Boron adsorption resin and preparation method thereof and method for extracting boron from salt lake brine

Abstract

The present application relates to a boron adsorption resin and a preparation method thereof and a method for extracting boron from salt lake brine. The preparation method of the boron adsorption resin comprises the following steps: mixing a catechol compound having a structure as shown in the general formula (III), an inorganic base and a first solvent, performing an alkalization treatment, and preparing a precursor; mixing a macroporous resin having a structure as shown in the general formula (II), a second solvent, a catalyst and the precursor, performing an N-alkylation reaction, and preparing an intermediate; acidifying the intermediate to prepare a boron adsorption resin. The preparation method can obtain a boron adsorption resin with high yield, high purity and high adsorption capacity.

Description

Technical Field

[0001] The present application relates to the technical field of salt lake brine treatment, and in particular to a boron adsorption resin and a preparation method thereof, and a method for extracting boron from salt lake brine. Background Art

[0002] Most of the boron in nature exists in boron magnesium ore and salt lake brine, which is an important source for the production of boric acid. Among them, the mining process of boron magnesium ore is cumbersome and complicated, the production cost is high, and its storage capacity has dropped sharply, which limits the development of the boric acid industry. Salt lake brine is rich in high-value elements such as potassium, magnesium, boron, lithium, and strontium. It is a liquid boron ore with great development potential and has become the main way to produce boric acid.

[0003] The main methods for extracting boron from salt lake brine include precipitation, oxide adsorption, membrane separation and ion exchange. Among them, the precipitation method requires a large amount of precipitant, and there is loss in the precipitation separation process, resulting in incomplete separation, so the recovery rate of boron is low; the adsorption capacity of the oxide adsorbent used in the oxide adsorption method will decrease after long-term use, and regeneration is more time-consuming; the membrane separation method uses a selective semipermeable membrane as the separation medium, and adjusts the driving force such as pressure, potential or concentration on both sides of the membrane to achieve boron extraction, but the membrane separation method is greatly affected by the solution parameters and the maintenance cost is also high; the ion exchange method uses the complex reaction between the adsorption resin and boric acid to achieve the purpose of extracting boron, which has the advantages of high removal efficiency and simple operation. However, the low adsorption capacity of traditional boron adsorption resins restricts the industrial development of boron extraction from salt lake brine. Summary of the invention

[0004] Based on this, it is necessary to provide a boron adsorption resin and a preparation method thereof and a method for extracting boron from salt lake brine to solve the problem that the adsorption capacity of traditional boron adsorption resins is low, which restricts the industrial development of boron extraction from salt lake brine.

[0005] The above-mentioned purpose of the present application is achieved through the following technical solutions:

[0006] In a first aspect of the present application, a method for preparing a boron adsorption resin is provided, comprising the following steps:

[0007] Mixing a catechol compound having a structure as shown in the general formula (I), an inorganic base and a first solvent, and performing an alkalization treatment to prepare a precursor;

[0008] Mixing a macroporous resin having a structure as shown in the general formula (II), a second solvent, a catalyst and the precursor, and performing an N-alkylation reaction to prepare an intermediate;

[0009] acidifying the intermediate to prepare a boron adsorption resin;

[0010] (I); (II);

[0011] wherein R1 is absent or is selected from one of substituted or unsubstituted alkylene, substituted or unsubstituted alkenylene, substituted or unsubstituted alkynylene and substituted or unsubstituted alkyleneoxy;

[0012] R2 is selected from one of H, substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl and substituted or unsubstituted aryl;

[0013] n is a positive integer, and X is a halogen.

[0014] In one embodiment, the catechol compound includes one or more of dopamine hydrochloride, dopamine hydrobromide, 4-[(methylamino)methyl]catechol hydrobromide and 4-[(ethylamino)methyl]catechol hydrobromide.

[0015] In one embodiment, the inorganic base includes one or more of NaOH, KOH, LiOH, Ba(OH)2, Na2CO3 and NaHCO3.

[0016] In one embodiment, mixing a catechol compound having a structure as shown in the general formula (I), an inorganic base and a first solvent comprises the following steps:

[0017] The inorganic base and the first solvent are mixed to prepare an alkaline solution, and the catechol compound is added to the alkaline solution.

[0018] In one embodiment, one or more of the following conditions are met:

[0019] (1) The molar ratio of the catechol compound to the inorganic base is 1:(1-1.2);

[0020] (2) The mass fraction of the catechol compound in the phenol solution is 95% to 99%;

[0021] (3) The mass fraction of the inorganic base in the alkaline solution is 4% to 8%;

[0022] (4) The alkalization treatment time is 2h~6h.

[0023] In one embodiment, mixing a macroporous resin having a structure as shown in general formula (II), a second solvent, a catalyst and the precursor comprises the following steps:

[0024] The macroporous resin and the second solvent are mixed, subjected to swelling treatment, and the precursor and the catalyst are added.

[0025] In one embodiment, one or more of the following conditions are met:

[0026] (1) The second solvent includes one or more of N,N-dimethylformamide, N,N-dimethylacetamide, tetrahydrofuran, methanol and ethanol;

[0027] (2) The mass ratio of the macroporous resin to the second solvent is 1:(2-6);

[0028] (3) The temperature of the swelling treatment is 20°C to 40°C;

[0029] (4) The swelling treatment time is 1h~6h.

[0030] In one embodiment, one or more of the following conditions are met:

[0031] (1) The catalyst comprises one or more of a halide and a noble metal;

[0032] (2) The mass ratio of the macroporous resin to the catalyst is 1:(0.05-0.1);

[0033] (3) The mass ratio of the macroporous resin to the precursor is 1:(2-5);

[0034] (4) The temperature of the N-alkylation reaction is 30°C to 140°C;

[0035] (5) The N-alkylation reaction time is 6 h to 24 h.

[0036] In one embodiment, the acid solution used in the acidification treatment includes one or more of an aqueous solution of HCl, an aqueous solution of H2SO4 and an aqueous solution of HNO3.

[0037] In one embodiment, one or more of the following conditions are met:

[0038] (1) The mass ratio of the intermediate to the acid solution is 1:(1-1.5);

[0039] (2) The mass fraction of the acid in the acid solution is 5% to 20%;

[0040] (3) The acidification treatment time is 2h~6h.

[0041] In a second aspect of the present application, a boron adsorption resin is provided, which is prepared by the method for preparing the boron adsorption resin as described above.

[0042] In one embodiment, the adsorption capacity of the boron adsorption resin is ≥2.1 mg / g.

[0043] In one embodiment, the porosity of the boron adsorption resin is 65% to 75%.

[0044] In one embodiment, the particle size of the boron adsorption resin is 0.3 mm to 1.1 mm.

[0045] In a third aspect of the present application, a method for extracting boron from salt lake brine is provided, comprising the following steps:

[0046] The salt lake brine is subjected to adsorption treatment using the boron adsorption resin as described above.

[0047] This application has the following beneficial effects:

[0048] The present application uses a catechol compound having a structure as shown in the general formula (I) and a macroporous resin having a structure as shown in the general formula (II) as raw materials. The imino group (-NH-) in the catechol compound can undergo an N-alkylation reaction with the halomethyl group (-CH2-X) of the macroporous resin, thereby obtaining a boron adsorption resin containing a polyhydroxyl functional group. Thanks to the highly rigid benzene ring structure, the phenolic hydroxyl groups in the boron adsorption resin are all in a cis-ortho structure, and can undergo a chelation reaction with boric acid to form a stable monocyclic or bicyclic chelate, so that the adsorption capacity is significantly improved. At the same time, the preparation method realizes the protection and deprotection of the phenolic hydroxyl group by the alkalization treatment before the N-alkylation reaction and the acidification treatment after the N-alkylation reaction, prevents the phenolic hydroxyl group from affecting the pH, and reduces the occurrence of side reactions, thereby obtaining a boron adsorption resin with high yield, high purity and high adsorption capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Figure 1 The synthetic route of the boron adsorption resin of Example 1;

[0050] Figure 2 This is the infrared spectrum of product A in Example 1;

[0051] Figure 3 is a curve diagram showing the adsorption capacity of product A of Example 1 as a function of adsorption time;

[0052] Figure 4 This is a relationship diagram between the regeneration times and the boron adsorption rate of product A in Example 1. DETAILED DESCRIPTION

[0053] In order to make the above-mentioned purposes, features and advantages of the present application more obvious and easy to understand, the specific implementation methods of the present application are described in detail below. In the following description, many specific details are set forth to facilitate a full understanding of the present application. However, the present application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar improvements without violating the connotation of the present application, so the present application is not limited by the specific embodiments disclosed below.

[0054] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of this application, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0055] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific embodiments and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0056] Unless otherwise specified or incompatible herewith, the terms and phrases used herein shall have the following meanings:

[0057] "Alkyl" refers to a monovalent residue formed by the loss of a hydrogen atom from a saturated hydrocarbon containing a primary (normal) carbon atom, a secondary carbon atom, a tertiary carbon atom, a quaternary carbon atom, or a combination thereof.

[0058] "Alkoxy" refers to a group of the structure -O-alkyl, ie, an alkyl group as defined above attached to the adjacent group via an oxygen atom.

[0059] "Alkenyl" refers to a group containing at least one unsaturated site, i.e., a carbon-carbon sp 2 A monovalent residue formed by a hydrogen atom on a double-bonded positive carbon atom, secondary carbon atom, tertiary carbon atom or ring carbon atom of a hydrocarbon.

[0060] "Alkynyl" refers to a monovalent radical derived from a hydrocarbon containing a normal, secondary, tertiary or cyclic carbon atom having at least one unsaturated site, ie, a carbon-carbon sp triple bond, resulting from the loss of a hydrogen atom.

[0061] "Aryl" refers to an aromatic hydrocarbon group derived from an aromatic ring compound by removing a hydrogen atom, and can be a monocyclic aromatic group, a condensed aromatic group, or a polycyclic aromatic group. For polycyclic rings, at least one is an aromatic ring system. Suitable examples include, but are not limited to, benzene, biphenyl, naphthalene, anthracene, phenanthrene, pyrene, perylene, triphenylene, and their derivatives.

[0062] "Alkylene" refers to a hydrocarbon group with two monovalent radical centers derived from an alkyl group by removing a hydrogen atom, which may be a saturated branched alkyl group or a saturated straight chain alkyl group. Suitable examples include, but are not limited to, methylene (-CH2-), 1,1-ethyl (-CH(CH3)-), 1,2-ethyl (-CH2CH2-), 1,1-propyl (-CH(CH2CH3)-), 1,2-propyl (-CH2CH(CH3)-), 1,3-propyl (-CH2CH2CH2-)) and 1,4-butyl (-CH2CH2CH2CH2-).

[0063] "Alkyleneoxy" refers to a group of the structure -O-alkylene-, ie, an alkylene group as defined above attached to the adjacent group through an oxygen atom.

[0064] "Alkenylene" refers to a hydrocarbon group having two monovalent radical centers derived from an alkenyl group by removing a hydrogen atom, which may be an unsaturated branched hydrocarbon group or an unsaturated straight chain hydrocarbon group. Suitable examples include, but are not limited to, 1,2-vinyl (-CH=CH-).

[0065] "Alkyne" refers to a hydrocarbon group having two monovalent radical centers derived from an alkynyl group by removing a hydrogen atom, which may be an unsaturated branched hydrocarbon group or an unsaturated straight hydrocarbon group. Suitable examples include, but are not limited to, ethynyl (-C≡C-), propargyl (-CH2C≡C-) and 4-pentynyl (-CH2CH2CH2C≡C-).

[0066] "Halogen" or "halo" refers to F, Cl, Br or I.

[0067] "Substitution" means that a hydrogen atom in the substituted group is replaced by a substituent.

[0068] "Substituted or unsubstituted" means that the defined group may be substituted or unsubstituted. When the defined group is substituted, it should be understood that the defined group may be substituted by one or more substituents R.

[0069] In the present application, when a substituent with the same symbol appears multiple times, each substituent may be the same or different from each other. For example, when a general formula contains multiple R, R may be the same or different from each other.

[0070] In the present application, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0071] In this application, when it comes to numerical ranges, unless otherwise specified, the above numerical ranges are deemed to be continuous and include the minimum and maximum values ​​of the range, as well as each value between such minimum and maximum values. Further, when a range refers to an integer, each integer between the minimum and maximum values ​​of the range is included. In addition, when multiple ranges are provided to describe features or characteristics, the ranges can be merged. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges included therein.

[0072] The percentage contents involved in this application, unless otherwise specified, refer to mass percentage for solid-liquid mixture and solid-solid mixture, and refer to volume percentage for liquid-liquid mixture.

[0073] The temperature parameters in this application, unless otherwise specified, allow for both constant temperature treatment and treatment within a certain temperature range. The constant temperature treatment allows the temperature to fluctuate within the accuracy range of instrument control.

[0074] Boron exists in salt lake brine mainly in the form of boric acid (B(OH)3); boric acid is a weak acid and will hydrolyze to form B(OH)4 - In addition, boric acid can also polymerize to form polyborate ions, such as the most common tetraborate ion (B4O7 2- ). Boric acid can be complexed with cis-ortho-dihydroxyl or cis-meta-dihydroxyl to form a five-membered or six-membered monocyclic chelate, and the monocyclic chelate can continue to complex to form a corresponding bicyclic chelate, thereby achieving the purpose of boron extraction. Boron adsorption resins usually contain polyhydroxyl functional groups, so they can selectively adsorb boric acid. For example, the boron-specific adsorption resin Amberlite IRA 743 prepared from chlorinated balls and N-methylglucamine contains polyhydroxyl functional groups. However, traditional boron adsorption resins often find it difficult to ensure that all hydroxyl groups are in a high-energy cis conformation, that is, there are some hydroxyl functional groups that cannot undergo complexation reactions. Therefore, the adsorption capacity of these boron adsorption resins is low, which restricts the application of boron adsorption resins in boron extraction from salt lake brines.

[0075] Based on this, in the first aspect of the present application, a method for preparing a boron adsorption resin is provided to solve the problem that the adsorption capacity of traditional boron adsorption resins is low, which restricts the industrial development of boron extraction from salt lake brine.

[0076] In some embodiments, the method for preparing a boron adsorption resin comprises the following steps:

[0077] Mixing a catechol compound having a structure as shown in the general formula (I), an inorganic base and a first solvent, and performing an alkalization treatment to prepare a precursor;

[0078] A macroporous resin having a structure as shown in the general formula (II), a second solvent, a catalyst and a precursor are mixed and subjected to an N-alkylation reaction to prepare an intermediate;

[0079] Acidifying the intermediate to prepare boron adsorption resin;

[0080] (I); (II);

[0081] wherein R1 is absent or is selected from one of substituted or unsubstituted alkylene, substituted or unsubstituted alkenylene, substituted or unsubstituted alkynylene and substituted or unsubstituted alkyleneoxy;

[0082] R2 is selected from one of H, substituted or unsubstituted alkyl, substituted or unsubstituted alkoxy, substituted or unsubstituted alkenyl, substituted or unsubstituted alkynyl and substituted or unsubstituted aryl;

[0083] n is a positive integer, and X is a halogen.

[0084] The present application uses a catechol compound having a structure as shown in the general formula (I) and a macroporous resin having a structure as shown in the general formula (II) as raw materials. The imino group (-NH-) in the catechol compound can undergo an N-alkylation reaction with the halomethyl group (-CH2-X) of the macroporous resin, thereby obtaining a boron adsorption resin containing a polyhydroxyl functional group. Thanks to the highly rigid benzene ring structure, the phenolic hydroxyl groups in the boron adsorption resin are all in a cis-ortho structure, and can undergo a chelation reaction with boric acid to form a stable monocyclic or bicyclic chelate, so that the adsorption capacity is significantly improved. At the same time, the preparation method realizes the protection and deprotection of the phenolic hydroxyl group by the alkalization treatment before the N-alkylation reaction and the acidification treatment after the N-alkylation reaction, prevents the phenolic hydroxyl group from affecting the pH, and reduces the occurrence of side reactions, thereby obtaining a boron adsorption resin with high yield, high purity and high adsorption capacity.

[0085] In addition, the preparation method provided by the present application has a simple synthetic route, and the modification and protection of the phenolic hydroxyl group can be achieved without using alkyl substitution and removal, and amino or imino groups can be grafted onto the catechol compound without synthetic means such as amination reaction, so the boron adsorption resin has a high yield and high purity. The raw materials used in the preparation method are cheap and easy to obtain, and the reaction conditions and temperature are green, environmentally friendly, easy to implement, and suitable for industrial application.

[0086] It can be understood that in the structure shown in general formula (II), n is a positive integer, including but not limited to: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 15, 20, 25, 30, 35, 40, 45, 50, 100, 200, 300, 400, 500, 1000.

[0087] Optionally, X is selected from F, Cl, Br or I. Preferably, X is Cl or Br. More preferably, X is Cl. It can be understood that in the structure shown in the general formula (II), when X is Cl, the macroporous resin is a chlorine ball. Among the styrene-based adsorption resins, styrene-divinylbenzene copolymers are called white balls; the white balls are subjected to a chloromethylation reaction to introduce a -CH2Cl active group into the adsorption resin, and the styrene-based adsorption resin with a -CH2Cl active group is called a chlorine ball.

[0088] Optionally, R1 is absent or selected from one of a substituted or unsubstituted alkylene group having 1 to 8 C atoms, a substituted or unsubstituted alkyleneoxy group having 1 to 8 C atoms, a substituted or unsubstituted alkenylene group having 1 to 8 C atoms, and a substituted or unsubstituted alkynylene group having 1 to 8 C atoms. Further optionally, R1 is selected from one of methylene (-CH2-), 1,1-ethyl (-CH(CH3)-), 1,2-ethyl (-CH2CH2-), 1,1-propyl (-CH(CH2CH3)-), 1,2-propyl (-CH2CH(CH3)-), 1,3-propyl (-CH2CH2CH2-)), 1,4-butyl (-CH2CH2CH2CH2-), methyleneoxy (-O-CH2-) and ethyleneoxy (-O-CH2CH2-). Preferably, R1 is one or more of methylene (—CH2—), 1,1-ethyl (—CH(CH3)—), and 1,2-ethyl (—CH2CH2—).

[0089] Optionally, R2 is selected from one of H, halogen, substituted or unsubstituted alkyl having 1 to 8 C atoms, substituted or unsubstituted alkoxy having 1 to 8 C atoms, substituted or unsubstituted alkenyl having 1 to 8 C atoms, substituted or unsubstituted alkynyl having 1 to 8 C atoms and substituted or unsubstituted aryl having 6 to 8 C atoms. Further optionally, R2 is selected from one of H, halogen, methyl (-CH3), ethyl (-CH2CH3), 1-propyl (-CH2CH2CH3), 2-propyl (-CH(CH3)2), 1-butyl (-CH2CH2CH2CH3), 2-methyl-1-propyl (-CH2CH(CH3)2), 2-butyl (CH(CH3)CH2CH3), 2-methyl-2-propyl (-C(CH3)3), octyl (-(CH2)7CH3), methoxy (-O-CH3), ethoxy (-O-CH2CH3), tert-butoxy (-OC(CH3)3) and phenyl. Preferably, R2 is one or more of methyl (-CH3) and ethyl (-CH2CH3).

[0090] It can be understood that in the structure shown in general formula (I), "-R1-NH-R2" can be located at the ortho position or the meta position of the phenolic hydroxyl group. Preferably, "-R1-NH-R2" is located at the meta position of the phenolic hydroxyl group.

[0091] It can be understood that in the structure shown in the general formula (I), "·HX" indicates that it is a hydrohalide salt of an organic substance, including but not limited to: hydrofluoride, hydrochloride (or hydrochloride), hydrobromide, and hydroiodide.

[0092] Optionally, the catechol compound includes one or more of dopamine hydrochloride, dopamine hydrobromide, 4-[(methylamino)methyl]catechol hydrobromide and 4-[(ethylamino)methyl]catechol hydrobromide. Preferably, the catechol compound includes one or more of dopamine hydrochloride, dopamine hydrobromide and 4-[(methylamino)methyl]catechol hydrobromide. More preferably, the catechol compound includes one or more of dopamine hydrochloride and dopamine hydrobromide.

[0093] Dopamine hydrochloride and dopamine hydrobromide have a structure as shown in the general formula (III), that is, R1 is 1,2-ethyl (-CH2CH2-), R2 is H, and X is Cl or Br. The boron adsorption resin prepared using dopamine hydrochloride or dopamine hydrobromide as a raw material has a structure as shown in the general formula (IV), which is a polystyrene-based adsorption resin with a catechol functional group grafted on the side chain, and the polystyrene-based main chain and the catechol functional group are connected by -CH2CH2-. Compared with the structure in which R1 does not exist or is -CH2-, the side chain molecular chain of the structure shown in the general formula (IV) is longer, the intermolecular force is stronger, the structure is more stable, and the selective adsorption effect of boron is better.

[0094] (III); (IV).

[0095] Optionally, the inorganic base includes one or more of NaOH, KOH, LiOH, Ba(OH)2, Na2CO3 and NaHCO3. Preferably, the inorganic base includes one or more of NaOH, KOH, LiOH and Ba(OH)2. The strong base can be used to alkalize the phenolic hydroxyl groups in the catechol compound, effectively preventing the phenolic hydroxyl groups from participating in the side reaction.

[0096] In some embodiments, mixing a catechol compound having a structure as shown in general formula (I), an inorganic base and a first solvent comprises the following steps:

[0097] An inorganic base and a first solvent are mixed to prepare an alkaline solution, and a catechol compound is added to the alkaline solution.

[0098] Optionally, the first solvent includes one or more of methanol, ethanol and isopropanol.

[0099] Optionally, the molar ratio of the catechol compound to the inorganic base is 1:(1-1.2), including but not limited to: 1:1, 1:1.05, 1:1.1, 1:1.15, 1:1.2.

[0100] Optionally, the purity of the catechol compound is 95% to 99%.

[0101] Optionally, the mass fraction of the inorganic base in the alkaline solution is 4% to 8%, including but not limited to: 4%, 5%, 6%, 7%, and 8%.

[0102] Optionally, the alkalization treatment time is 2h~6h, including but not limited to: 2h, 3h, 4h, 5h, 6h.

[0103] In some embodiments, mixing a macroporous resin having a structure as shown in general formula (I), a second solvent, a precursor and a catalyst comprises the following steps:

[0104] The macroporous resin and the second solvent are mixed, subjected to swelling treatment, and the precursor and the catalyst are added.

[0105] It can be understood that swelling refers to the phenomenon that the volume of a high molecular polymer (such as a macroporous resin, etc.) expands in a solvent. Swelling the macroporous resin in the first solvent can make the molecular structure of the macroporous resin loose, and the precursor can easily enter the interior of the chlorine ball to react, thereby accelerating the reaction rate and improving the reaction uniformity.

[0106] Optionally, the second solvent includes one or more of N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), tetrahydrofuran (THF), methanol (MeOH) and ethanol (EtOH); preferably, the second solvent includes one or more of N,N-dimethylacetamide (DMAc) and tetrahydrofuran (THF). It is understood that the second solvent does not react with the macroporous resin, precursor or catalyst, and the amount of the second solvent is determined by factors such as reaction time, reaction temperature, type of solvent, type of raw material and reaction scale.

[0107] Optionally, the mass ratio of the macroporous resin to the second solvent is 1:(2-6), including but not limited to: 1:2, 1:2.5, 1:3, 1:3.5, 1:4, 1:4.5, 1:5, 1:5.5, 1:6.

[0108] Optionally, the temperature of the swelling reaction is 20°C to 40°C, including but not limited to: 20°C, 22°C, 24°C, 26°C, 28°C, 30°C, 32°C, 34°C, 36°C, 38°C, 40°C.

[0109] Optionally, the swelling reaction time is 1 h to 6 h, including but not limited to: 1 h, 2 h, 3 h, 4 h, 5 h, 6 h. Preferably, the swelling reaction time is 1 h to 3 h.

[0110] Optionally, the catalyst includes one or more of halides and noble metals. Among them, the halides include one or more of fluorides, chlorides, bromides and iodides, preferably iodides, such as potassium iodide (KI) and sodium iodide (NaI); the noble metals include one or more of gold, silver, ruthenium, rhodium, palladium, osmium, iridium and platinum, preferably platinum. More preferably, the catalyst is KI.

[0111] Optionally, the mass ratio of the macroporous resin to the catalyst is 1:(0.05-0.1), including but not limited to: 1:0.05, 1:0.06, 1:0.07, 1:0.08, 1:0.09, 1:0.1.

[0112] Optionally, the mass ratio of the macroporous resin to the precursor is 1:(2-5), including but not limited to: 1:2, 1:3, 1:4, 1:5.

[0113] Optionally, the temperature of the N-alkylation reaction is 30° C. to 140° C., including but not limited to: 30° C., 40° C., 50° C., 60° C., 70° C., 80° C., 90° C., 100° C., 110° C., 120° C., 130° C., 140° C. Preferably, the temperature of the N-alkylation reaction is 40° C. to 80° C.

[0114] Optionally, the N-alkylation reaction time is 6 h to 24 h, including but not limited to: 6 h, 7 h, 8 h, 9 h, 10 h, 11 h, 12 h, 13 h, 14 h, 15 h, 16 h, 17 h, 18 h, 19 h, 20 h, 21 h, 22 h, 23 h, 24 h. Preferably, the N-alkylation reaction time is 12 h to 18 h.

[0115] Optionally, the rotation speed of the N-alkylation reaction is 220 rpm to 400 rpm, including but not limited to: 220 rpm, 250 rpm, 280 rpm, 300 rpm, 320 rpm, 350 rpm, 380 rpm, 400 rpm.

[0116] In some embodiments, the acid solution used in the acidification treatment includes one or more of an aqueous solution of HCl, an aqueous solution of H2SO4, and an aqueous solution of HNO3. Preferably, the acid solution used in the acidification treatment is an aqueous solution of HCl, i.e., a hydrochloric acid solution.

[0117] Optionally, the mass ratio of the intermediate to the acid solution is 1:(1-1.5), including but not limited to: 1:1, 1:1.1, 1:1.2, 1:1.3, 1:1.4, 1:1.5;

[0118] Optionally, the mass fraction of the acid in the acid solution is 5% to 20%, including but not limited to: 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%. Preferably, the mass fraction of the acid in the acid solution is 8% to 12%.

[0119] Optionally, the acidification treatment time is 2h~6h, including but not limited to: 2h, 3h, 4h, 5h, 6h.

[0120] In some embodiments, after the alkalization treatment, after the N-alkylation reaction, and after the acidification treatment, a purification step is further included independently.

[0121] Optionally, the purification treatment includes one or more of filtration treatment, washing treatment, drying treatment and distillation treatment. Among them, the filtration treatment includes one or more of normal pressure filtration treatment and reduced pressure suction filtration treatment; the washing liquid of the washing treatment includes one or more of distilled water, reverse osmosis water, pure water, ultrapure water, methanol, ethanol and acetone; the temperature of the drying treatment is 40℃~80℃; the distillation treatment includes one or more of normal pressure distillation treatment and reduced pressure distillation treatment.

[0122] In a second aspect of the present application, a boron adsorption resin is provided, which is prepared by the method for preparing the boron adsorption resin as described above.

[0123] Optionally, the adsorption capacity of the boron adsorption resin is ≥2.1 mg / g, including but not limited to: 2.1 mg / g, 2.3 mg / g, 2.5 mg / g, 2.8 mg / g, 3 mg / g, 3.2 mg / g, 3.5 mg / g, 3.8 mg / g, 4 mg / g.

[0124] It is understandable that the adsorption capacity of boron adsorption resin will be affected by the boron content in the solution system, and the existence form of boron will also be affected by the boron content in the solution system. Boron in solution systems such as boron-containing wastewater and salt lake brine can usually be expressed as "B4O7 2- " is expressed in the form of comprehensive statistics. The test conditions for the adsorption capacity of the above-mentioned boron adsorption resin are: the boron-containing wastewater is adsorbed by the boron adsorption resin, and then the B4O7 of the boron-containing wastewater before and after the adsorption treatment is tested by ICP-MS. 2- The change of content can be used to calculate the boron adsorption resin at a certain B4O7 2- content and adsorption capacity under a certain adsorption time.

[0125] In some specific embodiments, the B4O7 of the boron-containing wastewater 2- When the content is 200ppm and the adsorption time is 4h, the adsorption capacity of the boron adsorption resin is ≥2.1mg / g.

[0126] Optionally, the porosity of the boron adsorption resin is 65% to 75%, including but not limited to: 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, and 75%.

[0127] Optionally, the particle size of the boron adsorption resin is 0.3 mm to 1.1 mm, including but not limited to: 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1.0 mm, and 1.1 mm.

[0128] In a third aspect of the present application, a method for extracting boron from salt lake brine is provided, comprising the following steps:

[0129] The salt lake brine is subjected to adsorption treatment using the boron adsorption resin as described above.

[0130] Optionally, the mass volume ratio of the boron adsorption resin to the salt lake brine is 5g / L~500g / L, including but not limited to: 5g / L, 10g / L, 20g / L, 50g / L, 80g / L, 100g / L, 150g / L, 200g / L, 250g / L, 300g / L, 350g / L, 400g / L, 450g / L, 500g / L.

[0131] Optionally, the pH of the adsorption treatment is 6 to 10, including but not limited to: 6, 6.5, 7, 7.5, 8, 8.5, 9, 9.5, 10. Compared with traditional boron adsorption resins, the boron adsorption resin prepared in the present application is applicable to a wider pH range, and can be applied to the boron extraction treatment of different salt lakes such as chloride salt lakes, sulfate salt lakes and carbonate salt lakes, with good economic and environmental benefits.

[0132] Optionally, the temperature of the adsorption treatment is 25°C~50°C, including but not limited to: 25°C, 30°C, 35°C, 40°C, 45°C, 50°C.

[0133] Optionally, the flow rate of the adsorption treatment is 5BV / h~15BV / h, including but not limited to: 5BV / h, 6BV / h, 7BV / h, 8BV / h, 9BV / h, 10BV / h, 11BV / h, 12BV / h, 13BV / h, 14BV / h, 15BV / h.

[0134] It can be understood that the time of adsorption treatment takes into account the content of each component of salt lake brine, the treatment amount of salt lake brine, the amount of boron adsorption resin, the temperature and flow rate of adsorption treatment, etc. Optionally, the time of adsorption treatment is 0.5h~5h, including but not limited to: 0.5h, 1h, 2h, 3h, 4h, 5h.

[0135] The present application is further described in detail below in conjunction with specific embodiments.

[0136] In the following specific examples and comparative examples, the raw materials used, unless otherwise specified, are all commercially available products; the instruments used, unless otherwise specified, are all commercially available products; the processes used, unless otherwise specified, are all conventionally selected by those skilled in the art. Among them, the chlorine balls were purchased from Wandong High-Tech (Tianchang) Co., Ltd., with a brand number of LQ117.

[0137] Example 1

[0138] See also Figure 1 , which is the synthesis route of the boron adsorption resin of this embodiment. Among them, compound 11 is a chlorine ball (i.e., a macroporous resin), compound 12 is a precursor, compound 13 is an intermediate, and compound 14 is a boron adsorption resin, i.e., product A prepared in this embodiment.

[0139] The preparation method of the boron adsorption resin of this embodiment is as follows:

[0140] (1) According to the molar ratio of dopamine hydrochloride to NaOH being 1:1, dopamine hydrochloride is added to an 8% by mass NaOH aqueous solution, and the mixture is immersed for 2 hours for alkalization treatment, filtered, and the obtained filter residue is dried at 80° C. to obtain a precursor.

[0141] (2) Take 50 mL of N,N-dimethylformamide (DMAc), add 20 g of chlorine balls, control the speed to 400 rpm, raise the temperature to 40 °C, and perform swelling treatment for 2 h to obtain a mixed solution containing chlorine balls.

[0142] (3) Add 50 g of the precursor and 1 g of the catalyst KI to the mixed solution containing the chlorine balls, raise the temperature to 66 °C, and carry out N-alkylation reaction under reflux conditions for 16 h. Filter and wash the resulting residue with ethanol and pure water in turn, and dry at 60 °C to obtain an intermediate.

[0143] (4) The intermediate was added to a 10% hydrochloric acid solution in a mass ratio of 1:1, and the mixture was immersed for 4 h for acidification. The residue was filtered and washed with pure water and dried at 80°C to obtain a boron adsorption resin, which was recorded as product A.

[0144] Example 2

[0145] The preparation method of the boron adsorption resin of this embodiment is as follows:

[0146] (1) According to the molar ratio of dopamine hydrochloride to NaOH being 1:1, dopamine hydrochloride is added to an 8% by mass NaOH aqueous solution, and the mixture is immersed for 2 hours for alkalization treatment, filtered, and the obtained filter residue is dried at 80° C. to obtain a precursor.

[0147] (2) Take 50 mL of tetrahydrofuran (THF), add 20 g of chlorine balls, control the rotation speed to 400 rpm, raise the temperature to 40°C, and perform swelling treatment for 2 hours to obtain a mixed solution containing chlorine balls.

[0148] (3) Add 50 g of the precursor and 1 g of the catalyst KI to the mixed solution containing the chlorine balls, raise the temperature to 80 °C, and carry out N-alkylation reaction under reflux conditions for 18 h. Filter and wash the resulting residue with ethanol and pure water in turn, and dry at 60 °C to obtain an intermediate.

[0149] (4) The intermediate was added to a 10% hydrochloric acid solution in a mass ratio of 1:1, and the mixture was immersed for 4 h for acidification. The residue was filtered and washed with pure water and dried at 80°C to obtain a boron adsorption resin, which was recorded as product B.

[0150] Example 3

[0151] The preparation method of the boron adsorption resin of this embodiment is as follows:

[0152] (1) According to the molar ratio of dopamine hydrochloride to KOH being 1:1, dopamine hydrochloride is added to an 8% by mass KOH aqueous solution, and the mixture is immersed for 2 hours for alkalization treatment, filtered, and the obtained filter residue is dried at 80° C. to obtain a precursor.

[0153] (2) Take 50 mL of tetrahydrofuran (THF), add 20 g of chlorine balls, control the rotation speed to 400 rpm, raise the temperature to 40°C, and perform swelling treatment for 2 hours to obtain a mixed solution containing chlorine balls.

[0154] (3) Add 50 g of the precursor and 1 g of the catalyst KI to the mixed solution containing the chlorine balls, raise the temperature to 66 °C, and carry out N-alkylation reaction under reflux conditions for 16 h. Filter and wash the resulting residue with ethanol and pure water in turn, and dry at 60 °C to obtain an intermediate.

[0155] (4) The intermediate was added to a 10% hydrochloric acid solution in a mass ratio of 1:1, and the mixture was immersed for 4 h for acidification. The residue was filtered and washed with pure water and dried at 80°C to obtain a boron adsorption resin, which was recorded as product C.

[0156] Example 4

[0157] The preparation method of the boron adsorption resin of this embodiment is as follows:

[0158] (1) According to the molar ratio of dopamine hydrochloride to KOH being 1:1, dopamine hydrochloride is added to an 8% by mass KOH aqueous solution, and the mixture is immersed for 2 hours for alkalization treatment, filtered, and the obtained filter residue is dried at 80° C. to obtain a precursor.

[0159] (2) Take 50 mL of tetrahydrofuran (THF), add 20 g of chlorine balls, control the rotation speed to 400 rpm, raise the temperature to 40°C, and perform swelling treatment for 2 hours to obtain a mixed solution containing chlorine balls.

[0160] (3) Add 40 g of the precursor and 1 g of the catalyst KI to the mixed solution containing the chlorine balls, raise the temperature to 66 °C, and carry out N-alkylation reaction under reflux conditions for 16 h. Filter and wash the resulting filter residue with ethanol and pure water in turn, and dry at 60 °C to obtain an intermediate.

[0161] (4) The intermediate was added to a 10% hydrochloric acid solution in a mass ratio of 1:1, and the mixture was immersed for 4 h for acidification. The residue was filtered and washed with pure water and dried at 80°C to obtain a boron adsorption resin, which was recorded as product D.

[0162] Example 5

[0163] The preparation method of the boron adsorption resin of this embodiment is as follows:

[0164] (1) According to the molar ratio of 4-[(methylamino)methyl]catechol hydrobromide to KOH being 1:1, 4-[(methylamino)methyl]catechol hydrobromide was added to an 8% by mass KOH aqueous solution, and the mixture was immersed for 2 h for alkalization treatment, filtered, and the obtained filter residue was dried at 80° C. to obtain a precursor.

[0165] (2) Take 50 mL of tetrahydrofuran (THF), add 20 g of chlorine balls, control the rotation speed to 400 rpm, raise the temperature to 40°C, and perform swelling treatment for 2 hours to obtain a mixed solution containing chlorine balls.

[0166] (3) Add 50 g of the precursor and 1 g of the catalyst KI to the mixed solution containing the chlorine balls, raise the temperature to 66 °C, and carry out N-alkylation reaction under reflux conditions for 16 h. Filter and wash the resulting residue with ethanol and pure water in turn, and dry at 60 °C to obtain an intermediate.

[0167] (4) The intermediate was added to a 10% hydrochloric acid solution in a mass ratio of 1:1, and the mixture was immersed for 4 h for acidification. The residue was filtered and washed with pure water and dried at 80°C to obtain a boron adsorption resin, which was recorded as product E.

[0168] Comparative Example 1

[0169] In this comparative example, a commercially available boron adsorption resin (Zhejiang Zhengguang Industrial Co., Ltd., D870B) was selected, and its raw materials were chlorine balls and N-methylglucamine, which was recorded as product F.

[0170] Test Case

[0171] (1) Please refer to Figure 2 , which is the infrared spectrum of product A of Example 1. Among them, at 3150cm -1 ~3050cm -1 The absorption peak at 3350cm indicates that the surface of product A contains -NH2. -1 ~3250cm -1 The absorption peak indicates that the product A has -OH on its surface, which proves that the product A has the structure shown in the general formula (IV).

[0172] (2) Preparation of B4O7 2- For the boron-containing wastewater with a content of 200 ppm, 100 mL of boron-containing wastewater was taken into a conical flask, 10 mL (about 8.3 g) of the product was added, and the conical flask was placed in a constant temperature oscillator for 4 hours to obtain the adsorption waste liquid; it was filtered using a 0.45 μm microfiltration membrane and B4O7 was determined by ICP-MS. 2- The adsorption capacity was calculated and the results are shown in Table 1.

[0173] (3) The adsorption capacity of all products was tested by ICP-MS. The results are shown in Table 1. The curve of the adsorption capacity of product A in Example 1 versus adsorption time is shown in Table 1. Figure 3 As shown. The boron adsorption resin adsorbed to saturation is regenerated using alkali solution, the alkali in the alkali solution is NaOH or KOH, the total volume of the alkali solution is 3BV, the mass fraction of the alkali solution is 5%, the desorption flow rate is 3BV / h, and the desorption temperature is 40°C; the regenerated boron adsorption resin is adsorbed using the method described in step (2), and five regeneration-adsorption cycles are performed continuously. The calculation formula for the boron adsorption rate after each cycle is: η=C e / C o ×100%, η represents the boron adsorption rate, C o represents the adsorption capacity of the first adsorption treatment, C e The relationship between the number of regenerations of product A in Example 1 and the boron adsorption rate is as follows: Figure 4 shown.

[0174] Table 1. Comparison of adsorption performance of various products

[0175]

[0176] * Boron in boron-containing wastewater and salt lake brine is usually expressed as “B4O7 2- ” is expressed in the form of comprehensive statistics.

[0177] As shown in Table 1, product F is a commercially available boron adsorption resin. Under the same adsorption conditions, its adsorption rate for boron oxide compounds is 83.60%, and its adsorption capacity is only 1.83 mg / g, indicating a poor boron adsorption effect.

[0178] Products A~E are all boron adsorption resins containing catechol functional groups. Thanks to the phenolic hydroxyl groups at the cis-ortho positions, their adsorption rates for boron oxide compounds are maintained at 88.85%~97.45% under the same adsorption conditions, and their adsorption capacities are maintained at 2.14mg / g~2.35mg / g, and their boron adsorption performance is significantly improved. Figure 3 It can be seen that the saturated adsorption capacity of product A can reach more than 4.3 mg / g; Figure 4 It can be seen that after 5 adsorption-desorption experiments, the boron adsorption rate of product A decreased from 98% to 90%, and the adsorption performance was relatively stable.

[0179] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0180] The above-described embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of protection of the present application. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the scope of protection of the present application. Therefore, the scope of protection of the present application shall be subject to the attached claims, and the description may be used to interpret the content of the claims.

Claims

1. A method for preparing a boron adsorption resin, characterized in that: The following steps are involved: Mixing a catechol compound having a structure as shown in the general formula (III), an inorganic base and a first solvent, and performing an alkalization treatment to prepare a precursor; Mixing a macroporous resin having a structure as shown in general formula (II), a second solvent, a catalyst and the precursor, and performing an N-alkylation reaction to prepare an intermediate; acidifying the intermediate to prepare a boron adsorption resin; Wherein, n is a positive integer, and X is a halogen; The inorganic base includes one or more of NaOH, KOH, LiOH and Ba(OH)2, the molar ratio of the catechol compound to the inorganic base is 1:(1-1.2), the mass fraction of the inorganic base in the alkaline solution is 4%-8%, and the alkalization treatment time is 2h-6h; The acid solution used in the acidification treatment includes one or more of an aqueous solution of HCl, an aqueous solution of H2SO4 and an aqueous solution of HNO3, the mass ratio of the intermediate to the acid solution is 1:(1-1.5), the mass fraction of the acid in the acid solution is 5%-20%, and the time of the acidification treatment is 2h-6h.

2. The method for preparing a boron adsorption resin according to claim 1, characterized in that: The catechol compound includes one or more of dopamine hydrochloride and dopamine hydrobromide.

3. The method for preparing a boron adsorption resin according to claim 1, characterized in that: The inorganic base is NaOH.

4. The method for preparing a boron adsorption resin according to any one of claims 1 to 3, characterized in that: Mixing a catechol compound having a structure as shown in general formula (III), an inorganic base and a first solvent comprises the following steps: The inorganic base and the first solvent are mixed to prepare an alkaline solution, and the catechol compound is added to the alkaline solution.

5. The method for preparing a boron adsorption resin according to claim 4, characterized in that: The purity of the catechol compound is 95% to 99%.

6. The method for preparing a boron adsorption resin according to any one of claims 1 to 3, characterized in that: Mixing a macroporous resin having a structure as shown in general formula (II), a second solvent, a catalyst and the precursor comprises the following steps: The macroporous resin and the second solvent are mixed, subjected to swelling treatment, and the precursor and the catalyst are added.

7. The method for preparing a boron adsorption resin according to claim 6, characterized in that: One or more of the following conditions are met: (1) the second solvent comprises one or more of N,N-dimethylformamide, N,N-dimethylacetamide, tetrahydrofuran, methanol and ethanol; (2) The mass ratio of the macroporous resin to the second solvent is 1:(2-6); (3) The temperature of the swelling treatment is 20°C to 40°C; (4) The swelling treatment time is 1 h to 6 h.

8. The method for preparing a boron adsorption resin according to claim 7, characterized in that: One or more of the following conditions are met: (1) The catalyst comprises one or more of a halide and a noble metal; (2) The mass ratio of the macroporous resin to the catalyst is 1:(0.05-0.1); (3) The mass ratio of the macroporous resin to the precursor is 1:(2-5); (4) The temperature of the N-alkylation reaction is 30° C. to 140° C.; (5) The N-alkylation reaction time is 6 h to 24 h.

9. A boron adsorption resin, characterized in that: The boron adsorption resin is prepared by the preparation method of the boron adsorption resin according to any one of claims 1 to 8.

10. The boron adsorption resin according to claim 9, characterized in that One or more of the following conditions are met: (1) The adsorption capacity of the boron adsorption resin is ≥2.1 mg / g; (2) The porosity of the boron adsorption resin is 65% to 75%; (3) The particle size of the boron adsorption resin is 0.3 mm to 1.1 mm.

11. A method for extracting boron from salt lake brine, characterized in that: The following steps are involved: The boron adsorption resin as claimed in claim 9 or 10 is used to perform adsorption treatment on salt lake brine.

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