KR20140123040A - Extraction of uranium from wet-process phosphoric acid - Google Patents

Abstract

In a preferred embodiment, the method of extracting uranium from wet phosphoric acid (WPA) comprises separating uranium from WPA to produce a loaded uranium solution stream and a uranium depleted WPA stream. The loaded uranium solution stream is then contacted with the ion exchange resin. Contacting a solution comprising an ion exchange resin and an anion to elute the uranium species bound to the resin to produce a loaded uranium effluent stream. The loaded uranium effluent stream is treated to provide a uranium-containing product.

Description

[0001] EXTRACTION OF URANIUM FROM WET-PROCESS PHOSPHORIC ACID [0002]

Cross reference of related application

The present invention claims priority to U.S. Provisional Application No. 61 / 553,742, filed October 31, 2011, entitled " Uranium Extraction Process ", and U.S. Application No. 13 / 931,112 (2012) entitled " Extraction of Uranium from Wet Phosphorus & Filed July 23, 2012) and U.S. Serial No. 13 / 555,606 (filed July 23, 2012) entitled " Extraction of Uranium from Wet Phosphorus ", both of which are assigned to the assignee of the present invention, U.S. Provisional Application No. 61 / 161,133 (U.S. Application No. 12 / 510,294, now U.S. Provisional Application No. 61 / 085,177, filed July 31, 2008, entitled "Extraction of Uranium from Wet Phosphorus," filed on March 18, 2009, Patent No. 8,226,910) (filed on July 28, 2009). Each of which is incorporated herein by reference in its entirety.

Field of invention

The present invention relates to the field of extraction of uranium from wet phosphoric acid.

Phosphoric acid (H ₃ PO ₄ ) is generally produced by wet process for reacting naturally occurring phosphorus rock with sulfuric acid for use in fertilizer production to provide a so-called wet-process phosphoric acid (WPA). Depending on the source of the carcass, it may contain useful metals which are dissolved by sulfuric acid and form impurity components of WPA, such as uranium, vanadium and yttrium.

In the United States, since the early 1950s, there are factories in operation to recover useful amounts of uranium from WPA. However, it is important that uranium can be extracted from WPA in a cost-effective manner due to fluctuations in the spot price of uranium. Until now, numerous factories that have operated the uranium extraction process have used a solvent extraction process to extract uranium from WPA. Another process that has recently received considerable attention is an ion exchange process in which uranium-containing WPA is loaded onto an ion exchange resin. WPA is washed away from the resin leaving uranium bound to the resin. Then, the uranium is eluted from the resin. U.S. Patent No. 4,599,221 (Ketzinel et al.) Discloses a process for extracting uranium from WPA using an ion exchange process.

Unfortunately, the existing uranium extraction process is not very simple. Some of the problems are crude materials that contain a range of organic and inorganic contaminants or species that can interfere with the extraction process and significantly affect the commercial viability of the process.

The Applicant has previously found that certain process efficiencies are realized by lowering the iron concentration of WPA and extracting the uranium compound from WPA after reducing the valence of any residual ferric iron in WPA to ferrous. The details thereof are disclosed in U.S. Patent No. 8,226,910, the entire contents of which are incorporated herein by reference.

There remains a need for other improved processes for overcoming one or more of the problems associated with other processes and / or for extracting uranium from more efficient WPA.

In a first aspect, the present invention provides a method of extracting uranium from wet phosphoric acid (WPA) comprising: (a) separating uranium from WPA to produce a loaded uranium solution stream and a uranium depleted WPA stream step; (b) contacting the loaded uranium solution stream with an ion exchange resin; (c) contacting an ion exchange resin with a solution containing an anion to elute the uranium species bound to the resin to produce a loaded uranium effluent stream; And (d) treating the loaded uranium effluent stream to provide a uranium-containing product.

In some embodiments, the anion used to elute the uranium species in step (c) is selected from the group consisting of a chloride anion, a sulfate anion, a nitrate anion, and combinations thereof.

In some embodiments of the first aspect of the present invention, a valence reduction step is performed prior to step (a), including reduction of the valence of the ferric ion in WPA. The valence reduction step may be carried out by chemical reduction, such as addition of metallic iron, ferrofosporous alloy or ferrosilicon alloy; Or by electrochemical reduction (ER).

In some embodiments of the first aspect of the present invention, the iron removal step may be preceded by the step (a) and / or (if used) the valence reduction step. The iron removal step involves reducing the iron content in WPA by reducing the content of iron species dissolved in WPA relative to the content of uranium species in WPA, thereby producing WPA with a lower iron content with uranium species. The iron concentration of WPA can be lowered by precipitating at least a portion of the iron present in WPA as iron ammonium phosphate.

In a second aspect, the present invention provides a method of extracting uranium from a wet phosphoric acid (WPA) comprising: (a) contacting a uranium laden WPA with a first ion exchange resin to form uranium depleted WPA; (b) separating uranium depleted WPA from the first ion exchange resin; (c) contacting the first ion exchange resin with an oxidizing agent to oxidize the uranium species on the first ion exchange resin; (d) contacting the first ion exchange resin with ammonia to remove impurities from the resin, wherein the impurities are vanadium ions, organic species, or combinations thereof; (e) separating impurities from the first ion exchange resin; (f) contacting the first ion exchange resin with ammonium carbonate to remove the oxidized uranium species from the resin to form a uranium enriched ammonium carbonate stream; (g) contacting the uranium-enriched ammonium carbonate stream with a second ion exchange resin to form uranium-depleted ammonium carbonate; (h) separating uranium-depleted ammonium carbonate from the second ion exchange resin; And (i) eluting the uranium species from the second ion exchange resin to form a uranyl solution.

In some embodiments, the oxidizing agent is selected from the group consisting of air, oxygen, hydrogen peroxide, WPA, and combinations thereof.

In some embodiments, the elution of step (i) is carried out using a solution comprising an anion selected from the group consisting of a chloride anion, a nitrate anion, a sulfate anion, and combinations thereof.

In some embodiments of the second aspect of the present invention, a valence reduction step comprising reduction of the valence of the ferric ions in WPA prior to step (a) may be performed. The valence reduction step may be carried out by chemical reduction, such as addition of metallic iron, ferrofosporous alloy or ferrosilicon alloy; Or by electrochemical reduction (ER).

In some embodiments of the second aspect of the present invention, an iron removal step may be performed prior to the valence reduction step (a) and / or (if used). The iron removal step involves reducing the iron content in WPA by reducing the content of iron species dissolved in WPA relative to the content of uranium species in WPA, thereby producing WPA with a lower iron content with uranium species. The iron concentration of WPA can be lowered by precipitating at least a portion of the iron present in WPA as iron ammonium phosphate.

In a third aspect, the present invention provides a method of extracting uranium from wet phosphoric acid (WPA) comprising the steps of: (a) contacting an uranium loaded WPA with an oxidizing agent to form an oxidized WPA stream; (b) contacting the oxidized WPA stream with an organic solvent; (c) separating the uranium-enriched organic solvent stream from the aqueous WPA stream; (d) contacting the uranium-enriched organic solvent stream with an ammonium carbonate stream to form a uranium enriched ammonium carbonate stream; (e) contacting the uranium enriched ammonium carbonate stream with an ion exchange resin; (f) separating the uranium-depleted ammonium carbonate stream from the ion exchange resin; (g) contacting the ion exchange resin with a solution comprising chloride ions; And (h) separating the uranyl solution from the ion exchange resin.

In some embodiments, the organic solvent used in step (b) includes di (2-ethylhexyl) phosphoric acid and trioctylphosphine oxide (i.e., the "DEHPA TOPO" system).

In some embodiments of the third aspect of the present invention, an iron removal step is performed prior to the valence reduction step. The iron removal step involves reducing the iron content in WPA by reducing the content of iron species dissolved in WPA relative to the content of uranium species in WPA, thereby producing WPA with a lower iron content with uranium species. The iron concentration of WPA can be lowered by precipitating at least a portion of the iron present in WPA as iron ammonium phosphate.

In some embodiments of any one of the first, second, or third aspect of the invention, the uranyl solution may be further treated to provide a uranium-containing product. This further treatment may include a precipitation step.

For a better understanding of the present invention, reference is now made to the following detailed description taken in conjunction with the accompanying drawings, which illustrate various embodiments of the invention.

Figure 1 shows a general flow diagram of a process according to the first exemplary embodiment of the present invention;
Figure 2 shows a general flow diagram of a process according to the second exemplary embodiment of the present invention;
Figure 3 shows a general flow diagram of a process according to the third exemplary embodiment of the present invention;
Figure 4 shows a general flow diagram of a process according to the fourth exemplary embodiment of the present invention;
Figure 5 shows a general flow diagram of a process according to the fifth exemplary embodiment of the present invention;
Figure 6 shows a general flow diagram of a process according to the sixth exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention now will be described more fully hereinafter with reference to the accompanying drawings, in which preferred embodiments of the invention are shown. It should be understood, however, that the invention can be embodied in many different forms and should not be construed as limited to the embodiments described herein alone.

1 is a flow diagram of a first exemplary embodiment of the present invention that is a process 10 for extracting uranium from a wet phosphoric acid (WPA) 12. Process 10 includes a first separation step 14 for separating uranium from the WPA in a first ion exchange (IX) or solvent extraction (SX) step. The first separating step 14 provides the loaded uranium solution stream 16 and the uranium depleted WPA stream 18. [ The loaded uranium solution stream 16 in the secondary ion exchange step 20 is then contacted with the anion exchange resin. During the ion exchange step (20), the uranium species is bound to the anion exchange resin. The anion exchange resin is then contacted with a solution comprising chloride ions 22 to elute bound uranium species from the resin to produce a loaded uranium effluent stream 24. Other anions that can be used to elute bound uranium species from an anion exchange resin include nitrates and sulphates. In some embodiments, the secondary ion exchange step 20 may be performed using a cation exchange resin or a chelating resin. The loaded uranium effluent stream 24 is then treated in an additional treatment stage 26 to provide the uranium-containing product 28.

The wet phosphoric acid (WPA) 12 may be any WPA feed. WPA is generally produced by reacting phosphorus acid with sulfuric acid. Before being put into the process of the present invention, WPA can be processed in one or more preprocessing steps. For example, WPA feed 12 may contain a significant amount of suspended solids, predominantly sodium fluorosilicate and gypsum, which can cause problems at later stages of the process at a concentration of approximately 30% WPA. In this case, the WPA can be purged. The clarification step may include filtering WPA to remove insoluble material. In particular, the purge step can use existing purifiers and additional purifiers of the WPA plant, complement the existing purifiers, reduce total suspended solids (TSS) and reduce process variations due to upstream changes. In this embodiment, the WPA can be purified, for example, by a conventional purifier. A flocculant is administered to the clarifier to promote precipitation of the suspended solid. The underflow from the clarifier can be passed back to the clarifier and the overflow can be delivered to the next stage of the process.

Preferably, the WPA 12 is an aqueous solution comprising about 20 wt% to about 40 wt% WPA. In some embodiments, WPA 12 is an aqueous solution comprising about 30 wt% WPA.

The first separation step 14 may be an ion exchange (IX) step or a solvent exchange (SX) step.

In some embodiments, the first separation step 14 is an ion exchange step. The WPA feed 12 (which may or may not be a WPA of reduced iron content or WPA as described in more detail below) may be an ion exchange (IX) column containing one or more ion exchange resins containing a chelate ion exchange resin . Typically, each train in the IX column has one column of nominal phase lead, one catch (or tail) column, and one column of elution / idle at any time. The uranium depleted WPA stream 18 is returned to the WPA storage tank and used for fertilizer production.

Once one of the IX columns of the train is loaded, it is taken offline and eluted. The elution procedure involves eluting the IX column with an 8-bed volume (BV: Bed Volume) of an ammonium carbonate solution. Uranium forms a stable, soluble uranyl tricarbonate complex in an ammonium carbonate solution, while impurities, such as iron, form insoluble compounds. Precipitated iron may be removed from the effluent using a filter prior to entering the secondary IX where additional blocking of impurities occurs. Thereafter, the loaded uranium solution stream 16 containing the uranyl carbonate from the first separation step 14 is transferred to the secondary anion exchange step 20 to extract uranium from the resin, recycle the ammonium carbonate . If necessary, the nominal 10% bleed can be removed to control the impurity accumulation of the effluent and replaced with fresh ammonium carbonate solution. The solution containing the chloride ion 22 is then used to elute the uranium bound to the IX column in the secondary anion exchange step 20 to produce the uranium-containing product 28. Other anions that may be used in this step include sulphates and nitrates.

In some other embodiments, the first separation step 14 is a solvent extraction step. WPA feed 12 (which may or may not be a WPA of reduced iron content or WPA as described in more detail below) may be added to WPA as an air / oxygen mixture and / or as a chemical oxidant such as hydrogen peroxide or Lt; RTI ID = 0.0 > WPA < / RTI > stream. The oxidized WPA is then transferred to a solvent extractor. The solvent extraction step (14) uses any organic solvent having a high affinity for uranium. Examples of this type of solvent include DEHPA TOPO (di-2-ethylhexylphosphate and trioctylphosphine oxide) systems. In some embodiments, the solvent extraction step (14) is a multi-extraction DEHPA TOPO (di-2-ethylhexylphosphoric acid and / or di-2-ethylhexylphosphonic acid) running at approximately 40 < 0 > C, wherein the nominal phase concentration is 0.5 M DEHPA and 0.125 M TOPO in a kerosenic organic diluent. Trioctylphosphine oxide) system. Further details of DEHPA TOPO can be found in Hurst et al., Ind. Eng. Chem. Process Des. Develop. , 1972, 11, 122-128], the details of which are incorporated herein by reference. The uranium depleted WPA stream 18 is returned to the WPA storage tank and used for fertilizer production.

In some embodiments, a uranium solution stream 16 is provided in which the pregnant organic phase is stripped and loaded with ammonium carbonate.

The processes described in connection with FIG. 1 are diverse and additional steps may be added as needed. For example, different sources of phosphorus arms have different compositions. As a result, the feed stream of WPA from different sources of the carcass arm will usually have different impurities, any of which can interfere with the uranium extraction process. As a result, the efficiency of uranium extraction can be enhanced by incorporating further steps into the process of the present invention. Some additional embodiments of the process of the present invention incorporating additional steps are described below.

FIG. 2 is a flow chart describing a second exemplary embodiment of the present invention that is a process 40 for extracting uranium from a wet phosphoric acid (WPA) 12. The process 40 includes contacting the uranium loaded WPA 12 with the first ion exchange resin in a first ion exchange step 42. The first ion exchange resin is a chelate resin. The resin is contacted with the oxidizing agent (52) in the oxidation step (54) under conditions that separate the uranium depleted WPA stream (44) from the first ion exchange resin and then oxidize substantially all uranium species on the resin. The first ion exchange resin is then contacted with the stream comprising ammonia (46) in a stripping step (48) under conditions that remove at least some of the bound vanadium ions and / or organic species from the resin. The vanadium and / or organic species rich stream 50 is then separated from the first ion exchange resin. The first ion exchange resin is then contacted with an ammonium carbonate stream 56 in an elution step 58 under conditions to remove the uranium species oxidized from the resin to provide a uranium enriched ammonium carbonate stream 60. The uranium enriched ammonium carbonate stream 60 is then contacted with an anion exchange resin in a second ion exchange step 62 and the uranium depleted ammonium carbonate stream 64 is separated from the second ion exchange resin. The elution step (66) then elutes the uranium species from the second ion exchange resin to provide uranyl solution (68). Elution step 66 may be carried out using a solution comprising a suitable anion, such as chloride, nitrate or sulfate.

FIG. 3 is a flow chart describing a third exemplary embodiment of the present invention, which is a process 40 for extracting uranium from a wet phosphoric acid (WPA) 12. The process steps 42, 48, 54, 58, 62 and 64 of this embodiment are described in connection with the second exemplary embodiment and are the same as those shown in Fig. In a third embodiment, a valence reduction step (70) is performed prior to the first ion exchange step (42). The valence reduction step 70 comprises reducing the valence of the ferric ion in the WPA 12 to produce the valence reduced WPA 72 and then a first ion exchange step 42 is performed. The valence reduction step 70 may be important because any ferric iron has a deleterious effect on subsequent processing steps of the uranium extraction process. The ion exchange (IX) resin used in the subsequent step (s) for uranium extraction has a high affinity for loading ferric iron (Fe ³⁺ ) ions that inhibit uranium loading. For this reason, the iron in the WPA feed 12 is preferably in the ferrous (Fe ²⁺ ) state.

The valence reduction of the valence reduction step (70) can be performed by contacting a suitable reducing agent with WPA containing ferric (Fe ³⁺ ) ions. Formulations suitable for the present invention include (but are not limited to) metallic iron; Ferrofosporous alloy; And ferrosilicon alloys. Alternatively or additionally, valence reduction of the valence reduction step (70) may be performed by reducing ferric iron (Fe < ^{3 +} >) ions of WPA in an electro-reduction step.

In some embodiments, the valence reduction step (70) includes adding metallic iron to a reactor containing WPA (12) to reduce ferric iron to ferrous iron. For example, the concentrate may be pumped into three stirred tanks for a total residence time of three hours. The finely divided or granulated iron may be added to the first of the two reactors as a 120% stoichiometric equivalent (relative to the content of ferric iron). Alternatively, the metallic iron may be replaced with or used with a ferrofosporous alloy or a ferrosilicon alloy.

In some embodiments, the valence reduction step 70 comprises electroreduction. Electrical reduction can be advantageous because it is easy to control the electrolytic reduction without adding chemical species to WPA. In one form of the electrowetting step, the WPA feed is delivered to a continuously running electri- cally reducing cell.

FIG. 4 is a flow chart describing a fourth exemplary embodiment of the present invention, which is a process 40 for extracting uranium from a wet phosphoric acid (WPA) 12. In this embodiment, process steps 42, 48, 54, 58, 62, 64 and 70 are described in connection with the third exemplary embodiment and are the same as those shown in Fig. In a fourth embodiment, an iron removal step 74 is performed prior to the valence reduction step 70. The iron removal step (74) involves reducing the content of iron species dissolved in WPA relative to the content of uranium species in WPA (76) to produce WPA (76) with reduced iron content with uranium species. The lower iron content of WPA (76) has a lower content of dissolved iron species than the raw WPA (12). Thereafter, a valence reduction step (70) is performed on the WPA (76) with a reduced iron content, including performing a reduction step on the WPA (76) with a lower iron content, Reduce the valence of iron species.

The purpose of the iron removal step (74) is to lower the iron content. This can be done by removing most of the total iron present through precipitation of iron ammonium phosphate (IAP) compounds or pre-treated WPA from the feed. The IAP precipitation step is designed to remove the portion of ferric iron as a partial step prior to the valence reduction step. In addition, IAP precipitation reduces scaling species (fluorosilicate and gypsum) in the lower iron content WPA 76 prior to the ion exchange step, thereby improving the operability of the ion exchange step.

In the iron removal step of the exemplary embodiment, the WPA is delivered to a small premix tank and ammonia is added in a stoichiometric excess of about 300-1000% of the calculated ammonia needed to form the IAP. From the premix tank, the treated stream is transferred to the overflow reactor. The treated stream has a total residence time in the overflow reactor of 7 to 12 hours to complete the IAP precipitation process. The overflow from the overflow reactor is passed to a centrifuge, or other solid-liquid separator, where the IAP is separated from the WPA. The lowered iron content WPA 76 (low solids concentration) is then transferred to the iron atom reduction step 70.

Figure 5 is a flow chart describing a fifth exemplary embodiment of the present invention that is a process 80 for extracting uranium from a wet phosphoric acid (WPA) 12. The process 80 includes an oxidation step 82 of contacting the uranium loaded WPA 12 with an oxidant 84 to provide an oxidized WPA stream 86. The oxidized WPA stream 86 is then contacted with a solvent 88 comprising di (2-ethylhexyl) phosphoric acid and trioctylphosphine oxide in a solvent extraction step 90. Enriched organic solvent stream 92 under conditions that separate the uranium-enriched organic solvent stream 92 from the WPA containing the aqueous stream 94 and provide a uranium enriched ammonium carbonate stream 98 in the stripping step 96 92) is brought into contact with the ammonium carbonate solution (94). The uranium enriched ammonium carbonate stream 98 is then contacted with the ion exchange resin in an ion exchange step 100. The uranium depleted ammonium carbonate stream 102 is separated from the ion exchange resin and the resin is contacted with a solution containing the chloride ions 104 and the uranyl solution 106 is separated from the ion exchange resin.

Figure 6 is a flow chart describing a sixth exemplary embodiment of the present invention that is a process 80 for extracting uranium from a wet phosphoric acid (WPA) 12. The process steps 82, 90, 96, and 100 of this embodiment are described in connection with the fifth exemplary embodiment and are the same as those shown in FIG. In a sixth embodiment, an iron removal step 108 is performed prior to the solvent extraction step 90. The iron removal step 108 comprises generating a WPA 110 of reduced iron content by lowering the iron concentration of WPA 12 and thereafter performing a solvent extraction step 90. The iron removal step can be carried out as described above.

In certain exemplary embodiments, uranium-containing product 28 or uranyl solution 106 can be further treated to produce a commercial uranium product. In some embodiments, uranium can be precipitated from uranium-containing product 28 or uranyl solution 106. The step of precipitating uranium from the uranium-containing product 28 or the uranyl solution 106 can be carried out by acidification and removal of the produced carbon dioxide, caustic soda necessary to maintain a pH suitable for the precipitation reaction, as well as uranyl peroxide Seed formation. The drying step of the precipitated product involves thickening the precipitate in a high-speed booster and drying at 260 DEG C in a low temperature drier.

The uranium-containing product 28 or uranyl solution 106 is pumped into the first of the three consecutive tanks. Hydrogen peroxide and caustic soda may be added to precipitate the uranium of the oxide. The total residence time in the precipitation reactor is 3 hours. After transferring the underflow to the thickener, the precipitate is dried at approximately 260 DEG C, followed by the drum injection and finally packaging in the shipping container.

The word " comprises, " or variations thereof, such as "comprising" or "comprising ", shall not be taken to imply any other element, integer or step, Element, integer or step, or group of elements, integers or steps.

All publications mentioned herein are incorporated herein by reference. Any discussion of the literature, acts, materials, devices, articles, and the like contained in this specification is for the sole purpose of providing the context of the present invention. Any or all such problems as existed prior to the priority date of each claim of this specification in Australia or elsewhere are not to be taken as part of the prior art basis or as a common sense reference in the field relating to the present invention.

It will be understood by those skilled in the art that numerous changes and / or modifications can be made to the invention as illustrated in the specific embodiments without departing from the spirit or scope of the invention as broadly described. The embodiments of the invention should, therefore, be considered in all respects as illustrative and not restrictive.

Many modifications and other embodiments of the invention will come to mind to one skilled in the art having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Accordingly, it is to be understood that the invention is not to be limited to the specific embodiments disclosed, and that modifications and embodiments are included within the scope of the claims as guided by this disclosure.

Claims (19)

A method for extracting uranium from wet-process phosphoric acid (WPA)
(a) separating uranium from WPA to produce a loaded uranium solution stream and a uranium depleted WPA stream;
(b) contacting the loaded uranium solution stream with an ion exchange resin;
(c) contacting an ion exchange resin with a solution containing an anion to elute the uranium species bound to the resin to produce a loaded uranium effluent stream; And
(d) treating the loaded uranium effluent stream to provide a uranium-containing product. The method of claim 1 wherein the anion used to elute the uranium species in step (c) is selected from the group consisting of a chloride anion, a sulfate anion, a nitrate anion, and combinations thereof. 2. The method of claim 1, wherein a valence reduction step is performed prior to step (a), the valence reduction step comprising reduction of the valence of ferric ions in WPA. In a third aspect, an iron removal step is carried out prior to the step (a) and / or (if used) the valence reduction step. The method according to claim 1, wherein, prior to step (a)
Reducing the content of iron species solubilized in WPA relative to the content of uranium species in WPA to produce WPA with a reduced iron content having uranium species; And
Performing a reducing step on the reduced iron content of WPA, wherein the valence of the dissolved iron species remaining in the WPA of reduced iron content is reduced
Lt; / RTI > As a method for extracting uranium from wet phosphoric acid (WPA)
(a) contacting uranium loading (laden) WPA with a first ion exchange resin to form uranium depleted WPA;
(b) separating uranium depleted WPA from the first ion exchange resin;
(c) contacting the first ion exchange resin with an oxidizing agent to oxidize the uranium species on the first ion exchange resin;
(d) contacting the first ion exchange resin with ammonia to remove impurities from the resin, wherein the impurities are vanadium ions, organic species, or combinations thereof;
(e) separating impurities from the first ion exchange resin;
(f) contacting the first ion exchange resin with ammonium carbonate to remove the oxidized uranium species from the resin to form a uranium enriched ammonium carbonate stream;
(g) contacting the uranium-enriched ammonium carbonate stream with a second ion exchange resin to form uranium-depleted ammonium carbonate;
(h) separating uranium-depleted ammonium carbonate from the second ion exchange resin; And
(i) eluting the uranium species from the second ion exchange resin to form a uranyl solution. 7. The method of claim 6, wherein the oxidizing agent is selected from the group consisting of air, oxygen, hydrogen peroxide, WPA, and combinations thereof. 7. The method of claim 6, wherein the elution of step (i) is carried out using a solution comprising an anion selected from the group consisting of a chloride anion, a sulfate anion, a nitrate anion, and combinations thereof. 7. The method of claim 6, wherein a valence reduction step is performed prior to step (a) comprising reduction of the valence of ferric ions in WPA. 10. The method of claim 9, wherein an iron removal step is performed prior to the valence reduction step. 7. The method of claim 6 wherein the uranyl solution is further treated to provide a uranium-containing product. 12. The method of claim 11, wherein the further treatment comprises a precipitation step. The method according to claim 6, wherein, prior to step (a)
Reducing the content of iron species solubilized in WPA relative to the content of uranium species in WPA to produce WPA with a reduced iron content having uranium species; And
Performing a reducing step on the reduced iron content of WPA, wherein the valence of the dissolved iron species remaining in the WPA of reduced iron content is reduced
Lt; / RTI > As a method for extracting uranium from wet phosphoric acid (WPA)
(a) contacting the uranium loaded WPA with an oxidizing agent to form an oxidized WPA stream;
(b) contacting the oxidized WPA stream with an organic solvent;
(c) separating the uranium-enriched organic solvent stream from the aqueous WPA stream;
(d) contacting the uranium-enriched organic solvent stream with an ammonium carbonate stream to form a uranium enriched ammonium carbonate stream;
(e) contacting the uranium enriched ammonium carbonate stream with an ion exchange resin;
(f) separating the uranium-depleted ammonium carbonate stream from the ion exchange resin;
(g) contacting the ion exchange resin with a solution comprising chloride ions; And
(h) separating the uranyl solution from the ion exchange resin. 15. The process of claim 14, wherein the organic solvent comprises di (2-ethylhexyl) phosphoric acid and trioctylphosphine oxide. 15. The method of claim 14, wherein an iron removal step is performed prior to step (a). 15. The method of claim 14 wherein the uranyl solution is further treated to provide a uranium-containing product. 18. The method of claim 17, wherein the further treatment comprises a precipitation step. 15. The method of claim 14, wherein prior to step (a)
Reducing the content of iron species solubilized in WPA relative to the content of uranium species in WPA to produce WPA with a reduced iron content having uranium species; And
Performing a reducing step on the reduced iron content of WPA, wherein the valence of the dissolved iron species remaining in the WPA of reduced iron content is reduced
Lt; / RTI >

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