Method for preparing 6N-grade ammonium rhenate

Abstract

The invention provides a method for preparing 6N-grade ammonium rhenate, and relates to the technical field of ammonium rhenate purification. The chelate resin is treated with ammonia water, and treated chelate resin is obtained; sequentially introducing the ammonium rhenate solution into the treated chelating resin, the strongly acidic macroporous cationic resin and the strongly acidic gel type cationic resin for ion exchange to obtain a high-purity ammonium rhenate solution; the high-purity ammonium rhenate solution is subjected to evaporation concentration and freezing crystallization, and 6N ammonium rhenate is prepared; wherein the main body structure of the chelating resin comprises a crosslinked polystyrene / styrene-divinylbenzene copolymer. The preparation method is simple and convenient to operate and high in practicability.

Description

Technical Field

[0001] The present application relates to the technical field of ammonium rhenate purification, and in particular to a method for preparing 6N grade ammonium rhenate. Background Art

[0002] Rhenium, a rare refractory metal, plays an irreplaceable role in cutting-edge fields such as single-crystal blades for aerospace engines, radiation-resistant materials for the nuclear industry, and semiconductor targets due to its excellent high-temperature mechanical properties, corrosion resistance, and electronic characteristics. As high-tech industries increase their requirements for material performance, the purity of metallic rhenium directly affects its application effectiveness. For example, 6N-grade (purity ≥99.9999%) high-purity rhenium can significantly reduce impurity segregation at grain boundaries and improve structural stability and electrical consistency at high temperatures. Therefore, the development of an efficient and stable high-purity rhenium preparation process has become an urgent need in the industry.

[0003] High-purity ammonium rhenate plays a crucial role in the preparation of high-purity rhenium. It is a crucial precursor for the production of high-purity rhenium. Subsequent processing of high-purity ammonium rhenate yields high-purity rhenium metal. Its purity directly impacts the quality and performance of the resulting high-purity rhenium. Therefore, obtaining high-purity ammonium rhenate is a key step in achieving high-purity rhenium production. Ion exchange, due to its high selectivity and gentle operation, has become the mainstream technology for achieving this goal.

[0004] Ion exchange resins play a key role in the preparation of high-purity ammonium rhenate, but they also face numerous challenges that need to be overcome. Conventional ion exchange resins suffer from poor selectivity and limited exchange capacity when treating ammonium rhenate solutions. In particular, improving the ion exchange resin's adsorption selectivity for target ions, ensuring efficient removal of impurity ions in complex solution systems, while also maintaining the resin's stability and service life, are key challenges that must be addressed in the preparation of high-purity ammonium rhenate. The present invention aims to provide a novel method for preparing 6N-grade ammonium rhenate to address these challenges.

[0005] The bottleneck of the traditional ion exchange method for preparing high-purity ammonium rhenate mainly lies in the resin performance: first, conventional chelating resins have insufficient selectivity for monovalent metal ion impurities (such as Na+, K+) in ammonium rhenate, and impurity removal is not thorough; second, if the pore structure and ion form of traditional cationic resins are not optimized, it is easy to lead to low dynamic exchange capacity, making it difficult to deeply remove metal impurities; third, in the multi-stage resin series process, if the resin types are not properly matched, it may cause additional impurities to be introduced or capacity to be reduced, restricting large-scale production. Therefore, how to improve the adsorption selectivity of ion exchange resins for target ions, ensure their efficient removal of impurity ions in complex solution systems, and at the same time ensure the stability and service life of the resin has become a key problem that needs to be solved in the preparation of high-purity ammonium rhenate. The present invention aims to provide a new method for preparing 6N-grade ammonium rhenate to solve the above problems. Summary of the Invention

[0006] The purpose of this application is to provide a method for preparing 6N grade ammonium rhenate to solve the above problems.

[0007] To achieve the above objectives, the present application provides a method for preparing 6N grade ammonium rhenate, comprising:

[0008] treating the chelate resin with aqueous ammonia to obtain a treated chelate resin;

[0009] The ammonium rhenate solution is sequentially passed through the treated chelating resin, the strongly acidic macroporous cationic resin and the strongly acidic gel cationic resin to perform ion exchange to obtain a high-purity ammonium rhenate solution;

[0010] The high-purity ammonium rhenate solution is evaporated, concentrated, and frozen and crystallized to obtain 6N ammonium rhenate;

[0011] Wherein, the main structure of the chelating resin includes cross-linked polystyrene / styrene-divinylbenzene copolymer.

[0012] Optionally, the volume of the ammonia water introduced is 0.1BV-0.5BV.

[0013] Optionally, the method for preparing 6N grade ammonium rhenate satisfies at least one of the following conditions:

[0014] A. the functional groups of the chelating resin include one or more of isothiourea, iminodiacetic acid, dimethylphosphine, methylmercaptan, amine polyhydroxyl, dimethylpyridine amino and aminomethylphosphonic acid;

[0015] B. The particle size of the chelating resin is 0.13mm-1.2mm.

[0016] Optionally, the method for preparing 6N grade ammonium rhenate satisfies at least one of the following conditions:

[0017] A. The main structure of the strongly acidic macroporous cationic resin comprises a cross-linked polystyrene / styrene-divinylbenzene copolymer;

[0018] B. the functional groups of the strongly acidic macroporous cationic resin include sulfonic acid groups;

[0019] C. The particle size of the strongly acidic macroporous cationic resin is 0.13-1.2 mm.

[0020] Optionally, the method for preparing 6N grade ammonium rhenate satisfies at least one of the following conditions:

[0021] A. The main structure of the strongly acidic gel-type cationic resin comprises a cross-linked polystyrene / styrene-divinylbenzene copolymer;

[0022] B. the functional groups of the strongly acidic gel-type cationic resin include sulfonic acid groups;

[0023] C. The particle size of the strongly acidic gel-type cationic resin is 0.13 mm to 1.2 mm.

[0024] Optionally, the method for preparing 6N grade ammonium rhenate satisfies at least one of the following conditions:

[0025] A. described chelate resin comprises hydrogen type chelate resin and / or sodium type chelate resin;

[0026] B. The strongly acidic macroporous cationic resin comprises a hydrogen-type strongly acidic macroporous cationic resin and / or a sodium-type strongly acidic macroporous cationic resin;

[0027] C. The strongly acidic gel-type cationic resin includes a hydrogen-type strongly acidic gel-type cationic resin.

[0028] Optionally, after the treatment, the chelating resin, the strongly acidic macroporous cationic resin and the strongly acidic gel cationic resin are sequentially subjected to a first acid wash, an alkali wash, a second acid wash and a water wash before the ion exchange.

[0029] Optionally, the method for preparing 6N grade ammonium rhenate satisfies at least one of the following conditions:

[0030] A. The concentration of the acid solution in the first pickling or the second pickling is independently 4%-8%, and the volume of the acid solution in the first pickling or the second pickling is independently 2BV-5BV. The concentration of the alkaline solution in the alkali wash is 4%-8%, and the volume of the alkaline solution is 2BV-5BV.

[0031] B. the pH value of the resin after the washing is neutral;

[0032] C. when described resin comprised sodium type chelate resin or described stern-acid macroporous cationic resin comprised described sodium type stern-acid macroporous cationic resin, after described resin and described stern-acid macroporous cationic resin were carried out successively first pickling, described alkali cleaning, described second pickling and described washing, also repeated to carry out successively>described 3rd pickling and described second washing of 3 times.

[0033] Optionally, the container for loading the chelating resin, the strongly acidic macroporous cationic resin and the strongly acidic gel-type cationic resin is cylindrical;

[0034] When the solution is introduced, the flow rate at the corners of the container is controlled to be greater than the flow rate at the middle, and the temperature at the corners is controlled to be greater than the temperature at the middle;

[0035] The solution includes the ammonia water, the ammonium rhenate solution, the acid solution for the acid washing, and the water for the water washing.

[0036] Optionally, the flow rate difference between the corner flow rate and the middle flow rate is 10 mL / min-50 mL / min;

[0037] The temperature difference between the corner temperature and the middle temperature is 10°C-20°C.

[0038] Compared with the prior art, the advantages of this application include:

[0039] The method for preparing 6N-grade ammonium rhenate provided in the present application uses a multi-stage special ion exchange resin to adsorb the ammonium rhenate solution. First, the chelating resin is used as the first-stage ion exchange resin, and the adsorption effect on high-valent ions such as +2 and +3 is better than that on +1 ions. This is because the chelating resin is a macroporous resin with large pore space, which can allow ions with a small radius to pass through. Moreover, since the chelating resin has characteristic functional groups, it can achieve better selectivity for high-valent ions. Secondly, the second-stage ion exchange resin is connected in series after the chelating resin. The strongly acidic macroporous cationic resin can remove trace high-valent ions in the chelating resin, ensuring ion removal. Thorough; finally, the pores of the third-stage ion exchange resin, a strongly acidic gel-type cationic resin, are relatively small, and can achieve the removal of impurities such as +1-valent K and Na; wherein, the ammonium rhenate solution is passed through a chelating resin treated with ammonia water for adsorption. The intermolecular force of the chelating resin is strong. If the ammonium rhenate is directly adsorbed, the ammonium rhenate will be partially adsorbed to the surface of the chelating resin, resulting in a lower recovery rate of the ammonium rhenate. When the ammonia solution is passed through, the ammonium radical and the hydroxide radical interact with the chelating resin, offsetting the interaction between the chelating resin and the rhenate radical. When the ammonium rhenate solution is adsorbed, the rhenate radical ions are not adsorbed, and the actual production recovery rate of the ammonium rhenate is not affected. The preparation method is simple and convenient to operate and has strong practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope of the present application.

[0041] Figure 1 Schematic diagram of the container for loading ion exchange resin. DETAILED DESCRIPTION

[0042] As used herein:

[0043] "Prepared from" is synonymous with "comprising." As used herein, the terms "comprising," "including," "having," "containing," or any other variations thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises the listed elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

[0044] The conjunction "consisting of" excludes any unspecified element, step, or component. If used in a claim, this phrase renders the claim closed, excluding materials other than those described, except for conventional impurities associated therewith. When the phrase "consisting of" appears in a clause of the body of a claim, rather than immediately following the subject matter, it limits only the elements described in that clause; other elements are not excluded from the claim as a whole.

[0045] When an amount, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper preferred values and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pairing of any range upper limit or preferred value with any range lower limit or preferred value, regardless of whether the range is disclosed alone. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted as including the range "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5", etc. When a numerical range is described herein, unless otherwise stated, the range is intended to include its end values and all integers and fractions within the range.

[0046] In these examples, parts and percentages are by mass unless otherwise indicated.

[0047] "Parts by mass" refers to the basic unit of measurement used to express the mass ratio of multiple components. One part can represent any unit of mass, such as 1g or 2.689g. If we say that the mass of component A is a parts and the mass of component B is b parts, this means the ratio of the mass of component A to the mass of component B is a:b. Alternatively, we could say that the mass of component A is aK and the mass of component B is bK (K is an arbitrary number representing a multiplication factor). It's important to note that, unlike parts by mass, the sum of the mass of all components is not limited to 100 parts.

[0048] "And / or" is used to indicate that one or both of the stated situations may occur, for example, A and / or B includes (A and B) and (A or B).

[0049] The present application provides a method for preparing 6N grade ammonium rhenate, comprising:

[0050] treating the chelate resin with aqueous ammonia to obtain a treated chelate resin;

[0051] The ammonium rhenate solution is sequentially passed through the treated chelating resin, the strongly acidic macroporous cationic resin and the strongly acidic gel cationic resin to perform ion exchange to obtain a high-purity ammonium rhenate solution;

[0052] It should be noted that chelating resin has excellent effect on the removal of heavy metal ions, and can achieve high-content removal of heavy metal ions to trace amounts, and the heavy metal removal effect remains >95% after regeneration, avoiding the contamination of strong acid macroporous resin / gel-type resin by heavy metals. Heavy metal contamination refers to the fact that heavy metal ions such as Fe, lead, and mercury easily combine with the functional groups of the resin, occupying exchange sites, thereby affecting the ion exchange capacity of the resin; heavy metal contamination can also cause the color of the resin to change, such as becoming dark gray, brown or black, and may be accompanied by particle degradation. Heavy metal deposition can cause changes in the particle structure of the resin, and the resin particles may crack or pulverize, thereby reducing the service life; and, since the pores of the gel-type resin are small and easily blocked, but the exchange efficiency and precision are high, it is set after the strong acid macroporous cationic resin as the third-stage series gel-type resin;

[0053] It should also be noted that the chelating resin is a macroporous type, and the macroporous resin structure ensures the superiority of ion diffusion, thereby providing efficient complete removal and regeneration performance; when the chelating resin is connected to the strong acid resin, since the strong acid resin has excellent activity in the pH range of 0-14, if a weak cationic resin is used, the weak cationic resin will not work under strong acid and cannot be directly connected in series. The pH needs to be adjusted before it can be connected in series. If a chelating resin is not used and a strong acidic cationic resin is directly used for impurity removal, heavy metal ions will poison and inactivate the resin, and the resin life will be short. Chelating resin can effectively change the resin poisoning and inactivation phenomenon. The cations adsorbed in the third-level strong acid gel-type cationic resin are K, Na, etc., which are easily adsorbed and eluted, thereby extending the overall life of the resin; chelating resin provides efficient complete removal and regeneration performance;

[0054] Therefore, by using one or a combination of selective chelating resins to selectively remove special heavy metal cations or other divalent cations in the ammonium rhenate solution, and then using universal cationic resins to remove other cations, high-purity preparation of ammonium rhenate can be achieved;

[0055] Adjusting the temperature of the ion exchange resin distribution is to increase the temperature of the corners to promote the dissolution of ammonium rhenate and the movement of ions, thereby reducing the generation of impurities.

[0056] Furthermore, the chelating resin, the strongly acidic macroporous cationic resin and the strongly acidic gel-type cationic resin provided in this application can be connected in series;

[0057] The high-purity ammonium rhenate solution is evaporated, concentrated, and frozen and crystallized to obtain 6N ammonium rhenate;

[0058] Wherein, the main structure of the chelating resin includes cross-linked polystyrene / styrene-divinylbenzene copolymer.

[0059] In some embodiments, the volume of the ammonia solution introduced is 0.1 BV-0.5 BV.

[0060] Optionally, the volume of the ammonia solution introduced can be 0.1BV, 0.2BV, 0.3BV, 0.4BV, 0.5BV or any value between 0.1BV and 0.5BV.

[0061] In some embodiments, the method for preparing 6N grade ammonium rhenate satisfies at least one of the following conditions:

[0062] A. the functional groups of the chelating resin include one or more of isothiourea, iminodiacetic acid, dimethylphosphine, methylmercaptan, amine polyhydroxyl, dimethylpyridine amino and aminomethylphosphonic acid;

[0063] It should be noted that, due to the characteristic functional groups of chelating resin, it can achieve better selectivity for high-valent ions; the dissociation state of impurity ions in solution is also affected by pH, and high-valent metal ions such as Al 3+ 、Fe 3+ The ions may exist in the form of hydrated ions at low pH and may form hydroxide precipitation at high pH. Therefore, when the pH is in the range of 2 to 12, chelating resins can effectively adsorb these ions. Moreover, the pH value of the chelating resin after ammonia treatment is weakly alkaline. For example, the pH value of the treated chelating resin is 7-10. Within this range, the adsorption of the chelating resin after ammonia treatment is the best.

[0064] There are also coordination bonds, hydrogen bonds and other weak forces between the characteristic functional groups in the chelating resin and the high-valent cationic impurities. Specifically, the functional groups of the chelating resin (such as iminodiethyl) can form stable coordination bonds with metal ions, thereby achieving selective adsorption; the OH groups on the resin surface - There is hydrogen bonding between the functional groups and H2O molecules, which can increase the efficiency of the adsorption process;

[0065] To remove heavy metals such as Ni, Zn, Co, Cu, etc., chelating resins containing iminodiacetic acid, dimethyl phosphine, and dimethylpyridinium amine functional groups can be used; to remove calcium and magnesium, chelating resins containing aminomethylphosphonic acid functional groups can be used; to remove Hg, etc., chelating resins containing isothiourea functional groups can be used; to remove precious metals, etc., chelating resins containing methyl mercaptan functional groups can be used; to remove B, etc., chelating resins containing amine polyhydroxy functional groups can be used; to remove characteristic cations such as iron, copper, manganese, calcium, magnesium, chlorine, thallium, etc., characteristic removal selective special functional groups can be selected respectively;

[0066] By selectively adsorbing impurities, chelating resins can significantly improve the purity of ammonium rhenate solutions. Efficient adsorption of high-valent metal impurities can reduce contamination in subsequent processes, thereby improving the purity of the final product. The adsorption process requires a balance between impurity removal and retention of the target product. Improper control of adsorption conditions (such as pH and flow rate) can affect the yield of the target product. Therefore, optimizing adsorption conditions is crucial for simultaneously improving purity and yield.

[0067] B. The particle size of the chelating resin is 0.13mm-1.2mm.

[0068] Optionally, the particle size of the chelating resin can be 0.13 mm, 0.2 mm, 0.5 mm, 0.8 mm, 1 mm, 1.2 mm or any value between 0.13 mm and 1.2 mm.

[0069] In some embodiments, the method for preparing 6N grade ammonium rhenate satisfies at least one of the following conditions:

[0070] A. The main structure of the strongly acidic macroporous cationic resin comprises a cross-linked polystyrene / styrene-divinylbenzene copolymer;

[0071] B. the functional groups of the strongly acidic macroporous cationic resin include sulfonic acid groups;

[0072] C. The particle size of the strongly acidic macroporous cationic resin is 0.13-1.2 mm.

[0073] Optionally, the particle size of the strongly acidic macroporous cationic resin may be 0.13 mm, 0.2 mm, 0.5 mm, 0.8 mm, 1 mm, 1.2 mm or any value between 0.13 mm and 1.2 mm.

[0074] In some embodiments, the method for preparing 6N grade ammonium rhenate satisfies at least one of the following conditions:

[0075] A. The main structure of the strongly acidic gel-type cationic resin comprises a cross-linked polystyrene / styrene-divinylbenzene copolymer;

[0076] B. the functional groups of the strongly acidic gel-type cationic resin include sulfonic acid groups;

[0077] It should be noted that when the functional groups of the strong acid gel cationic resin and the strong acid macroporous cationic resin include sulfonic acid groups, the negative charge of the functional group of the cation exchange resin (such as sulfonic acid group) and the high-valent cationic impurities are adsorbed by electrostatic attraction, thereby achieving a better impurity removal effect;

[0078] C. The particle size of the strongly acidic gel-type cationic resin is 0.13 mm to 1.2 mm.

[0079] Optionally, the particle size of the strongly acidic gel-type cationic resin may be 0.13 mm, 0.2 mm, 0.5 mm, 0.8 mm, 1 mm, 1.2 mm or any value between 0.13 mm and 1.2 mm.

[0080] In some embodiments, the method for preparing 6N grade ammonium rhenate satisfies at least one of the following conditions:

[0081] A. described chelate resin comprises hydrogen type chelate resin and / or sodium type chelate resin;

[0082] B. The strongly acidic macroporous cationic resin comprises a hydrogen-type strongly acidic macroporous cationic resin and / or a sodium-type strongly acidic macroporous cationic resin;

[0083] C. The strongly acidic gel-type cationic resin includes a hydrogen-type strongly acidic gel-type cationic resin.

[0084] In some embodiments, the treated chelating resin, the strongly acidic macroporous cationic resin and the strongly acidic gel cationic resin are sequentially subjected to a first acid wash, an alkali wash, a second acid wash and a water wash before undergoing the ion exchange.

[0085] It should be noted that the water washing flow rate must be higher than the acid washing flow rate and the alkaline washing flow rate.

[0086] In some embodiments, the washing method includes acid backwash, water backwash, acid forward wash, and water forward wash performed in sequence.

[0087] In some embodiments, the method for preparing 6N grade ammonium rhenate satisfies at least one of the following conditions:

[0088] A. The concentration of the acid solution in the first pickling or the second pickling is independently 4%-8%, and the volume of the acid solution in the first pickling or the second pickling is independently 2BV-5BV. The concentration of the alkaline solution in the alkali wash is 4%-8%, and the volume of the alkaline solution is 2BV-5BV.

[0089] It should be noted that the acid solution includes but is not limited to one or more of sulfuric acid, hydrochloric acid, and nitric acid. When the concentration of the acid solution is lower than 4%, the hydrogen ion content in the solution is low, the pickling effect is poor, and the washing time needs to be extended to produce a large amount of acid solution; when the concentration is high, the acid concentration in the solution is too high (such as hydrochloric acid and nitric acid) and will volatilize, and the pickling effect will not be much different;

[0090] Optionally, the concentration of the acid solution for the first pickling and the second pickling can be independently 4%, 5%, 6%, 7%, 8% or any value between 4% and 8%, and the volume of the acid solution for the first pickling and the second pickling can be independently 2BV, 3BV, 4BV, 5BV or any value between 2BV and 5BV; the concentration of the alkaline solution for alkali washing can be 4%, 5%, 6%, 7%, 8% or any value between 4% and 8%, and the volume of the alkaline solution can be 2BV, 3BV, 4BV, 5BV or any value between 2BV and 5BV;

[0091] B. the pH value of the resin after the washing is neutral;

[0092] C. when described resin comprised sodium type chelate resin or described stern-acid macroporous cationic resin comprised described sodium type stern-acid macroporous cationic resin, after described resin and described stern-acid macroporous cationic resin were repeated to carry out described first pickling, described alkali cleaning, described second pickling and described washing successively, also repeated to carry out described 3rd pickling and described second washing successively>3 times.

[0093] It should be noted that when the resin is sodium type, it needs to be transformed. There are a large number of sodium ions in the sodium type resin. During ion exchange, the sodium ions are exchanged with impurity ions, and the sodium ions enter the ammonium rhenate solution, causing the sodium ion content to increase sharply. The chelating resin has poor sodium adsorption capacity. A large amount of sodium will enter the lower-level strong acid macroporous cationic resin and be adsorbed by the strong acid macroporous cationic resin, increasing the burden on the strong acid macroporous cationic resin; the resin is easily saturated, causing the sodium concentration in the ammonium rhenate to exceed the standard, and the removal effect of other ions decreases due to the resin saturation effect. Therefore, the sodium type ion exchange resin must be transformed into a hydrogen type before using the ion exchange resin.

[0094] In some embodiments, the container for loading the chelating resin, the strong acidic macroporous cationic resin, and the strong acidic gel cationic resin is cylindrical;

[0095] In some embodiments, the resin container is loaded as Figure 1 As shown, the resin bed height is exemplarily greater than 80 cm. This is because the resin bed is too short, the reaction time of ammonium rhenate ions in the resin is too short, and the ion exchange effect is not ideal. The ammonium rhenate solution enters from above the resin bed and reacts in the resin bed by the dual effects of gravity and pump flow rate, so there are certain requirements for the resin bed height. Exemplarily, multiple inlets are provided above the resin loading container, each inlet is connected to a pump, and the solution flow rate can be adjusted according to the demand.

[0096] When the solution is introduced, the flow rate at the corners of the container is controlled to be greater than the flow rate at the middle, and the temperature at the corners is controlled to be greater than the temperature at the middle;

[0097] It should be noted that the corner position is the area close to the wall of the cylindrical container. Under laminar flow conditions, the flow velocity at the corner tends to 0 (affected by the viscous resistance of the wall), and eddies or boundary layers may form in turbulent flow. The center position refers to the position located at the central axis of the cylindrical container. Therefore, ammonium rhenate crystals are easily generated during the resin adsorption process at the corner of the container, or impurities are easily deposited and difficult to be eluted during the regeneration process. Therefore, increasing the temperature at the corner position can promote the dissolution of ammonium rhenate and the movement speed of ions, thereby reducing impurity formation.

[0098] The solution includes the ammonia water, the ammonium rhenate solution, the acid solution, and the water.

[0099] In some embodiments, by controlling the flow rate at the corners of the container to be greater than the flow rate in the middle, and the temperature at the corners to be greater than the temperature in the middle, the ammonia water can act more fully on the chelating resin, thereby reducing the loss of ammonium rhenate ions; and impurities at the corners can be removed during the acid washing and water washing processes, thereby improving the purity of ammonium rhenate in the ion exchange process.

[0100] In addition, in addition to the process of preparing 6N grade ammonium rhenate, the resin regeneration process can also control the flow rate at the corners of the container to be greater than the flow rate in the middle, and the temperature at the corners to be greater than the temperature in the middle, so as to achieve better regeneration effect.

[0101] In some embodiments, the flow rate difference between the corner flow rate and the middle flow rate is 10 mL / min-50 mL / min;

[0102] Optionally, the flow rate difference between the corner flow rate and the middle flow rate can be 10 mL / min, 20 mL / min, 30 mL / min, 40 mL / min, 50 mL / min, or any value between 10 mL / min and 50 mL / min;

[0103] It should be noted that due to the temperature difference in the resin, the reaction speed of ammonium rhenate varies within the temperature range. The reaction speed is faster at the corners where the temperature is higher. The flow rate can be appropriately increased to remove the reacted rhenate ions in time to prevent the introduction of impurities due to excessive reaction time.

[0104] The temperature difference between the corner temperature and the middle temperature is 10°C-20°C.

[0105] Optionally, the temperature difference between the corner temperature and the middle temperature may be 10°C, 15°C, 20°C or any value between 10°C and 20°C.

[0106] It should be noted that if the temperature difference is too high, the temperature of the resin at the edges and corners will be too high, the thermal motion of the ions will intensify, and the ions in the ammonium rhenate will tend to gather and react at the edges and corners, which can easily cause local resin oversaturation. If the temperature difference is too low, the resin at the edges and corners will participate less in the reaction than the resin in the middle, and the ion reaction will be uneven.

[0107] The embodiments of the present application will be described in detail below in conjunction with specific examples, but it will be understood by those skilled in the art that the following examples are only used to illustrate the present application and should not be considered as limiting the scope of the present application. In the examples, if specific conditions are not specified, they are carried out according to normal conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0108] Example 1

[0109] This embodiment provides a method for preparing 6N grade ammonium rhenate, wherein the main structure of the hydrogen-type chelating resin used is a cross-linked polystyrene / styrene-divinylbenzene copolymer, the functional group includes iminodiacetic acid group, and the particle size is 1-1.2mm (>95%).

[0110] The main structure of the hydrogen-type strongly acidic macroporous cationic resin is a cross-linked polystyrene / styrene-divinylbenzene copolymer, the functional groups include sulfonic acid groups, and the particle size is 1-1.2 mm (>95%).

[0111] The main structure of the hydrogen-type strongly acidic gel-type cationic resin is a cross-linked polystyrene / styrene-divinylbenzene copolymer, the functional groups include sulfonic acid groups, and the particle size is 0.2mm-0.5mm (>95%).

[0112] The specific steps of the preparation include:

[0113] S1: dissolving ammonium rhenate in deionized water to obtain an ammonium rhenate solution with a mass percentage concentration of 5%;

[0114] S2: resin is loaded in the cylindrical container, at first, employing feeds the hydrochloric acid soln (concentration is 4%) that volume is 4BV and carries out pickling, secondly, feeds the sodium hydroxide solution (concentration is 4%) that volume is 4BV and carries out alkali cleaning again, then, feeds the hydrochloric acid soln (concentration is 4%) that volume is 4BV and carries out pickling, best, feeds water and washes, obtaining pH is 7 resin, in addition, hydrogen type stern acid macroporous cationic resin and hydrogen type stern acid gel type cationic resin are washed and pickled according to above-mentioned consistent method respectively;

[0115] S3: performing ion exchange on the ammonium rhenate solution treated in step S2, respectively, with the chelate resin, the strongly acidic macroporous cationic resin, and the strongly acidic gel cationic resin to obtain a high-purity ammonium rhenate solution;

[0116] S4: Evaporating and concentrating the high-purity ammonium rhenate solution and freezing and crystallizing it to obtain 6N ammonium rhenate.

[0117] In this embodiment, when the solution (hydrochloric acid solution, water, ammonia solution and ammonium rhenate solution) is introduced into the container, different pumps are used for feeding at the corners and the middle of the feed port above the container. The pump flow rates are controlled differently to control the flow rate of the solution corners of the container to be greater than the flow rate in the middle. Heating oil is introduced into the outer interlayer of the container to control the temperature of the resin corners in the container to be greater than the temperature in the middle. The flow rate difference between the corner flow rate and the middle flow rate is 10 min, and the temperature difference between the corner temperature and the middle temperature is 10°C.

[0118] Comparative Example 1

[0119] The difference from Example 1 is: the chelating resin is not processed using ammoniacal liquor.

[0120] Comparative Example 2

[0121] The difference from Example 1 is: chelating resin is not set.

[0122] Comparative Example 3

[0123] The difference from Example 1 is that no strongly acidic macroporous cationic resin is provided.

[0124] Comparative Example 4

[0125] The difference from Example 1 is that no strong acid gel-type cationic resin is provided.

[0126] Comparative Example 5

[0127] The difference from Example 1 is that the order of introducing the resins is different, and the ammonium rhenate solution is introduced into the chelating resin, the strongly acidic gel-type cationic resin and the strongly acidic macroporous cationic resin in sequence.

[0128] Comparative Example 6

[0129] The difference from Example 1 is that when the solutions (hydrochloric acid solution, water, ammonia water and ammonium rhenate solution) are naturally introduced into the container, the temperature at the corners of the resin in the container is consistent with the temperature in the middle.

[0130] Comparative Example 7

[0131] The difference from Example 1 is that when the solutions (hydrochloric acid solution, water, ammonia water and ammonium rhenate solution) are naturally introduced into the container, the flow rate at the corners and the flow rate in the middle of the container are consistent.

[0132] The yield and purity of the ammonium rhenate prepared in the above examples and comparative examples were tested, and the specific data are shown in Table 1.

[0133] Table 1 Yield and purity test

[0134] Test components Yield / % purity Example 1 98.54％ 99.9999％ Comparative Example 1 65.87％ 99.9999％ Comparative Example 2 97.65％ 99.9983％ Comparative Example 3 96.52％ 99.9995％ Comparative Example 4 95.20％ 99.9983％ Comparative Example 5 97.82％ 99.9998％ Comparative Example 6 95.16％ 99.9994％ Comparative Example 7 95.34％ 99.9993％

[0135] analyze:

[0136] From the above results, it can be seen that according to Example 1 and Comparative Example 1, since no ammonia water was used to occupy the space, the rhenate ions were adsorbed by the chelating resin during the ion exchange process, resulting in a large amount of loss and a sharp drop in yield.

[0137] According to Comparative Examples 2-4 and Example 1, the lack of any resin will affect the purity, and the purity cannot reach 99.9999%. Without the chelating resin or the last stage of strong acid gel resin, the purity of ammonium rhenate can only reach 99.99%.

[0138] According to Comparative Example 5 and Example 1, if the ion exchange sequence is changed and the strongly acidic gel resin is not in the last stage, the monovalent ions may not be completely removed, and the purity is at the level of 99.999%.

[0139] According to Comparative Examples 6 and 7 and Example 1, the adjustment of the flow rate and temperature at the corners and the middle of the ammonium rhenate ion exchange resin column without controlling the flow rate difference and temperature difference will affect the ion exchange process to a certain extent, resulting in a purity of 99.999% level without a flow rate difference and / or temperature difference, resulting in local enrichment of ammonium rhenate and a decrease in yield.

[0140] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present application.

[0141] Furthermore, those skilled in the art will appreciate that although some embodiments herein include certain features included in other embodiments but not others, combinations of features from different embodiments are intended to be within the scope of this application and to form distinct embodiments. For example, in the claims above, any of the claimed embodiments may be used in any combination. The information disclosed in this background section is intended solely to enhance understanding of the overall background of this application and should not be construed as an admission or any implication that such information constitutes prior art known to those skilled in the art.

Claims

1. A method for preparing 6N grade ammonium rhenate, characterized in that: include: treating the chelate resin with aqueous ammonia to obtain a treated chelate resin; The ammonium rhenate solution is sequentially passed through the treated chelating resin, the strongly acidic macroporous cationic resin and the strongly acidic gel cationic resin to perform ion exchange to obtain a high-purity ammonium rhenate solution; The high-purity ammonium rhenate solution is evaporated, concentrated, and frozen and crystallized to obtain 6N ammonium rhenate; Wherein, the main structure of the chelating resin includes cross-linked polystyrene / styrene-divinylbenzene copolymer.

2. The method for preparing 6N grade ammonium rhenate according to claim 1, wherein: The volume of the ammonia water introduced is 0.1BV-0.5BV.

3. The method for preparing 6N grade ammonium rhenate according to claim 1, wherein: At least one of the following conditions is met: A. the functional groups of the chelating resin include one or more of isothiourea, iminodiacetic acid, dimethylphosphine, methyl mercaptan, amine polyhydroxyl, dimethylpyridine amino, aminomethylphosphonic acid and aminomethylphosphonic acid; B. The particle size of the chelating resin is 0.13mm-1.2mm.

4. The method for preparing 6N grade ammonium rhenate according to claim 1, wherein: At least one of the following conditions is met: A. The main structure of the strongly acidic macroporous cationic resin comprises a cross-linked polystyrene / styrene-divinylbenzene copolymer; B. the functional groups of the strongly acidic macroporous cationic resin include sulfonic acid groups; C. The particle size of the strongly acidic macroporous cationic resin is 0.13-1.2 mm.

5. The method for preparing 6N grade ammonium rhenate according to claim 1, characterized in that: At least one of the following conditions is met: A. The main structure of the strongly acidic gel-type cationic resin comprises a cross-linked polystyrene / styrene-divinylbenzene copolymer; B. the functional groups of the strongly acidic gel-type cationic resin include sulfonic acid groups; C. The particle size of the strongly acidic gel-type cationic resin is 0.13 mm to 1.2 mm.

6. The method for preparing 6N grade ammonium rhenate according to any one of claims 1 to 5, characterized in that: At least one of the following conditions is met: A. the chelate resin comprises a hydrogen type chelate resin and / or a sodium type chelate resin; B. The strongly acidic macroporous cationic resin comprises a hydrogen-type strongly acidic macroporous cationic resin and / or a sodium-type strongly acidic macroporous cationic resin; C. The strongly acidic gel-type cationic resin includes a hydrogen-type strongly acidic gel-type cationic resin.

7. The method for preparing 6N grade ammonium rhenate according to claim 6, characterized in that: Before the ion exchange, the treated chelating resin, the strongly acidic macroporous cationic resin and the strongly acidic gel cationic resin are sequentially subjected to a first acid wash, an alkali wash, a second acid wash and a first water wash.

8. The method for preparing 6N grade ammonium rhenate according to claim 7, characterized in that: At least one of the following conditions is met: A. The concentration of the acid solution in the first pickling or the second pickling is independently 4%-8%, and the volume of the acid solution in the first pickling or the second pickling is independently 2BV-5BV. The concentration of the alkaline solution in the alkali wash is 4%-8%, and the volume of the alkaline solution is 2BV-5BV. B. the pH value of the resin after the washing is neutral; C. when described resin comprises sodium type chelate resin or described strontically acidic macroporous cationic resin comprises described sodium type strontically acidic macroporous cationic resin, after described resin and described strontically acidic macroporous cationic resin are carried out successively first pickling, described alkali cleaning, described second pickling and described washing, also repeat to carry out successively>the 3rd pickling and the second washing of 3 times.

9. The method for preparing 6N grade ammonium rhenate according to claim 8, characterized in that: The container for loading the chelating resin, the strongly acidic macroporous cationic resin and the strongly acidic gel-type cationic resin is cylindrical; When the solution is introduced, the flow rate at the corners of the container is controlled to be greater than the flow rate at the middle, and the temperature at the corners is controlled to be greater than the temperature at the middle; The solution includes the ammonia water, the ammonium rhenate solution, the acid solution, and the water.

10. The method for preparing 6N grade ammonium rhenate according to claim 9, characterized in that: The flow rate difference between the corner flow rate and the middle flow rate is 10mL / min-50mL / min; The temperature difference between the corner temperature and the middle temperature is 10°C-20°C.

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