed as limiting. Each group element may be referenced and claimed individually or in any combination with other elements of the group or other elements found herein. It is anticipated that one or more elements of a group may be included in or removed from the group for convenience and / or patentability reasons. When any such inclusion or removal is made, this specification shall be deemed to contain the group as modified and therefore shall perform the written description of all Markush groups used in the appended claims.

[0137] The following exemplary embodiments and examples illustrate the exemplary methods provided herein. These exemplary embodiments and examples are not intended to limit the scope of the disclosure and should not be construed as such. It will become apparent that the methods may be practiced in ways other than those specifically described herein. Numerous modifications and variations are possible from the perspective of the teachings herein and are therefore within the scope of the disclosure. Exemplary Embodiments

[0138] The following are exemplary embodiments. 1. A single-cycle continuous ion exchange (CIX) system for recovering uranium, namely, a) A primary CIX system including a gradient elution (GE) or resin clogging (RC) system, b) Primary regeneration solution evaporation system, c) Uranyl precipitate filtration / washing / digestion system, d) Acidified uranyl salt solution precipitation system, e) Precipitated uranium washing / calcination system, Includes, Optionally, the primary CIX system includes GE or RC systems. Optionally, a single-cycle CIX system may include a uranium product storage and automated packaging system. A single-cycle continuous ion exchange (CIX) system. 2. The single-cycle CIX apparatus according to Embodiment 1, wherein the primary regeneration solution evaporation system includes a recovery condenser for recovering decomposed compounds, such as ammonia. 3. A dual-cycle CIX (Civil Ion Extraction and Recovery) apparatus for uranium recovery, namely, a) A primary CIX system including a GE or RC system, b) Secondary CIX systems including GE or RC systems, c) Secondary regeneration solution precipitation system, d) Uranyl precipitate filtration / washing / digestion system, e) Precipitated uranium washing / calcination system, Includes, Optionally, the primary and / or secondary CIX systems include GE or RC systems. Optionally, a single-cycle CIX system may include a uranium product storage and automated packaging system. Dual-cycle CIX device. 4. The apparatus further includes a pretreatment system prior to the primary CIX system, wherein the pretreatment system includes a clay addition system / step, a flocculant addition system / step, and / or a purification system / step, as described in any one of Embodiments 1-3, for a single-cycle or double-cycle CIX apparatus. 5. The primary CIX system is a single-cycle or dual-cycle CIX apparatus according to any one of Embodiments 1-4, comprising a complexed cation exchange (CE) medium. 6. The secondary CIX system is a dual-cycle CIX apparatus according to any one of embodiments 3-5, comprising an anion exchange (AE) medium. 7. The system is a single-cycle or dual-cycle CIX apparatus according to any one of Embodiments 1-6, which enables the recycling, return, or storage of the solution. 8. The system is a single or dual-cycle CIX apparatus according to any one of Embodiments 1-7, enabling routine cleaning of the solid media of the primary CIX and / or secondary CIX. 9. The single or dual-cycle CIX apparatus according to Embodiment 8, wherein the primary and secondary CIX systems have at least one area within the system that operates in an upward flow mode to allow expansion of the solid medium for at least one cleaning per cycle of the CIX system. 10. The system is a single or dual-cycle CIX apparatus according to any one of Embodiments 1-9, which is sequentially connected for the recovery of uranium from a source. 11. A method for recovering uranium, a) A step of providing a source of uranium, b) Providing one or more CIX systems comprising a solid medium for binding uranium, c) A step of applying a uranium source to a solid medium under conditions that bind uranium to the solid medium, d) A step of recovering uranium by a single-cycle or double-cycle CIX process, Includes, A single-cycle CIX process includes either a GE or RC process. Dual-cycle ion exchange processes include GE and / or RC processes. method. 12. The method according to Embodiment 11, wherein the CIX system is a primary CIX system of a single-cycle CIX device. 13. The method according to Embodiment 11, wherein two CIX systems are present, and the two CIX systems are the primary and secondary CIX systems of a dual-cycle CIX device. 14. The method according to any one of Embodiments 11-13, wherein the primary CIX system comprises a complexed cation exchange (CE) resin for bonding uranium. 15. The method according to Embodiment 11 or 13, wherein the secondary CIX system includes an anion exchange (AE) resin for bonding uranium. 16. The method according to any one of Embodiments 11-15, further comprising the step of pre-treating the uranium source before step c). 17. The method according to Embodiment 16, wherein the pretreatment step includes filtering or purifying the uranium source using activated clay, activated carbon, activated silica, a flocculant, or a combination thereof. 18. The method according to any one of Embodiments 11-17, wherein the source of uranium is a source of phosphoric acid containing uranium in any oxidation state. 19. The method according to any one of Embodiments 11-18, wherein the source of uranium comprises a phosphoric acid solution or a phosphoric acid raw material. 20. CE media is, A weakly acidic CE medium containing a chelating aminomethylphosphonic acid group, Aminophosphon chelate media, A macroporous polystyrene-based chelating medium containing an iminodiacetic acid group, or A composition or material comprising a chemical having a chelating group, functionality, or moiety that binds uranium, or comprising an iminodiacetic acid group, a chelating aminomethylphosphonic acid group, or an aminophosphonic group, wherein the composition or material optionally comprises beads, wires, meshes, nanobeads, nanotubes, or hydrogels. The method according to any one of embodiments 11-19, including the method described in any one of embodiments 11-19. 21. The method according to any one of Embodiments 11-20, wherein the step of recovering uranium by a single-cycle ion exchange process or a double-cycle ion exchange process includes pre-treating the CE medium with an alkaline solution to neutralize free acids in the CE medium, and subsequently regenerating the CE medium with an alkaline carbonate solution at a pH greater than about 9.0 to produce a uranium-loaded primary regeneration solution and a regenerated CE medium. 22. The method according to Embodiment 21, wherein the alkaline solution for pre-treating the CE medium comprises ammonium hydroxide or sodium hydroxide. 23. The method according to Embodiment 21 or 22, wherein, when pre-treating the CE medium, at least one area is operated in an upward flow mode to allow purging of trace amounts of solids from the CIX system. 24. The method according to any one of Embodiments 21-23, wherein the step of regenerating the CE medium using an alkaline carbonate solution comprises converting uranium into an anionic uranyl carbonate complex and producing a uranium-loaded primary regeneration solution containing the anionic uranyl carbonate complex, the alkaline carbonate solution comprising ammonium carbonate, sodium carbonate, or potassium carbonate. 25. The method according to any one of Embodiments 21-24, wherein the step of regenerating the CE medium further includes washing the regenerated CE medium with water or a weakly acidic solution before re-entering the CE medium into the CIX process. 26. The method according to any one of Embodiments 21-25, further comprising the step of pre-treating the CE medium with an alkaline solution containing a portion of the initial regeneration solution, thereby reloading the CE medium with uranium contained in the initial regeneration solution. 27. The method according to any one of Embodiments 21-27, wherein the single-cycle ion exchange process further comprises the steps of concentrating the uranium-loaded primary regeneration solution in an evaporation unit to reduce its water content, decomposing excess alkali carbonate to form bicarbonates, reducing the pH of the solution, and forming a uranyl precipitate, wherein the alkali carbonate is ammonium carbonate, sodium carbonate, or potassium carbonate, and optionally, the alkali carbonate is ammonium carbonate and the uranyl precipitate is uranylammonium tricarbonate. 28. The method according to Embodiment 27, further comprising the steps of filtering the uranyl precipitate and subsequently washing the precipitate with water to remove excess alkali carbonate or contaminated carbonate / bicarbonate from the uranyl precipitate. 29. The method further comprises the step of recovering the compounds released in the decomposition of excess alkali carbonate and reusing the recovered compounds and the resulting solution in a CIX apparatus, wherein optionally the released compounds are ammonia, as described in Embodiment 27 or 28. 30. The method further comprises the step of digesting the uranyl precipitate with an acid solution to produce a uranyl salt solution, wherein the acid solution optionally includes sulfuric acid, nitric acid, or hydrochloric acid, as described in any one of Embodiments 27-29. 31. The method further comprises the step of treating a uranyl salt solution with an alkaline solution to raise the pH of the solution to about pH 2.5 to about pH 7 or about pH 3.5 to about pH 6 to obtain a pH-adjusted solution, wherein optionally the alkaline solution contains alkali hydroxide and optionally the alkaline solution has a pH above about pH 10, as described in Embodiment 30. 32. The method further comprises the step of adding a chemical to a pH adjusting solution in an amount sufficient to form a precipitate, wherein the chemical is hydrogen peroxide, ammonium hydroxide, ammonium carbonate, sodium hydroxide, sodium carbonate, or potassium hydroxide, and optionally, the chemical is hydrogen peroxide and the precipitate is a uranyl peroxide precipitate, according to Embodiment 31. 33. The method further comprises the steps of (i) separating the precipitate from the pH adjusting solution by (i) allowing the precipitate to settle, filtering or centrifuging it and subsequently washing the precipitate with water, or (ii) washing the precipitate on a filter or repulping the precipitate with water and subsequently allowing the precipitate to settle, filtering or centrifuging it, and optionally further comprising the step of additionally washing the precipitate with water, the method according to Embodiment 32. 34. The method according to Embodiment 32, further comprising the step of drying the precipitate to form a dry solid. 35. The method further comprises the step of heating a dry solid to a temperature sufficient to decompose or calcine the dry solid, optionally, the dry solid being uranyl peroxide, and the step of calcining the dry solid forming uranium oxide, as described in Embodiment 34. 36. The method according to any one of Embodiments 21-25, wherein the dual-cycle ion exchange process further comprises the step of treating a uranium-loaded primary regeneration solution in a second CIX system containing an anion exchange (AE) medium, and the anionic uranyl carbonate complex is transferred to the AE medium. 37. The method according to Embodiment 36, wherein the AE medium contains a functional group comprising a type 1 quaternary ammonium. 38. The method according to Embodiment 36 or 37, further comprising the step of treating the AE medium with an aqueous solution to produce a washed AE medium. 39. The method further comprises the steps of treating the AE medium washed with an acidic solution to remove uranium from the AE medium and to produce a uranium-loaded secondary regeneration solution containing uranium in cationic form and a regenerated AE medium, wherein the acidic solution optionally includes dilute sulfuric acid, nitric acid, or hydrochloric acid, as described in Embodiment 38. 40. The method according to Embodiment 39, wherein the step of processing the AE medium cleaned with an acidic solution is performed in an upward flow mode with respect to at least one of the contact steps (in at least one of the compartments) to purge any trace amounts of any solids that may have accumulated in the CIX system. 41. The method according to Embodiment 39 or 40, further comprising the step of processing the regenerated AE medium with water. 42. The method according to Embodiment 41, further comprising the step of post-treating the regenerated AE medium with an alkaline solution before its re-entry into the second CIX system. 43. The method further comprises the step of treating a uranium-loaded secondary regeneration solution with an alkaline solution to raise the pH of the solution to approximately pH 2.5 to approximately pH 7 or approximately pH 3.5 to approximately pH 6 to obtain a pH-adjusted solution, wherein optionally the alkaline solution comprises alkali hydroxide, ammonium hydroxide, or sodium hydroxide in a concentration ranging from 10% to approximately 30%, and optionally the alkaline solution has a pH greater than pH 10, as described in any one of Embodiments 36-42. 44. The method further comprises the step of adding a chemical to a pH adjusting solution in an amount sufficient to form a precipitate, wherein the chemical is hydrogen peroxide, ammonium hydroxide, ammonium carbonate, sodium hydroxide, sodium carbonate, or potassium hydroxide, and optionally, the chemical is hydrogen peroxide and the precipitate is a uranyl peroxide precipitate, according to Embodiment 43. 45. The method further comprises the steps of (i) separating the precipitate from the pH adjusting solution by (i) allowing the precipitate to settle, filtering or centrifuging it and subsequently washing the precipitate with water, or (ii) washing the precipitate on a filter or repulping the precipitate with water and subsequently allowing the precipitate to settle, filtering or centrifuging it, and optionally further comprising the step of additionally washing the precipitate with water, as described in Embodiment 44. 46. ​​The method according to Embodiment 45, further comprising the step of drying the precipitate to form a dry solid. 47. The method further comprises the step of heating a dry solid to a temperature sufficient to decompose or calcine the dry solid, optionally, the dry solid being uranyl peroxide, and the step of calcining the dry solid forming uranium oxide, as described in Embodiment 46. 48. The primary CIX system is the method according to any one of embodiments 11-47, including a GE or RC system. 49. A secondary CIX system is the method according to any one of embodiments 11, 13-26, and 36-47, including a GE or RC system. 50. Primary and secondary CIX systems are those according to any one of Embodiments 11, 13-26, 36-47, and 49, including GE and / or RC systems. 51. The method according to any one of Embodiments 11-50, wherein a GE process carried out in a primary CIX system of a single-cycle or dual-cycle CIX process includes the step of applying a diluted base solution to the primary CE medium during a regeneration pretreatment step, which is performed after the primary CE medium has been loaded with uranium and before the regeneration of the primary CE medium. 52. The method according to Embodiment 51, wherein the GE process includes the step of applying an increased-strength diluted base solution to remove non-uranium cations from the primary CE medium. 53. The method according to Embodiment 51 or 52, wherein the diluted base solution comprises a diluted carbonate solution such as a diluted ammonium carbonate solution, a diluted sodium carbonate solution, or a diluted potassium carbonate solution, and optionally selected, the diluted base solution comprises an ammonium carbonate solution. 54. The method according to any one of Embodiments 11-50, wherein the RC process carried out in the primary CIX system of a single-cycle or dual-cycle CIX process includes the step of adjusting the pH of a portion of the uranium-loaded primary regeneration solution using a dilute acid to obtain a cloud solution. 55. The method according to Embodiment 54, wherein a portion of the uranium-loaded primary regeneration solution is obtained from the initial application of the primary regeneration solution to the primary CE medium, or from a low-purity recycled / stored uranium-loaded regeneration solution. 56. The method according to embodiment 54 or 55, wherein the step of adjusting the pH of a portion of the uranium-loaded primary regeneration solution converts the uranium in the solution into a cation form and obtains a cloud solution. 57. The RC process further includes the step of applying a cloud solution onto the primary CE medium during the regeneration pretreatment step, which is performed after the primary CE medium has been loaded with uranium and before the regeneration of the primary CE medium, as in Embodiment 56. 58. The method according to Embodiment 57, wherein the step of applying the cloud solution onto the primary CE medium is to reload the primary CE medium with uranium and displace non-uranium contaminants from the primary CE medium. 59. The GE process implemented in the secondary CIX system of a dual-cycle CIX process includes the step of applying a weakly acidic solution to the secondary AE medium during the regeneration pretreatment step, which is performed after the secondary AE medium has been loaded with uranium and before the regeneration of the secondary AE medium, as described in any one of Embodiments 11, 13-26, and 36-57. 60. The method according to Embodiment 59, wherein the GE process includes the step of applying a weakly acidic solution of increased strength to remove non-uranium anions from the secondary AE medium. 61. The method according to Embodiment 59 or 60, wherein the weakly acidic solution includes a weak sulfuric acid solution, a weak hydrochloric acid solution, or a weak nitric acid solution. 62. The method according to any one of Embodiments 11, 13-26, and 36-58, wherein the RC process performed in the secondary CIX system of a dual-cycle CIX process includes the step of adjusting the pH of a portion of the uranium-loaded secondary regeneration solution using a weak base to obtain a cloud solution. 63. The method according to Embodiment 62, wherein a portion of the uranium-loaded secondary regeneration solution is obtained from the initial application of the secondary regeneration solution to the secondary AE medium, or from a low-purity recycled / stored uranium-loaded regeneration solution. 64. The method according to embodiment 62 or 63, wherein the step of adjusting the pH of a portion of the uranium-loaded secondary regeneration solution converts the uranium in the solution into anionic form and obtains a cloud solution. 65. The RC process further includes the step of applying a cloud solution onto the secondary AE medium during the regeneration pretreatment step, which is performed after the secondary AE medium has been loaded with uranium and before the regeneration of the secondary AE medium, as in Embodiment 64. 66. The method according to embodiment 65, wherein the step of applying the cloud solution onto the secondary AE medium is used to reload the secondary AE medium with uranium and displace non-uranium contaminants from the secondary AE medium. 67. A single-cycle CIX system or a dual-cycle CIX system as described in any one of Embodiments 1-10, comprising one or more areas, in either the GE or RC system. 68. The GE system is a single-cycle CIX system or a double-cycle CIX system as described in Embodiment 67, which includes different areas for applying acids or bases of different strengths to a solid medium. 69. The RC system is a single-cycle CIX system or a double-cycle CIX system as described in Embodiment 67, which includes different areas for applying a pH-adjusted secondary regeneration solution. 70. A single-cycle CIX system or a dual-cycle CIX system according to any one of embodiments 67-69, wherein the GE or RC system includes an area for regenerating an AE or CE medium.

[0139] Some embodiments of the present invention, including the best modes known to the inventors for carrying out the invention, are described herein. Naturally, modifications to these described embodiments will be obvious to those skilled in the art, upon careful reading of the foregoing description. The inventors anticipate that those skilled in the art will appropriately adopt such modifications, and they intend that the invention may be practiced in ways other than those specifically described herein. Thus, the invention includes all modifications and equivalents of the subject matter enumerated in the claims appended herein, as permitted by applicable law. Furthermore, any combination of the elements described above in all possible modifications is encompassed by the invention unless otherwise shown herein or otherwise clearly contradicted by context.

[0140] The subject matter described above is provided for illustrative purposes only and should not be construed as limiting. Various modifications and changes can be made to the subject matter described herein without following the exemplary embodiments and uses shown and described herein, and without departing from the true spirit and scope of the invention as set forth in the following claims.

[0141] All publications, patents, and patent applications referenced herein are incorporated herein by reference in the same way that each individual publication, patent, or patent application is incorporated by specific and individual reference. While the foregoing has been described in terms of various embodiments, those skilled in the art will understand that various modifications, substitutions, omissions, and changes can be made without departing from the spirit thereof. (Item 1) A single-cycle continuous ion exchange (CIX) system for recovering uranium, a) A primary CIX system including a gradient elution (GE) or resin crowding (RC) system, b) Primary regeneration solution evaporation system, c) Uranyl precipitate filtration / washing / digestion system, d) Acidified uranyl salt solution precipitation system, e) Precipitated uranium washing / calcination system and A single-cycle continuous ion exchange (CIX) system equipped with [specific features / features]. (Item 2) The above system further comprises a pre-processing system prior to the primary CIX system, as described in item 1, for the single-cycle CIX apparatus. (Item 3) A dual-cycle CIX (Centralized Intensification and Recovery) device for uranium recovery, hereinafter referred to as: a) A primary CIX system including a GE or RC system, b) Secondary CIX systems including GE or RC systems, c) Secondary regeneration solution precipitation system, d) Uranyl precipitate filtration / washing / digestion system, e) Precipitated uranium washing / calcination system and Includes, A dual-cycle CIX system in which, optionally, only one of the primary or secondary CIX systems is equipped with a GE or RC system, while the other is not equipped with a GE or RC system. (Item 4) The above system further comprises a pre-processing system prior to the primary CIX system, as described in item 3, for the dual-cycle CIX apparatus. (Item 5) The primary CIX system described above is a single-cycle CIX apparatus as described in item 1 or 2, or a dual-cycle CIX apparatus as described in item 3 or 4, comprising a chelate or complexed cation exchange (CE) medium. (Item 6) The above secondary CIX system is a dual-cycle CIX apparatus as described in item 3 or 4, comprising an anion exchange (AE) medium. (Item 7) The above system is a single-cycle CIX apparatus as described in any one of items 1, 2, or 5, or a dual-cycle CIX apparatus as described in any one of items 3-6, which enables the recycling, return, or storage of the solution. (Item 8) The above system is a single or dual-cycle CIX apparatus as described in any one of items 1-7, which enables routine cleaning of the solid media of the primary CIX and / or the secondary CIX. (Item 9) The above primary and secondary CIX systems are single or dual-cycle CIX devices as described in item 8, which operate in an upward flow mode to allow the expansion of the above solid medium for cleaning. (Item 10) The above system is a single or dual-cycle CIX device as described in any one of items 1-9, which is sequentially connected for uranium recovery. (Item 11) A method for recovering uranium, a) A step of providing a source of uranium, b) Providing one or more CIX systems comprising a solid medium for binding uranium, c) A step of applying the uranium source to the solid medium under conditions that bind the uranium to the solid medium, d) The step of recovering the above uranium by a single-cycle or double-cycle CIX process Includes, The above single-cycle CIX process comprises a GE or RC process, The above dual-cycle ion exchange process is a method comprising a GE and / or RC process. (Item 12) The above CIX system is the primary CIX system of a single-cycle CIX device, as described in item 11. (Item 13) The method according to item 11, wherein two CIX systems exist, and the two CIX systems are the primary and secondary CIX systems of a dual-cycle CIX device. (Item 14) The above primary CIX system comprises a chelate or complexed cation exchange (CE) resin for bonding uranium, as described in any one of items 11-13. (Item 15) The above secondary CIX system is the method according to item 11 or 13, comprising an anion exchange (AE) resin for bonding uranium. (Item 16) The method described above further includes the step of pre-treating the uranium source before step c), as described in any one of items 11-15. (Item 17) The method according to item 16, wherein the pretreatment step includes filtering or purifying the uranium source using activated clay, activated carbon, activated silica, a coagulant, or a combination thereof. (Item 18) The above-mentioned source of uranium is a source of phosphoric acid comprising uranium in any oxidation state, as described in any one of items 11-17. (Item 19) The above-mentioned source of uranium is the method described in any one of items 11-18, comprising a phosphoric acid solution or a phosphoric acid raw material. (Item 20) The above CE medium is Weakly acidic CE medium with chelating aminomethylphosphonic acid group, Aminophosphon chelate media, A macroporous polystyrene-based chelating medium containing an iminodiacetic acid group, or A composition or material comprising a chemical having a chelating group, functionality, or moiety that binds uranium, or comprising an iminodiacetic acid group, a chelating aminomethylphosphonic acid group, or an aminophosphonic group, wherein the composition or material optionally comprises beads, wires, meshes, nanobeads, nanotubes, or hydrogels. The method described in any one of items 11-19, comprising: (Item 21) The method according to any one of items 11-20, wherein the step of recovering the uranium by a single-cycle CIX process or a double-cycle CIX process includes pre-treating the CE medium with an alkaline solution to neutralize the free acids in the CE medium, and subsequently regenerating the CE medium with an alkaline carbonate solution at a pH greater than about 9.0 to produce a uranium-loaded primary regeneration solution and a regenerated CE medium. (Item 22) The method according to item 21, wherein the alkaline solution for pretreatment of the CE medium comprises ammonium hydroxide or sodium hydroxide. (Item 23) The step of pre-treating the CE medium described above is performed in an upward flow mode, according to the method described in item 21 or 22. (Item 24) The method according to any one of items 21-23, wherein the step of regenerating the CE medium using an alkaline carbonate solution comprises converting the uranium into an anionic uranyl carbonate complex to produce the uranium-loaded primary regeneration solution comprising the anionic uranyl carbonate complex, the alkaline carbonate solution comprising ammonium carbonate, sodium carbonate, or potassium carbonate. (Item 25) The method according to any one of items 21-24, wherein the step of regenerating the CE medium further includes washing the regenerated CE medium with water or a weakly acidic solution before re-entering the CE medium into the CIX process. (Item 26) The method according to any one of items 21-25, further comprising the step of pre-treating the CE medium with an alkaline solution containing a portion of the initial regeneration solution, thereby reloading the CE medium with uranium contained in the initial regeneration solution. (Item 27) The method according to any one of items 21-27, wherein the single-cycle ion exchange process described above further comprises the steps of concentrating the uranium-loaded primary regeneration solution in an evaporation unit to reduce its water content, decomposing excess alkali carbonate, and subsequently reducing the pH of the solution to form a uranyl precipitate. (Item 28) The method according to item 27, further comprising the steps of filtering the uranyl precipitate and subsequently washing the precipitate with water to remove excess alkali carbonate or contaminating carbonate / bicarbonate from the uranyl precipitate. (Item 29) The method according to item 27 or 28, further comprising the steps of recovering the compounds released in the decomposition of excess alkali carbonate and reusing the recovered compounds and the resulting solution. (Item 30) The method described above further comprises the step of digesting the uranyl precipitate with an acid solution to produce a uranyl salt solution, wherein the acid solution optionally comprises sulfuric acid, nitric acid, or hydrochloric acid, as described in any one of items 27-29. (Item 31) The method described above further comprises the step of treating the uranyl salt solution with an alkaline solution to raise the pH of the solution to about pH 2.5 to about pH 7 or about pH 3.5 to about pH 6 to obtain a pH-adjusted solution, wherein optionally the alkaline solution comprises alkali hydroxide, and optionally the alkaline solution has a pH greater than about pH 10, as described in item 30. (Item 32) The method according to item 31, further comprising the step of adding hydrogen peroxide to the pH adjusting solution in an amount sufficient to form a uranyl peroxide precipitate. (Item 33) The method described above further comprises the steps of (i) separating the uranyl peroxide precipitate from the pH adjusting solution by (i) allowing the precipitate to settle, filtering or centrifuging it, and subsequently washing the precipitate with water, or (ii) washing the precipitate on a filter or repulping the precipitate with water, and subsequently allowing the precipitate to settle, filtering or centrifuging it, and optionally further comprising the step of additionally washing the uranyl peroxide precipitate with water, as described in item 32. (Item 34) The method described above further comprises the step of drying the uranyl peroxide precipitate to form a dry solid, as described in item 32. (Item 35) The method according to item 34, further comprising the step of decomposing or calcining the dry solid and heating the dry solid to a temperature sufficient to form uranium oxide. (Item 36) The method according to any one of items 21-25, wherein the above double-cycle ion exchange process further comprises the step of treating the uranium-loaded primary regeneration solution in a second CIX system containing an anion exchange (AE) medium, and the anionic uranyl carbonate complex is transferred to the AE medium. (Item 37) The above AE medium is the method according to item 36, comprising a functional group containing a type 1 quaternary ammonium. (Item 38) The method according to item 36 or 37, further comprising the step of treating the AE medium with an aqueous solution to produce a washed AE medium. (Item 39) The method described above further comprises the steps of treating the washed AE medium with an acidic solution to remove uranium from the AE medium and producing a uranium-loaded secondary regeneration solution containing uranium in cationic form and a regenerated AE medium, wherein the acidic solution optionally comprises dilute sulfuric acid, nitric acid, or hydrochloric acid, according to item 38. (Item 40) The step of treating the cleaned AE medium with the above acidic solution is performed in an upward flow mode, as described in item 39. (Item 41) The method described above further comprises the step of treating the regenerated AE medium with water, as described in item 39 or 40. (Item 42) The method according to item 41, further comprising the step of post-treating the regenerated AE medium with an alkaline solution before its re-entry into the second CIX system. (Item 43) The method further comprises the step of treating the uranium-loaded secondary regeneration solution with an alkaline solution to raise the pH of the solution to approximately pH 2.5 to approximately pH 7 or approximately pH 3.5 to approximately pH 6 to obtain a pH-adjusted solution, wherein optionally the alkaline solution comprises alkali hydroxide, ammonium hydroxide, or sodium hydroxide in a concentration ranging from 10% to approximately 30%, and optionally the alkaline solution has a pH greater than pH 10, as described in any one of items 36-42. (Item 44) The method according to item 43, further comprising the step of adding hydrogen peroxide to the pH adjusting solution in an amount sufficient to form a uranyl peroxide precipitate. (Item 45) The method described above further comprises the steps of (i) separating the uranyl peroxide precipitate from the pH adjusting solution by (i) allowing the precipitate to settle, filtering or centrifuging it, and subsequently washing the precipitate with water, or (ii) washing the precipitate on a filter or repulping the precipitate with water, and subsequently allowing the precipitate to settle, filtering or centrifuging it, and optionally further comprising the step of additionally washing the uranyl peroxide precipitate with water, as described in item 44. (Item 46) The method described above further comprises the step of drying the uranyl peroxide precipitate to form a dry solid, as described in item 45. (Item 47) The method according to item 46, further comprising the step of decomposing or calcining the dry solid and heating the dry solid to a temperature sufficient to form uranium oxide. (Item 48) The above primary CIX system is the method described in any one of items 11-47, comprising a GE or RC system. (Item 49) The above secondary CIX system is the method described in any one of items 11, 13-26, and 36-47, comprising a GE or RC system. (Item 50) The above primary and secondary CIX systems are those comprising a GE and / or RC system, as described in any one of items 11, 13-26, 36-47, and 49. (Item 51) The GE process performed in the primary CIX system of the single-cycle or dual-cycle CIX process described above is the method according to any one of items 11-50, comprising the step of applying a diluted base solution to the primary CE medium during the regeneration pretreatment step. (Item 52) The GE process described above is the method according to item 51, comprising the step of applying the diluted base solution of increased strength to remove non-uranium cations from the primary CE medium. (Item 53) The above-mentioned diluted base solution comprises an ammonium carbonate solution, a diluted sodium carbonate solution, or a diluted potassium carbonate solution, as described in item 51 or 52. (Item 54) The method according to any one of items 11-50, wherein the RC process performed in the primary CIX system of the single-cycle or dual-cycle CIX process described above includes the step of adjusting the pH of a portion of the uranium-loaded primary regeneration solution using a dilute acid to obtain a cloud solution. (Item 55) The method described in item 54, wherein a portion of the uranium-loaded primary regeneration solution is obtained from the initial application of the primary regeneration solution to the primary CE medium, or from a low-purity recycled / stored uranium-loaded regeneration solution. (Item 56) The step of adjusting the pH of a portion of the uranium-loaded primary regeneration solution described above is the method described in item 54 or 55, which converts the uranium in the solution into a cation form and obtains a cloud solution. (Item 57) The method according to item 56, wherein the RC process further includes the step of applying the cloud solution onto the primary CE medium during the regeneration pretreatment step. (Item 58) The step of applying the cloud solution onto the primary CE medium is to reload the uranium onto the primary CE medium and displace non-uranium contaminants from the primary CE medium, as described in item 57. (Item 59) The GE process performed in the secondary CIX system of the dual-cycle CIX process described above, comprising the step of applying a weakly acidic solution to the secondary AE medium during the regeneration pretreatment step, according to any one of items 11, 13-26, and 36-57. (Item 60) The GE process described above is the method according to item 59, comprising the step of applying the weakly acidic solution of increased strength to remove non-uranium anions from the secondary AE medium. (Item 61) The method according to item 59 or 60, wherein the weakly acidic solution comprises a weak sulfuric acid solution, a weak hydrochloric acid solution, or a weak nitric acid solution. (Item 62) The RC process performed in the secondary CIX system of the dual-cycle CIX process described above is the method according to any one of items 11, 13-26, and 36-58, comprising the step of adjusting the pH of a portion of the uranium-loaded secondary regeneration solution using a weak base to obtain a cloud solution. (Item 63) The method described in item 62, wherein a portion of the above-mentioned uranium-loaded secondary regeneration solution is obtained from the initial application of the above-mentioned secondary regeneration solution to the above-mentioned secondary AE medium, or from a low-purity recycled / stored uranium-loaded regeneration solution. (Item 64) The step of adjusting the pH of a portion of the above uranium-loaded secondary regeneration solution is to convert the above uranium in the solution into anionic form and obtain a cloud solution, as described in item 62 or 63. (Item 65) The RC process described above further includes the step of applying the cloud solution onto the secondary AE medium during the regeneration pretreatment step, which is performed after the secondary AE medium has been loaded with uranium and before the regeneration of the secondary AE medium, as described in item 64. (Item 66) The step of applying the cloud solution onto the secondary AE medium is to reload the uranium onto the secondary AE medium and displace non-uranium contaminants from the secondary AE medium, as described in item 65. (Item 67) The above GE or RC system is a single-cycle CIX system or a dual-cycle CIX system as described in any one of items 1-10, comprising one or more zones. (Item 68) The above GE system is a single-cycle CIX system or a double-cycle CIX system as described in item 67, comprising different areas for applying acids or bases of different strengths to the solid medium. (Item 69) The above RC system is a single-cycle CIX system or a double-cycle CIX system as described in item 67, comprising different areas for applying a pH-adjusted secondary regeneration solution. (Item 70) The above GE or RC system is a single-cycle CIX system or a dual-cycle CIX system as described in any one of items 67-69, comprising an area for regenerating the above AE or CE medium.

Claims

1. A continuous ion exchange (CIX) apparatus for recovering uranium, a) A single-cycle continuous ion exchange (CIX) system, or b) Dual-cycle CIX apparatus for uranium recovery Equipped with, The single-cycle CIX apparatus, i) A primary CIX system comprising a resin crowding (RC) system, wherein the RC system within the primary CIX system of the single-cycle CIX apparatus is configured to adjust the pH of a portion of the uranium-loaded primary regeneration solution using a dilute acid to obtain a cloud solution, the cloud solution displaces non-uranium contaminants by reloading uranium onto a solid medium, ii) Primary regeneration solution evaporation system, iii) Uranyl precipitate filtration / washing / digestion system, iv) Acidified uranyl salt solution precipitation system, v) Precipitated uranium washing / calcination system and Equipped with, The aforementioned dual-cycle CIX apparatus, hereinafter referred to as, i) A primary CIX system including an RC system, wherein the RC system within the primary CIX system of the dual-cycle CIX apparatus is configured to adjust the pH of a portion of the uranium-loaded primary regeneration solution using the dilute acid to obtain the cloud solution, the cloud solution displaces non-uranium contaminants by reloading uranium onto the solid medium, ii) A secondary CIX system including an RC system, iii) Secondary regeneration solution precipitation system, iv) Uranyl precipitate filtration / washing / digestion system, v) Precipitated uranium washing / calcination system and A continuous ion exchange (CIX) system, including [specific component].

2. The continuous ion exchange (CIX) apparatus comprises the single-cycle CIX apparatus, The continuous ion exchange (CIX) apparatus according to claim 1, wherein the single-cycle CIX apparatus comprises the RC system having one or more zones.

3. The continuous ion exchange (CIX) apparatus comprises the single-cycle CIX apparatus, The continuous ion exchange (CIX) apparatus according to claim 1 or 2, wherein the single-cycle CIX apparatus comprises a pretreatment system prior to the primary CIX system.

4. The continuous ion exchange (CIX) apparatus comprises the double-cycle CIX apparatus, The continuous ion exchange (CIX) apparatus according to claim 1, wherein only one of the primary or secondary CIX systems is equipped with an RC system, and the other is not equipped with an RC system.

5. The continuous ion exchange (CIX) apparatus comprises the double-cycle CIX apparatus, The continuous ion exchange (CIX) apparatus according to claim 1 or 4, wherein the RC system comprises one or more zones.

6. The continuous ion exchange (CIX) apparatus comprises the double-cycle CIX apparatus, The continuous ion exchange (CIX) apparatus according to any one of claims 1, 4 to 5, wherein the dual-cycle CIX apparatus comprises a pretreatment system before the primary CIX system.

7. A method for recovering uranium, wherein the method is a. To provide a source of uranium, b. To provide one or more CIX systems including a solid medium for binding uranium, c. Applying the uranium source to the solid medium under conditions that bond the uranium to the solid medium, d. Recovering the uranium by a single-cycle or double-cycle CIX process. Includes, The single-cycle CIX process comprises a single CIX system which is a primary CIX system, and the single-cycle CIX process further comprises an RC process. The dual-cycle CIX process comprises two CIX systems, including the primary and secondary CIX systems, the dual-cycle CIX system further comprising an RC process, the RC process being carried out within the primary CIX system of the single-cycle or dual-cycle CIX process comprising adjusting the pH of a portion of the uranium-loaded primary regeneration solution using a dilute acid to obtain a cloud solution, the cloud solution displacing non-uranium contaminants by reloading uranium onto the solid medium, the method.

8. The method according to claim 7, further comprising pre-treating the uranium source before step c).

9. The method according to claim 8, wherein the pretreatment includes filtering or purifying the uranium source using activated clay, activated carbon, activated silica, a flocculant, or a combination thereof.

10. The method according to any one of claims 7 to 9, wherein the primary CIX system comprises a chelate or complexed cation exchange (CE) resin for bonding uranium.

11. The CE resin is, A weakly acidic CE medium containing a chelating aminomethylphosphonic acid group, Aminophosphon chelate media, A macroporous polystyrene-based chelating medium containing an iminodiacetic acid group, or A composition or material containing a chemical having a chelating group, functionality, or part that binds uranium, or comprising an iminodiacetic acid group, a chelating aminomethylphosphonic acid group, or an aminophosphonic group. The method according to claim 10, comprising:

12. The method according to claim 11, wherein the composition or material comprises beads, wires, meshes, nanobeads, nanotubes, or hydrogels.

13. The method according to any one of claims 7 to 12, wherein the secondary CIX system comprises an anion exchange (AE) resin for bonding uranium.

14. The method according to claim 13, wherein the AE resin comprises a functional group containing a type 1 quaternary ammonium.

15. The method according to any one of claims 7 to 14, wherein the uranium source is a phosphoric acid source comprising uranium in any oxidation state.

16. The method according to any one of claims 11 to 15, wherein the recovery of the uranium by a single-cycle CIX process or a double-cycle CIX process comprises pre-treating the CE medium with an alkaline solution to neutralize the free acids in the CE medium, and subsequently regenerating the CE medium with an alkaline carbonate solution at a pH greater than about 9.0 to produce the uranium-loaded primary regeneration solution and the regenerated CE medium.

17. The method according to claim 16, wherein the alkaline solution for pre-treating the CE medium comprises ammonium hydroxide or sodium hydroxide.

18. The method according to claim 16 or 17, wherein regenerating the CE medium using the alkaline carbonate solution comprises converting the uranium into an anionic uranyl carbonate complex and producing the uranium-loaded primary regeneration solution comprising the anionic uranyl carbonate complex, the alkaline carbonate solution comprising ammonium carbonate, sodium carbonate, or potassium carbonate.

19. The method according to claim 18, wherein the regeneration of the CE medium further comprises washing the regenerated CE medium with water or a weakly acidic solution before re-entering the CE medium into the single-cycle or double-cycle CIX process.

20. The method according to any one of claims 16 to 19, wherein the single-cycle CIX process further comprises concentrating the uranium-loaded primary regeneration solution in an evaporation unit to reduce its water content, decomposing excess alkali carbonate, and subsequently reducing the pH of the uranium-loaded primary regeneration solution to form a uranyl precipitate.

21. The method according to claim 20, further comprising filtering the uranyl precipitate, and subsequently washing the precipitate with water to remove excess alkali carbonate or contaminated carbonate / bicarbonate from the uranyl precipitate.

22. The method according to claim 20 or 21, further comprising digesting the uranyl precipitate with an acid solution to produce a uranyl salt solution.

23. The method according to claim 22, wherein the acid solution comprises sulfuric acid, nitric acid, or hydrochloric acid.

24. The method according to claim 22 or 23, further comprising treating the uranyl salt solution with an alkaline solution to raise the pH of the uranyl salt solution to about pH 2.5 to about pH 7 or about pH 3.5 to about pH 6 to obtain a pH-adjusted solution.

25. The method according to claim 24, wherein the alkaline solution comprises alkali hydroxide.

26. The method according to claim 24 or 25, wherein the alkaline solution has a pH greater than approximately pH 10.

27. The method according to claim 18 or 19, wherein the dual-cycle CIX process further comprises processing the uranium-loaded primary regeneration solution in a second CIX system comprising an anion exchange (AE) medium, the anionic uranyl carbonate complex being transferred to the AE medium.

28. The method according to claim 27, further comprising treating the AE medium with an aqueous solution to produce a washed AE medium.

29. The method according to claim 28, further comprising treating the washed AE medium with an acidic solution to remove uranium from the AE medium to produce a uranium-loaded secondary regeneration solution containing uranium in cationic form and a regenerated AE medium.

30. The method according to claim 29, wherein the acidic solution comprises dilute sulfuric acid, nitric acid, or hydrochloric acid.

31. The method according to claim 29 or 30, further comprising treating the uranium-loaded secondary regeneration solution with an alkaline solution to raise the pH of the uranium-loaded secondary regeneration solution to approximately pH 2.5 to approximately pH 7 or approximately pH 3.5 to approximately pH 6 to obtain a pH-adjusted solution.

32. The method according to claim 31, wherein the alkaline solution comprises alkali hydroxide, ammonium hydroxide, or sodium hydroxide in a concentration ranging from 10% to about 30%.

33. The method according to claim 31 or 32, wherein the alkaline solution has a pH greater than 10.

34. The method according to any one of claims 24 to 26, 31 to 33, further comprising adding hydrogen peroxide to the pH adjusting solution in an amount sufficient to form a uranyl peroxide precipitate.

35. The method according to claim 34, further comprising (i) separating the uranyl peroxide precipitate from the pH adjusting solution by (i) allowing the precipitate to settle, filtering or centrifuging, and subsequently washing the precipitate with water, or (ii) washing the precipitate on a filter or repulping the precipitate with water, and subsequently settling, filtering or centrifuging the precipitate.

36. The method according to claim 34 or 35, further comprising additionally washing the uranyl peroxide precipitate with water.

37. The method according to any one of claims 34 to 36, further comprising drying the uranyl peroxide precipitate to form a dry solid.

38. The method according to claim 37, further comprising decomposing or calcining the dry solid and heating the dry solid to a temperature sufficient to form uranium oxide.

39. The primary CIX system includes an RC system, and the secondary CIX system includes an RC system, or The primary and secondary CIX systems include an RC system. The method according to any one of claims 7 to 38.

40. The method according to any one of claims 16 to 38, wherein the portion of the uranium-loaded primary regeneration solution is obtained from the initial application of the uranium-loaded primary regeneration solution to a primary CE medium, or from a low-purity recycled / stored uranium-loaded regeneration solution.

41. The method according to claim 40, wherein the RC process further comprises applying the cloud solution onto the primary CE medium during the regeneration pretreatment step of the primary CIX system.

42. The method according to any one of claims 29 to 33, wherein the RC process performed in the secondary CIX system of the dual-cycle CIX process includes adjusting the pH of a portion of the uranium-loaded secondary regeneration solution using a weak base to obtain a cloud solution.

43. The method according to claim 42, wherein the portion of the uranium-loaded secondary regeneration solution is obtained from the initial application of the uranium-loaded secondary regeneration solution to a secondary AE medium, or from a low-purity recycled / stored uranium-loaded regeneration solution.

44. The method according to claim 43, wherein the RC process further comprises applying the cloud solution onto the secondary AE medium during the regeneration pretreatment step of the primary CIX system, which is performed after the secondary AE medium has been loaded with uranium and before the regeneration of the secondary AE medium.

45. A continuous ion exchange (CIX) apparatus according to any one of claims 1 to 6, wherein the primary CIX system includes a GE system, or the secondary CIX system includes a GE system.

46. The method according to any one of claims 7 to 45, wherein the single-cycle CIX process further comprises a GE process, or the dual-cycle CIX system further comprises a GE process.

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