Phosphorus-containing amino acid extractant modified silica spheres, method for preparing the same and use thereof

Abstract

The present application relates to a phosphorus-containing amino acid extractant modified silica sphere and its preparation method and application. The preparation method comprises: (1) reacting a phosphorus-containing amino acid compound of the following formula I with a silane coupling agent to obtain a coupled extractant, wherein one end of the silane coupling agent away from the silane moiety is covalently connected to the N atom of the phosphorus-containing amino acid compound of formula I; (2) reacting the coupled extractant with a silica sphere to obtain a modified silica sphere, wherein the silane moiety of the silane coupling agent is connected to the silica sphere. The modified silica sphere of the present application can be used for the extraction separation of yttrium, has the advantages of large adsorption capacity, strong selectivity and simple preparation method, can be widely used for the separation and preparation of high-purity yttrium, and has good application prospect.

Description

Technical Field

[0001] This invention belongs to the field of yttrium extraction technology, and relates to a modified silica sphere containing phosphorus amino acid extractant, its preparation method and application. Background Technology

[0002] Yttrium has a wide range of applications. In steel and non-ferrous alloy smelting, yttrium is often used as an additive to enhance the oxidation resistance and ductility of these alloys, as well as improve their electrical conductivity and mechanical strength. High-yttrium structural alloys containing up to 90% yttrium can be used in aerospace and other applications requiring low density and high melting points. In recent years, high-purity yttrium has also been used in laser materials, phosphors for color televisions, microwave technology, and sound energy transmission technologies. Furthermore, in recent years, high-purity yttrium has also been used in high-temperature resistant spray coatings, as a diluent for nuclear reactor fuels, as an additive in permanent magnet materials, and as a getter in the electronics industry.

[0003] Yttrium, along with heavy rare earth elements, forms the yttrium group, making them difficult to separate. Traditional methods for separating yttrium primarily use naphthenic acids as extractants. However, with improvements in catalytic cracking processes in the petroleum industry, the yield of naphthenic acids, as a byproduct, is decreasing. Furthermore, naphthenic acids require a relatively high pH level to extract rare earth elements during the separation process. Naphthenic acids also have high solubility in water, which can easily cause environmental pollution. Even after separation using naphthenic acids, the separation coefficient between yttrium and light rare earth elements remains low, making subsequent separation extremely challenging.

[0004] Currently, the extraction and separation of yttrium mainly employs liquid-phase extraction systems, with limited in-depth research on solid-phase extraction systems for yttrium separation. Solid-phase extraction systems generate less waste and facilitate solid-liquid separation. Therefore, developing solid-phase extraction systems capable of selective adsorption and separation of yttrium and their preparation methods is of great significance. Summary of the Invention

[0005] This invention provides a modified silica sphere, its preparation method, and its application. The modified silica sphere of this invention can be used for the extraction and separation of yttrium, and has the advantages of large adsorption capacity, strong selectivity, and simple preparation method. It can be widely used for the separation and preparation of high-purity yttrium and has good application prospects.

[0006] In a first aspect, the present invention provides a method for preparing modified silicon spheres, the method comprising the following steps:

[0007] (1) React the phosphorus-containing amino acid compound of Formula I with a silane coupling agent to obtain a coupling extractant, wherein one end of the silane coupling agent away from the silane is covalently attached to the N atom of the phosphorus-containing amino acid compound of Formula I.

[0008]

[0009] in,

[0010] R1 and R2 are each independently selected from C1-C14 Alkyl, C6-C 10 Aryl, C1-C4 alkyl, C6-C 10 Aryl and C6-C 10 Aryl C1-C4 alkyl, preferably selected from C1-C8 alkyl, phenyl, C1-C4 alkylphenyl and phenyl C1-C4 alkyl;

[0011] R3 is selected from hydrogen, C1-C6 alkyl, C6-C 12 Aryl, C1-C4 alkyl, C6-C 10 Aryl and C6-C 10 Aryl C1-C4 alkyl;

[0012] Z is C1-C 12 Alkylene, preferably C1-C4 alkylene;

[0013] R4 and R5 are each independently selected from hydrogen, C1-C 10 Alkyl, C3-C 10 cycloalkyl, C6-C 12 Aryl, C1-C4 alkyl, C6-C 10 Aryl and C6-C 10 Aryl C1-C4 alkyl, carboxyl C1-C4 alkyl;

[0014] Alternatively, R4 and R5, together with the carbon atoms bonded to them, can form C3-C. 10 Cycloalkyl groups, especially C5-C8 cycloalkyl groups;

[0015] (2) The coupling extractant is reacted with the silicon spheres to obtain modified silicon spheres, wherein the silane portion of the silane coupling agent is attached to the silicon spheres.

[0016] The method for preparing modified silica spheres of the present invention involves grafting a phosphorus-containing amino acid compound of Formula I onto the surface of silica spheres using a silane coupling agent. The modified silica spheres of the present invention have the advantages of high adsorption capacity, strong selectivity, and a simple preparation method, and can be widely used for the separation and preparation of high-purity yttrium, showing promising application prospects.

[0017] The present invention will now be described in further detail.

[0018] Phosphorus-containing amino acid compounds

[0019] In some embodiments, the phosphorus-containing amino acid compound of formula I is a compound of general formula II:

[0020]

[0021] The definitions of R1, R2, R3, R4 and R5 are the same as in general formula I.

[0022] In some embodiments, R1 and R2 in general formulas I and II may be the same or different. Furthermore, it is preferred that R1 and R2 are the same, and more preferably they are the same C1-C8 alkyl, phenyl, C1-C4 alkylphenyl, and phenylC1-C4 alkyl.

[0023] In some embodiments, R3 is hydrogen, C1-C4 alkyl, or C6-C4 alkyl. 10 Aryl group, preferably hydrogen, C1-C2 alkyl, phenyl, benzyl, tolyl, ethylphenyl, or xylyl.

[0024] In some embodiments, R4 is hydrogen, and R5 is selected from hydrogen, C1-C6 alkyl, C5-C7 cycloalkyl, C6-C6 alkyl, C5-C7 cycloalkyl, C6-C6 cycloalkyl, C5-C7 ... 10 Aryl, C1-C4 alkyl, C6-C 10 Aryl, C6-C 10 Aryl C1-C4 alkyl and carboxyl C1-C4 alkyl, preferably hydrogen, C1-C4 alkyl, C5-C7 cycloalkyl, phenyl, benzyl, tolyl, ethylphenyl, xylyl, or carboxyl C1-C4 alkyl; more preferably hydrogen, C1-C2 alkyl, cyclopentyl, cyclohexyl, cycloheptyl, phenyl, benzyl, tolyl, ethylphenyl, xylyl, or carboxyl C1-C4 alkyl.

[0025] Specifically, the phosphorus-containing amino acid compound is selected from one or more of ((di(phenoxy)phosphoryl)methyl)glycine, ((di((phenylmethyl)oxy)phosphoryl)methyl)glycine, ((di(phenoxy)phosphoryl)propyl)glycine, ((di(phenoxy)phosphoryl)methyl)phenylalanine, ((di(ethyl)oxy)phosphoryl)methyl)glycine, ((di((2-ethylhexyl)oxy)phosphoryl)(phenyl)methyl)glycine, and ((di((2-ethylhexyl)oxy)phosphoryl)(phenyl)methyl)phenylalanine.

[0026] In this invention, the phosphorus-containing amino acid compound of general formula I can also exist in the form of a salt. There are no particular restrictions on the salt, as long as its cation does not have an adverse effect on the reaction. For example, it can be an ammonium salt, an alkali metal salt (e.g., lithium salt, sodium salt, potassium salt) or an alkaline earth metal salt (e.g., magnesium salt, calcium salt), preferably an ammonium salt or a sodium salt.

[0027] The phosphorus-containing amino acid compounds of Formula I can be synthesized in a manner similar to that known in the prior art (e.g., US4486359, CN115433842A, etc.) or the methods described below and in the examples.

[0028] For example, phosphorus-containing amino acid compounds of general formula I can be synthesized as shown in reaction formula 1:

[0029]

[0030] Compounds II, III, and IV underwent a condensation reaction to yield a phosphorus-containing amino acid compound of general formula I.

[0031] The definitions of R1, R2, R3, R4, R5, and Z are the same as those described above.

[0032] The carbonyl compound III can be an aliphatic aldehyde (such as formaldehyde, acetaldehyde, propionaldehyde, paraformaldehyde, etc.) or an aromatic aldehyde (such as benzaldehyde, phenylacetaldehyde, etc.).

[0033] Compounds II and IV may be commercially available products or synthesized using known methods in the prior art.

[0034] In some embodiments, compound II may be diphenyl phosphite, dimethyl phosphite, diethyl phosphite, di(n-propyl) phosphite, di(isopropyl) phosphite, di(2-ethylhexyl) phosphite, or di(2-methylhexyl) phosphite.

[0035] In some embodiments, compound IV may be any one or a combination of at least two selected from glycine, alanine, valine, leucine, isoleucine, tertiary leucine, aspartic acid, phenylalanine, glutamic acid, and γ-aminobutyric acid, but is not limited thereto. The amino acids used herein may be D-type, L-type, or a combination of both.

[0036] The structures of some amino acids are shown in the table below:

[0037]

[0038] There are no particular restrictions on the molar ratio of compounds II, III, and IV, as long as the final target product can be obtained. Preferably, the molar ratio of compounds II, III, and IV can be 1:0.1-5:0.1-5, for example 1:0.5-2:0.5-2, or for example, about 1:1:1.

[0039] The condensation reaction can be carried out in bulk or in an organic solvent. For example, the organic solvent can be any one selected from methanol, ethanol, acetonitrile, and tetrahydrofuran.

[0040] There are no particular restrictions on the amount of organic solvent used, which can be appropriately selected by those skilled in the art. For example, the mass of the organic solvent can be 2 to 10 times the sum of the masses of compounds II, III and IV, such as 2, 3, 4, 5, 6, 7, 8, 9 or 10 times, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0041] The condensation reaction can be carried out under stirring. Moderate stirring is beneficial for the uniform mixing of reactants and promotes the reaction. The stirring speed can be appropriately selected by those skilled in the art based on the reaction scale, reaction equipment, etc. For example, the stirring speed can be 100-500 rpm, such as 100 rpm, 200 rpm, 300 rpm, 400 rpm, or 500 rpm, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0042] There is no particular limitation on the reaction time of the condensation reaction, as long as the product can be obtained in an appropriate yield. The specific reaction time can be selected appropriately according to the reaction scale, reaction temperature, etc. For example, the reaction time can be 2-6 hours, such as 2 hours, 3 hours, 4 hours, 5 hours or 6 hours, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0043] There is no particular limitation on the reaction temperature of the condensation reaction, as long as the reaction can occur and the desired product is obtained. For example, the reaction temperature can be 50-80℃, such as 50℃, 60℃, 70℃ or 80℃, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0044] Furthermore, based on the structure of the phosphorus-containing amino acid compound of Formula I disclosed above, those skilled in the art can design new synthetic routes by referring to known synthetic methods in the prior art. Therefore, the synthetic method of the phosphorus-containing amino acid compound of Formula I is not limited to the above-described method.

[0045] Silane coupling agents

[0046] In this invention, the silane coupling agent acts as a linking group, connecting to the silicon sphere through the interaction of the silane group with the surface groups of the silicon sphere, and covalently connecting to the phosphorus-containing amino acid compound at the other end, thereby grafting the phosphorus-containing amino acid compound onto the silicon sphere to obtain modified silicon spheres.

[0047] Any silane coupling agent that can achieve the above objectives can be selected.

[0048] In some embodiments, the silane coupling agent has a functional group capable of directly reacting with the amine group in the structure of the phosphorus-containing amino acid compound of Formula I. In this case, the silane coupling agent can be directly reacted with the phosphorus-containing amino acid compound of Formula I so that one end of the silane coupling agent is directly covalently attached to the amine group in the structure of the phosphorus-containing amino acid compound of Formula I.

[0049] In some embodiments, the silane coupling agent is shown in formula V:

[0050]

[0051] R6, R7 and R8 are each independently selected from C1-C4 alkyl and C1-C4 alkoxy, and at least one is an alkoxy; preferably, each is independently selected from C1-C2 alkyl and C1-C2 alkoxy, and at least one is an alkoxy.

[0052] R9 is selected from halogens (especially Cl, bromine and iodine), epoxy groups (i.e. oxacyclopropane), epoxy methoxy groups (i.e. glycidyl ether oxy groups), and isocyanate groups;

[0053] n is an integer from 1 to 8.

[0054] In some embodiments, the silane coupling agent is selected from epoxy silanes, halogen silanes, and isocyanate silanes, each having an epoxy group, a halogen group, and an isocyanate group that can react with an amine group. These silanes can be trialkoxysilanes, dialkoxysilanes, or monoalkoxysilanes.

[0055] Epoxysilanes refer to silane coupling agents that contain at least one epoxy group in their molecule. For example, epoxysilanes can be 3-(2,3-epoxypropoxy)propyltrimethoxysilane (GPTS), 5,6-epoxyhexyltriethoxysilane, 3-glycidyl etheroxypropylmethyldiethoxysilane, 3-(2,3-epoxypropoxy)propyltrimethoxysilane, 3-glycidyl etheroxypropyltriethoxysilane, 3-[(2,3)-epoxypropoxy]propylmethyldiethoxysilane, 3-(2,3-epoxypropoxy)propyltrimethoxysilane, (3-epoxypropoxypropyl)dimethylethoxysilane, etc., but are not limited to these.

[0056] When using epoxy silanes, the epoxy group in the silane coupling agent can undergo an addition reaction with the amine group in the phosphorus-containing amino acid compound structure of Formula I, thereby opening the ring and causing one end of the silane coupling agent to be covalently attached to the amine group in the phosphorus-containing amino acid compound structure of Formula I.

[0057] Halogenated silanes are silane coupling agents that contain at least one halogen group in their molecule. Halogens include fluorine, chlorine, bromine, and iodine. Chlorine and bromine are particularly common halogen groups in silane coupling agents. Examples of halogenated silanes include 3-bromopropyltrimethoxysilane, 4-bromobutyltrimethoxysilane, 5-bromopentyltrimethoxysilane, 7-bromoheptyltrimethoxysilane, 3-chloroisopropyltrimethoxysilane, chloromethyltrimethoxysilane, chloromethyltriethoxysilane, 3-chloropropyltrimethoxysilane (CPTS), 3-chloropropyltriethoxysilane, 3-iodopropyltrimethoxysilane, chloromethylmethyldiethoxysilane, 3-chloropropylmethyldiethoxysilane, 3-chloropropylmethyltrimethoxysilane, chloromethyldimethylethoxysilane, chloromethyldimethylmethoxysilane, etc., but not limited to these.

[0058] When using halogenated silanes, the silane coupling agent can undergo an amination reaction with the amino group in the phosphorus-containing amino acid compound of Formula I, thereby removing the halogen group and covalently attaching one end of the silane coupling agent to the amino group in the phosphorus-containing amino acid compound of Formula I. To promote the amination reaction, it can be carried out in the presence of an acid-binding agent. Common acid-binding agents include, but are not limited to, 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU).

[0059] Isocyanate silanes refer to silane coupling agents whose molecules contain at least one isocyanate. For example, isocyanate silanes can be 3-isocyanate propyltriethoxysilane, 3-isocyanate propyltrimethoxysilane, 3-isocyanate propylmethyldiethoxysilane, 3-isocyanate propylmethyldimethoxysilane, etc., but are not limited to these.

[0060] When isocyanate silanes are used, the isocyanate group in the silane coupling agent can undergo a nucleophilic addition reaction with the amino group in the structure of the phosphorus-containing amino acid compound of Formula I to generate a urea group, thereby covalently attaching one end of the silane coupling agent to the amino group in the structure of the phosphorus-containing amino acid compound of Formula I.

[0061] Silane coupling agents can also be hydroxysilanes, aldehyde silanes, carboxyl silanes, etc. Through the reaction of hydroxyl, aldehyde, carboxyl, and other groups with amine groups, one end of the silane coupling agent is covalently attached to the amine group in the structure of the phosphorus-containing amino acid compound of formula I.

[0062] In other embodiments, the silane coupling agent does not have a functional group that can directly react with the amino group in the structure of the phosphorus-containing amino acid compound of Formula I. In this case, one end of the silane coupling agent can be covalently linked to the amino group in the structure of the phosphorus-containing amino acid compound of Formula I by adding another compound that acts as a linking agent. Alternatively, the silane coupling agent can be modified to have a functional group that can directly react with the amino group in the structure of the phosphorus-containing amino acid compound of Formula I.

[0063] Preparation of Coupling Extractants

[0064] The reaction of the phosphorus-containing amino acid compound of formula I with the silane coupling agent in step (1) is as described above. The specific conditions can be appropriately selected according to the reaction type and in combination with the techniques known in the art.

[0065] The molar ratio of the phosphorus-containing amino acid compound of Formula I to the silane coupling agent is not particularly limited, as long as the final target product can be obtained. Preferably, the molar ratio of the silane coupling agent to the phosphorus-containing amino acid compound of Formula I can be 1:0.5-2, for example, 1:0.5, 1:0.75, 1:1, 1:1.2, 1:1.4, 1:1.6, 1:1.8, 1:2, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0066] The reaction of the phosphorus-containing amino acid compound of Formula I with the silane coupling agent can be carried out in bulk or in an organic solvent. For example, the organic solvent can be any one or more selected from methanol, ethanol, acetonitrile, and toluene.

[0067] There are no particular restrictions on the amount of organic solvent used, which can be appropriately selected by those skilled in the art. For example, the mass of the organic solvent can be 2 to 5 times the sum of the phosphorus-containing amino acid compound of Formula I and the silane coupling agent, such as 2, 3, 4, or 5 times, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0068] In some embodiments, the reaction can be carried out under stirring. Moderate stirring is beneficial for the uniform mixing of reactants and promotes the reaction. The stirring speed can be appropriately selected by those skilled in the art based on the scale of the reaction, the reaction equipment, etc. For example, the stirring speed is 100-500 rpm, such as 100 rpm, 200 rpm, 300 rpm, 400 rpm, or 500 rpm, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0069] There is no particular limitation on the reaction time, as long as the product can be obtained in an appropriate yield. The specific reaction time can be selected appropriately according to the reaction scale, reaction temperature, etc. For example, the reaction time can be 24-72 hours, such as 24 hours, 36 hours, 48 ​​hours, 60 hours, or 72 hours, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0070] There is no particular limitation on the reaction temperature, as long as the reaction can occur and the desired product is obtained. For example, the reaction temperature can be 60-90℃, such as 60℃, 65℃, 70℃, 75℃, 80℃, 85℃ or 90℃, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0071] In some embodiments, the prepared coupling extractant is selected from the following compounds:

[0072]

[0073]

[0074] The definitions of R1 to R5 and Z are the same as in Equation I, and the definitions of R6 to R8 and n are the same as in Equation V.

[0075] In some embodiments, the prepared coupling extractant is selected from the following compounds:

[0076]

[0077]

[0078] The definitions of R1 to R5 are the same as in Equation II, and the definitions of R6 to R8 and n are the same as in Equation V.

[0079] The reaction of coupling extractant with silicon spheres

[0080] In the reaction between the coupling extractant and the silicon spheres in step (2), the silane groups of the coupling extractant will hydrolyze and react with the OH groups on the surface of the silicon spheres to eventually form a covalent bond.

[0081] The term "silicon spheres" here refers to silica microspheres. There are no particular limitations on the silica spheres, as long as they are suitable for use as a chromatographic column substrate. For example, the silica spheres may have a particle size of 100-200 mesh and / or 400-500 μm. 2 Specific surface area per g, but not limited to this.

[0082] In step (2), there is no particular limitation on the mass ratio of silicon spheres to coupling extractant, as long as an appropriate amount of coupling extractant can be grafted onto the silicon spheres. For example, the mass ratio of silicon spheres to coupling extractant can be 1:1-2, such as 1:1, 1:1.2, 1:1.4, 1:1.6, 1:1.8, 1:2, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0083] Step (2) can be carried out in an organic solvent. For example, the organic solvent can be any one or more selected from dimethylformamide, toluene, and dimethyl sulfoxide.

[0084] There are no particular restrictions on the amount of organic solvent used, which can be appropriately selected by those skilled in the art. For example, the mass of the organic solvent can be 2-5 times the sum of the mass of the coupling extractant and the silica spheres, such as 2, 3, 4, or 5 times, but is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0085] The reaction can be carried out under stirring. Moderate stirring is beneficial for the uniform mixing of reactants and promotes the reaction. The stirring speed can be appropriately selected by those skilled in the art based on the scale of the reaction, the reaction equipment, etc. For example, the stirring speed can be 100-500 rpm, such as 100 rpm, 200 rpm, 300 rpm, 400 rpm, or 500 rpm, but is not limited to the listed values; other unlisted values ​​within this range are also applicable.

[0086] There is no particular limitation on the reaction time, as long as the product can be obtained in an appropriate yield. The specific reaction time can be selected appropriately according to the reaction scale, reaction temperature, etc. For example, the reaction time can be 1-100h, or 24-72h, such as 24h, 36h, 48h, 60h, or 72h, but it is not limited to the listed values. Other unlisted values ​​within this range are also applicable.

[0087] There is no particular limitation on the reaction temperature, as long as the reaction can occur and the desired product is obtained. For example, the reaction temperature is 90-110℃, such as 90℃, 95℃, 100℃, 105℃, or 110℃, but it is not limited to the listed values; other unlisted values ​​within this range are also applicable. The reaction temperature may affect the efficiency of grafting the coupling extractant onto the silicon sphere surface. When the reaction temperature is too low, the grafting speed of the coupling extractant onto the silicon sphere surface is slow, and it is impossible to obtain silicon spheres with good performance in a short time, requiring an excessively long reaction time. When the reaction temperature is too high, the reaction will be too vigorous, making it difficult to control the reaction progress. An excessively long reaction time may cause the phosphorus-containing amino acid extractant to break away from the coupling agent, greatly reducing the performance of the silicon spheres.

[0088] Step (2) may also include a purification step. The purification step may include saponifying the obtained reaction product, and then washing it with deionized water and ethanol, respectively, to obtain the modified silica spheres. The saponification may be carried out using an alkali, such as sodium hydroxide or sodium carbonate.

[0089] In a second aspect, the present invention provides a modified silicon sphere, which is obtained by the preparation method described in the first aspect.

[0090] CN115433842A discloses that the phosphorus-containing amino acid compound of Formula I has different extraction rates for yttrium and lanthanides, and the separation coefficient βLn / Y between lanthanides (Ln) and yttrium is large, thus it can be used as an extractant for the extraction and separation of yttrium. However, the phosphorus-containing amino acid compound in CN115433842A is mainly used as a solvent extraction compound, and CN115433842A only generally mentions that the phosphorus-containing amino acid compound can be prepared into a solid-phase extraction system, but does not provide corresponding examples. Its preferred solid-phase extraction system prepared by impregnation and in-situ polymerization does not involve changes in the molecular structure and spatial stereostructure of the extractant.

[0091] In the modified silicon spheres of this invention, the amine groups of the phosphorus-containing amino acid compound of Formula I are covalently linked to a silane coupling agent and grafted into the silicon spheres, thereby altering the electron cloud distribution and corresponding spatial structure at the amine groups. Currently, the mechanism by which the phosphorus-containing amino acid compound of Formula I extracts and separates rare earth elements is unknown. Therefore, it is impossible to deduce whether the modified silicon spheres of this invention can still extract rare earth elements, particularly whether they still exhibit different extraction rates for yttrium and lanthanides, thus enabling their use as an extractant for the extraction and separation of yttrium.

[0092] Furthermore, in the case of CN115433842A, the phosphorus-containing amino acid compound of Formula I must have sufficiently low water solubility to be used in solvent extraction and solid-phase extraction systems. For example, if the phosphorus-containing amino acid compound of Formula I is water-soluble, it will dissolve directly in the rare earth element feed solution and will not be able to produce an extraction effect. Alternatively, if the phosphorus-containing amino acid compound of Formula I can be used for extraction, but its high water solubility leads to excessive dissolution loss during production, it will also be unsuitable for production.

[0093] Surprisingly, the inventors have experimentally demonstrated that the modified silica spheres of this invention can extract rare earth elements, exhibiting different extraction rates for yttrium and lanthanides, and can be used as an extractant for the extraction and separation of yttrium. Furthermore, with the modified silica spheres of this invention, there are no requirements regarding the water solubility of phosphorus-containing amino acid compounds of Formula I, thereby allowing the application of a wider range of phosphorus-containing amino acid compounds of Formula I, reducing production costs, and even improving extraction efficiency.

[0094] Therefore, in a third aspect, the present invention provides an application of the modified silica spheres as described in the second aspect as a solid-phase extractant for separating yttrium from lanthanides. In other words, the present invention provides an application of the aforementioned modified silica spheres as a solid-phase extractant for preparing an extraction system for separating yttrium from lanthanides in a rare earth element feed solution.

[0095] Furthermore, during the experiments, it was also discovered that the modified silicon spheres of the present invention, as a solid-phase extractant, exhibit different extraction rates and distribution ratios for different lanthanide elements. Therefore, they can be used to separate different lanthanide elements in a rare earth element feed solution via solid-liquid extraction. For example, they can be used to group lanthanide elements, such as into light, medium, and heavy rare earth elements, or to separate them into groups containing two or more (e.g., two, three, four, etc.) similar lanthanide elements, or to separate individual lanthanide elements.

[0096] Therefore, the present invention also provides the application of the modified silica spheres described in the second aspect as a solid-phase extractant for the separation of lanthanides. In other words, the present invention provides the use of the above-described modified silica spheres as a solid-phase extractant for the preparation of an extraction system for the separation of lanthanides.

[0097] To achieve the extraction, the rare earth element feed solution can be brought into contact with the modified silicon spheres of the present invention, thereby achieving the separation.

[0098] Beneficial effects

[0099] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0100] This invention involves in-situ grafting of a phosphorus-containing amino acid extractant onto the surface of silicon spheres using a coupling agent, resulting in modified silicon spheres with selective adsorption of rare earth elements. The modified silicon spheres of this invention have a simple preparation method, exhibit selectivity in mixed rare earth solutions, and can be used to separate and prepare high-purity yttrium, showing promising application prospects. Compared to current separation technologies, the modified silicon spheres of this invention possess stronger selective adsorption capabilities, demonstrating significant potential in the preparation of high-purity yttrium.

[0101] the term

[0102] In this invention, "separation of yttrium" refers to the extraction of yttrium (i.e., trivalent yttrium(III) or trivalent yttrium ions Y) through an extraction method. 3 + ) and other rare earth elements (i.e., lanthanides or trivalent lanthanide ions Ln) 3+ Separate.

[0103] In this invention, rare earth elements refer to lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, yttrium, and scandium. Among them, light rare earth elements refer to lanthanum, cerium, praseodymium, and neodymium; medium and heavy rare earth elements refer to samarium, europium, gadolinium, terbium, dysprosium, holmium, europium, erbium, thulium, ytterbium, lutetium, yttrium, and scandium.

[0104] The term C1-C used in this invention 14Alkyl refers to straight-chain or branched alkyl groups containing 1 to 14 carbon atoms, such as straight-chain or branched alkyl groups having 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, or 14 carbon atoms. It includes, without limitation, methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, isobutyl, n-pentyl, neopentyl, isopentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, tridecyl, tetradecyl, etc. The meanings of C1-C8 alkyl, C1-C4 alkyl, etc., follow the same logic.

[0105] The term C6-C used in this invention 10 Aryl refers to aryl groups containing 6 to 12 carbon atoms on a ring, such as aryl groups having 6, 7, 8, 9, 10, 11 or 12 carbon atoms on a ring, and non-limitingly includes phenyl and naphthyl groups.

[0106] The term C1-C4 alkyl-C6-C used in this invention 10 Aryl groups include, for example, tolyl, ethylphenyl, xylyl, trimethylyl, etc.

[0107] The term C6-C used in this invention 10 Aryl C1-C4 alkyl groups include, for example, benzyl, phenethyl, etc.

[0108] The term C3-C used in this invention 10 Cycloalkyl refers to saturated cyclic alkyl groups containing 3 to 10 carbon atoms, including, without limitation, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, etc.

[0109] Unless otherwise stated, numerical values ​​in this invention represent approximate measures or limitations on the range of embodiments including minute deviations from a given value and having approximately the mentioned value as well as having the mentioned precise value. Except in the detailed description of the final embodiments, all numerical values ​​of parameters (e.g., quantities or conditions) in this application (including the appended claims) should in all cases be understood to be modified by the term "approximately," regardless of whether "approximately" actually appears before the numerical value. "Approximately" indicates that the stated numerical value allows for slight inaccuracies (some close to precision at that value; approximately or reasonably close to the value; approximate). If the inaccuracy provided by "approximately" is not understood in this general sense in the art, then "approximately" as used herein at least indicates a variation that can be produced by common methods of measuring and using these parameters. For example, "approximately" can include variations less than or equal to 15%, less than or equal to 10%, less than or equal to 5%, less than or equal to 4%, less than or equal to 3%, less than or equal to 2%, less than or equal to 1%, less than or equal to 0.5%, less than or equal to 0.1%, and in some respects, less than or equal to 0.01%.

[0110] The present invention has been described in detail above, but the present invention is not limited to the above content. Attached Figure Description

[0111] Figure 1 This is a scanning electron microscope image of the modified silicon spheres prepared in Example 1 of the present invention. Detailed Implementation

[0112] To facilitate understanding of the present invention, specific embodiments are provided below to further illustrate the technical solution of the present invention. Those skilled in the art should understand that the embodiments described are merely illustrative of the present invention and should not be construed as limiting the scope of the invention.

[0113] Reagents and sources:

[0114] (1) Diphenyl phosphite and diethyl phosphite were purchased from Shanghai Laiya Chemical Co., Ltd.

[0115] (2) Reagents such as paraformaldehyde, benzaldehyde, glycine, aspartic acid, phenylalanine, triethylamine, potassium hydroxide, methanol, toluene, xylene, and heptane were purchased from Aladdin Reagent Co., Ltd.

[0116] (3) 3-(2,3-epoxypropoxy)propyltrimethoxysilane (GPTS) and 3-chloropropyltrimethoxysilane (CPTS) were purchased from McLean Ltd.

[0117] (4) The silica spheres were purchased from Qingdao Jiyida Silica Globule Reagent Factory. Their particle size was 100-200 mesh, and their specific surface area was 400-500 m². 2 / g.

[0118] (5) The rare earth solution was prepared in the laboratory.

[0119] (6) Other reagents (such as acids) are all commercially available analytical grade reagents.

[0120] The concentrations of rare earth ions were determined using ICP-OES (instrument model: Optical-8000, manufacturer: Perkin Elmer).

[0121] Example 1

[0122] The preparation method of modified silicon spheres is shown in the reaction formula below, but this reaction formula is only illustrative and is not intended to limit the present invention.

[0123]

[0124] The preparation method includes the following steps:

[0125] (1) Diphenyl phosphite, glycine and paraformaldehyde were mixed in tetrahydrofuran in the presence of triethylamine at a molar ratio of 1:1:1 (total reagent to tetrahydrofuran mass ratio of 1:4). The mixture was stirred at 200 rpm for 4 h at 60 °C. The product was separated and purified to obtain a phosphorus-containing amino acid extractant.

[0126] (2) The phosphorus-containing amino acid extractant obtained in step (1) is mixed with GPTS in methanol (the mass ratio of total reagent to methanol is 1:2), and the mixture is stirred at 200 rpm at 65°C for 48 h. The product is evaporated to dry methanol to obtain the coupling extractant.

[0127] (3) The coupling extractant obtained in step (2) is mixed with the silica balls in toluene (the mass ratio of total reagent to toluene is 1:3), and stirred at 200 rpm for 72 h at 95 °C. After filtration, it is saponified with 0.15 mol / L sodium carbonate solution for 3 h, washed with deionized water until neutral, and then washed three times with anhydrous ethanol. It is then vacuum dried at 60 °C for 24 h to obtain the modified silica balls.

[0128] Modified silicon spheres: 1 H NMR (500MHz, CDCl3) δ7.13-5.55 (m, Ph-H), 4.00-1.80 (m, Si-H, Si-OH), 1.37-0.61 (m, CH, CH2, CH3).

[0129] Figure 1 This shows a scanning electron microscope image of the prepared modified silicon spheres.

[0130] Example 2

[0131] The only difference between this embodiment and Embodiment 1 is that, except for stirring at 100 rpm for 3 hours at 70°C in step (1), everything else is the same as in Embodiment 1.

[0132] Modified silicon spheres: 1 H NMR (500MHz, CDCl3) δ7.07-6.12(m,Ph-H), 4.23-1.74(m,Si-H,Si-OH), 1.41-0.76(m,CH,CH2,CH3).

[0133] Example 3

[0134] The preparation method of modified silicon spheres is shown in the reaction formula below, but this reaction formula is only illustrative and is not intended to limit the present invention.

[0135]

[0136] The only difference between this embodiment and Embodiment 1 is that, except for replacing “glycine” with “aspartic acid” in step (1), everything else is the same as in Embodiment 1.

[0137] Modified silicon spheres: 1 H NMR (500MHz, CDCl3) δ6.84-5.50 (m, Ph-H), 4.16-1.89 (m, Si-H, Si-OH), 1.62-0.84 (m, CH, CH2, CH3).

[0138] Example 4

[0139] The preparation method of modified silicon spheres is shown in the reaction formula below, but this reaction formula is only illustrative and is not intended to limit the present invention.

[0140]

[0141] The only difference between this embodiment and embodiment 1 is that, except for replacing “GPTS” with “CPTS” in step (2), everything else is the same as in embodiment 1.

[0142] Modified silicon spheres: 1 H NMR (500MHz, CDCl3) δ6.78-6.94(m,Ph-H), 5.71-3.34(m,Si-H,Si-OH), 3.28(m,Cl-CH2-R), 1.79-0.81(m,CH,CH2,CH3).

[0143] Example 5

[0144] The preparation method of modified silicon spheres is shown in the reaction formula below, but this reaction formula is only illustrative and is not intended to limit the present invention.

[0145]

[0146] The only difference between this embodiment and Embodiment 1 is that, except for replacing “diphenyl phosphite” with “diethyl phosphite” in step (1), everything else is the same as in Embodiment 1.

[0147] Modified silicon spheres: 1 H NMR (500MHz, CDCl3) δ4.81-3.44 (m, Si-H, Si-OH), 1.42-0.86 (m, CH, CH2, CH3).

[0148] Example 6

[0149] The preparation method of modified silicon spheres is shown in the reaction formula below, but this reaction formula is only illustrative and is not intended to limit the present invention.

[0150]

[0151] The only difference between this embodiment and Embodiment 1 is that, except for replacing “paraformaldehyde” with “acetone” in step (1), everything else is the same as in Embodiment 1.

[0152] Modified silicon spheres: 1 H NMR (500MHz, CDCl3) δ7.07-6.79 (m, Ph-H), 5.08-3.87 (m, Si-H, Si-OH), 1.71-0.79 (m, CH, CH2, CH3).

[0153] Example 7

[0154] The only difference between this embodiment and Example 1 is that, except for mixing in acetonitrile in step (2) and stirring at 200 rpm for 48 hours at 80°C, everything else is the same as in Example 1.

[0155] Modified silicon spheres: 1 H NMR (500MHz, CDCl3) δ7.11-6.91(m,Ph-H), 5.01-3.74(m,Si-H,Si-OH), 1.64-0.72(m,CH,CH2,CH3).

[0156] Example 8

[0157] The only difference between this embodiment and Example 1 is that, except for mixing in dimethylformamide in step (3) and stirring at 200 rpm for 72 hours at 90°C, everything else is the same as in Example 1.

[0158] Modified silicon spheres: 1 H NMR (500MHz, CDCl3) δ7.05-6.87(m,Ph-H), 4.87-3.56(m,Si-H,Si-OH), 1.74-0.86(m,CH,CH2,CH3).

[0159] Extraction Examples

[0160] 0.1 g of the modified silicon spheres prepared in Examples 1-8 were weighed and placed in conical flasks. 5 mL of a rare earth element solution containing 1 mmol / L of each of the fifteen rare earth ions (La(III), Ce(III), Pr(III), Nd(III), Sm(III), Eu(III), Gd(III), Tb(III), Dy(III), Ho(III), Er(III), Tm(III), Yb(III), Lu(III), and Y(III)) and pH=4 was added to the conical flask. The solution was shaken on a constant temperature shaker at a shaking rate of 200 rpm for 24 h for static adsorption. After sampling and filtering the solution in the conical flask, the ion concentration in the solution was detected using an ICP instrument.

[0161] The following calculations were performed to determine the extraction rate E%, partition ratio D, and separation coefficient β between the lanthanides (Ln) and yttrium. Ln / Y :

[0162]

[0163]

[0164]

[0165] Among them, [M] (aq,init) and [M] (aq) These represent the initial and equilibrium concentrations of metal ions in the aqueous phase, respectively. Ln For the distribution ratio of the lanthanides, D Y The allocation ratio for yttrium.

[0166] The separation coefficients and adsorption capacities of La(III), Ce(III), Pr(III), Nd(III), Sm(III), Eu(III), Gd(III), Tb(III), Dy(III), Ho(III), Er(III), Tm(III), Yb(III), and Lu(III) to Y(III) are shown in Table 1.

[0167] Table 1

[0168]

[0169] The data in Table 1 show that the modified silicon spheres with selective adsorption were obtained in Examples 1-8. The preparation method of the modified silicon spheres is simple, can be used in industrial production, and is widely used for selective adsorption and separation of yttrium, showing good application prospects.

[0170] The specific embodiments described above further illustrate the purpose, technical solution, and beneficial effects of the present invention. It should be understood that the above descriptions are merely specific embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for preparing modified silicon spheres, the method comprising the following steps: (1) React the phosphorus-containing amino acid compound of Formula I with a silane coupling agent to obtain a coupling extractant, wherein the end of the silane coupling agent away from the silane is covalently attached to the N atom of the phosphorus-containing amino acid compound of Formula I. （I） in, R1 and R2 are each independently selected from C1-C 14 Alkyl, C6-C 10 Aryl, C1-C4 alkyl, C6-C 10 Aryl and C6-C 10 Aryl C1-C4 alkyl; R3 is selected from hydrogen, C1-C6 alkyl, C6-C 12 Aryl, C1-C4 alkyl, C6-C 10 Aryl and C6-C 10 Aryl C1-C4 alkyl; Z is C1-C 12 Alkylene; R4 and R5 are each independently selected from hydrogen, C1-C 10 Alkyl, C3-C 10 cycloalkyl, C6-C 12 Aryl, C1-C4 alkyl, C6-C 10 Aryl and C6-C 10 aryl C1-C4 alkyl, carboxyl C1-C4 alkyl, or, R4 and R5 together with the carbon atom attached thereto form C3-C 10 cycloalkyl; The silane coupling agent is shown in formula V below: （V） R6, R7 and R8 are each independently selected from C1-C4 alkyl and C1-C4 alkoxy groups, and at least one of them is an alkoxy group; R9 is selected from halogen, epoxy group, epoxy methoxy group and isocyanate group; n is an integer from 1 to 8; (2) The coupling extractant is reacted with the silicon spheres to obtain modified silicon spheres, wherein the silane portion of the silane coupling agent is attached to the silicon spheres.

2. The method according to claim 1, wherein, R1 and R2 are each independently selected from C1-C8 alkyl, phenyl, C1-C4 alkylphenyl and phenylC1-C4 alkyl; R3 is selected from hydrogen, C1-C6 alkyl, C6-C 12 Aryl, C1-C4 alkyl, C6-C 10 Aryl and C6-C 10 Aryl C1-C4 alkyl; Z is a C1-C4 alkylene group; R4 and R5 are each independently selected from hydrogen, C1-C 10 Alkyl, C3-C 10 cycloalkyl, C6-C 12 Aryl, C1-C4 alkyl, C6-C 10 Aryl and C6-C 10 Aryl C1-C4 alkyl, carboxyl C1-C4 alkyl, or, R4 and R5 together with the carbon atom attached thereto form C5-C8 cycloalkyl.

3. The method according to claim 1 or 2, wherein, The phosphorus-containing amino acid compounds of Formula I are compounds of the following general Formula II: (II) The definitions of R1, R2, R3, R4 and R5 are the same as in Equation I.

4. The method according to claim 3, wherein, R1 and R2 are the same; and / or R3 is hydrogen, C1-C4 alkyl, or C6-C4 alkyl. 10 aryl; and / or R4 is hydrogen, and R5 is selected from hydrogen, C1-C6 alkyl, C5-C7 cycloalkyl, C6-C6 alkyl, and C7-C6 alkyl. 10 Aryl, C1-C4 alkyl, C6-C 10 Aryl, C6-C 10 Aryl C1-C4 alkyl and carboxyl C1-C4 alkyl.

5. The method according to claim 3, wherein, R1 and R2 are the same C1-C8 alkyl, phenyl, C1-C4 alkylphenyl, and phenylC1-C4 alkyl; and / or R3 is hydrogen, C1-C2 alkyl, phenyl, benzyl, tolyl, ethylphenyl, xylyl; and / or R4 is hydrogen, and R5 is hydrogen, C1-C4 alkyl, C5-C7 cycloalkyl, phenyl, benzyl, tolyl, ethylphenyl, xylyl, or carboxyl C1-C4 alkyl.

6. The method according to claim 5, wherein, R5 is hydrogen, C1-C2 alkyl, cyclopentyl, cyclohexyl, cycloheptyl, phenyl, benzyl, tolyl, ethylphenyl, xylyl, or carboxyl C1-C4 alkyl.

7. The method according to claim 1, wherein, The phosphorus-containing amino acid compound of Formula I is selected from one or more of the following: ((di(phenoxy)phosphoryl)methyl)glycine, ((di((phenylmethyl)oxy)phosphoryl)methyl)glycine, ((di(phenoxy)phosphoryl)propyl)glycine, ((di(phenoxy)phosphoryl)methyl)phenylalanine, ((di((ethyl)oxy)phosphoryl)methyl)glycine, ((di((2-ethylhexyl)oxy)phosphoryl)(phenyl)methyl)glycine, and ((di((2-ethylhexyl)oxy)phosphoryl)(phenyl)methyl)phenylalanine.

8. The method according to claim 1, wherein, R6, R7 and R8 are each independently selected from C1-C2 alkyl and C1-C2 alkoxy groups, and at least one of them is an alkoxy group; R9 is selected from Cl, bromine, iodine, epoxy group, epoxy methoxy group and isocyanate group.

9. The method according to claim 1, wherein, The silane coupling agent is selected from epoxy silane, halogen silane, and isocyanate silane; The epoxy silane is selected from 3-(2,3-epoxypropoxy)propyltrimethoxysilane, 5,6-epoxyhexyltriethoxysilane, 3-glycidyl etheroxypropylmethyldiethoxysilane, 3-(2,3-epoxypropoxy)propyltrimethoxysilane, 3-glycidyl etheroxypropyltriethoxysilane, 3-[(2,3)-epoxypropoxy]propylmethyldiethoxysilane, 3-(2,3-epoxypropoxy)propyltrimethoxysilane, and (3-epoxypropoxypropyl)dimethylethoxysilane; The halogenated silane is selected from 3-bromopropyltrimethoxysilane, 4-bromobutyltrimethoxysilane, 5-bromopentyltrimethoxysilane, 7-bromoheptyltrimethoxysilane, 3-chloroisopropyltrimethoxysilane, chloromethyltrimethoxysilane, chloromethyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 3-iodopropyltrimethoxysilane, chloromethylmethyldiethoxysilane, 3-chloropropylmethyldiethoxysilane, 3-chloropropylmethyltrimethoxysilane, chloromethyldimethylethoxysilane, and chloromethyldimethylmethoxysilane. The isocyanate silane is selected from 3-isocyanate propyltriethoxysilane, 3-isocyanate propyltrimethoxysilane, 3-isocyanate propylmethyldiethoxysilane, and 3-isocyanate propylmethyldimethoxysilane.

10. The method according to claim 1, wherein, In step (1), The molar ratio of the silane coupling agent to the phosphorus-containing amino acid compound of formula I is 1:0.5-2; and / or The reaction of the phosphorus-containing amino acid compound of Formula I with the silane coupling agent is carried out in bulk or in an organic solvent; and / or the mass of the organic solvent is 2-5 times the sum of the phosphorus-containing amino acid compound of Formula I and the silane coupling agent; and / or The reaction time is 24-72 h; and / or The reaction temperature is 60-90℃.

11. The method according to claim 10, wherein, The organic solvent is any one or more selected from methanol, ethanol, acetonitrile, and toluene.

12. The method according to claim 1, wherein, In step (2), The silicon spheres have a particle size of 100-200 mesh and / or 400-500 μm. 2 Specific surface area per g; and / or The mass ratio of silica spheres to coupling extractant is 1:1-2; and / or Step (2) is carried out in an organic solvent; and / or the mass of said organic solvent is 2-5 times the sum of the masses of the coupling extractant and the silica spheres; and / or The reaction time is 1-100 h; and / or The reaction temperature is 90-110℃.

13. The method of claim 12, wherein, The organic solvent is selected from any one or more of dimethylformamide, toluene, and dimethyl sulfoxide; and / or the reaction time is 24-72 h.

14. The method according to claim 1, wherein, Step (2) also includes a purification step, which includes saponifying the obtained reaction product and then washing it with deionized water and ethanol respectively to obtain the modified silica spheres.

15. A modified silicon sphere, said modified silicon sphere being obtained by the method according to any one of claims 1-14.

16. The modified silicon spheres according to claim 15 are used as a solid-phase extractant for the separation of yttrium from lanthanides.

17. The modified silica spheres according to claim 15 are used as a solid-phase extractant for the separation of lanthanide elements.

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