Amino acid modified silicon ball as well as preparation method and application thereof

Abstract

The invention relates to an amino acid modified silicon ball as well as a preparation method and application thereof. The amino acid modified silicon ball is prepared by the following steps: reacting an amino acid compound with a silane coupling agent to obtain a coupling extraction agent, wherein one end, far away from a silane part, of the silane coupling agent is covalently connected to an N atom of amino in the amino acid compound; and (2) reacting the coupling extraction agent with the silicon balls to obtain modified silicon balls, wherein the silane part of the silane coupling agent is connected to the silicon balls. The amino acid modified silicon ball has the advantages of large adsorption capacity, strong selectivity, fast adsorption kinetics, low elution acidity, simple preparation method and the like, can be widely used for separating and preparing high-purity yttrium, and has a good application prospect.

Description

Technical Field

[0001] The invention relates to a rare earth element solid phase extraction material, in particular to an amino acid modified silicon ball and a preparation method and application thereof. Background Art

[0002] Yttrium is a widely distributed rare earth element, which has a wide range of applications in fluorescent materials, optical glass, special ceramics, spray materials, etc. However, high-precision applications require high-purity elements. For example, 3N-grade Y2O3 can be used to make incandescent gas lampshades, 4N-grade Y2O3 can be used for fluorescent materials, and 5N-grade Y2O3 can be used for NdYAG laser crystals. At the same time, the higher the purity of Y2O3, the more expensive it is. Therefore, based on the scope of application and economic factors, it is urgent to develop an efficient yttrium separation technology.

[0003] Due to the lanthanide contraction, yttrium has similar properties to lanthanide elements. At the same time, yttrium often coexists with other rare earth minerals, so it is difficult to separate yttrium from other rare earths.

[0004] Traditional yttrium purification methods mainly include solvent extraction and ion exchange. Solvent extraction has the advantages of good selectivity and large processing capacity, but the preparation of high-purity rare earth requires multiple stages and complex equipment. In addition, the mainstream yttrium extractant cyclohexane acid has the disadvantages of high water solubility, low acidity, and poor separation ability of lanthanide elements and yttrium.

[0005] Based on the strong separation ability of column chromatography, ion exchange is suitable for the preparation of high-purity rare earths, but expensive eluents and poor selectivity limit the development of ion exchange technology. Therefore, in order to combine the high selectivity of solvent extraction and the strong separation ability of column chromatography, it is very meaningful to develop a new adsorbent with the ability to selectively adsorb and separate yttrium as a column chromatography filler to prepare high-purity yttrium. Summary of the invention

[0006] There are no reports on the use of amino acids to extract rare earth elements, and most amino acids are soluble in water and cannot be extracted by solvents. The inventors obtained an amino acid-modified silicon sphere by in-situ grafting of amino acids onto the surface of silicon spheres using a silane coupling agent, and applied it to the solid-liquid extraction of yttrium. It was unexpectedly found that the amino acid-modified silicon sphere can be used to extract and separate yttrium. The amino acid-modified silicon sphere of the present invention has the advantages of large adsorption capacity, strong selectivity, fast adsorption kinetics, low elution acidity and simple preparation method, and can be widely used in the separation and preparation of high-purity yttrium, and has good application prospects.

[0007] In a first aspect, the present invention provides a method for preparing modified silicon spheres, the method comprising the following steps:

[0008] (1) reacting an amino acid compound with a silane coupling agent to obtain a coupled extractant, wherein the end of the silane coupling agent away from the silane portion is covalently linked to the N atom of the amino group in the amino acid compound; (2) reacting the coupled extractant with a silica sphere to obtain a modified silica sphere, wherein the silane portion of the silane coupling agent is linked to the silica sphere.

[0009] The method for preparing modified silicon spheres of the present invention uses a silane coupling agent to in-situ graft the amino acid compound of formula I onto the surface of the silicon sphere. The amino acid-modified silicon spheres of the present invention have the advantages of large adsorption capacity, strong selectivity, fast adsorption kinetics, low elution acidity and simple preparation method, and can be widely used in the separation and preparation of high-purity yttrium, and have good application prospects.

[0010] The present invention is described in further detail below.

[0011] Amino Acid Compounds

[0012] In the present invention, the amino acid compound refers to a compound having both an amino group (including primary and secondary amino groups) and a -COOH functional group in the molecule, and at least one amino group and one -COOH are connected by an alkylene group.

[0013] In some embodiments, the amino acid compound is a compound of Formula I:

[0014]

[0015] Wherein, R1 is hydrogen, C1-C 12 Alkyl, C3-C 10 Cycloalkyl, C6-C 10 Aryl, C1-C4 alkyl, C6-C 10 Aryl, or C6-C 10 Aryl C1-C4 alkyl, preferably hydrogen, C1-C 10 Alkyl, C5-C 10 Cycloalkyl, phenyl, C1-C4 alkylphenyl, or phenyl C1-C4 alkyl; more preferably R1 is hydrogen, C1-C8 alkyl, C5-C8 cycloalkyl, phenyl, C1-C4 alkylphenyl and phenyl C1-C4 alkyl; also preferably hydrogen, C1-C6 alkyl;

[0016] R2 is selected from hydrogen, C1-C 10 Alkyl, C3-C 10 Cycloalkyl, C6-C 12 Aryl, C1-C4 alkyl, C6-C 10 Aryl, C6-C 10 Aryl C1-C4 alkyl, hydroxy C6-C 10Aryl C1-C4 alkyl, carboxyl C1-C4 alkyl, hydroxy C1-C4 alkyl, guanidine C1-C4 alkyl, imidazole C1-C4 alkyl, indolyl C1-C4 alkyl, carbamoyl C1-C4 alkyl, amino C1-C4 alkyl, mercapto C1-C4 alkyl; preferably selected from hydrogen, C1-C6 alkyl, C5-C8 cycloalkyl, C6-C 10 Aryl, C1-C4 alkyl, C6-C 10 Aryl, C6-C 10 Aryl C1-C4 alkyl, hydroxy C6-C 10 Aryl C1-C4 alkyl, carboxyl C1-C4 alkyl, hydroxy C1-C4 alkyl, guanyl C1-C4 alkyl, imidazolyl C1-C4 alkyl, indolyl C1-C4 alkyl, carbamoyl C1-C4 alkyl, amino C1-C4 alkyl, mercapto C1-C4 alkyl, more preferably selected from hydrogen, C1-C4 alkyl, C5-C7 cycloalkyl, phenyl, benzyl, hydroxyphenylmethyl, tolyl, ethylphenyl, xylyl, carboxymethyl, carboxyethyl, hydroxymethyl, hydroxyethyl, guanylpropyl, imidazolylmethyl, indolylmethyl, carbamoylmethyl, carbamoylethyl, aminobutyl, mercaptomethyl;

[0017] R3 is 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; preferably hydrogen, C1-C6 alkyl; more preferably hydrogen;

[0018] Or R2 and R3 and the carbon atom to which they are connected together form a C3-C 10 Cycloalkyl, especially C5-C8 cycloalkyl;

[0019] Z is C1-C 12 The alkylene group is preferably a C1-C4 alkylene group.

[0020] In some embodiments, the amino acid compound is a compound of Formula II:

[0021]

[0022] Wherein, the definitions of R1 and R2 are the same as those in Formula I.

[0023] In some embodiments, the amino acid compound is a compound of Formula III:

[0024]

[0025] Wherein, the definition of R1 is the same as that in Formula I.

[0026] In some embodiments, the amino acid compound is a natural amino acid or a modified natural amino acid.

[0027] The natural amino acid can be one or more selected from glycine, threonine, tyrosine, aspartic acid, glutamic acid, arginine, histidine, serine, valine, leucine, isoleucine, tert-leucine, alanine, phenylalanine, asparagine, tryptophan, glutamine, lysine, gamma-aminobutyric acid, and cysteine. The amino acid used here can be D-type, L-type, or a combination of the two.

[0028] The structures of some amino acids are shown in the following table:

[0029]

[0030]

[0031] Modified natural amino acid refers to the compound obtained by replacing a hydrogen on the amino group of natural amino acid with a alkyl group. For example, modified natural amino acid can be N-ethyl aspartic acid, N-propyl aspartic acid, N-sec-butyl aspartic acid, N-isobutyl aspartic acid, N-cyclopentane aspartic acid, N-2 ethylhexyl aspartic acid.

[0032] The modified natural amino acid can be a commercially available product or prepared by any suitable method. For example, a natural amino acid can be subjected to an amination reaction with a halogenated hydrocarbon R1X (wherein R1 is a hydrocarbon group) to obtain a compound of formula I or II in which R1 is not hydrogen, and the reaction formula is as follows:

[0033]

[0034] in,

[0035] X is a halogen, such as Cl, Br or I,

[0036] Except that R1 is not hydrogen, the definition of R1 is the same as in formula I,

[0037] R2 is as defined in Formula I.

[0038] The reaction of natural amino acid with halogenated hydrocarbon R1X can be carried out under any suitable conditions, for example, it can be carried out in the presence of a base and an acid binding agent. The acid binding agent is, for example, 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), and the base is, for example, triethylamine, diethylamine, ethylenediamine, but not limited thereto. In addition, the reaction can be carried out in an organic solvent, and the organic solvent can be, for example, methanol, ethanol, acetonitrile, tetrahydrofuran, dioxane, etc., but not limited thereto. The reaction can be carried out at any suitable temperature, for example, the reaction temperature can be 55-75°C, for example, it can be 55°C, 60°C, 65°C, 70°C or 75°C, but it is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable. The reaction can be carried out for any suitable time, as long as the desired product is obtained. For example, the reaction time can be 6-10h, for example, it can be 6h, 7h, 8h, 9h or 10h, but it is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0039] Silane coupling agent

[0040] In the present invention, the silane coupling agent acts as a connecting group, which is connected to the silicon sphere through the action of the silane group and the surface group of the silicon sphere on the one hand, and is covalently connected to the amino acid compound (such as the compound of Formula I, II or III) through the other end, thereby grafting the amino acid compound to the silicon sphere to obtain a modified silicon sphere.

[0041] The silane coupling agent can be any silane coupling agent that can achieve the above-mentioned purpose.

[0042] In some embodiments, the silane coupling agent has a functional group that can directly react with the amino group in the structure of the amino acid compound (e.g., the compound of Formula I, II, or III). In this case, the silane coupling agent can be directly reacted with the amino acid compound so that one end of the silane coupling agent is directly covalently linked to the amino group in the amino acid compound structure.

[0043] In some embodiments, the silane coupling agent is represented by the following formula IV:

[0044]

[0045] Wherein, R4, R5 and R6 are each independently selected from C1-C4 alkyl and C1-C4 alkoxy, and at least one is an alkoxy; preferably, each independently selected from C1-C2 alkyl and C1-C2 alkoxy, and at least one is an alkoxy;

[0046] R7 is selected from halogen (especially Cl, bromine and iodine), epoxy (ie oxirane), epoxymethoxy (ie glycidyloxy) and isocyanate;

[0047] n is an integer from 1 to 8.

[0048] In some embodiments, the silane coupling agent is selected from epoxy silane, halogen silane, isocyanate silane, which respectively has an epoxy group, a halogen group and an isocyanate group that can react with an amino group. These silanes can be trialkoxy silanes, dialkoxy silanes or monoalkoxy silanes.

[0049] Epoxysilane refers to a silane coupling agent with at least one epoxy group in the molecule. For example, epoxysilane can be 3-(2,3-epoxypropyloxy)propyltrimethoxysilane (KH-560), 5,6-epoxyhexyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-(2,3-epoxypropyloxy)propyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-[(2,3)-epoxypropyloxy]propylmethyldimethoxysilane, 3-(2,3-epoxypropyloxy)propyltrimethoxysilane, (3-epoxypropyloxy)dimethylethoxysilane, etc., but are not limited thereto.

[0050] In the case of using epoxy silane, the epoxy group in the silane coupling agent can undergo an addition reaction with the amino group in the structure of the amino acid compound (e.g., the compound of Formula I, II or III) to open the ring and allow one end of the silane coupling agent to be covalently connected to the amino group in the amino acid compound structure.

[0051] Halogen silane refers to a silane coupling agent with at least one halogen group in the molecule. Halogen includes fluorine, chlorine, bromine and iodine. The halogen groups particularly common in silane coupling agents are chlorine and bromine. For example, the halogen silane can be 3-bromopropyltrimethoxysilane, 4-bromobutyltrimethoxysilane, 5-bromopentyltrimethoxysilane, 7-bromoheptyltrimethoxysilane, 3-chloroisopropyltrimethoxysilane, chloromethyltrimethoxysilane, chloromethyltriethoxysilane, 3-chloropropyltrimethoxysilane, 3-chloropropyltriethoxysilane, 3-iodopropyltrimethoxysilane, chloromethylmethyldiethoxysilane, 3-chloropropylmethyldiethoxysilane, 3-chloropropylmethyltrimethoxysilane, chloromethyldimethylethoxysilane, chloromethyldimethylmethoxysilane, but is not limited thereto.

[0052] In the case of using halogen silane, the silane coupling agent can be used as a halogenated hydrocarbon to react with the amino group in the structure of the amino acid compound (e.g., a compound of formula I, II, or III) to remove the halogen group and covalently connect one end of the silane coupling agent to the amino group in the structure of the amino acid compound. In order to promote the amination reaction, it can be carried out in the presence of an acid binding agent. Common acid binding agents are, for example, 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU), but are not limited thereto.

[0053] Isocyanate silane refers to a silane coupling agent with at least one isocyanate in the molecule. For example, the isocyanate silane can be 3-isocyanate propyl triethoxy silane, 3-isocyanate propyl trimethoxy silane, 3-isocyanate propyl methyl diethoxy silane, 3-isocyanate propyl methyl dimethoxy silane, etc., but is not limited thereto.

[0054] In the case of using isocyanate silane, the isocyanate group in the silane coupling agent can undergo a nucleophilic addition reaction with the amino group in the structure of the amino acid compound (e.g., the compound of Formula I, II or III) to generate a urea group and covalently connect one end of the silane coupling agent to the amino group in the structure of the amino acid compound.

[0055] The silane coupling agent can also be hydroxysilane, aldehyde silane, carboxyl silane, etc., and one end of the silane coupling agent is covalently connected to the amino group in the structure of the amino acid compound (such as the compound of formula I, II or III) through the reaction of the hydroxyl group, aldehyde group, carboxyl group and the like with the amino group.

[0056] 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 amino acid compound (e.g., the compound of Formula I, II or III). In this case, one end of the silane coupling agent can be covalently connected to the amino group in the structure of the amino acid compound (e.g., the compound of Formula I, II or III) through a connecting group by adding another compound that plays a connecting role as a connecting agent, or 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 amino acid compound (e.g., the compound of Formula I, II or III).

[0057] Preparation of coupling extractant

[0058] The reaction of the amino acid compound (e.g., compound of formula I, II or III) with the silane coupling agent in step (1) to prepare the coupling extractant is as described above, and the specific conditions can be appropriately selected according to the reaction type combined with techniques known in the art.

[0059] The molar ratio of the amino acid compound 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 amino acid compound can be 1:0.5-2, or 1:1-1.2, for example, it can be 1:0.5, 1:0.75, 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, and other values ​​not listed in the numerical range are also applicable.

[0060] The reaction of the amino acid compound and the silane coupling agent 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, tetrahydrofuran, and dioxane, but is not limited thereto.

[0061] There is no particular restriction on the amount of the organic solvent, which can be appropriately selected by those skilled in the art. For example, the mass of the organic solvent can be 5-20 times, or 10-15 times, of the compound of formula I, such as 5, 6, 7, 8, 9, 10, 12, 14, 16, 18, 20 times, etc., but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0062] In some embodiments, the reaction can be carried out under stirring. Appropriate stirring is conducive to uniform mixing of the reactants and promotes the reaction. The stirring speed can be appropriately selected by those skilled in the art according to the reaction scale, reaction equipment, etc. For example, the stirring speed is 100-500rpm, for example, it can be 100rpm, 200rpm, 300rpm, 400rpm or 500rpm, but it is not limited to the listed values, and other values ​​not listed in the numerical range are also applicable.

[0063] The reaction time of the reaction is not particularly limited, as long as the product can be obtained with an appropriate yield. The specific reaction time can be appropriately selected according to the reaction scale, reaction temperature, etc. For example, the reaction time can be 24-72h, or 36-48h, for example, it can be 24h, 36h, 48h, 60h or 72h, but it is not limited to the listed values, and other unlisted values ​​within the numerical range are also applicable.

[0064] The reaction temperature of the reaction is not particularly limited, as long as the reaction can occur to obtain the target product. For example, the reaction temperature can be 60-90°C, or 65-80°C, such as 60°C, 65°C, 70°C, 75°C, 80°C, 85°C or 90°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0065] In some embodiments, the prepared coupling extractant is selected from the following compounds:

[0066]

[0067] wherein R1 to R3 are defined the same as in Formula I, and R4 to R6 and n are defined the same as in Formula IV.

[0068] In some embodiments, the prepared coupling extractant is selected from the following compounds:

[0069]

[0070] wherein R1 and R2 are defined as in Formula I, and R4 to R6 and n are defined as in Formula IV.

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

[0072]

[0073]

[0074] wherein R1 is defined as in Formula I, and R4 to R6 and n are defined as in Formula IV.

[0075] Reaction of coupling extractant with silica spheres

[0076] In the reaction between the coupling extractant and the silica spheres in step (2), the silane groups of the coupling extractant will hydrolyze and react with the OH groups on the surface of the silica spheres, ultimately forming a covalent bond.

[0077] The silica spheres herein refer to silica microspheres. There are no particular restrictions 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 300-500 m 2 / g specific surface area, but not limited thereto.

[0078] In step (2), the mass ratio of the coupling extractant to the silica sphere is not particularly limited, as long as an appropriate amount of the coupling extractant can be grafted onto the silica sphere. For example, the mass ratio of the coupling extractant to the silica sphere can be 1:0.5-2, such as 1:0.8-1.2, such as 1:0.5, 1:0.8, 1:1, 1:1.2, 1:1.4, 1:1.6, 1:1.8, 1:2, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0079] In step (2), the coupling extractant can be first diluted with a diluent and then reacted with the silica spheres. The diluent includes methanol, ethanol, propanol, etc., and can be any one or more thereof, but is not limited thereto. The mass of the diluent can be 1-1.2 times the mass of the modified coupled amino acid, but is not limited thereto.

[0080] In step (2), the reaction of the coupling extractant and the silicon spheres can be carried out in an organic solvent. The organic solvent includes toluene, xylene, trimethylbenzene, cyclohexane, n-heptane, isooctane, etc., and can be any one or more thereof, but is not limited thereto. There is no particular restriction on the amount of the organic solvent, and it can be appropriately selected by those skilled in the art. For example, the mass of the organic solvent can be 10-15 times that of the coupling extractant, such as 10, 11, 12, 13, 14, 15 times, but is not limited to the listed values, and other values ​​not listed within this numerical range are also applicable.

[0081] In step (2), the reaction of the coupling extractant and the silica spheres can be carried out under stirring. Moderate stirring is conducive to uniform mixing of the reactants and promotes the reaction. The stirring speed can be appropriately selected by those skilled in the art according to the reaction scale, reaction equipment, etc. For example, the stirring speed can be 100-500 rpm, for example, 100 rpm, 200 rpm, 300 rpm, 400 rpm or 500 rpm, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0082] In step (2), the temperature at which the coupling extractant reacts with the silica spheres is not particularly limited, as long as the reaction can occur to obtain the target product. For example, the reaction temperature is 90-120°C, or 90-110°C, such as 90°C, 95°C, 100°C, 105°C or 110°C, but is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0083] In step (2), the reaction time of the coupling extractant and the silica spheres is not particularly limited, as long as the product can be obtained at an appropriate yield. The specific reaction time can be appropriately selected according to the reaction scale, reaction temperature, etc. For example, the reaction time is 1-100h, such as 24-72h, or 48-72h, for example, it can be 24h, 36h, 48h, 60h or 72h, but it is not limited to the listed values, and other values ​​not listed within the numerical range are also applicable.

[0084] Step (2) may further include a purification step. The purification step may include saponifying the obtained reaction product, then washing it with deionized water and ethanol respectively, and drying it to obtain the modified silicon sphere. The saponification may be performed using an alkali, such as sodium hydroxide, sodium carbonate, etc.

[0085] In a second aspect, the present invention provides a modified silicon sphere, which is obtained by the preparation method described in the first aspect.

[0086] Surprisingly, the inventors have confirmed through experiments that the modified silicon spheres of the present invention can extract rare earth elements, have different extraction rates for yttrium and lanthanide elements, and can be used as an extractant to extract and separate yttrium.

[0087] Therefore, in a third aspect, the present invention provides a use of the modified silicon spheres as described in the second aspect as a solid phase extractant for separating yttrium from lanthanide elements. In other words, the present invention provides the use of the modified silicon spheres as a solid phase extractant for preparing an extraction system for separating yttrium from lanthanide elements in a rare earth element solution.

[0088] In addition, during the experiment, it was found that the modified silica balls of the present invention as solid phase extractants have different extraction rates and distribution ratios for different lanthanide elements, and thus can be used to separate different lanthanide elements in rare earth element liquid by solid-liquid extraction. For example, it can be used to group lanthanide elements, such as light, medium, and heavy rare earth elements, or separate them into groups containing two or more (for example, two, three, four, etc.) similar lanthanide elements, or to separate a single lanthanide element.

[0089] Therefore, the present invention also provides the use of the modified silica spheres as a solid phase extractant for separating lanthanide elements. In other words, the present invention provides the use of the modified silica spheres as a solid phase extractant for preparing an extraction system for separating lanthanide elements.

[0090] In order to achieve the extraction, the rare earth element liquid can be contacted with the modified silicon spheres of the present invention, thereby achieving the separation.

[0091] Beneficial Effects

[0092] Compared with the prior art, the present invention has the following beneficial effects:

[0093] The present invention grafts a water-soluble amino acid compound onto the surface of a silicon ball in situ through a coupling agent to obtain a modified silicon ball having a selective adsorption effect on rare earth elements. The modified silicon-based material of the present invention has the advantages of large adsorption capacity, strong selectivity, fast adsorption kinetics, low elution acidity and simple preparation method, and can be widely used in the separation and preparation of high-purity yttrium, and has good application prospects.

[0094] the term

[0095] In the present invention, "separation of yttrium" refers to the extraction of yttrium (i.e., trivalent yttrium (III) or trivalent yttrium ion Y 3 + ) and other rare earth elements (i.e. lanthanide elements or trivalent lanthanide ions Ln 3+ ) separated.

[0096] In the present invention, rare earth elements refer to lanthanum, cerium, praseodymium, neodymium, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, yttrium and scandium, among which light rare earths refer to lanthanum, cerium, praseodymium and neodymium; medium and heavy rare earths refer to samarium, europium, gadolinium, terbium, dysprosium, holmium, europium, erbium, thulium, ytterbium, lutetium, yttrium and scandium.

[0097] The terms C1-C 12 Alkyl refers to a straight or branched chain alkyl group containing 1 to 12 carbon atoms, such as a straight or branched chain alkyl group having 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12 carbon atoms, including but not limited to methyl, ethyl, n-propyl, isopropyl, n-butyl, tert-butyl, isobutyl, n-pentyl, neopentyl, isopentyl, hexyl, heptyl, octyl, nonyl, decyl, undecyl, dodecyl, etc. 10 The meanings of alkyl, C1-C8 alkyl, C1-C4 alkyl, etc. are deduced by analogy.

[0098] The term C6-C used in the present invention 10 Aryl refers to an aromatic group containing 6 to 12 carbon atoms in the ring, for example, an aromatic group having 6, 7, 8, 9, 10, 11 or 12 carbon atoms in the ring, including but not limited to phenyl and naphthyl.

[0099] The term C1-C4 alkyl C6-C 10 Examples of the aryl group include tolyl, ethylphenyl, xylyl, mesityl and the like.

[0100] The term C6-C used in the present invention 10 The aryl C1-C4 alkyl group includes, for example, benzyl, phenethyl and the like.

[0101] The term C3-C used in the present invention 10 Cycloalkyl refers to a saturated cyclic alkyl group containing 3 to 10 carbon atoms, including but not limited to cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl and the like.

[0102] Unless otherwise stated, the numerical values ​​in the present invention represent approximate measurements or limitations of the range of embodiments including slight deviations from given values ​​and having approximately the mentioned values ​​and having the mentioned exact values. Except for the last example described in detail, all numerical values ​​of parameters (e.g., quantities or conditions) in this application document (including the appended claims) should be understood as modified by the term "approximately" in all cases, regardless of whether "approximately" actually appears before the numerical value. "Approximately" means that the numerical value described allows for slight imprecision (some close to precision in the value; approximately or reasonably close to the value; approximately). If the imprecision provided by "approximately" is not understood in this ordinary sense in the art, the "approximately" used herein at least represents the changes that can be produced by ordinary methods of measuring and using these parameters. For example, "approximately" can include 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% of the change, and in some aspects, less than or equal to 0.01% of the change.

[0103] The present invention has been described above in detail, but the present invention is not limited to the above contents. BRIEF DESCRIPTION OF THE DRAWINGS

[0104] Figure 1 This is a scanning electron microscope (SEM) image of the modified silicon sphere prepared in Preparation Example 1 of the present invention.

[0105] Figure 2 This is a kinetic curve diagram of the adsorption of La(III), Gd(III) and Lu(III) by the modified silicon spheres prepared in Preparation Example 1 of the present invention measured in Example 2.

[0106] Figure 3 This is a diagram showing the acid elution of Lu(III) adsorbed on the modified silica spheres prepared in Preparation Example 1 of the present invention as measured in Example 3. DETAILED DESCRIPTION

[0107] To facilitate understanding of the present invention, the technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0108] Reagents and sources:

[0109] (1) Diphenyl phosphite and diethyl phosphite were purchased from Shanghai Laiyashi Chemical Co., Ltd.

[0110] (2) Aspartic acid was purchased from Aladdin Reagent Co., Ltd.

[0111] (3) 3-Chloropropyltrimethoxysilane (CPTS) was purchased from MacLean Co.

[0112] (4) Silica spheres were purchased from Qingdao Jiyida Silica Sphere Reagent Factory, with a particle size of 100-200 mesh and a specific surface area of ​​400-500 m 2 / g.

[0113] (5) The rare earth liquid was prepared in the laboratory.

[0114] (6) Other reagents (such as acids) were all commercially available analytical grade reagents.

[0115] The rare earth ion concentrations were measured using ICP-OES (instrument model: Optical-8000, manufacturer: Perkin Elmer).

[0116] Preparation Example 1

[0117] The preparation method of the modified silicon sphere is shown in the following reaction formula, but the reaction formula is only illustrative and is not intended to limit the present invention.

[0118]

[0119] The modified silica spheres were prepared according to the following method: aspartic acid, DBU and 3-chloropropyltrimethoxysilane were added to acetonitrile (the mass was 15 times the mass of aspartic acid) in a molar ratio of 1:2:1, the system was reacted at 65°C for 36 hours, the product was separated and purified to obtain coupled aspartic acid; the coupled aspartic acid obtained and an equal mass of silica spheres were added to toluene (the mass was 15 times the mass of the coupled amino acid), the reaction was carried out at 110°C for 48 hours, the organic solvent was removed and the mixture was washed with ethanol to obtain a crude modified silica sphere product; the crude product was saponified in a 0.5 mol / L sodium carbonate solution (the mass was 50 times the mass of the crude modified silica sphere product) for 20 minutes, then washed with deionized water and ethanol in turn, and vacuum dried to obtain the modified silica spheres.

[0120] Modified silica ball: 1 H NMR (500MHz, CDCl3) δ5.44-4.13 (m, Si-H, Si-OH), 1.63-1.37 (m, CH, CH2, CH3).

[0121] Figure 1 This is a scanning electron microscope (SEM) image of the modified silicon sphere prepared in Example 1 of the present invention.

[0122] Preparation Example 2

[0123] The preparation method of the modified silicon sphere is shown in the following reaction formula, but the reaction formula is only illustrative and is not intended to limit the present invention.

[0124]

[0125] The modified silica spheres were prepared according to the following method: (1) aspartic acid, ethyl bromide and DBU were added to acetonitrile (the mass of which was 15 times the mass of the amino acid) in a molar ratio of 1:1:2, and the system was reacted at 65°C for 10 h. The product was separated and purified to obtain modified aspartic acid; the obtained modified aspartic acid and an equal amount of coupling agent 3-chloropropyltrimethoxysilane were added to acetonitrile (the mass of which was 15 times the mass of the modified aspartic acid) and mixed. The system was reacted at 65°C for 36 h to remove the organic solvent. The obtained modified coupled aspartic acid and an equal mass of silica spheres were added to toluene (the mass was 15 times that of the coupled amino acid), and the mixture was reacted at 110° C. for 48 h. The organic solvent was removed and the mixture was washed with ethanol to obtain a crude modified silica sphere product. The obtained crude modified silica sphere product was saponified in a 0.5 mol / L sodium carbonate solution (the mass was 50 times that of the crude modified silica sphere product) for 20 min, and then washed with deionized water and ethanol in turn, and dried in vacuo to obtain the modified silica spheres.

[0126] Modified silica ball: 1 H NMR (500MHz, CDCl3) δ5.69-4.16 (m, Si-H, Si-OH), 1.66-1.38 (m, CH, CH2, CH3).

[0127] Preparation Example 3

[0128] Except that "bromoethane" is replaced by "1-bromopropane", the other operating conditions are the same as those in Preparation Example 2.

[0129] The theoretical structure of the modified silicon sphere obtained in Preparation Example 3 is as follows, but the structural formula is only illustrative and is not intended to limit the present invention.

[0130]

[0131] Modified silica ball: 1 H NMR (500MHz, CDCl3) δ5.57-4.21 (m, Si-H, Si-OH), 1.62-1.34 (m, CH, CH2, CH3).

[0132] Preparation Example 4

[0133] Except that "ethyl bromide" is replaced by "2-bromobutane", the other operating conditions are the same as those in Preparation Example 2.

[0134] The theoretical structure of the modified silicon sphere obtained in Preparation Example 4 is as follows, but the structural formula is only illustrative and is not intended to limit the present invention.

[0135]

[0136] Modified silica ball: 1 H NMR (500MHz,CDCl3)δ5.42-3.96(m,Si-H,Si-OH),1.77-1.37(m,CH,CH2,CH3). Preparation Example 5

[0137] Except that "ethyl bromide" is replaced by "1-bromo-2-methylpropane", the other operating conditions are the same as those in Preparation Example 2.

[0138] The theoretical structure of the modified silicon sphere obtained in Preparation Example 5 is as follows, but the structural formula is only illustrative and is not intended to limit the present invention.

[0139]

[0140] Modified silica ball: 1 H NMR (500MHz, CDCl3) δ5.49-4.09 (m, Si-H, Si-OH), 1.68-1.41 (m, CH, CH2, CH3).

[0141] Preparation Example 6

[0142] Except that "ethyl bromide" is replaced by "cyclopentyl bromide", the other operating conditions are the same as those in Preparation Example 2.

[0143] The theoretical structure of the modified silicon sphere obtained in Preparation Example 6 is as follows, but the structural formula is only illustrative and is not intended to limit the present invention.

[0144]

[0145] Modified silica ball: 1 H NMR (500MHz, CDCl3) δ5.67-4.16 (m, Si-H, Si-OH), 1.66-1.38 (m, CH, CH2, CH3).

[0146] Preparation Example 7

[0147] Except that "bromoethane" is replaced by "1-bromo-2-ethylhexane", the other operating conditions are the same as those in Preparation Example 2.

[0148] The theoretical structure of the modified silicon sphere obtained in Preparation Example 7 is as follows, but the structural formula is only illustrative and is not intended to limit the present invention.

[0149]

[0150] Modified silica ball: 1 H NMR (500MHz, CDCl3) δ5.61-4.18 (m, Si-H, Si-OH), 1.58-1.39 (m, CH, CH2, CH3).

[0151] Example 1

[0152] Weigh 50 mg (± 0.2 mg) of the modified silicon spheres prepared in Preparation Examples 1-7 and place them in a threaded sample bottle, add 10 mL of a solution containing 15 kinds of 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 the concentration is 0.25 mmol / L, pH = 5, and shake on an air bath thermostatic shaker at an oscillation rate of 300 rpm at 25°C for 24 hours to perform a static adsorption experiment. After the adsorption is completed, filter and take a water sample, use ICP-OES to determine the concentration of each ion in the solution before and after adsorption, and calculate the separation coefficient.

[0153] 50 mg (±0.2 mg) of the modified silica spheres prepared in Preparation Examples 1-7 were weighed and placed in threaded sample bottles, 10 mL of 2 mmol / L pH = 5 Lu (III) solution was added to the bottles, and the bottles were shaken at 25°C for 24 h on an air bath thermostatic shaker with an oscillation rate of 300 rpm. After the adsorption was completed, the water samples were filtered and the Lu (III) concentration of the solution before and after adsorption was determined by ICP-OES to calculate the adsorption capacity.

[0154] The adsorption capacity, distribution ratio and separation coefficient of the material can be calculated using formulas (1), (2) and (3), respectively.

[0155]

[0156]

[0157]

[0158] Where Q represents the adsorption capacity, K d represents the distribution ratio, β A / B represents the separation coefficient of A to B, C i With C t They represent the rare earth ion concentrations before and after adsorption, V represents the volume of the feed solution, and m represents the amount of adsorbent used.

[0159] In the static adsorption experiment, the separation coefficients of the other fourteen rare earth ions for yttrium and the adsorption capacity for Lu(III) displayed by the modified silicon spheres prepared in Preparation Examples 1-7 are shown in Table 1.

[0160] Table 1

[0161]

[0162] From the results in Table 1, we can see that:

[0163] (1) The modified silica spheres obtained in Preparation Example 1 have the advantages of large adsorption capacity, strong selectivity, and simple preparation method. They can be widely used as column fillers for the preparation of high-purity yttrium and have broad application prospects.

[0164] (2) By comparing Preparation Example 1 with Preparation Examples 2-7, it can be seen that by adding a hydrocarbon group at the N atom, the increased steric hindrance causes the adsorption groups to be less bonded to the surface of the silicon-based carrier, resulting in a decrease in the adsorption capacity, but the increased steric hindrance also significantly affects the selectivity of the remaining rare earth ions for yttrium.

[0165] (3) The relevant data of Preparation Examples 1-7 show that the modified silicon spheres of the present invention have extraction selectivity for rare earths other than yttrium (especially heavy rare earths) relative to yttrium, among which the separation factors of holmium, erbium, thulium, ytterbium and lutetium for yttrium are greater than those of several reported yttrium extractants NA, CA-12, POPA and PPPA (Wang et al. Sep. Purif. Technol. 2017, 184: 280-287; Wu et al. J. Rare Earth. 2022, 40(6): 958-964), indicating that the modified silicon spheres obtained by the preparation method described in the present invention have the ability to separate yttrium from other rare earths.

[0166] Example 2

[0167] 50 mg (±0.2 mg) of the modified silica spheres prepared in Preparation Example 1 were weighed and placed in threaded sample bottles. 10 mL of La(III), Gd(III), and Lu(III) solutions with a concentration of 1.5 mmol / L and a pH of 5 were added to the bottles. The mixture was shaken on a constant temperature shaker with an oscillation rate of 300 rpm at 25°C for 3-240 min to perform a kinetic experiment. The results are shown in Table 1. Figure 2 .

[0168] Depend on Figure 2 It can be seen that the modified silicon spheres obtained in Preparation Example 1 have fast adsorption kinetics for rare earth ions. Taking Lu(III) as an example, in the first 3 minutes of adsorption, about 60% of the equilibrium adsorption capacity of Lu(III) is adsorbed; in the first 10 minutes of adsorption, about 88% of the equilibrium adsorption capacity of Lu(III) is adsorbed; in the first 30 minutes of adsorption, the adsorption equilibrium is established. The adsorption equilibrium time of the adsorbent is shorter than the adsorption equilibrium time of the adsorbents reported in CN112280090A and CN108786712A. The fast adsorption kinetics is a significant advantage of the adsorbent.

[0169] Example 3

[0170] 100 mg (±0.5 mg) of the adsorbent prepared in Preparation Example 1 was weighed and placed in a threaded sample bottle, and 20 mL of Lu (III) solution with a concentration of 1.5 mmol / L and a pH of 5 was added to the bottle, and the mixture was shaken at 25°C for 60 min on an air bath thermostatic shaker with an oscillation rate of 300 rpm. After the shaking, the solid was filtered and washed with clean water several times until there was no Lu (III) ion in the eluent. After the solid was dried, 20 mL of 0.01 mol / L, 0.05 mol / L, 0.1 mol / L, 0.5 mol / L, and 1 mol / L HCl were used to elute the mixture on an air bath thermostatic shaker with an oscillation rate of 300 rpm at 25°C for 60 min. The Lu (III) concentration in the eluted solution was tested by ICP-OES, and the elution rate was calculated.

[0171] The elution rate can be calculated using formula (4).

[0172]

[0173] Among them, E represents the elution rate, C H represents the Lu(Ⅲ) concentration in the eluted solution, V H Represents the volume of the pickling solution, C i With C t They represent the rare earth ion concentrations before and after adsorption, and V represents the volume of the feed solution.

[0174] The results of the elution experiment are shown in Figure 3 .

[0175] Depend on Figure 3 It can be seen that the adsorbent material obtained in Preparation Example 1 has a lower elution acidity after adsorbing rare earth, and 0.01 mol / L HCl can wash away 98% of the adsorbed Lu (III).

[0176] Example 4

[0177] 75g of the adsorbent obtained in Preparation Example 1 was weighed and filled on a chromatography column with a diameter of 1cm and a total length of 1.5m. Clean water was passed to wash the adsorbent and compact it, and air was passed to discharge the water in the column. YCl3 liquid with a pH of 5, a concentration of 20mM, and a purity of 99.98% was passed, and the fractions were collected. The concentration of the main element yttrium was determined by ICP-OES, and the concentration of the remaining 14 impurities was determined by ICP-MS. After column purification, YCl3 with a purity of 99.997% was obtained, and 95.87% and 92.39% of Ho and Er in the raw material were removed, respectively.

[0178] Example 5

[0179] 200g of the adsorbent obtained in Preparation Example 1 was weighed and filled on a chromatography column with a diameter of 1cm and a total length of 4m. Clean water was passed to wash the adsorbent and compact it, and air was passed to discharge the water in the column. YCl3 liquid with a pH of 5, a concentration of 20mM, and a purity of 99.98% was passed, and the fractions were collected. The concentration of the main element yttrium was determined by ICP-OES, and the concentration of the remaining 14 impurities was determined by ICP-MS. After column purification, 99.9993% YCl3 was obtained, and 97.32% and 94.74% of Ho and Er in the raw material were removed, respectively.

[0180] Example 6

[0181] 400 g of the adsorbent obtained in Preparation Example 1 was weighed and filled on a chromatography column with a diameter of 1 cm and a total length of 8 m. Clean water was passed to wash the adsorbent and compact it, and air was passed to discharge the water in the column. YCl3 liquid with a pH of 5, a concentration of 20 mM, and a purity of 99.98% was passed, and the fractions were collected. The concentration of the main element yttrium was determined by ICP-OES, and the concentration of the remaining 14 impurities was determined by ICP-MS. After column purification, 99.9999% YCl3 was obtained, and 99.89% and 99.31% of Ho and Er in the raw material were removed, respectively.

[0182] In summary, the present invention uses a coupling agent to chemically bond amino acids or modified amino acids to the surface of silicon balls, thereby obtaining a modified silicon ball having the function of selectively adsorbing and separating rare earth and yttrium. The modified silicon ball of the present invention has the advantages of large adsorption capacity, strong selectivity, fast adsorption rate, low elution acidity and simple preparation method, and can be widely used in the separation and preparation of high-purity yttrium, and has good application prospects.

[0183] The specific embodiments described above further illustrate the objectives, technical solutions and beneficial effects of the present invention in detail. It should be understood that the above description is only a specific embodiment of the present invention and is 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 in the protection scope of the present invention.

Claims

1. A method for preparing modified silicon spheres, the method comprising the following steps: (1) reacting an amino acid compound with a silane coupling agent to obtain a coupled extractant, wherein one end of the silane coupling agent away from the silane portion is covalently linked to the N atom of the amino group in the amino acid compound; (2) reacting a coupling extractant with silica spheres to obtain modified silica spheres, wherein the silane portion of the silane coupling agent is connected to the silica spheres.

2. The method according to claim 1, wherein: The amino acid compound is a compound of the following formula I: Wherein, R1 is hydrogen, C1-C 12 Alkyl, C3-C 10 Cycloalkyl, C6-C 10 Aryl, C1-C4 alkyl, C6-C 10 Aryl, or C6-C 10 Aryl C1-C4 alkyl, preferably hydrogen, C1-C 10 Alkyl, C5-C 10 Cycloalkyl, phenyl, C1-C4 alkylphenyl, or phenyl C1-C4 alkyl; more preferably R1 is hydrogen, C1-C8 alkyl, C5-C8 cycloalkyl, phenyl, C1-C4 alkylphenyl and phenyl C1-C4 alkyl; also preferably hydrogen, C1-C6 alkyl; R2 is selected from hydrogen, C1-C 10 Alkyl, C3-C 10 Cycloalkyl, C6-C 12 Aryl, C1-C4 alkyl, C6-C 10 Aryl, C6-C 10 Aryl C1-C4 alkyl, hydroxy C6-C 10 Aryl C1-C4 alkyl, carboxyl C1-C4 alkyl, hydroxy C1-C4 alkyl, guanidine C1-C4 alkyl, imidazole C1-C4 alkyl, indolyl C1-C4 alkyl, carbamoyl C1-C4 alkyl, amino C1-C4 alkyl, mercapto C1-C4 alkyl; preferably selected from hydrogen, C1-C6 alkyl, C5-C8 cycloalkyl, C6-C 10 Aryl, C1-C4 alkyl, C6-C 10 Aryl, C6-C 10 Aryl C1-C4 alkyl, hydroxy C6-C 10 Aryl C1-C4 alkyl, carboxyl C1-C4 alkyl, hydroxy C1-C4 alkyl, guanyl C1-C4 alkyl, imidazolyl C1-C4 alkyl, indolyl C1-C4 alkyl, carbamoyl C1-C4 alkyl, amino C1-C4 alkyl, mercapto C1-C4 alkyl, more preferably selected from hydrogen, C1-C4 alkyl, C5-C7 cycloalkyl, phenyl, benzyl, hydroxyphenylmethyl, tolyl, ethylphenyl, xylyl, carboxymethyl, carboxyethyl, hydroxymethyl, hydroxyethyl, guanylpropyl, imidazolylmethyl, indolylmethyl, carbamoylmethyl, carbamoylethyl, aminobutyl, mercaptomethyl; R3 is 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; preferably hydrogen, C1-C6 alkyl; more preferably hydrogen; Or R2 and R3 and the carbon atom to which they are connected together form a C3-C 10 Cycloalkyl, especially C5-C8 cycloalkyl; Z is C1-C 12 Alkylene, preferably C1-C4 alkylene; Alternatively, the amino acid compound is a compound of formula II: Wherein, the definitions of R1 and R2 are the same as those in Formula I; Alternatively, the amino acid compound is a compound of the following formula III: Wherein, the definition of R1 is the same as that in Formula I; Alternatively, the amino acid compound is a natural amino acid or a modified natural amino acid; In particular, the natural amino acid is one or more selected from glycine, threonine, tyrosine, aspartic acid, glutamic acid, arginine, histidine, serine, valine, leucine, isoleucine, tert-leucine, alanine, phenylalanine, asparagine, tryptophan, glutamine, lysine, γ-aminobutyric acid, and cysteine; the modified natural amino acid is one or more selected from N-ethylaspartic acid, N-propylaspartic acid, N-sec-butylaspartic acid, N-isobutylaspartic acid, N-cyclopentaneaspartic acid, and N-2-ethylhexylaspartic acid.

3. The method according to claim 1 or 2, wherein: The silane coupling agent is shown in the following formula IV: Wherein, R4, R5 and R6 are each independently selected from C1-C4 alkyl and C1-C4 alkoxy, and at least one is an alkoxy; preferably, each independently selected from C1-C2 alkyl and C1-C2 alkoxy, and at least one is an alkoxy; R7 is selected from halogen (especially Cl, bromine and iodine), epoxy, epoxymethoxy and isocyanate; n is an integer from 1 to 8; Alternatively, the silane coupling agent is selected from epoxy silane, halogen silane, isocyanate silane; In particular, the epoxysilane is selected from 3-(2,3-epoxypropoxy)propyltrimethoxysilane, 5,6-epoxyhexyltriethoxysilane, 3-glycidoxypropylmethyldiethoxysilane, 3-(2,3-epoxypropoxy)propyltrimethoxysilane, 3-glycidoxypropyltriethoxysilane, 3-[(2,3)-epoxypropoxy]propylmethyldimethoxysilane, 3-(2,3-epoxypropoxy)propyltrimethoxysilane, (3-epoxypropoxypropyl)dimethylethoxysilane; The halogen 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, chloromethyldimethylmethoxysilane; The isocyanate silane is selected from 3-isocyanate propyl triethoxy silane, 3-isocyanate propyl trimethoxy silane, 3-isocyanate propyl methyl diethoxy silane, and 3-isocyanate propyl methyl dimethoxy silane.

4. The method according to any one of claims 1 to 3, wherein: The molar ratio of the silane coupling agent to the amino acid compound is 1:0.5-2, or 1:1-1.2; The reaction of the amino acid compound and the silane coupling agent is carried out in an organic solvent, for example, the organic solvent is any one selected from methanol, ethanol, acetonitrile, tetrahydrofuran, and dioxane, and the mass of the organic solvent is 5-20 times, or 10-15 times, that of the compound of formula I; The reaction time of the amino acid compound and the silane coupling agent is 24-72 hours, or 36-48 hours; the reaction temperature is 60-90°C, or 65-80°C.

5. The method according to claim 3 or 4, wherein: The prepared coupling extractant is selected from the following compounds: wherein R1 to R3 are defined as in Formula I in claim 2, and R4 to R6 and n are defined as in Formula IV in claim 3; Or the prepared coupling extractant is selected from the following compounds: wherein R1 and R2 are defined as in Formula I in claim 2, and R4 to R6 and n are defined as in Formula IV in claim 3; Alternatively, the prepared coupling extractant is selected from the following compounds: wherein R1 is defined as in Formula I in claim 2, and R4 to R6 and n are defined as in Formula IV in claim 3.

6. The method according to any one of claims 1 to 5, wherein: In step (2), The silicon spheres have a particle size of 100-200 mesh, and / or 300-500 m 2 / g specific surface area, and / or The mass ratio of the coupling extractant to the silica spheres is 1:0.5-2, for example 1:0.8-1.2; and / or The reaction of the coupling extractant and the silica spheres is carried out in an organic solvent, wherein the organic solvent is selected from any one or more of toluene, xylene, trimethylbenzene, cyclohexane, n-heptane, and isooctane, and / or the mass of the organic solvent is 10-15 times that of the coupling extractant, and / or The reaction temperature of the coupling extractant and the silica sphere is 90-120° C., or 90-110° C., and / or the reaction time is 1-100 h, such as 24-72 h, or 48-72 h; and / or Step (2) also includes a purification step. The purification step includes saponifying the obtained reaction product, then washing it with deionized water and ethanol respectively, and drying it to obtain the modified silicon sphere.

7. A modified silicon sphere obtained by the method according to any one of claims 1 to 6.

8. Use of the modified silica spheres according to claim 7 as a solid phase extractant for separating yttrium from lanthanide elements.

9. Use of the modified silicon spheres according to claim 7 as a solid phase extractant for preparing an extraction system for separating yttrium from lanthanide elements in a rare earth element solution.

10. Use of the modified silica spheres according to claim 7 as a solid phase extractant for separating lanthanide elements.

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