An extraction resin, its preparation method, and its application in the purification of ammonium molybdate.

Abstract

This invention provides an extraction resin, its preparation method, and its application in the purification of ammonium molybdate. The extraction resin is prepared by loading an alkylphosphine-primary amine mixed extractant onto an inert support through vacuum stirring. Specifically, swelling treatment increases the specific surface area and porosity of the inert support, and the synergistic effect of the mixed extractant enhances the selective adsorption capacity for impurities in molybdate. Vacuum stirring ensures uniform dispersion of the extractant and a strong bond with the resin. This preparation method effectively solves the problems of uneven dispersion, easy loss, and easy saturation of extractants in traditional extraction resins, providing a more efficient separation material for high-purity molybdenum production.

Description

Technical Field

[0001] This application relates to the field of metal purification technology, and more specifically, to an extraction resin, a preparation method thereof, and its application in the purification of ammonium molybdate. Background Technology

[0002] Molybdenum is a rare, dispersed metallic material with excellent properties. Metallic molybdenum possesses a high melting point, good electrical and thermal conductivity, corrosion resistance, and excellent resistance to thermal fatigue. It also has moderate hardness and strong toughness and ductility. High-purity molybdenum can be used to prepare molybdenum sputtering targets, which are then deposited onto various substrates to form sputtered films widely used in various electronic products. Furthermore, high-purity molybdenum is also used in rocket nozzles, chemical reagents, and catalysts.

[0003] Currently, the production of high-purity molybdenum metal mainly involves purifying ammonium molybdate using hydrometallurgical processes such as extraction, ion exchange, and temperature-controlled recrystallization. Among these, extraction chromatography is a novel column chromatography method for separating inorganic substances. It uses an inert support containing the extractant to prepare an extraction resin as the stationary phase and an aqueous solution as the mobile phase to achieve the separation of different substances. However, existing extraction resins still suffer from problems such as poor purification effect on ammonium molybdate, uneven dispersion of the extractant, poor binding force with the resin, easy loss, low adsorption / extraction dosage, and easy saturation. Summary of the Invention

[0004] To address the aforementioned problems, this invention provides an extraction resin, its preparation method, and its application in the purification of ammonium molybdate. The extraction resin is prepared by loading an alkylphosphine-primary amine mixed extractant onto an inert support through vacuum stirring. The swelling treatment increases the specific surface area and porosity of the inert support, and the synergistic effect of the mixed extractant enhances the adsorption capacity for impurities in molybdate. Vacuum stirring ensures uniform dispersion of the extractant and a strong bond with the resin. This preparation method effectively solves the problems of uneven dispersion, easy loss, and easy saturation of the extractant in traditional extraction resins, providing a more efficient separation material for high-purity molybdenum production.

[0005] In a first aspect, the present invention provides a method for preparing an extraction resin, the method comprising:

[0006] The inert support is immersed in the impregnation solution to allow it to swell fully; the extractant and an appropriate amount of impregnation solution are mixed to form a mixed solution;

[0007] The mixed solution is mixed with the swollen inert support, stirred under vacuum to load the extractant onto the swollen inert support, and then dried to obtain the extraction resin.

[0008] The inert support is selected from at least one of polystyrene, polystyrene-divinylbenzene, polyethylene, polyacrylate and polyurethane foam.

[0009] The extractant is formed by mixing alkylphosphine oxide and primary amine.

[0010] Optionally, the amount of the extractant is 30%-50% of the mass of the inert support.

[0011] Optionally, the alkylphosphine oxide is a trialkylphosphine oxide or a tri-n-octylphosphine oxide;

[0012] The primary amine is a secondary carbon primary amine or 3-(nonoxy)propane-1-amine.

[0013] Optionally, the molar ratio of the alkylphosphine oxide to the primary amine is (1-5):1.

[0014] Optionally, the inert support is polystyrene-divinylbenzene or polyacrylate.

[0015] Optionally, the impregnation solution is selected from at least one of methanol, ethanol, dichloromethane, and benzene.

[0016] Optionally, the stirring speed is 25 rpm-60 rpm, and the stirring time is 1 h-6 h.

[0017] In a second aspect, the present invention provides an extraction resin, which is obtained by the preparation method described in the first aspect above.

[0018] Thirdly, the present invention provides an application of an extraction resin in the purification of ammonium molybdate, wherein the extraction resin is obtained by the preparation method described in the first aspect above, and the extraction resin is used to purify an ammonium molybdate solution with a concentration not exceeding 40 g / L, and to obtain ammonium molybdate with a purity of at least 99.99%.

[0019] Optionally, the purification method includes:

[0020] The extraction resin was placed in deionized water, swollen, and then packed into a chromatography column.

[0021] Dilute hydrochloric acid was passed through the swollen extraction resin at a flow rate of 2 BV / h-5 BV / h to obtain the activated extraction resin.

[0022] An ammonium molybdate solution with a concentration not exceeding 40 g / L is passed through a chromatography column packed with the activated extraction resin at a flow rate of 3 BV / h to 7 BV / h to remove impurities and obtain ammonium molybdate with a purity of at least 99.99%.

[0023] In summary, the present invention has at least the following beneficial technical effects:

[0024] 1. This invention provides a method for preparing an extraction resin. An inert support is immersed in an impregnation solution to allow it to fully swell. An extractant is then mixed with an appropriate amount of the impregnation solution to form a mixed solution. This mixed solution is then mixed with the swollen inert support, and the mixture is stirred under vacuum conditions to load the extractant onto the swollen inert support. After drying, the extraction resin is obtained. This invention significantly improves the purification effect of the extraction resin on ammonium molybdate by using inert supports such as polystyrene and polystyrene-divinylbenzene, combined with a mixed extractant composed of alkylphosphine oxide and primary amine, and by using vacuum stirring and loading. Specifically, the synergistic effect of the components in the mixed extractant enhances the selective adsorption capacity for impurities in molybdate, effectively solving the problem of low separation efficiency in traditional methods. By combining impregnation with vacuum stirring, the extractant is uniformly distributed and firmly bonded on the inert support, significantly reducing extractant loss. At the same time, the inert support after swelling treatment has a larger specific surface area and higher porosity, which not only allows it to load more extractant but also delays saturation, thereby greatly improving the adsorption capacity and stability of the extraction resin and overcoming defects such as uneven extractant dispersion, easy saturation, and poor binding force.

[0025] 2. This invention provides an extraction resin that uses an extractant composed of alkylphosphine oxide and a primary amine, combined with an inert support, to achieve highly efficient and selective separation of ammonium molybdate solutions. In the extraction resin, the uniform distribution and stable binding of the extractant within the resin carrier significantly improves the utilization efficiency and lifespan of the extractant. The swollen resin carrier possesses superior pore structure and surface properties, effectively overcoming the limitations of traditional extraction resins in the purification of ammonium molybdate, and providing a reliable separation material for the production of high-purity molybdenum products.

[0026] 3. This invention provides an application of an extraction resin in the purification of ammonium molybdate. This extraction resin is suitable for the deep purification of low-to-medium concentration ammonium molybdate solutions, efficiently removing impurity elements and stably obtaining ultra-high purity ammonium molybdate products. Its loaded extractant has a stronger adsorption capacity for impurity ions in the solution, effectively reducing the co-extraction of molybdate ions. In application, this extraction resin exhibits stable separation performance, good mass transfer efficiency, and long-term recyclability, thus improving the overall efficiency of the ammonium molybdate purification process. Attached Figure Description

[0027] To more clearly illustrate the technical solutions of the embodiments of this application, the drawings used in the description of the embodiments of this application will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 A flowchart illustrating the preparation method of the extraction resin proposed in this application is shown;

[0029] Figure 2 A flowchart of the method for purifying ammonium molybdate with extraction resin according to an embodiment of this application is shown. Detailed Implementation

[0030] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0031] In the accompanying drawings, the size of constituent elements, the thickness of layers, or areas may sometimes be exaggerated for clarity. Therefore, any implementation of this disclosure is not necessarily limited to the dimensions shown in the drawings, and the shapes and sizes of the components in the drawings do not reflect true proportions. Furthermore, the drawings schematically illustrate ideal examples, and any implementation of this disclosure is not limited to the shapes or values ​​shown in the drawings.

[0032] In related technologies, the purity of metallic molybdenum has a significant impact on its electronic properties, directly affecting the application areas of high-purity molybdenum. For example, alkali metal impurities such as potassium and sodium can easily become mobile ions in the molybdenum lattice, forming dead spots in the insulating layer that can easily lead to breakdown. Impurities such as iron and nickel can cause interfacial leakage or increase oxygen levels. Therefore, the requirements for trace impurities in high-purity molybdenum metal are extremely stringent. In the fields of flat panel display coating and solar cells, the purity requirement for raw molybdenum is a mass fraction of 4N (99.99%) or higher, while in the integrated circuit field, the purity requirement for high-purity molybdenum powder is 5N (99.999%) or higher.

[0033] Currently, the production of high-purity molybdenum metal mainly involves purifying ammonium molybdate using hydrometallurgical processes such as extraction, ion exchange, and temperature-controlled recrystallization. Extraction and ion exchange are the most widely used methods; however, both have limitations. For example, extraction results in significant organic phase loss and generates organic waste that impacts the environment, while also increasing the carbon content in the product. Ion exchange involves complex resin synthesis and has a limited number of regeneration cycles. Another approach involves purifying already reduced molybdenum metal using powder metallurgy, electron beam melting, and zone melting. However, these methods often suffer from long production cycles, high equipment investment, and severe pollution, and are difficult to effectively remove high-melting-point metals such as tungsten. Therefore, this invention, starting from ammonium molybdate raw materials, studies the removal of trace impurities, which can alleviate the pressure on downstream impurity removal.

[0034] This invention reveals that extractive chromatography is a novel column chromatography method for separating inorganic substances. It uses an inert support containing the extractant as the stationary phase and an aqueous solution as the mobile phase to achieve the separation of different substances. By impregnating the extractant onto a weakly polar macroporous adsorption resin, it combines the high selectivity and efficiency of solvent extraction with the simplicity and pollution-free nature of ion exchange technology. It also overcomes the drawbacks of some extractants, such as difficulty in separation, high levels of organic residue, and limitations imposed by extraction equilibrium on the separation limits. Furthermore, it exhibits better selectivity than ion exchange resins.

[0035] However, existing extraction resins still have certain problems, such as poor purification effect on ammonium molybdate, uneven dispersion of extractant, poor binding force with resin, easy loss, low adsorption and extraction dosage, and easy saturation.

[0036] Based on the problems existing in the relevant technologies, see Figure 1 This invention provides a method for preparing an extraction resin, the method comprising:

[0037] Step S1: Immerse the inert support in the impregnation solution to allow it to swell fully; take the extractant and an appropriate amount of impregnation solution, and mix them to form a mixed solution;

[0038] The inert support is selected from at least one of polystyrene, polystyrene-divinylbenzene, polyethylene, polyacrylate and polyurethane foam.

[0039] In this invention, polystyrene, polystyrene-divinylbenzene, and other polymeric materials are used as inert supports, forming a synergistic effect with the impregnation liquid and extractant loading, which significantly improves the overall performance of the extraction resin. The aforementioned inert supports swell moderately under the action of the impregnation liquid, forming a uniform pore structure. This not only enhances the dispersibility of the extractant but also improves the binding strength of the extractant through intermolecular forces, thereby significantly reducing the risk of extractant loss. Furthermore, the synergistic effect of polystyrene-based materials on the adsorption of organic matter and the extractant further optimizes the selective adsorption capacity for impurities, enabling the extraction resin to possess both high capacity and high stability during the purification process.

[0040] Among them, cross-linked polymers such as polystyrene-divinylbenzene, with their rigid skeleton and moderate swelling properties, ensure the stability of the carrier structure. The extraction resin prepared using the above-mentioned inert support has excellent mechanical strength, high specific surface area, and stable extractant retention capacity, effectively solving the problems of low extractant loading and easy loss of traditional extraction resins.

[0041] In practice, the inert support can be selected from one of polystyrene, polystyrene-divinylbenzene, polyethylene, polyacrylate and polyurethane foam, or any combination of several.

[0042] In this invention, the inert support is polystyrene-divinylbenzene or polyacrylate.

[0043] The cross-linked structure of polystyrene-divinylbenzene provides a stable three-dimensional network and suitable pore size distribution, enabling controlled swelling under the action of the impregnation solution and creating a favorable loading environment for the extractant. Meanwhile, polyacrylate, due to its structural characteristics, enhances its affinity for the extractant. These two inert supports not only possess excellent chemical stability and mechanical strength, but their unique surface properties also promote uniform dispersion and strong bonding of the extractant, effectively solving the problems of uneven extractant distribution and easy loss in traditional resins.

[0044] In this invention, the impregnation solution is selected from at least one of methanol, ethanol, dichloromethane, and benzene.

[0045] Using solvents such as methanol and ethanol, or organic solvents such as dichloromethane and benzene, as impregnation solutions can effectively promote the swelling process of the inert support and enhance the openness of its pore structure. When impregnating the extractant, the impregnation solution composed of the above components also helps to uniformly disperse the extractant in the inert support and improves the bonding strength between the extractant molecules and the inert support. In this invention, suitable impregnation solutions can be selected for extractant components with different properties to optimize their loading effect, thereby preparing an extraction resin with more uniform extractant distribution and stronger bonding.

[0046] In this invention, the inert support can be soaked in the impregnation solution for 1 h to 3 h; for example, the inert support can be soaked in the impregnation solution for 1 h, 1.5 h, 2 h, 2.5 h, or 3 h to allow the inert support to fully swell.

[0047] In this invention, the amount of the extractant is 30%-50% of the mass of the inert support.

[0048] In practice, the amount of extractant can be 30%, 35%, 40%, 45%, or 50% of the mass of the inert support.

[0049] In this invention, by controlling the amount of extractant within the range of 30%-50% of the mass of the inert support, the pore capacity of the inert support is fully utilized while avoiding the problems of aggregation or loss caused by excessive extractant. This allows the extractant molecules to be fully and uniformly distributed in the pore structure of the inert support, forming a stable binding state. This solves the problems of uneven extractant distribution, easy saturation, and easy loss in traditional preparation methods, resulting in an extractant resin with superior adsorption selectivity and a longer service life during ammonium molybdate purification.

[0050] In this invention, the extractant is formed by mixing alkylphosphine oxide and primary amine.

[0051] The synergistic effect of a composite extractant of alkylphosphine oxide and primary amine is fully realized through the control of polystyrene-based inert support and loading. The protonated amine extractant enhances the selectivity for polyacid impurities that easily form in ammonium molybdate, while the introduction of alkylphosphine oxide further enhances the interaction between the extractant molecules and the inert support, further reducing extractant loss, significantly improving the separation coefficient, and solving problems such as easy saturation of single extractants and co-adsorption of impurities.

[0052] In this invention, the alkylphosphine oxide is a trialkylphosphine oxide or a tri-n-octylphosphine oxide;

[0053] The primary amine is a secondary carbon primary amine or 3-(nonoxy)propane-1-amine.

[0054] In specific implementation, the extractant may be composed of trialkylphosphine oxide and secondary carbon primary amine, or trialkylphosphine oxide and 3-(nonoxy)propane-1-amine, or tri-n-octylphosphine oxide and secondary carbon primary amine, or tri-n-octylphosphine oxide and 3-(nonoxy)propane-1-amine.

[0055] In this invention, trialkylphosphine oxides, due to their long-chain alkyl structure, can highly match the hydrophobicity of the polystyrene-divinylbenzene inert support, and can also form hydrogen bonds with amines to enhance binding stability, thereby enhancing the nonpolar interaction with the polyacrylate inert support. This invention combines the above-mentioned alkylphosphine oxides with primary amines, ensuring the extractant remains stable at a loading of 30%-50%. This not only improves the adsorption capacity and purity of ammonium molybdate (≥99.99%), but also reduces the extractant loss rate to an extremely low level through intermolecular synergistic effects, solving the problems of poor selectivity and easy loss of extraction resins prepared by traditional processes.

[0056] In this invention, the molar ratio of the alkylphosphine oxide to the primary amine is (1-5):1.

[0057] In practice, the molar ratio of alkylphosphine oxide to primary amine can be 1:1, 2:1, 3:1, 4:1, or 5:1.

[0058] In this invention, the molar ratio of alkylphosphine oxide to primary amine is controlled between (1-5):1. This is based on the chemical properties of trialkylphosphine oxide / tri-n-octylphosphine oxide and primary amines with specific structures. The two extractants have a synergistic effect when mixed, achieving stronger selectivity for impurities than a single extractant. Under the non-polar framework adsorption of the inert support and the swelling effect of the impregnation solution, combined with vacuum loading and an extractant loading of 30%-50%, the orderly arrangement of the extractant within the pores of the inert support is ensured—the long-chain alkyl groups of the alkylphosphine oxide are tightly adsorbed with the inert support framework. At the same time, the adsorption stability of the primary amine, which becomes more polar after protonation, is enhanced through hydrogen bonding. This solves the problems of low adsorption stability and insufficient selectivity of extractants in traditional processes, enabling the extraction resin to have high adsorption capacity, ultra-high selectivity, and long-term stability during the purification of ammonium molybdate.

[0059] Step S2: Mix the mixed solution with the swollen inert support, stir under vacuum conditions to load the extractant onto the swollen inert support, and dry to obtain the extraction resin.

[0060] In practice, the system of mixing the solution with the swollen inert support is transferred into a flask, which is then placed in a rotary evaporator. The rotary evaporator is used to rotate and stir the solution in a vacuum environment at room temperature, so that the solution is fully immersed in the swollen inert support.

[0061] In this invention, the stirring speed is 25 rpm-60 rpm, and the stirring time is 1 h-6 h.

[0062] In practice, the stirring speed can be 25 rpm, 30 rpm, 35 rpm, 40 rpm, 45 rpm, 50 rpm, 55 rpm, or 60 rpm, and the stirring time can be 1 h, 2 h, 3 h, 4 h, 5 h, or 6 h.

[0063] In this invention, by setting the vacuum stirring speed within the range of 25 rpm to 60 rpm and the stirring time within the range of 1 h to 6 h, it is possible to ensure that the impregnation solution fully penetrates the pores of the inert support while avoiding uneven distribution of the extractant caused by high-speed shearing. The 1 h to 6 h duration, matched with the (1-5):1 extractant ratio and 30%-50% loading, allows trialkylphosphine oxides and other compounds to gradually form a stable assembly structure with primary amine molecules, enabling the extractant to achieve uniform molecular-level anchoring on the inert support framework, thereby reducing the extractant loss rate. Furthermore, by maintaining the integrity of the alkylphosphine oxide active sites, the adsorption selectivity of the extraction resin for ammonium molybdate is improved, providing process assurance for the industrial production of high-purity molybdenum products of grade 4N and above.

[0064] In this invention, the drying process in step S2 includes rotary evaporation and drying.

[0065] Rotary evaporation includes:

[0066] The stirred mixture was heated to 40 °C and rotary evaporated to allow the impregnating agent to fully evaporate until the resin was in a dispersed solid state.

[0067] Drying includes: transferring the dispersed solid obtained by rotary evaporation to an oven at 30 ℃-60 ℃ and drying for 6 h-12 h to obtain the extract resin.

[0068] In this invention, the extractant is first subjected to rotary evaporation at 40 °C to allow the impregnation solution to evaporate gently, avoiding damage to the molecular structure of the alkylphosphine-primary amine composite extractant at high temperatures, while ensuring that the extractant loaded on the inert support remains uniformly distributed. Subsequently, the extractant is dried at a low temperature of 30 °C-60 °C for 6 h-12 h, which is combined with a stirring process of 25 rpm-60 rpm to form a process connection, so that the extractant forms a stable bond with the inert support under the condition of a (1-5):1 ratio.

[0069] The segmented drying method described above not only preserves the active sites of the extractant but also prevents the enrichment of the extractant in micro-regions by controlling the evaporation rate, so that the final extracted resin still maintains excellent pore structure and surface properties even with an extractant loading of 30%-50%.

[0070] In summary, the method for preparing the extraction resin provided by this invention involves immersing an inert support in an impregnation solution to allow it to swell fully, thereby relaxing the polymer chains and expanding the pore structure, thus increasing the specific surface area and internal accessibility of the inert support. This allows the subsequently loaded extractant to be more evenly distributed inside and on the surface of the inert support, avoiding local overloading or uncovered areas, and solving the problem of uneven dispersion of traditional extractants.

[0071] Stirring and swelling the inert support under vacuum conditions with the mixed solution promotes the diffusion of extractant molecules into the inert support. This enhances the physical adsorption and chemical bonding between the extractant and the inert support, reduces the risk of extractant loss, and simultaneously increases the extractant loading while delaying saturation.

[0072] A mixed extractant of alkylphosphine oxide and primary amine is used. Protonation of the primary amine significantly improves selectivity for impurities, while the coordination and hydrogen bonding of the phosphine oxide significantly enhance the stability of the extract and its adsorption strength on the support. This improves the purification efficiency of ammonium molybdate while reducing competitive adsorption interference. Highly cross-linked polymers such as polystyrene-divinylbenzene are selected as the inert support. Their three-dimensional network structure and chemical inertness can withstand strong acid / alkali environments, thereby enhancing the mechanical strength and chemical stability of the extraction resin, maintaining structural integrity during long-term cyclic use, and reducing extractant loss due to breakage. Drying treatment, by slowly removing the impregnation solution, allows extractant molecules to form a stable immobilized layer within the pores of the inert support, further reducing elution loss during use and extending the resin's lifespan.

[0073] The present invention also provides an extraction resin, which is obtained by the preparation method described above.

[0074] This extraction resin possesses high impurity selectivity, high adsorption capacity, and long-term stability, and can stably produce ammonium molybdate with a purity of ≥99.99%. It solves the problems of extractant loss, easy saturation, and low separation efficiency of traditional extraction resins, and provides a reliable material basis for the industrial production of high-purity molybdenum.

[0075] The present invention also provides an application of an extraction resin in the purification of ammonium molybdate, wherein the extraction resin is obtained by the preparation method described above, and the extraction resin is used to purify an ammonium molybdate solution with a concentration not exceeding 40 g / L, and to obtain ammonium molybdate with a purity of at least 99.99%.

[0076] The extraction resin prepared in this invention is suitable for the efficient purification of ammonium molybdate solutions with a concentration ≤40 g / L. During application, the three-dimensional porous structure of the extraction resin and the alkylphosphine-primary amine active sites work synergistically to achieve highly selective capture of impurity ions; simultaneously, the 30%-50% extractant loading ensures sufficient adsorption capacity. This extraction resin solves the problems of incomplete impurity removal and easy resin deactivation in traditional processes, enabling the stable production of ultra-high purity ammonium molybdate exceeding 99.99%.

[0077] See Figure 2 In this invention, the purification method includes:

[0078] Step S11: Place the extraction resin in deionized water, swell it, and then pack it into a chromatography column;

[0079] Step S21: Pass dilute hydrochloric acid through the swollen extraction resin at a flow rate of 2 BV / h-5 BV / h to obtain activated extraction resin;

[0080] In practice, dilute hydrochloric acid can be passed through the swollen extraction resin at flow rates of 2 BV / h, 3 BV / h, 4 BV / h, and 5 BV / h.

[0081] In this invention, after activation, the protonated amine extractant exists in the form of ion pairs. The extraction mechanism is mainly based on ion association, which makes it easier to preferentially extract isopolyacids and heteropolyacids anions formed by impurities, thereby improving the separation coefficient of the extraction resin by efficiently adsorbing impurity ions.

[0082] Step S31: Pass an ammonium molybdate solution with a concentration of no more than 40 g / L through a chromatography column packed with the activated extraction resin at a flow rate of 3 BV / h-7 BV / h to remove impurities and obtain ammonium molybdate with a purity of at least 99.99%.

[0083] In practice, the ammonium molybdate solution can be passed through a chromatography column packed with activated extraction resin at flow rates of 3 BV / h, 4 BV / h, 5 BV / h, 6 BV / h, and 7 BV / h.

[0084] In summary, the purification method provided by this invention utilizes dilute hydrochloric acid to activate the extraction resin, protonating the primary amine groups into positively charged active sites. This allows for the efficient adsorption of anionic impurities via ion association. Meanwhile, alkylphosphine oxides enhance the stability of the extract through hydrogen bonding and coordination, creating a synergistic extraction effect superior to that of a single extractant. Ultimately, this results in a stable ammonium molybdate purity exceeding 99.99%. This improves the separation coefficient between impurities and molybdate, thereby reducing costs and increasing resource utilization in high-purity molybdenum production.

[0085] To enable those skilled in the art to more clearly understand the present invention, the following embodiments are provided to illustrate in detail the extraction resin, preparation method, and application in the purification of ammonium molybdate.

[0086] Example 1

[0087] AB-8 macroporous adsorption resin was used as an inert support. The backbone component of AB-8 macroporous adsorption resin is polystyrene-divinylbenzene. Anhydrous ethanol was used as the impregnation solution. AB-8 macroporous adsorption resin was placed in the impregnation solution and soaked for 2 hours to allow it to fully swell.

[0088] Trialkylphosphine oxide (TRPO) and secondary carbon primary amine are mixed in a molar ratio of 1:1 to prepare an extractant. The extractant is then added to an appropriate amount of anhydrous ethanol and mixed thoroughly to form a mixed solution.

[0089] The mixed solution was added to anhydrous ethanol containing a swollen inert support, wherein the amount of extractant accounted for 50% of the mass of the inert support. The resulting mixture was placed in a flask and transferred to a rotary evaporator. The flask was stirred under vacuum and ambient temperature conditions provided by the rotary evaporator for 1 hour at a speed of 45 rpm to ensure that the mixed solution was fully impregnated into the swollen inert support and that the extractant was loaded onto the swollen inert support.

[0090] After being fully loaded, the internal temperature of the rotary evaporator is raised to 40 °C for rotary evaporation. When the impregnating agent is fully volatilized and the resin is in a dispersed solid state, it is then transferred to a 30 °C oven for drying for 12 h to complete the drying process and obtain the extraction resin for purifying ammonium molybdate.

[0091] The extraction resin prepared in Example 1 was swollen in deionized water and then packed into a chromatography column. An ammonium molybdate solution with a concentration of 28 g / L from a copper smelting system was injected into the chromatography column packed with the extraction resin and passed through at a flow rate of 2 Bv / h to obtain a high-purity ammonium molybdate solution. After heating and crystallization, and washing, the ammonium molybdate product was obtained. The product was analyzed, and the results are shown in Table 1 below.

[0092] Table 1. Determination results of ammonium molybdate products (I)

[0093]

[0094] Table 1 shows that, for crude ammonium molybdate raw materials with different initial purities, under industrial conditions of pH 5.2-5.5, the extraction resin can stably produce high-purity products with a purity ≥99.99%. The separation coefficient of the extraction resin prepared in Example 1 in the purification of ammonium molybdate is calculated to be 112, indicating that the extraction resin has extremely strong selective adsorption capacity for impurity ions.

[0095] Example 2

[0096] AB-8 macroporous adsorption resin was used as an inert support. The backbone component of AB-8 macroporous adsorption resin is polystyrene-divinylbenzene. Anhydrous ethanol was used as the impregnation solution. AB-8 macroporous adsorption resin was placed in the impregnation solution and soaked for 2 hours to allow it to fully swell.

[0097] Tri-n-octylphosphine oxide (TOPO) and secondary carbon primary amine were mixed in a molar ratio of 2:1 to prepare an extractant. The extractant was then added to an appropriate amount of anhydrous ethanol and mixed thoroughly to form a mixed solution.

[0098] The mixed solution was added to anhydrous ethanol containing a swollen inert support, wherein the amount of extractant accounted for 30% of the mass of the inert support. The resulting mixture was placed in a flask and transferred to a rotary evaporator. The flask was stirred under vacuum and ambient temperature conditions provided by the rotary evaporator for 1.5 h at a speed of 50 rpm to ensure that the mixed solution was fully impregnated into the swollen inert support and that the extractant was loaded onto the swollen inert support.

[0099] After being fully loaded, the internal temperature of the rotary evaporator is raised to 40 °C for rotary evaporation. When the impregnating agent is fully volatilized and the resin is in a dispersed solid state, it is then transferred to a 65 °C oven for drying for 6 hours to complete the drying process and obtain the extraction resin for purifying ammonium molybdate.

[0100] The extraction resin prepared in Example 2 was swollen in deionized water and then packed into a chromatography column. Dilute hydrochloric acid was passed through the column at a flow rate of 3 Bv / h to activate the extraction resin. A 5 g / L ammonium molybdate solution from the molybdenum smelting system was then injected into the chromatography column containing the activated extraction resin and passed through at a flow rate of 5 Bv / h to obtain a high-purity ammonium molybdate solution. After heating and crystallization, and washing, the ammonium molybdate product was obtained. The product was analyzed, and the results are shown in Table 2 below.

[0101] Table 2. Determination results of ammonium molybdate products (II)

[0102]

[0103] Table 2 shows that, for crude ammonium molybdate raw materials from molybdenum smelters with different initial purities, under operating conditions of pH 5.4-5.5, this resin can stably produce ultra-high purity ammonium molybdate with a purity ≥99.99%. Calculations show that the separation coefficient of the extraction resin prepared in Example 2 in purifying ammonium molybdate is 155. This high separation coefficient indicates that the selective adsorption capacity of this extraction resin for impurities is significantly superior to that of traditional materials. In particular, the synergistic effect of the branched structure of the secondary carbon primary amine and the long alkyl chain of TOPO can significantly improve the separation coefficient of the extraction resin, enhance its adsorption capacity for impurities, and obtain high-purity ammonium molybdate.

[0104] Example 3

[0105] XAD-7 macroporous adsorption resin was used as an inert support. The backbone component of XAD-7 macroporous adsorption resin is polyacrylate. Anhydrous ethanol was used as the impregnation solution. XAD-7 macroporous adsorption resin was placed in the impregnation solution and soaked for 3 hours to allow it to fully swell.

[0106] Trialkylphosphine oxide (TRPO) and secondary carbon primary amine are mixed in a molar ratio of 2:1 to prepare an extractant. The extractant is then added to an appropriate amount of anhydrous ethanol and mixed thoroughly to form a mixed solution.

[0107] The mixed solution was added to anhydrous ethanol containing a swollen inert support, wherein the amount of extractant accounted for 30% of the mass of the inert support. The resulting mixture was placed in a flask and transferred to a rotary evaporator. The flask was stirred under vacuum and ambient temperature conditions provided by the rotary evaporator for 1 hour at a speed of 40 rpm to ensure that the mixed solution was fully impregnated into the swollen inert support and that the extractant was loaded onto the swollen inert support.

[0108] After being fully loaded, the internal temperature of the rotary evaporator is raised to 40 °C for rotary evaporation. When the impregnating agent is fully volatilized and the resin is in a dispersed solid state, it is then transferred to a 30 °C oven for drying for 12 h to complete the drying process and obtain the extraction resin for purifying ammonium molybdate.

[0109] The extraction resin prepared in Example 3 was swollen in deionized water and then packed into a chromatography column. A 20 g / L ammonium molybdate solution from a molybdenum smelting system was injected into the chromatography column packed with the extraction resin and passed through at a flow rate of 5 Bv / h to obtain a high-purity ammonium molybdate solution. The solution was then heated for crystallization and washed to obtain the ammonium molybdate product. The product was analyzed, and the results are shown in Table 3 below.

[0110] Table 3. Determination results of ammonium molybdate products (III)

[0111]

[0112] Table 3 shows that the extraction resin prepared in Example 3, through the synergistic effect of the polyacrylate support (XAD-7) and the extractant composed of trialkylphosphine oxide (TRPO) / secondary carbon amine, stably produces a high-purity product with a purity ≥99.99% for crude ammonium molybdate raw material with an initial purity of 98.75%-99.15% under pH 5.4-5.5 conditions. The separation coefficient of the extraction resin prepared in Example 3 in purifying ammonium molybdate was calculated to be 162. Compared to the 5 g / L solution treated in Example 2, Example 3 maintained high-efficiency separation even at a high concentration of 20 g / L, indicating that the non-polar framework of polyacrylate and the synergistic effect of TRPO are more suitable for the mass transfer requirements of high-concentration systems. The framework structure of XAD-7 is more conducive to extractant adsorption, while the short-chain alkyl structure of TRPO has better compatibility with the resin; the synergy of both can improve the impurity retention capacity.

[0113] Example 4

[0114] The only difference between Example 4 and Example 1 is the molar ratio of trialkylphosphine oxide to secondary amine. In Example 4, the molar ratio of trialkylphosphine oxide to secondary amine is 5:1.

[0115] Example 5

[0116] Polystyrene and polyurethane foam were used as inert supports. The impregnation solution was a mixture of methanol and ethanol. The polystyrene and polyurethane foam were placed in the impregnation solution and soaked for 3 hours to allow them to fully swell.

[0117] Trialkylphosphine oxide and 3-(nonoxy)propane-1-amine were mixed in a molar ratio of 1:1 to prepare an extractant. The extractant was then added to an appropriate amount of impregnation solution and mixed thoroughly to form a mixed solution.

[0118] The mixed solution was added to anhydrous ethanol containing a swollen inert support, wherein the amount of extractant accounted for 40% of the mass of the inert support. The resulting mixture was placed in a flask and transferred to a rotary evaporator. The flask was stirred under vacuum and ambient temperature conditions provided by the rotary evaporator for 3 hours at a speed of 45 rpm to ensure that the mixed solution was fully impregnated into the swollen inert support and that the extractant was loaded onto the swollen inert support.

[0119] After being fully loaded, the internal temperature of the rotary evaporator is raised to 40 °C for rotary evaporation. When the impregnating agent is fully volatilized and the resin is in a dispersed solid state, it is then transferred to a 30 °C oven for drying for 12 h to complete the drying process and obtain the extraction resin for purifying ammonium molybdate.

[0120] In summary, this invention provides an extraction resin, its preparation method, and its application in the purification of ammonium molybdate. The swelling treatment increases the specific surface area and porosity of the inert support, and the synergistic effect of the mixed extractant enhances the selective adsorption capacity for impurities in molybdate. Vacuum stirring ensures uniform dispersion and strong binding of the extractant. This preparation method effectively solves the problems of uneven dispersion, easy loss, and easy saturation of extractants in traditional extraction resins, providing a more efficient separation material for the production of high-purity molybdenum.

[0121] The various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0122] Although preferred embodiments of the present application have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of the embodiments of the present application.

[0123] Finally, it should be noted that in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or terminal device that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or terminal device. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or terminal device that includes said element.

[0124] The above provides a detailed description of the extraction resin, its preparation method, and its application in the purification of ammonium molybdate. Specific examples have been used to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. The application of an extraction resin in the purification of ammonium molybdate, characterized in that, Methods for preparing extraction resins include: The inert support is immersed in the impregnation solution to allow it to swell fully; the extractant and an appropriate amount of impregnation solution are mixed to form a mixed solution; The mixed solution is mixed with the swollen inert support, stirred under vacuum to load the extractant onto the swollen inert support, and dried to obtain the extraction resin; the impregnation solution is selected from at least one of methanol, ethanol, dichloromethane and benzene; The inert support is selected from at least one of polystyrene, polystyrene-divinylbenzene, polyethylene, polyacrylate and polyurethane foam. The extractant is formed by a mixture of alkylphosphine oxide and primary amine; The alkylphosphine oxide is a trialkylphosphine oxide or a tri-n-octylphosphine oxide; the molar ratio of the alkylphosphine oxide to the primary amine is (1-5):1; The primary amine is a secondary carbon primary amine or 3-(nonoxy)propane-1-amine; The extraction resin is used to purify ammonium molybdate solution with a concentration not exceeding 40 g / L, and to obtain ammonium molybdate with a purity of at least 99.99%.

2. The application of the extraction resin according to claim 1 in the purification of ammonium molybdate, characterized in that, The amount of the extractant used is 30%-50% of the mass of the inert support.

3. The application of the extraction resin according to claim 1 in the purification of ammonium molybdate, characterized in that, The inert support is polystyrene-divinylbenzene or polyacrylate.

4. The application of the extraction resin according to claim 1 in the purification of ammonium molybdate, characterized in that, The stirring speed is 25 rpm-60 rpm, and the stirring time is 1 h-6 h.

5. The application of the extraction resin according to claim 1 in the purification of ammonium molybdate, characterized in that, The purification method includes: The extraction resin was placed in deionized water, swollen, and then packed into a chromatography column. Dilute hydrochloric acid was passed through the swollen extraction resin at a flow rate of 2 BV / h-5 BV / h to obtain the activated extraction resin. An ammonium molybdate solution with a concentration not exceeding 40 g / L is passed through a chromatography column packed with the activated extraction resin at a flow rate of 3 BV / h to 7 BV / h to remove impurities and obtain ammonium molybdate with a purity of at least 99.99%.

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