Cesium extracting adsorbent and preparation method thereof and method for extracting cesium from salt lake brine

Abstract

The present invention relates to a cesium extracting adsorbent and a preparation method thereof and a method for extracting cesium from salt lake brine. The preparation method of the cesium extracting adsorbent comprises the following steps: mixing a salt solution A containing heteropoly anions and a salt solution B containing metal cations, allowing the heteropoly anions and the metal cations to undergo a complex reaction to prepare a cesium ion sieve, wherein the metal cations include one or more of titanium ions, zirconium ions, manganese ions, cobalt ions and niobium ions; adding the cesium ion sieve to a mixed solution containing a hydrophilic agent and an adhesive to prepare a slurry; and granulating the slurry to prepare the cesium extracting adsorbent. The cesium extracting adsorbent prepared by the method has a large adsorption capacity and excellent adsorption selectivity, and can achieve effective separation of rubidium and cesium.

Description

Technical Field

[0001] The invention relates to the technical field of adsorption materials, in particular to a cesium-extracting adsorbent and a preparation method thereof, and a method for extracting cesium from salt lake brine. Background Art

[0002] As one of the four rare light metals, cesium is widely used in the fields of materials and energy due to its excellent photoelectric properties, and plays a very important role in economy and strategy. At present, the industrial production of cesium is mainly based on the mining of solid cesium ore, but its extraction process is complicated, the product purity is low and the energy consumption is high. After investigation, it was found that the cesium resources in the salt lake are rich, the cesium element reserves are large, and it has good mining value.

[0003] The main methods for extracting cesium from salt lake brine include precipitation, solvent extraction, adsorption and fractional crystallization. Among them, the adsorption method, also known as the ion exchange method, has become the research focus of cesium extraction from salt lake brine due to its advantages of good selectivity, low cost, simple process and high recovery rate. However, the low adsorption capacity and poor adsorption selectivity of traditional cesium extraction adsorbents have caused great difficulties in the separation and purification of salt lake cesium resources. Summary of the invention

[0004] Based on this, it is necessary to provide a cesium extraction adsorbent and a preparation method thereof and a method for extracting cesium from salt lake brine to solve the problem that traditional cesium extraction adsorbents have low adsorption capacity and poor adsorption selectivity, which cause great difficulties in the separation and purification of salt lake cesium resources.

[0005] The above object of the present invention is achieved through the following technical solutions:

[0006] In a first aspect, the present invention provides a method for preparing a cesium adsorbent, comprising the following steps:

[0007] Mixing a salt solution A containing heteropoly anions and a salt solution B containing metal cations to allow the heteropoly anions and the metal cations to undergo a complex reaction to prepare a cesium ion sieve, wherein the metal cations include one or more of titanium ions, zirconium ions, manganese ions, cobalt ions and niobium ions;

[0008] Adding the cesium ion sieve into a mixed solution containing a hydrophilic agent and a binder to prepare a slurry;

[0009] The slurry is granulated to prepare the cesium extracting adsorbent.

[0010] In one embodiment, the B salt includes one or more of zirconium oxychloride, zirconium tetrachloride, zirconium sulfate, zirconium nitrate, titanium tetrachloride, titanium sulfate, titanium nitrate, manganese chloride, manganese sulfate, manganese nitrate, cobalt chloride, cobalt sulfate, cobalt nitrate and niobium pentachloride.

[0011] In one embodiment, the A salt includes one or more of ammonium pyrophosphomolybdate, sodium pyrophosphomolybdate, ammonium pyrophosphotungstate and sodium pyrophosphotungstate.

[0012] In one embodiment, the molar ratio of the A salt to the B salt is (0.1-2):1.

[0013] In one embodiment, the concentration of the A salt in the A salt solution is 1 mol / L to 3 mol / L.

[0014] In one embodiment, the concentration of the B salt in the B salt solution is 2 mol / L to 5 mol / L.

[0015] In one embodiment, the complexing reaction of the heteropoly anion and the metal cation comprises the following steps:

[0016] The mixture was reacted at room temperature for 1 h~2 h, and aged at 40°C~80°C for 5 h~6 h to prepare an aged mother solution.

[0017] In one embodiment, after preparing the aged mother solution, the following steps are also included:

[0018] Performing solid-liquid separation on the aged mother liquor to prepare a precipitate;

[0019] The precipitate is dried and ground to prepare the cesium ion sieve.

[0020] In one embodiment, the hydrophilic agent includes one or more of polyethylene glycol, polyvinyl alcohol, sodium dodecyl sulfate, sodium hexadecyl sulfonate and sodium dodecylbenzene sulfonate.

[0021] In one embodiment, the mass proportion of the hydrophilic agent in the mixed solution is 1% to 6%.

[0022] In one embodiment, the adhesive includes one or more of polyvinyl chloride, polyvinyl butyral, polyvinyl formal, polyethylene, polymethyl methacrylate, polyamide, polyoxymethylene, polyethylene terephthalate, polystyrene and polytetrafluoroethylene.

[0023] In one embodiment, the concentration of the binder in the mixed solution is 0.1 g / mL to 0.25 g / mL.

[0024] In one embodiment, the mass ratio of the mixed solution to the cesium ion sieve is (0.9~3.2):1.

[0025] In one embodiment, the mixed liquid further includes an organic solvent, and the organic solvent includes one or more of N,N-dimethylformamide, N,N-dimethylacetamide, N-methylpyrrolidone and acetone.

[0026] In one embodiment, the method of granulating the slurry comprises a phase transfer method.

[0027] In a second aspect, the present invention provides a cesium extraction adsorbent, which is prepared by the preparation method of the cesium extraction adsorbent described above.

[0028] In one embodiment, the particle size of the cesium extraction adsorbent is 0.5 mm to 1.2 mm.

[0029] In one embodiment, the porosity of the cesium extraction adsorbent is 30% to 45%.

[0030] In one embodiment, the saturated adsorption capacity of the cesium extraction adsorbent for cesium ions is ≥7.25 mg / g.

[0031] In a third aspect, the present invention provides a method for extracting cesium from salt lake brine, comprising the following steps:

[0032] The cesium extraction adsorbent described above is used to extract cesium from salt lake brine.

[0033] The present invention has the following beneficial effects:

[0034] The present invention prepares cesium ion sieve by the complex reaction between heteropoly anion and metal cation, and it contains one or more of titanium ion, zirconium ion, manganese ion, cobalt ion and niobium ion, and compared with traditional ammonium phosphomolybdate and ammonium phosphomolybdate, it has stronger binding force with cesium ion, therefore shows better adsorption selectivity, can realize the effective separation of rubidium and cesium. Cesium ion sieve is made into slurry with hydrophilic agent and binder, and granulation treatment is carried out, and powdered cesium ion sieve can be bonded to form particles, and structural strength is significantly enhanced, and it is avoided that it has defects such as difficult solid-liquid separation, high dissolution rate and poor adsorption performance. In the granulation process, hydrophilic agent can effectively regulate the structure of cesium adsorbent, increase its porosity and hydrophilicity, so that it is not only conducive to expanding internal diffusion channel and internal and external diffusion rate, so as to improve the permeability of cesium adsorbent, and more cesium ion adsorption sites can be exposed, and the contact area between salt lake brine and cesium ion sieve is increased, so as to greatly improve its adsorption capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] Figure 1 This is a physical picture of the cesium extraction adsorbent prepared in Example 5;

[0036] Figure 2This is a graph showing the results of 20 adsorption-desorption cycle experiments on the cesium extraction adsorbent of Example 5. DETAILED DESCRIPTION

[0037] In order to make the above-mentioned purpose, features and advantages of the present invention more obvious and easy to understand, the specific embodiments of the present invention are described in detail below. In the following description, many specific details are set forth to facilitate a full understanding of the present invention. However, the present invention 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 invention, so the present invention is not limited by the specific embodiments disclosed below.

[0038] 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 the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0039] 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 the present invention belongs. The terms used herein in the specification of the present invention are only for the purpose of describing specific embodiments and are not intended to limit the present invention. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0040] The composition of salt lake brine is complex, not only containing abundant cesium ions, but also containing a large number of alkali metal ions such as lithium, sodium, potassium, and rubidium. Compared with cesium ions, the content of these associated alkali metal ions is higher and their properties are very similar, especially the difference between the ionic radius of rubidium ions and cesium ions is the smallest, which makes the extraction of cesium very difficult.

[0041] At present, the main cesium adsorbents used are inorganic ion exchangers, including heteropolyacid salts, silicate titanates, multivalent metal phosphates, metal ferrocyanides and metal oxides. Among them, the adsorption of cesium ions by silicate titanates is easily interfered by other ions; the addition of metal phosphates has a poor effect on the cesium extraction in high-salt systems; the adsorption capacity of metal ferrocyanides is low, and it is difficult to separate rubidium and cesium; heteropolyacid salts are salt compounds corresponding to heteropoly acids (HPA), such as ammonium phosphomolybdate (AMP) and ammonium phosphotungstate (AWP), but the adsorption selectivity of traditional heteropolyacid salts for cesium ions is not ideal. Therefore, traditional cesium adsorbents have defects such as low adsorption capacity and poor adsorption selectivity, and it is difficult to achieve effective separation of rubidium and cesium, which causes great difficulties in the separation and purification of cesium resources in salt lakes.

[0042] Based on this, the first aspect of the present invention provides a method for preparing a cesium adsorbent to solve the problem that traditional cesium adsorbents are often difficult to achieve effective separation of rubidium and cesium, have defects such as low adsorption capacity and poor adsorption selectivity, and cause great difficulties in the separation and purification of cesium resources in salt lakes.

[0043] In some embodiments, the method for preparing a cesium adsorbent comprises the following steps:

[0044] Mixing a salt solution A containing heteropoly anions and a salt solution B containing metal cations to allow the heteropoly anions and the metal cations to undergo a complex reaction to prepare a cesium ion sieve, wherein the metal cations include one or more of titanium ions, zirconium ions, manganese ions, cobalt ions and niobium ions;

[0045] Adding the cesium ion sieve into a mixed solution containing a hydrophilic agent and a binder to prepare a slurry;

[0046] The slurry is granulated to prepare a cesium extracting adsorbent.

[0047] The present invention prepares cesium ion sieve by the complex reaction between heteropoly anion and metal cation, and it contains one or more of titanium ion, zirconium ion, manganese ion, cobalt ion and niobium ion, and compared with traditional ammonium phosphomolybdate and ammonium phosphomolybdate, it has stronger binding force with cesium ion, therefore shows better adsorption selectivity, can realize the effective separation of rubidium and cesium. Cesium ion sieve is made into slurry with hydrophilic agent and binder, and granulation treatment is carried out, and powdered cesium ion sieve can be bonded to form particles, and structural strength is significantly enhanced, and it is avoided that it has defects such as difficult solid-liquid separation, high dissolution rate and poor adsorption performance. In the granulation process, hydrophilic agent can effectively regulate the structure of cesium adsorbent, increase its porosity and hydrophilicity, so that it is not only conducive to expanding internal diffusion channel and internal and external diffusion rate, so as to improve the permeability of cesium adsorbent, and more cesium ion adsorption sites can be exposed, and the contact area between salt lake brine and cesium ion sieve is increased, so as to greatly improve its adsorption capacity.

[0048] In addition, the cesium extraction adsorbent prepared by the present invention also has the characteristics of fast adsorption rate, easy desorption of cesium ions, good chemical stability and structural stability, and excellent acid, alkali and salt resistance, and is very suitable for the industrial application of cesium extraction from salt lake brine.

[0049] In some embodiments, the B salt includes one or more of zirconium oxychloride, zirconium tetrachloride, zirconium sulfate, zirconium nitrate, titanium tetrachloride, titanium sulfate, titanium nitrate, manganese chloride, manganese sulfate, manganese nitrate, cobalt chloride, cobalt sulfate, cobalt nitrate, and niobium pentachloride.

[0050] In some embodiments, the A salt includes one or more of ammonium pyrophosphomolybdate, sodium pyrophosphomolybdate, ammonium pyrophosphotungstate, and sodium pyrophosphotungstate.

[0051] Optionally, the preparation method of salt solution A comprises the following steps: mixing salt solution A1 and salt solution A2, reacting at room temperature for 1 h to 3 h to obtain salt solution A; wherein salt A1 comprises one or more of sodium pyrophosphate and potassium pyrophosphate, salt A2 comprises one or more of ammonium molybdate, sodium molybdate, ammonium tungstate and sodium tungstate, and the molar ratio of salt A1 to salt A2 is 1:1.

[0052] It can be understood that the above-mentioned salt A, salt A1, salt A2 and salt B can all be salts containing bound water, such as zirconium oxychloride octahydrate (ZrOCl2·8H2O), or salts not containing bound water, such as anhydrous zirconium chloride (ZrCl4). Specifically, salt A is a phosphorus-containing heteropolyacid salt, and salt B is a transition metal salt. After salt A and salt B are mixed in an aqueous solution and undergo a complex reaction, the chemical composition of the obtained cesium ion sieve is a transition metal phosphorus-containing heteropolyacid salt.

[0053] Optionally, the cesium ion sieve includes metal cations and heteropoly anions; wherein the metal cations include one or more of titanium ions, zirconium ions, manganese ions, cobalt ions and niobium ions; and the heteropoly anions include one or more of pyrophosphomolybdate ions and pyrophosphotungstate ions.

[0054] Optionally, the cesium ion sieve comprises one or more of titanium pyrophosphomolybdate, zirconium pyrophosphomolybdate, manganese pyrophosphomolybdate, cobalt pyrophosphomolybdate, niobium pyrophosphomolybdate, titanium pyrophosphotungstate, zirconium pyrophosphotungstate, manganese pyrophosphotungstate, cobalt pyrophosphotungstate and niobium pyrophosphotungstate. Preferably, the cesium ion sieve comprises one or more of titanium pyrophosphomolybdate, zirconium pyrophosphomolybdate, titanium pyrophosphotungstate and zirconium pyrophosphotungstate.

[0055] Compared with traditional phosphomolybdates or phosphotungstates containing ammonium ions or alkali metal ions, the pore structure of transition metal pyrophosphomolybdates and transition metal pyrophosphotungstates is closer to the ionic radius of cesium ions, so they show greater adsorption capacity and higher selectivity for cesium ions. At the same time, the structures of these two transition metal heteropolyacid salts have higher stability and show excellent acid, alkali and salt resistance, which is conducive to improving their service life.

[0056] Optionally, the molar ratio of salt A to salt B is (0.1-2):1, for example, 0.1:1, 0.3:1, 0.5:1, 0.7:1, 0.9:1, 1:1, 1.2:1, 1.4:1, 1.6:1, 1.8:1, 2:1. Preferably, the molar ratio of salt A to salt B is (0.5-1):1.

[0057] Optionally, the concentration of the A salt in the A salt solution is 1 mol / L to 3 mol / L, including but not limited to: 1 mol / L, 1.2 mol / L, 1.5 mol / L, 1.8 mol / L, 2 mol / L, 2.2 mol / L, 2.5 mol / L, 2.8 mol / L, 3 mol / L. Preferably, the concentration of the A salt in the A salt solution is 1 mol / L to 2 mol / L.

[0058] Optionally, the concentration of B salt in the B salt solution is 2 mol / L to 5 mol / L, including but not limited to: 2 mol / L, 2.5 mol / L, 3 mol / L, 3.5 mol / L, 4 mol / L, 4.5 mol / L, 5 mol / L. Preferably, the concentration of B salt in the B salt solution is 2.5 mol / L to 3.5 mol / L.

[0059] By controlling the molar ratio and concentration of salt A and salt B, the pH in the complex reaction process can be regulated within an appropriate range, avoiding the step of acid-base adjustment before and after the complex reaction, simplifying the process steps and reducing production costs.

[0060] Optionally, after mixing the A salt solution containing heteropoly anions and the B salt solution containing metal cations, the pH of the solution is 5 to 8, such as 5, 5.5, 6, 6.5, 7, 7.5, 8, preferably 5.5 to 6.0.

[0061] In some embodiments, the complexation reaction of the heteropoly anion and the metal cation comprises the following steps:

[0062] The mixture was reacted at room temperature for 1 h~2 h, and aged at 40°C~80°C for 5 h~6 h to prepare an aged mother solution.

[0063] It can be understood that aging means that after the precipitation reaction, the mixed solution is allowed to stand for a period of time under certain conditions so that the components in the mixed solution can fully react, impurities contained in the precipitate can be removed, and the particles of the precipitate can be enlarged and the particle size distribution can be more uniform. If the aging treatment is carried out at room temperature, the resulting cesium ion sieve has problems such as small specific surface area, poor stability, and poor permeability, and the crystal structure is amorphous, and the adsorption capacity and selectivity for cesium ions are very poor. Aging at 40°C to 80°C is not only conducive to improving the specific surface area, stability and permeability of the cesium ion sieve, but also can promote it to form a special crystal structure and obtain a pore structure similar to the ionic radius of the cesium ion, thereby greatly improving the adsorption capacity and selectivity of the cesium ion sieve.

[0064] In some embodiments, after preparing the aged mother solution, the following steps are further included:

[0065] Performing solid-liquid separation on the aged mother liquor to prepare a precipitate;

[0066] The precipitate is dried and ground to prepare a cesium ion sieve.

[0067] Optionally, the solid-liquid separation treatment method includes one or more of filtration and centrifugation, wherein the filtration method can be ordinary filtration, or any one of suction filtration, pressure filtration, microfiltration and nanofiltration.

[0068] Optionally, the temperature of the drying process is 75°C~105°C, including but not limited to: 75°C, 80°C, 85°C, 90°C, 95°C, 100°C, 105°C.

[0069] Optionally, the drying time is 8h~24h, including but not limited to: 8h, 10h, 12h, 14h, 16h, 18h, 20h, 22h, 24h.

[0070] Optionally, after grinding, the particle size of the cesium ion sieve is 75μm~130μm, including but not limited to: 75μm, 80μm, 85μm, 90μm, 95μm, 100μm, 105μm, 110μm, 115μm, 120μm, 125μm and 130μm.

[0071] Through solid-liquid separation treatment, the residual raw materials and impurities in the product can be removed to improve the purity of the product; through grinding treatment, the particle size of the cesium ion sieve can be reduced and the particle size distribution can be more uniform, which is beneficial to increase the specific surface area of ​​the cesium ion sieve and expose more adsorption active sites, thereby improving its adsorption performance.

[0072] In some embodiments, the hydrophilic agent includes one or more of polyethylene glycol (PEG), polyvinyl alcohol (PVA), sodium dodecyl sulfate (SDS), sodium hexadecyl sulfonate (SAS), and sodium dodecylbenzene sulfonate (SDBS).

[0073] Optionally, the hydrophilic agent is polyethylene glycol (PEG) having a weight average molecular weight of 200 g / mol to 6000 g / mol, including but not limited to 200 g / mol, 500 g / mol, 800 g / mol, 1000 g / mol, 1500 g / mol, 2000 g / mol, 2500 g / mol, 3000 g / mol, 3500 g / mol, 4000 g / mol, 4500 g / mol, 5000 g / mol, 5500 g / mol, 6000 g / mol, preferably 400 g / mol to 1000 g / mol, and further preferably 1000 g / mol.

[0074] It can be understood that the above hydrophilic agent contains polar groups such as hydroxyl, carboxyl, sulfonic acid, and sulfuric acid, and has good water solubility. It can not only increase the porosity of the cesium adsorbent by dissolving and forming pores during the granulation process, and increase the contact area between the cesium ion sieve and the brine, but also greatly improve the hydrophilicity of the cesium adsorbent, accelerate the diffusion rate, and thus greatly increase the adsorption capacity. Among them, polyethylene glycol (PEG) has good water solubility, good compatibility with most organic matter, and can be complexed with the hydroxyl groups on the surface of the cesium ion sieve in the form of hydrogen bonds, and fully expose the hydrophilic groups such as hydroxyl groups on the surface of the cesium ion sieve during the dissolution in water, which plays a role in improving hydrophilicity, permeability, and adsorption capacity.

[0075] Optionally, the mass proportion of the hydrophilic agent in the mixed solution is 1% to 6%, including but not limited to: 1%, 2%, 3%, 4%, 5%, 6%. Preferably, the mass proportion of the hydrophilic agent in the mixed solution is 3% to 5%.

[0076] In some embodiments, the binder includes one or more of polyvinyl chloride (PVC), polyvinyl butyral (PVB), polyvinyl formal (PVF), polyethylene (PE), polymethyl methacrylate (PMMA), polyamide (PI), polyoxymethylene (POM), polyethylene terephthalate (PET), polystyrene (PS), and polytetrafluoroethylene (PTFE).

[0077] Optionally, the binder is polyvinyl chloride (PVC). PVC has extremely excellent compatibility with PEG, which is beneficial to enhancing the interaction between different components of the adsorbent and improving the dispersion uniformity, thereby improving the adsorption performance and structural strength of the adsorbent.

[0078] Optionally, the concentration of the binder in the mixed solution is 0.1 g / mL to 0.25 g / mL, including but not limited to: 0.1 g / mL, 0.12 g / mL, 0.15 g / mL, 0.18 g / mL, 0.2 g / mL, 0.21 g / mL, 0.24 g / mL, 0.25 g / mL. Preferably, the concentration of the binder in the mixed solution is 0.1 g / mL to 0.15 g / mL.

[0079] Optionally, the mass ratio of the mixed solution to the cesium ion sieve is (0.9-3.2):1, for example, 0.9:1, 1:1, 1.2:1, 1.5:1, 1.8:1, 2:1, 2.2:1, 2.5:1, 2.8:1, 3:1, 3.2:1. Preferably, the mass ratio of the mixed solution to the cesium ion sieve is (1.5-2.5):1.

[0080] In some embodiments, the mixed liquid further includes an organic solvent, and the organic solvent includes one or more of N,N-dimethylformamide (DMF), N,N-dimethylacetamide (DMAc), N-methylpyrrolidone (NMP) and acetone.

[0081] In some embodiments, the method of granulating the slurry comprises a phase transfer method.

[0082] Optionally, the slurry is granulated by a phase transfer method, comprising the following steps: dropping the slurry into an aqueous phase to form a granular cesium extracting adsorbent.

[0083] During the phase transfer method, the hydrophilic agent can utilize its hydrophilic ability to regulate the structure and performance of the cesium extraction adsorbent, increase the hydrophilicity and porosity of the cesium extraction adsorbent, make the particles of the cesium extraction adsorbent have good permeability, and significantly improve the adsorption performance.

[0084] In a second aspect, the present invention provides a cesium extraction adsorbent, which is prepared by the preparation method of the cesium extraction adsorbent described above.

[0085] In some embodiments, the components of the cesium extracting adsorbent include a cesium ion sieve and a binder; wherein the cesium ion sieve includes metal cations and heteropoly anions, the metal cations include one or more of titanium ions, zirconium ions, manganese ions, cobalt ions and niobium ions, and the heteropoly anions include one or more of pyrophosphomolybdate ions and pyrophosphotungstate ions.

[0086] Optionally, the cesium ion sieve comprises one or more of titanium pyrophosphomolybdate, zirconium pyrophosphomolybdate, manganese pyrophosphomolybdate, cobalt pyrophosphomolybdate, niobium pyrophosphomolybdate, titanium pyrophosphotungstate, zirconium pyrophosphotungstate, manganese pyrophosphotungstate, cobalt pyrophosphotungstate and niobium pyrophosphotungstate. Preferably, the cesium ion sieve comprises one or more of titanium pyrophosphomolybdate, zirconium pyrophosphomolybdate, titanium pyrophosphotungstate and zirconium pyrophosphotungstate.

[0087] Optionally, the particle size of the cesium extraction adsorbent is 0.5 mm to 1.2 mm, including but not limited to: 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, and 1.2 mm.

[0088] Optionally, the porosity of the cesium extraction adsorbent is 30% to 45%, including but not limited to: 30%, 33%, 36%, 39%, 42%, and 45%.

[0089] It can be understood that static adsorption refers to contacting the adsorbent and the substance to be adsorbed for a period of time under static conditions, and then conducting an adsorption experiment under equilibrium conditions, and the saturated adsorption capacity of the adsorbent can be tested. Optionally, under static adsorption conditions, the saturated adsorption capacity of the cesium adsorbent for cesium ions is ≥7.25mg / g, including but not limited to: 7.25mg / g, 7.5mg / g, 8mg / g, 8.5mg / g, 9mg / g, 9.5mg / g, 10mg / g, 10.5mg / g, 11mg / g, 11.5mg / g, 12mg / g, 12.5mg / g, 13mg / g, 14mg / g and 15mg / g. Preferably, the saturated adsorption capacity of the cesium adsorbent for cesium ions is 7.25mg / g~12.38mg / g.

[0090] Dynamic adsorption refers to the adsorption test of the adsorbent and the substance to be adsorbed after contacting for a period of time under flow conditions, and the adsorption capacity of the adsorbent can be tested. Unlike static adsorption, dynamic adsorption pays more attention to fluid dynamics and mass transfer processes. Optionally, under dynamic adsorption conditions with a flow rate of 6BV / h, the adsorption capacity of the cesium adsorbent for cesium ions is ≥1.5mg / g, including but not limited to: 1.5mg / g, 1.6mg / g, 1.7mg / g, 1.8mg / g, 1.9mg / g, 2.0mg / g, 2.1mg / g, 2.2mg / g, 2.3mg / g, 2.4mg / g, 2.5mg / g, 2.6mg / g, 2.7mg / g, 2.8mg / g, 2.9mg / g, 3.0mg / g, 3.1mg / g, 3.2mg / g, 3.5mg / g, 3.8mg / g and 4.0mg / g. Preferably, the adsorption capacity of the cesium extraction adsorbent for cesium ions is 1.5 mg / g to 3.2 mg / g.

[0091] In a third aspect, the present invention provides a method for extracting cesium from salt lake brine, which is the application of the above-mentioned cesium extraction adsorbent in salt lake brine.

[0092] In some embodiments, the method for extracting cesium from salt lake brine comprises the following steps:

[0093] The cesium extraction adsorbent described above is used to extract cesium from salt lake brine.

[0094] Optionally, the mass volume ratio of the cesium extracting adsorbent to the salt lake brine is 3g / mL~5g / mL, including but not limited to: 3g / mL, 3.2g / mL, 3.5g / mL, 3.8g / mL, 4g / mL, 4.2g / mL, 4.5g / mL, 4.8g / mL, 5g / mL.

[0095] Optionally, the cesium extraction treatment time is 1 h to 3 h, including but not limited to: 1 h, 1.5 h, 2 h, 2.5 h, 3 h.

[0096] Optionally, during cesium extraction treatment, the flow rate of the salt lake brine is 2BV / h~8BV / h, including but not limited to: 2BV / h, 2.5BV / h, 3BV / h, 3.5BV / h, 4BV / h, 4.5BV / h, 5BV / h, 5.5BVL / h, 6BV / h, 6.5BV / h, 7BV / h, 7.5BV / h and 8BV / h.

[0097] Optionally, before the salt lake brine is subjected to cesium extraction treatment, the following step is also included: activating the cesium extraction adsorbent. Specifically, the activation treatment includes the following steps: acid washing with a hydrochloric acid solution with a mass fraction of 1% to 2% to activate the cesium extraction adsorbent until the pH of the washed water is 5 to 6.

[0098] Optionally, after the salt lake brine is subjected to cesium extraction treatment, the following steps are also included: the cesium-loaded adsorbent obtained by the cesium extraction treatment is subjected to water washing and desorption treatment to regenerate the cesium-loaded adsorbent into a cesium extraction adsorbent. Specifically, after the cesium extraction treatment, the following steps are also included: using water washing to remove impurity ions remaining on the surface of the cesium-loaded adsorbent, the water can be pure water, ultrapure water or deionized water, the amount is 10BV, and the flow rate is 10BV / h; after water washing, the cesium-loaded adsorbent is subjected to desorption treatment by using a desorbent, the desorbent adopts a mixed solution of NH4Cl and KCl, the total concentration of NH4Cl and KCl is 1.5mol / L~2mol / L, the molar ratio of the two is (1~2):1, the amount of the desorbent is 2BV~3BV, the flow rate is 2BV / h, and the temperature is 50℃~60℃, thereby regenerating the cesium extraction adsorbent.

[0099] The present invention is further described in detail below with reference to specific embodiments.

[0100] In the following specific embodiments 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; and the processes used, unless otherwise specified, are all routinely selected by those skilled in the art.

[0101] Example 1

[0102] (1) Please refer to Table 1 to prepare 1.5 mol / L ammonium molybdate solution, 1.5 mol / L sodium pyrophosphate and 2.5 mol / L zirconium oxychloride solution; firstly, add an equal amount of sodium pyrophosphate to 50 mL of ammonium molybdate solution, react at room temperature for 1 hour to obtain an ammonium pyrophosphomolybdate solution; then add 100 mL of zirconium oxychloride solution, continue to react at room temperature for 1.5 hours; transfer to an oven, age at 60°C for 5 hours to obtain an aged mother liquor; filter the aged mother liquor to obtain a filter cake; dry the filter cake, and grind it to obtain a powdered cesium ion sieve.

[0103] (2) Take 100 mL of N,N-dimethylformamide (DMF), add 3% by weight of PEG-1000, stir until completely dissolved, then add 12.5 g of PVC powder and stir until completely dissolved to obtain a mixed solution.

[0104] (3) According to the mass ratio of the mixed liquid to the cesium ion sieve being 2:1, the cesium ion sieve was added into the mixed liquid, and the mixture was stirred evenly to obtain a slurry; the slurry was dropped into water to be transformed into particles, and the particles were washed with water for 1 to 2 times to obtain a cesium extraction adsorbent, which was recorded as HPCs-1.

[0105] Example 2

[0106] Please refer to Table 1, prepare 1.8 mol / L ammonium tungstate solution, 1.8 mol / L sodium pyrophosphate and 3.0 mol / L zirconium oxychloride solution; first add an equal amount of sodium pyrophosphate to 50 mL of ammonium tungstate solution, react at room temperature for 1 hour to obtain ammonium pyrophosphoric acid tungstate solution; then add 100 mL of zirconium oxychloride solution, continue to react at room temperature for 1 hour; transfer to an oven, age at 60°C for 2 hours to obtain an aged mother liquor; filter the aged mother liquor to obtain a filter cake; dry the filter cake, and grind it to obtain a powdered cesium ion sieve.

[0107] (2) Take 100 mL of N,N-dimethylacetamide (DMAc), add 5% by weight of PEG-1000, stir until completely dissolved, then add 12.5 g of PVC powder and stir until completely dissolved to obtain a mixed solution.

[0108] (3) According to the mass ratio of the mixed liquid to the cesium ion sieve being 2:1, the cesium ion sieve is added to the mixed liquid, and the mixture is stirred evenly to obtain a slurry; the slurry is dropped into water to be transformed into particles, and the particles are washed with water for 1 to 2 times to obtain a cesium extraction adsorbent, which is recorded as HPCs-2.

[0109] Example 3

[0110] (1) Please refer to Table 1 to prepare 1.8 mol / L ammonium molybdate solution, 1.8 mol / L sodium pyrophosphate and 3.0 mol / L titanium tetrachloride solution; firstly, add an equal amount of sodium pyrophosphate to 50 mL of ammonium molybdate solution, react at room temperature for 1 hour to obtain ammonium pyrophosphomolybdate solution; then add 100 mL of titanium tetrachloride solution, continue to react for 1.5 hours; transfer to an oven, age at 60°C for 2 hours to obtain an aged mother liquor; filter the aged mother liquor to obtain a filter cake; dry the filter cake, and grind it to obtain a powdered cesium ion sieve.

[0111] (2) Take 100 mL of N,N-dimethylacetamide (DMAc), add 4% by weight of PEG-1000, stir until completely dissolved, then add 12.5 g of PVC powder and stir until completely dissolved to obtain a mixed solution.

[0112] (3) According to the mass ratio of the mixed liquid to the cesium ion sieve of 2.6:1, the cesium ion sieve was added to the mixed liquid, and the mixture was stirred evenly to obtain a slurry; the slurry was dropped into water to be transformed into particles, and the particles were washed with water for 1 to 2 times to obtain a cesium extraction adsorbent, which was recorded as HPCs-3.

[0113] Example 4

[0114] (1) Please refer to Table 1 to prepare 1.8 mol / L sodium tungstate solution, 1.8 mol / L sodium pyrophosphate and 3.0 mol / L titanium tetrachloride solution; firstly, add an equal amount of sodium pyrophosphate to 50 mL of sodium tungstate solution and react at room temperature for 1 hour to obtain sodium pyrophosphorus tungstate solution; then add 100 mL of titanium tetrachloride solution and continue to react at room temperature for 1.5 hours; transfer to an oven and age at 60°C for 2 hours to obtain an aged mother liquor; filter the aged mother liquor to obtain a filter cake; dry the filter cake and grind it to obtain a powdered cesium ion sieve.

[0115] (2) Take 100 mL of N,N-dimethylacetamide (DMAc), add 4% by weight of PEG-1000, stir until completely dissolved, then add 12.5 g of PVC powder and stir until completely dissolved to obtain a mixed solution.

[0116] (3) According to the mass ratio of the mixed liquid to the cesium ion sieve of 2.6:1, the cesium ion sieve was added to the mixed liquid, and the mixture was stirred evenly to obtain a slurry; the slurry was dropped into water to be transformed into particles, and the particles were washed with water for 1 to 2 times to obtain a cesium extraction adsorbent, which was recorded as HPCs-4.

[0117] Example 5

[0118] (1) Please refer to Table 1 to prepare 1.8 mol / L sodium tungstate solution, 1.8 mol / L sodium pyrophosphate and 3.0 mol / L titanium nitrate solution; firstly, add an equal amount of sodium pyrophosphate to 50 mL of sodium tungstate solution and react at room temperature for 1 hour to obtain sodium pyrophosphoric acid tungstate solution; then add 100 mL of titanium nitrate solution and continue to react at room temperature for 2 hours; transfer to an oven and age at 60°C for 2 hours to obtain an aged mother liquor; filter the aged mother liquor to obtain a filter cake; dry the filter cake and grind it to obtain a powdered cesium ion sieve.

[0119] (2) Take 100 mL of N-methylpyrrolidone (NMP), add 4% by weight of PEG-1000, stir until completely dissolved, then add 12.5 g of PVC powder and stir until completely dissolved to obtain a mixed solution.

[0120] (3) According to the mass ratio of the mixed liquid to the cesium ion sieve of 0.9:1, the cesium ion sieve is added to the mixed liquid, and the mixture is stirred evenly to obtain a slurry; the slurry is dropped into water to be transformed into particles, and the particles are washed with water for 1 to 2 times to obtain a cesium extraction adsorbent, which is recorded as HPCs-5.

[0121] Example 6

[0122] The difference between this embodiment and embodiment 5 is that the hydrophilic agent is replaced with sodium dodecylbenzene sulfonate of equal mass, and the specific steps are as follows:

[0123] (1) Please refer to Table 1 to prepare 1.8 mol / L sodium tungstate solution, 1.8 mol / L sodium pyrophosphate and 3.0 mol / L titanium nitrate solution; firstly, add an equal amount of sodium pyrophosphate to 50 mL of sodium tungstate solution and react at room temperature for 1 hour to obtain sodium pyrophosphoric acid tungstate solution; then add 100 mL of titanium nitrate solution and continue to react at room temperature for 2 hours; transfer to an oven and age at 60°C for 2 hours to obtain an aged mother liquor; filter the aged mother liquor to obtain a filter cake; dry the filter cake and grind it to obtain a powdered cesium ion sieve.

[0124] (2) Take 100 mL of N-methylpyrrolidone (NMP), add 4% by weight of sodium dodecylbenzene sulfonate, stir until completely dissolved, then add 12.5 g of PVC powder and stir until completely dissolved to obtain a mixed solution.

[0125] (3) According to the mass ratio of the mixed liquid to the cesium ion sieve of 0.9:1, the cesium ion sieve is added to the mixed liquid, and the mixture is stirred evenly to obtain a slurry; the slurry is dropped into water to be transformed into particles, and the particles are washed with water for 1 to 2 times to obtain a cesium extraction adsorbent, which is recorded as HPCs-6.

[0126] Example 7

[0127] The difference between this embodiment and embodiment 5 is that the adhesive is replaced with polyvinyl butyral (PVB) of equal mass, and the specific steps are as follows:

[0128] (1) Please refer to Table 1 to prepare 1.8 mol / L sodium tungstate solution, 1.8 mol / L sodium pyrophosphate and 3.0 mol / L titanium nitrate solution; firstly, add an equal amount of sodium pyrophosphate to 50 mL of sodium tungstate solution and react at room temperature for 1 hour to obtain sodium pyrophosphoric acid tungstate solution; then add 100 mL of titanium nitrate solution and continue to react at room temperature for 2 hours; transfer to an oven and age at 60°C for 2 hours to obtain an aged mother liquor; filter the aged mother liquor to obtain a filter cake; dry the filter cake and grind it to obtain a powdered cesium ion sieve.

[0129] (2) Take 100 mL of N-methylpyrrolidone (NMP), add 4% by weight of PEG-1000, stir until completely dissolved, then add 12.5 g of PVB powder, stir until completely dissolved, and obtain a mixed solution.

[0130] (3) According to the mass ratio of the mixed liquid to the cesium ion sieve of 0.9:1, the cesium ion sieve was added to the mixed liquid, and the mixture was stirred evenly to obtain a slurry; the slurry was dropped into water to be transformed into particles, and the particles were washed with water for 1 to 2 times to obtain a cesium extraction adsorbent, which was recorded as HPCs-7.

[0131] Comparative Example 1

[0132] (1) Please refer to Table 1 to prepare 1.8 mol / L sodium tungstate solution, 1.8 mol / L sodium pyrophosphate and 3.0 mol / L titanium nitrate solution; firstly, add an equal amount of sodium pyrophosphate to 50 mL of sodium tungstate solution and react at room temperature for 1 hour to obtain sodium pyrophosphoric acid tungstate solution; then add 100 mL of titanium nitrate solution and continue to react at room temperature for 2 hours; transfer to an oven and age at 60°C for 2 hours to obtain an aged mother liquor; filter the aged mother liquor to obtain a filter cake; dry the filter cake and grind it to obtain a powdered cesium ion sieve.

[0133] (2) Take 100 mL of N-methylpyrrolidone (NMP), add 12.5 g of PVC powder, and stir until completely dissolved to obtain a mixed solution.

[0134] (3) According to the mass ratio of the mixed liquid to the cesium ion sieve of 0.9:1, the cesium ion sieve is added to the mixed liquid, and the mixture is stirred evenly to obtain a slurry; the slurry is dropped into water to be transformed into particles, and the particles are washed with water for 1 to 2 times to obtain a cesium extraction adsorbent, which is recorded as HPDCs-1.

[0135] Comparative Example 2

[0136] (1) Please refer to Table 1 to prepare 2.2 mol / L sodium tungstate solution, 2.2 mol / L sodium pyrophosphate and 4.0 mol / L titanium nitrate solution; firstly, add an equal amount of sodium pyrophosphate to 50 mL of sodium tungstate solution and react at room temperature for 1 hour to obtain sodium pyrophosphoric acid tungstate solution; then add 100 mL of titanium nitrate solution and continue to react at room temperature for 2 hours; transfer to an oven and age at 80°C for 2 hours to obtain an aged mother liquor; filter the aged mother liquor to obtain a filter cake; dry the filter cake and grind it to obtain a powdered cesium ion sieve.

[0137] (2) Take 100 mL of N-methylpyrrolidone (NMP), add 12.5 g of PVC powder, and stir until completely dissolved to obtain a mixed solution.

[0138] (3) According to the mass ratio of the mixed liquid to the cesium ion sieve of 1.5:1, the cesium ion sieve is added to the mixed liquid, and the mixture is stirred evenly to obtain a slurry; the slurry is dropped into water to be transformed into particles, and the particles are washed with water for 1 to 2 times to obtain a cesium extraction adsorbent, which is recorded as HPDCs-2.

[0139] Comparative Example 3

[0140] In this comparative example, the cesium ion sieve is replaced with ammonium phosphotungstate, and the preparation method of the cesium adsorbent is as follows:

[0141] (1) Take 100 mL of N-methylpyrrolidone (NMP), add 4% by weight of PEG-1000, stir until completely dissolved, then add 12.5 g of PVC powder and stir until completely dissolved to obtain a mixed solution.

[0142] (2) According to the mass ratio of the mixed solution to ammonium phosphotungstate of 0.9:1, ammonium phosphotungstate was added to the mixed solution, and the mixture was stirred evenly to obtain a slurry; the slurry was dropped into water to be transformed into particles, and the particles were washed with water for 1 to 2 times to obtain a cesium extraction adsorbent, which was recorded as HPDCs-3.

[0143] Comparative Example 4

[0144] In this comparative example, the cesium ion sieve is replaced with ammonium phosphomolybdate, and the preparation method of the cesium adsorbent is as follows:

[0145] (1) Take 100 mL of N-methylpyrrolidone (NMP), add 4% by weight of PEG-1000, stir until completely dissolved, then add 12.5 g of PVC powder and stir until completely dissolved to obtain a mixed solution.

[0146] (2) According to the mass ratio of the mixed solution to ammonium phosphomolybdate being 0.9:1, ammonium phosphomolybdate was added to the mixed solution, and the mixture was stirred evenly to obtain a slurry; the slurry was dropped into water to be transformed into particles, and the particles were washed with water for 1 to 2 times to obtain a cesium extraction adsorbent, which was recorded as HPDCs-4.

[0147] Test Case

[0148] 1. Adsorption performance test:

[0149] Take 10mL of cesium extraction adsorbent and load it into the chromatography column, then add it into 600mL of salt lake brine; the parameters of the salt lake brine are: Rb + Content 212mg / L, Cs + The content is 52.7 mg / L, the temperature is T=293.15K (20℃), and the adsorption time is t=10h. The adsorption treatment is carried out at 6BV / h, and the water samples are collected every 1h, diluted with deionized water, and the content of each ion in the water sample is measured by atomic absorption spectroscopy (AAS). The adsorption capacity and adsorption kinetics of the cesium extraction adsorbent are calculated. The results are shown in Table 2. Among them, Rb + Content and Cs + The contents are all ion contents in the salt lake brine after 10 hours of adsorption treatment; the adsorption capacity is calculated using the following formula: adsorption capacity = (ion content before adsorption - ion content after adsorption) × salt lake brine volume ÷ adsorbent volume; the adsorption selectivity is calculated using the following formula: adsorption selectivity = Cs + Adsorption capacity (mg / L) ÷ Rb + Adsorption amount (mg / L); adsorption rate was calculated according to the Langmuir isotherm adsorption equation.

[0150] (II) Regeneration performance test:

[0151] HPCs-5 was used to conduct 20 adsorption-desorption cycle experiments. The specific steps are as follows:

[0152] (1) Load 10 mL of cesium extraction adsorbent into the chromatography column;

[0153] (2) Use a hydrochloric acid solution with a mass fraction of 1% to 2% to perform acid washing to activate the cesium adsorbent until the pH of the washing water is 5 to 6;

[0154] (3) Add 600 mL of salt lake brine into the chromatography column for adsorption treatment to obtain a cesium-loaded adsorbent; wherein the ion content of the salt lake brine and the parameters of the adsorption treatment are as described in step (1);

[0155] (4) washing with 10 BV of pure water at a flow rate of 10 BV / h to remove impurity ions remaining on the surface of the cesium-loaded adsorbent;

[0156] (5) Desorbing the cesium-loaded adsorbent with a volume of 2 BV of desorbent at a flow rate of 2 BV / h, the desorbent was a mixed solution of NH4Cl and KCl (total concentration of 2 mol / L, molar ratio of 1:1), and the temperature was 50 °C to regenerate the cesium-extracting adsorbent;

[0157] (6) Repeat steps (2) to (5) to obtain the results of the adsorption-desorption cycle experiment. Figure 2 .

[0158] The cesium extraction adsorbent provided in this application is effective for Cs + The adsorption performance can be measured by three indicators: adsorption capacity, adsorption rate and adsorption selectivity. As shown in Table 2, the cesium extraction adsorbents of Examples 1 to 7 have the advantages of high adsorption capacity, fast adsorption rate and high adsorption selectivity. The adsorption capacity is between 1.848 mg / g and 3.078 mg / g, and the adsorption rate is between 3.2×10 -3 ml / (mg·min)~25×10 -3 ml / (mg·min), and in terms of the separation of rubidium and cesium, its adsorption selectivity is 0.8~10.9. The difference in adsorption performance between different cesium extraction adsorbents is affected by factors such as the crystal structure of the cesium ion sieve, the particle size of the cesium ion sieve, the hydrophilic agent and the binder. Among them, the cesium extraction adsorbent HPCs-5 of Example 5 has the largest adsorption capacity, the highest adsorption selectivity and the fastest adsorption rate.

[0159] The main difference between Comparative Examples 1 to 2 and Example 5 is that no hydrophilic agent is added, resulting in a significant reduction in the adsorption capacity, adsorption rate and adsorption selectivity of the cesium extraction adsorbent. The main difference between Comparative Examples 3 to 4 and Example 5 is the difference in the cesium ion sieve. Compared with titanium pyrophosphotungstate, ammonium phosphotungstate or ammonium phosphomolybdate is used as the cesium ion sieve, which also leads to a significant reduction in the adsorption capacity, adsorption rate and adsorption selectivity of the cesium extraction adsorbent. In addition, the adsorption capacity and selectivity of the cesium extraction adsorbent of Comparative Example 4 are comparable to or slightly higher than those of some embodiments, but its adsorption rate is much lower than that of the cesium extraction adsorbents of all embodiments, and it takes longer to reach the saturated adsorption amount, which is not conducive to the efficient cesium extraction treatment of salt lake brine.

[0160] See also Figure 1 , which is a physical picture of the cesium extraction adsorbent HPCs-5 of Example 5. The particle size of HPCs-5 is 0.6 mm, the adsorption capacity is 3.078 mg / mL, and the porosity is 36%.

[0161] See also Figure 2 , Figure 2Curve A in the figure is the curve showing the change of adsorption capacity with the number of cycles. Figure 2 Curve B in the figure shows the desorption rate changing with the number of cycles. Figure 2 It can be seen that the adsorption capacity of HPCs-5 remains basically unchanged, and the desorption rate is as high as 98.7%, which has very excellent regeneration performance.

[0162] From Tables 1~2 and Figure 2 It can be seen that the cesium adsorbent provided by the present application can effectively improve the adsorption rate of cesium ions while ensuring the adsorption capacity, has a good rubidium-cesium separation effect, and can be recycled; by comparing the embodiments with the comparative examples, it can be proved that the present application provides a method for preparing a cesium adsorbent for extracting cesium from salt lake brine, and by adding a hydrophilic agent such as PEG-1000, the internal and external diffusion rate of the adsorbent can be effectively increased, thereby improving the adsorption performance of the adsorbent.

[0163] Table 1. Product formula

[0164]

[0165] Table 2. Comparison of adsorption performance of products

[0166]

[0167] 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.

[0168] The above-mentioned embodiments only express several implementation methods of the present invention, and the description is relatively specific and detailed, but it cannot be understood as limiting the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, several modifications and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention. Therefore, the protection scope of the patent of the present invention shall be based on the attached claims, and the description can be used to interpret the content of the claims.

Claims

1. A method for extracting cesium from salt lake brine, characterized in that: The following steps are involved: The cesium extraction adsorbent is used to extract cesium from salt lake brine to achieve effective separation of rubidium and cesium; The preparation method of the cesium extraction adsorbent comprises the following steps: Prepare a sodium tungstate solution with a concentration of 1.8 mol / L, a sodium pyrophosphate solution with a concentration of 1.8 mol / L, and a titanium nitrate solution with a concentration of 3.0 mol / L; first take an equal amount of the sodium pyrophosphate solution and add it to 50 mL of the sodium tungstate solution, react at room temperature for 1 hour to obtain a sodium pyrophosphorus tungstate solution; then add 100 mL of the titanium nitrate solution, and continue to react at room temperature for 2 hours; transfer to an oven, and age at 60°C for 2 hours to obtain an aged mother liquor; filter the aged mother liquor to obtain a filter cake; dry the filter cake, and grind it to obtain a powdered cesium ion sieve; Take 100 mL of N-methylpyrrolidone, add 4% by weight of PEG-1000, stir until completely dissolved, then add 12.5 g of PVC powder, stir until completely dissolved, and obtain a mixed solution; According to the mass ratio of the mixed liquid to the cesium ion sieve being 0.9:1, the cesium ion sieve is added to the mixed liquid, and the mixture is stirred evenly to obtain a slurry; the slurry is dropped into water to be transformed into particles, and the particles are washed with water 1 to 2 times to obtain the cesium extraction adsorbent.

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