Rubidium adsorbent and its preparation method and application

Abstract

This invention provides a rubidium adsorbent, its preparation method, and its application, relating to the technical field of rubidium extraction from salt lakes. The rubidium adsorbent comprises a porous resin and an adsorbent matrix encapsulated within the porous resin; the adsorbent matrix has the following chemical formula: Li₂Zn₃Fe₂(CN). 12 ·9H2O. This invention not only solves the technical problem of low selectivity of rubidium adsorbent adsorption sites for rubidium ions, but also solves the technical problems of low adsorption performance and low production efficiency caused by first preparing adsorbent powder and then granulating it through a specific preparation method. Furthermore, it solves the problem of low product purity obtained by rubidium adsorbent in engineering applications through a specific rubidium extraction process. It achieves the technical effects of high selectivity of adsorbent for rubidium ions, simultaneous completion of adsorbent powder and powder granulation, high production efficiency, good economy, and obtaining high-purity rubidium chloride products from salt lake brine.

Description

Technical Field

[0001] This invention relates to the technical field of rubidium extraction from salt lakes, and in particular to a rubidium adsorbent, its preparation method, and its application. Background Technology

[0002] The extraction of rubidium from brine is a relatively simple process, requiring less energy and incurring lower costs, making it a major direction for the development of the rubidium production industry. Currently, the main methods for extracting rubidium from solutions include precipitation, ion exchange, and solvent extraction. Ion exchange is characterized by its simplicity, high recovery rate, and good selectivity, making it an important method for extracting rubidium from liquid resources such as brine.

[0003] Patent CN115522068A discloses a method for separating rubidium and cesium from a high-salt mother liquor. This patent uses a co-precipitation method to convert rubidium and cesium ions in the solution into a precipitate (Rb,Cs)2ZnFe(CN)6, which is then calcined at high temperature. The resulting solid residue is then soaked in organic solvent and water respectively to obtain rubidium carbonate product. Due to the low concentration of rubidium ions in the original solution, this method is time-consuming and expensive for solid-liquid separation, and the calcination process produces highly toxic hydrogen cyanide gas.

[0004] Patent CN117160404A relates to a porous composite material, its preparation method, and its application. The porous composite material comprises: a porous crosslinked polymer support and a metal salt loaded within the porous crosslinked polymer support; the chemical formula of the metal salt is M. x N y Fe(CN)6, where M represents a divalent metal ion and N represents a metal ion with a valence of trivalent or higher, 0 < x < 2, 0 < y < 1; This patent uses a cross-linking polymerization reaction between the oil phase and the aqueous phase to prepare the adsorbent, which is cumbersome and generates a large amount of toxic and harmful organic wastewater during the preparation process; In addition, this patent soaks the porous cross-linked polymer carrier in a raw material solution, and after the porous cross-linked polymer carrier is saturated with adsorption, it is then placed in another raw material solution for reaction. This synthesis method will lead to the effective component M of the adsorbent loaded on the carrier being reduced. x N y The very low Fe(CN)6 content is detrimental to increasing the adsorption capacity per unit volume; furthermore, the adsorbent obtained by this patent has the chemical formula M. x N y Fe(CN)6 has M as a divalent metal ion and N as a trivalent metal ion. The exchangeable cations in the lattice are divalent metal ions, but rubidium ions are monovalent ions. The charge of the adsorption sites in the lattice does not match the charge of the adsorbed ions, which leads to a decrease in the selectivity of the adsorbent.

[0005] Developing rubidium adsorbents with specific selectivity for rubidium ions is key to rubidium extraction from salt lake brine.

[0006] In view of this, the present invention is hereby proposed. Summary of the Invention

[0007] One of the objectives of this invention is to provide a rubidium adsorbent that has high selectivity for rubidium ions and advantages such as large adsorption capacity and stable adsorption performance.

[0008] The second objective of this invention is to provide a method for preparing rubidium adsorbents, which enables the simultaneous completion of powder synthesis and granulation, reduces the production process, improves production efficiency and economy, and also enhances the overall performance of rubidium adsorbents.

[0009] The third objective of this invention is to provide an application of rubidium adsorbent that facilitates the extraction of high-purity rubidium chloride products.

[0010] In order to achieve the above-mentioned objectives of the present invention, the following technical solution is adopted:

[0011] In a first aspect, a rubidium adsorbent includes a porous resin and an adsorbent body encapsulated in the porous resin;

[0012] The adsorbent matrix has the following chemical formula:

[0013] Li2Zn3Fe2(CN) 12 ·9H2O.

[0014] Furthermore, the porous resin includes PVB resin;

[0015] Preferably, the particle size of the rubidium adsorbent is 1 mm to 1.5 mm.

[0016] Secondly, a method for preparing the rubidium adsorbent according to any one of the above claims includes the following steps:

[0017] The first slurry containing Na4Fe(CN)6 and resin was dropped onto a ball containing Zn. 2+ and Rb + In the second slurry, phase inversion and co-precipitation reactions occur to obtain resin-encapsulated Na. x Rb 2-x Zn3Fe2(CN) 12 ·9H2O;

[0018] Will Na x Rb 2-x Zn3Fe2(CN) 12 Na in 9H2O + Replace with Rb + Then Rb + Replace with Li+ The rubidium adsorbent was obtained.

[0019] Furthermore, the amount of resin added is 7% to 14% of the mass of Na4Fe(CN)6;

[0020] Preferably, the solvent used in the first slurry includes at least one of ethanol and glycerol, and more preferably ethanol and glycerol;

[0021] Preferably, the amount of ethanol added is 100% to 150% of the mass of Na4Fe(CN)6;

[0022] Preferably, the amount of glycerol added is 15% to 40% of the mass of Na4Fe(CN)6;

[0023] Preferably, the viscosity of the first slurry is 2000 mPa·s to 5000 mPa·s.

[0024] Furthermore, the method of dripping the ball includes using a ball-drip device to drip the ball;

[0025] Preferably, the diameter of the orifice of the dropper is 1mm to 1.5mm;

[0026] Preferably, the number of holes in the ball dropper is 500 to 1000.

[0027] Furthermore, the Zn 2+ The sources include ZnCl2;

[0028] Preferably, the amount of ZnCl2 added is 150% to 250% of the amount of Na4Fe(CN)6.

[0029] Preferably, the Rb + Sources include RbCl;

[0030] Preferably, the amount of RbCl added is 100% to 150% of the amount of Na4Fe(CN)6.

[0031] Preferably, the solvent used in the second slurry includes at least one of ethanol and water, and more preferably ethanol and water.

[0032] Furthermore, the total time for the phase transformation and coprecipitation reaction is 12h to 24h;

[0033] Preferably, the Na + Replace with Rb + The reaction temperature is 80℃~95℃, and the reaction time is 3h~6h;

[0034] Preferably, the Rb + Replace with Li +The reaction time is 12h to 24h.

[0035] Thirdly, the application of any of the above-mentioned rubidium adsorbents in rubidium extraction from salt lakes.

[0036] Furthermore, the method for extracting rubidium from salt lakes includes the following steps:

[0037] After the rubidium adsorbent adsorbs rubidium ions from the salt lake brine, it is then analyzed through the regeneration solution to obtain Rb-containing... + The eluent, containing Rb + The eluent was subjected to precipitation to obtain precipitate RbB(C6H5)4;

[0038] The precipitate RbB(C6H5)4 was pulped with ammonium chloride solution and then subjected to solid-liquid separation to obtain a filtrate containing RbCl and a filter cake containing NH4B(C6H5)4. The filtrate containing RbCl was then evaporated to obtain RbCl.

[0039] Furthermore, the regeneration solution includes a LiCl solution;

[0040] Preferably, the Rb-containing + The precipitant used when precipitating the eluent includes LiB(C6H5)4;

[0041] Preferably, the solid-liquid separation method includes plate and frame filtration;

[0042] Preferably, the method for extracting rubidium from salt lakes further includes the following steps:

[0043] The NH4B(C6H5)4 filter cake was pulped, and then LiOH solution was added to react and obtain LiB(C6H5)4 solution, which was then reused for Rb-containing applications. + In the step of precipitation of the eluent.

[0044] Compared with the prior art, the present invention has at least the following beneficial effects:

[0045] The rubidium adsorbent provided by this invention solves the problem of low selectivity of rubidium ions at the adsorption sites of rubidium adsorbents. This rubidium adsorbent has high selectivity for rubidium ions and also has the advantages of large adsorption capacity and stable adsorption performance. The porous resin wraps around and fixes the adsorbent body, which can prevent the adsorbent powder from falling off. The extensive network pore structure of the porous resin can also improve the adsorption and elution of rubidium ions, thereby improving the ion exchange efficiency.

[0046] The rubidium adsorbent preparation method provided by this invention solves the problems of low adsorption performance and low production efficiency caused by first preparing adsorbent powder and then granulating it. This preparation method realizes the simultaneous completion of powder synthesis and powder granulation, which not only reduces the production process and improves production efficiency and economy, but also improves the overall performance of rubidium adsorbent.

[0047] The application of rubidium adsorbent provided by this invention solves the problem of low product purity in the engineering application of rubidium adsorbent, which is beneficial for extracting high-purity rubidium chloride products. Attached Figure Description

[0048] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0049] Figure 1 A process flow diagram of a method for preparing a rubidium adsorbent according to one embodiment of the present invention;

[0050] Figure 2 A process flow diagram for rubidium extraction from salt lakes provided for one embodiment of the present invention;

[0051] Figure 3 The images shown are physical photos and scanning electron microscope images of the rubidium adsorbent microspheres provided in Embodiment 1 of the present invention.

[0052] Figure 4 The XRD pattern of the rubidium adsorbent provided in Example 1 of this invention;

[0053] Figure 5 This is a graph showing the change in adsorption capacity of the rubidium adsorbent provided in Example 2 of the present invention;

[0054] Figure 6 This is a graph showing the purity variation of the RbCl product provided in Example 2 of the present invention.

[0055] Figure 7 The images shown are physical photos and scanning electron microscope images of the rubidium adsorbent microspheres provided in Embodiment 3 of the present invention.

[0056] Figure 8 The XRD pattern of the rubidium adsorbent provided in Example 3 of this invention;

[0057] Figure 9 This is a graph showing the change in adsorption capacity of the rubidium adsorbent provided in Example 4 of the present invention.

[0058] Figure 10This is a graph showing the purity variation of the RbCl product provided in Example 4 of the present invention.

[0059] Figure 11 The images shown are physical photos and scanning electron microscope images of the rubidium adsorbent microspheres provided in Embodiment 5 of the present invention.

[0060] Figure 12 The XRD pattern of the rubidium adsorbent provided in Example 5 of this invention;

[0061] Figure 13 This is a graph showing the change in adsorption capacity of the rubidium adsorbent provided in Example 6 of the present invention.

[0062] Figure 14 This is a graph showing the purity variation of the RbCl product provided in Example 6 of the present invention. Detailed Implementation

[0063] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are some embodiments of the present invention, but not all embodiments.

[0064] According to a first aspect of the present invention, a rubidium adsorbent is provided, comprising a porous resin and an adsorbent body encapsulated in the porous resin;

[0065] The adsorbent body has the following chemical formula:

[0066] Li2Zn3Fe2(CN) 12 ·9H2O.

[0067] The rubidium adsorbent provided by this invention solves the problem of low selectivity of rubidium ions at the adsorption sites of rubidium adsorbents. This rubidium adsorbent has high selectivity for rubidium ions and also has the advantages of large adsorption capacity and stable adsorption performance. The porous resin wraps around and fixes the adsorbent body, which can prevent the adsorbent powder from falling off. The extensive network pore structure of the porous resin can also improve the adsorption and elution of rubidium ions, thereby improving the ion exchange efficiency.

[0068] In a preferred embodiment, the porous resin includes, but is not limited to, PVB resin.

[0069] In this invention, PVB resin (polyvinyl butyral) is used as an organic binder, and the adsorbent body is coated with PVB resin. This can prevent the adsorbent powder from falling off. At the same time, the porous structure formed by PVB resin and the well-connected network of pores are more conducive to further improving the adsorption and elution of rubidium ions, thereby further improving the ion exchange efficiency of the rubidium adsorbent.

[0070] In a preferred embodiment, the particle size of the rubidium adsorbent can be 1 mm to 1.5 mm, with typical but non-limiting particle sizes such as 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, and 1.5 mm, which is more conducive to further improving the adsorption effect.

[0071] According to a second aspect of the present invention, a method for preparing the rubidium adsorbent according to any one of the above claims is provided, comprising the following steps:

[0072] (a) Dropping a first slurry containing Na4Fe(CN)6 and resin onto a surface containing Zn 2+ and Rb + In the second slurry, phase inversion and co-precipitation reactions occur to obtain resin-encapsulated Na. x Rb 2-x Zn3Fe2(CN) 12 ·9H2O;

[0073] It should be noted that in step (a), powder synthesis and granulation are carried out simultaneously. In this step, solid powder Na4Fe(CN)6 is blended with resin (organic binder), while non-organic particles are soaked in Na4Fe(CN)6 solution. Therefore, the effective content of rubidium adsorbent in the particles can be greatly increased, resulting in a larger rubidium adsorption capacity per unit volume.

[0074] (b) Put Na x Rb 2-x Zn3Fe2(CN) 12 Na in 9H2O + Replace with Rb + Then Rb + Replace with Li + Rubidium adsorbent was obtained.

[0075] In traditional preparation methods, after the adsorbent powder is obtained, it needs to be granulated for use. Current granulation methods cannot achieve simultaneous powder synthesis and granulation; synthesizing the powder first and then granulating it significantly reduces the powder's adsorption capacity and other properties. This invention, through a specific preparation method, breaks through the inefficient situation of synthesizing the powder first and then granulating it, achieving simultaneous powder synthesis and granulation. This reduces process steps, improves production efficiency and economy, and also enhances the overall performance of the rubidium adsorbent.

[0076] In summary, the rubidium adsorbent preparation method provided by this invention solves the problems of low adsorption performance and low production efficiency caused by first preparing adsorbent powder and then granulating it. This preparation method realizes the simultaneous completion of powder synthesis and powder granulation, which not only reduces the production process and improves production efficiency and economy, but also improves the overall performance of rubidium adsorbent.

[0077] In a preferred embodiment, the amount of resin (PVB) added can be 7% to 14% of the mass of Na4Fe(CN)6, for example, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, but is not limited thereto.

[0078] In a preferred embodiment, the solvent used in the first slurry includes, but is not limited to, at least one of ethanol and glycerol, preferably ethanol and glycerol.

[0079] In this invention, Na4Fe(CN)6 is one of the reaction raw materials for synthesizing the rubidium adsorbent precursor, and is insoluble in ethanol and glycerol; the resin (for example, it can be PVB resin, but is not limited thereto) is an organic binder, soluble in ethanol and glycerol; after mixing Na4Fe(CN)6, PVB resin, ethanol and glycerol, the PVB resin will dissolve in ethanol and glycerol to form a homogeneous slurry, while the Na4Fe(CN)6 powder will be uniformly dispersed in the organic slurry, thereby obtaining the first slurry, which can be denoted as Na4Fe(CN)6-PVB-ethanol-glycerol.

[0080] It should be noted that Na4Fe(CN)6 and PVB resin are blended in two alcohol solvents, ethanol and glycerol, instead of using ethanol alone. This is because ethanol has a high solubility for PVB resin, which enables efficient dissolution of the PVB resin. Furthermore, glycerol is used as a dispersant to ensure that the Na4Fe(CN)6 powder is evenly dispersed in the PVB-containing slurry, while preventing the Na4Fe(CN)6 powder from settling. This effectively achieves uniform dispersion of all substances in the slurry.

[0081] In a preferred embodiment, the amount of ethanol added can be 100% to 150% of the mass of Na4Fe(CN)6, for example, 100%, 110%, 120%, 130%, 140%, 150%, but not limited thereto; the amount of glycerol added can be 15% to 40% of the mass of Na4Fe(CN)6, for example, 15%, 20%, 25%, 30%, 35%, 40%, but not limited thereto.

[0082] In a preferred embodiment, the viscosity of the first slurry is 2000 mPa·s to 5000 mPa·s, with typical but non-limiting viscosities such as 2000 mPa·s, 3000 mPa·s, 4000 mPa·s, and 5000 mPa·s.

[0083] In a preferred embodiment, the method of dripping the ball includes, but is not limited to, using a ball-drip device; wherein the diameter of the orifice of the ball-drip device can be 1mm to 1.5mm, for example, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, but is not limited thereto.

[0084] In a preferred embodiment, Zn 2+ The source includes, but is not limited to, ZnCl2; wherein, the amount of ZnCl2 added can be 150% to 250% of the amount of Na4Fe(CN)6, for example, 150%, 160%, 170%, 180%, 190%, 200%, 210%, 220%, 230%, 240%, 250%, but is not limited to this.

[0085] In a preferred embodiment, Rb + The sources include, but are not limited to, RbCl; wherein, the amount of RbCl added can be 100% to 150% of the amount of Na4Fe(CN)6, for example, 100%, 110%, 120%, 130%, 140%, 150%, but not limited to this.

[0086] In the second slurry, ZnCl2 and RbCl are both reaction raw materials for the synthesis of rubidium adsorbent precursors; ethanol and water can be used as solvents (ethanol can account for 20% to 35% of the water mass) to dissolve ZnCl2 and RbCl to form a solution, thus obtaining the second slurry, which can be denoted as ZnCl2-RbCl-ethanol-H2O.

[0087] It should be noted that adding anhydrous ethanol (20%–35% of the H2O mass) to the ZnCl2-RbCl-H2O solution utilizes the hydrophilicity of ethanol to slow down the diffusion rate of H2O from the ZnCl2-RbCl-ethanol-H2O solution into the Na4Fe(CN)6-PVB interior, thereby slowing down the dissolution rate of Na4Fe(CN)6. This is beneficial to the dissolution of Zn in the ZnCl2-RbCl-ethanol-H2O solution. 2+ , Rb + Sufficient time is allowed for diffusion into the interior of Na4Fe(CN)6-PVB microspheres, while preventing the Na4Fe(CN)6 in the Na4Fe(CN)6-PVB microspheres from dissolving and diffusing into the ZnCl2-RbCl-ethanol-H2O solution, thus avoiding waste of raw materials.

[0088] In this invention, when the first slurry (Na4Fe(CN)6-PVB-ethanol-glycerol) is dripped into the second slurry (ZnCl2-RbCl-ethanol-H2O) through a dropper, the ethanol and glycerol in the Na4Fe(CN)6-PVB-ethanol-glycerol slurry rapidly dissolve and diffuse into the ZnCl2-RbCl-ethanol-H2O solution. The PVB organic binder, having lost the high concentration of ethanol and glycerol as solvents, quickly hardens and solidifies (PVB gels and hardens), transforming the soft Na4Fe(CN)6-PVB-ethanol-glycerol spheres into hard Na4Fe(CN)6-PVB spheres, thus achieving the granulation and molding process. This process is a dropper and phase inversion process. Simultaneously, the Zn in the ZnCl2-RbCl-ethanol-H2O solution... 2+ , Rb + H2O diffuses into the Na4Fe(CN)6-PVB hard microspheres. Upon contact with the Na4Fe(CN)6 powder, H2O slowly and gradually dissolves it. Zn 2+ and Rb + It undergoes a co-precipitation reaction with dissolved Na₄Fe(CN)₆ to form water-insoluble crystals of Na. x Rb 2-x Zn3Fe2(CN) 12 ·9H2O, the crystal is wrapped and fixed inside the sphere by PVB organic resin, the above process realizes Na x Rb 2-x Zn3Fe2(CN) 12 Simultaneous preparation of 9H2O powder and powder granulation resulted in Na+ encapsulated in PVB resin. x Rb 2-x Zn3Fe2(CN) 12 ·9H2O can be written as Na x Rb 2-x Zn3Fe2(CN) 12 ·9H2O-PVB hard microspheres.

[0089] In a preferred embodiment, the total time for the phase transformation and coprecipitation reaction can be 12h to 24h, for example, 12h, 14h, 16h, 18h, 20h, 22h, or 24h, but is not limited to this. This method is more conducive to a complete reaction and to improving the Na+ content. x Rb 2-x Zn3Fe2(CN) 12 • The formation effect of 9H2O-PVB hard microspheres.

[0090] In a preferred embodiment, Na x Rb 2-x Zn3Fe2(CN) 12·9H2O-PVB hard microspheres can react with RbCl solution, Na + Replace with Rb + This results in the generation of Rb2Zn3Fe2(CN). 12 ·9H2O.

[0091] Rb in RbCl solution + Diffusion migration to Na x Rb 2-x Zn3Fe2(CN) 12 ·9H2O-PVB inside the microsphere, and with Na x Rb 2-x Zn3Fe2(CN) 12 Na on 9H2O crystal + The substitution process transforms all exchangeable cations in the crystal lattice into Rb. + This process is an "ion imprinting-lattice perfection" process, which generates Rb2Zn3Fe2(CN). 12 ·9H2O yields Rb2Zn3Fe2(CN). 12 ·9H2O-PVB microspheres.

[0092] In a preferred embodiment, Na + Replace with Rb + The reaction temperature can range from 80℃ to 95℃, with typical but non-limiting reaction temperatures including 80℃, 82℃, 84℃, 86℃, 88℃, 90℃, 91℃, 92℃, 93℃, 94℃, and 95℃; Na + Replace with Rb + The reaction time can be 3h to 6h, with typical but non-limiting reaction times being 3h, 4h, 5h, and 6h.

[0093] It should be noted that Na x Rb 2-x Zn3Fe2(CN) 12 • 9H₂O-PVB microspheres transform into Rb₂Zn₃Fe₂(CN) 12 The 9H₂O-PVB microspheres were replaced with RbCl solution at 80℃~95℃. This process allows [Zn₃Fe₂(CN)₂] to be replaced. 12 ] 2- All imprinted ions in the crystal have been replaced by rubidium ions (Rb). + The imprinted sites are specifically selective for rubidium ions, thereby improving the adsorption selectivity of the rubidium adsorbent for rubidium ions; secondly, the crystal needs to absorb energy to complete the process during its growth and maturation. At a temperature of 80℃~95℃ and a time of 3h~6h, Rb2Zn3Fe2(CN) is generated.12 The crystal structure of 9H2O powder is more regular and complete, significantly reducing lattice defects, which is beneficial for improving the adsorption of Rb during the adsorption process. + The selectivity.

[0094] In a preferred embodiment, Rb2Zn3Fe2(CN) 12 ·9H2O-PVB microspheres can react with LiCl solution to obtain Rb + Replace with Li + This results in the formation of Li2Zn3Fe2(CN). 12 ·9H2O-PVB microspheres are rubidium adsorbent products.

[0095] LiCl solution Li + Diffusion to Rb2Zn3Fe2(CN) 12 The 9H2O-PVB microspheres are filled with Rb2Zn3Fe2(CN) and replaced. 12 Exchangeable ions Rb on 9H2O crystals + This process is a lithium replacement process, resulting in the rubidium adsorbent Li2Zn3Fe2(CN). 12 ·9H2O-PVB microsphere products.

[0096] It should be noted that Rb2Zn3Fe2(CN) 12 ·9H2O-PVB can be reacted by immersing it in a 4mol / L to 8mol / L LiCl solution, thereby transforming it into Li2Zn3Fe2(CN). 12 ·9H2O-PVB product; in this process, lithium ions (Li + It has a high migration rate and a small ionic radius, so it has high exchange efficiency in the ion exchange process and can increase the rubidium adsorption capacity per unit time.

[0097] In a preferred embodiment, at room temperature, Rb + Replace with Li + The reaction time can be from 12 hours to 24 hours, for example, 12 hours, 14 hours, 16 hours, 18 hours, 20 hours, 22 hours, or 24 hours, but it is not limited to this, which is more conducive to Rb + Completely replaced by Li + This is more conducive to improving the efficiency of Li2Zn3Fe2(CN). 12 • The formation effect of 9H2O-PVB microspheres.

[0098] A typical preparation method for a rubidium adsorbent includes dropping beads, phase inversion, coprecipitation, ion imprinting-lattice perfection, and lithium replacement, see [link to relevant documentation]. Figure 1 The specific steps are as follows:

[0099] Na x Rb 2-x Zn3Fe2(CN) 12 Synthesis of 9H2O-PVB hard microspheres:

[0100] The Na4Fe(CN)6-PVB-ethanol-glycerol slurry is fed into a dropper with 500-1000 holes and a diameter of 1-1.5 mm through a feed pump. The Na4Fe(CN)6-PVB-ethanol-glycerol slurry is then dropped into a ZnCl2-RbCl-ethanol-H2O solution through a 1-1.5 mm orifice, and allowed to stand for 12-24 hours to react.

[0101] The chemical reactions that occur are as follows:

[0102] 2Na4Fe(CN)6-PVB-ethanol-glycerol (soft paste) + 3ZnCl2 + (2-x)RbCl = Na x Rb 2-x Zn3Fe2(CN) 12 ·9H2O-PVB (hard spheres) + (8-x)NaCl + ethanol + glycerol;

[0103] During the above reaction process, the ethanol and glycerol in the Na4Fe(CN)6-PVB-ethanol-glycerol slurry dissolve and diffuse into the ZnCl2-RbCl-ethanol-H2O solution from the surface and interior of the microspheres. The PVB organic binder in the microspheres, having lost the high concentration of ethanol and glycerol as solvents, quickly hardens and solidifies, transforming the soft Na4Fe(CN)6-PVB-ethanol-glycerol microspheres into hard Na4Fe(CN)6-PVB microspheres. This process is a droplet-forming and phase-inversion process. Simultaneously, water from the ZnCl2-RbCl-ethanol-H2O solution diffuses into the hard Na4Fe(CN)6-PVB microspheres. Upon contact with the Na4Fe(CN)6 powder, the water slowly and gradually dissolves it, and the Zn in the ZnCl2-RbCl-ethanol-H2O solution... 2+ and Rb + It will diffuse from the solution into the Na4Fe(CN)6-PVB hard microspheres, Zn 2+ and Rb + It undergoes a co-precipitation reaction with dissolved Na₄Fe(CN)₆ to form Na₂ x Rb 2-x Zn3Fe2(CN) 12 ·9H2O is a water-insoluble solid, which is thus wrapped and fixed inside the sphere by PVB organic resin; the above process realizes Na x Rb 2- xZn3Fe2(CN) 12 The preparation of 9H2O powder and the granulation of powder were carried out simultaneously to obtain Na. x Rb 2-x Zn3Fe2(CN) 12 ·9H2O-PVB hard microspheres;

[0104] Rb2Zn3Fe2(CN) 12 Synthesis of 9H2O-PVB microspheres:

[0105] Na x Rb 2-x Zn3Fe2(CN) 12 · 9H2O-PVB hard microspheres were added to an RbCl solution with a molar concentration of 1 mol / L to 2 mol / L, and the solution was heated to 80℃ to 95℃ and reacted at a constant temperature for 3h to 6h.

[0106] The chemical reactions that occur are as follows:

[0107] Na x Rb 2-x Zn3Fe2(CN) 12 ·9H2O-PVB+xRbCl=Rb2Zn3Fe2(CN) 12 ·9H2O-PVB

[0108] +xNaCl;

[0109] During the above reaction process, Rb in the RbCl solution + Diffusion migration to Na x Rb 2-x Zn3Fe2(CN) 12 ·9H2O-PVB inside the microsphere, and with Na x Rb 2-x Zn3Fe2(CN) 12 Na on 9H2O crystal + The substitution process transforms all exchangeable cations in the crystal lattice into Rb. + Meanwhile, at a solution temperature of 80℃~95℃, the Rb2Zn3Fe2(CN) produced by the reaction... 12 The crystal structure of 9H2O powder is more regular and complete, which can significantly reduce lattice defects. This is beneficial to improving the adsorbent's ability to absorb Rb. + The selectivity; the above process is an "ion imprinting-lattice perfection" process, yielding Rb2Zn3Fe2(CN). 12 ·9H2O-PVB microspheres;

[0110] Li2Zn3Fe2(CN) 12Synthesis of 9H2O-PVB microspheres:

[0111] Rb2Zn3Fe2(CN) 12 · 9H2O-PVB microspheres were added to a LiCl solution with a molar concentration of 4 mol / L to 8 mol / L and allowed to stand at room temperature for 12 h to 24 h.

[0112] The chemical reactions that occur are as follows:

[0113] Rb2Zn3Fe2(CN) 12 ·9H2O-PVB+2LiCl=Li2Zn3Fe2(CN) 12 ·9H2O-PVB+

[0114] 2RbCl;

[0115] During the above reaction process, the high concentration of Li in the LiCl solution... + Diffusion to Rb2Zn3Fe2(CN) 12 The 9H2O-PVB microspheres are filled with Rb2Zn3Fe2(CN) and replaced. 12 Exchangeable ions Rb on 9H2O crystals + This process is a lithium substitution process, yielding Li₂Zn₃Fe₂(CN). 12 The 9H2O-PVB microsphere product is a rubidium adsorbent.

[0116] According to a third aspect of the present invention, the application of the rubidium adsorbent described in any of the above claims in rubidium extraction from salt lakes is provided.

[0117] The application of rubidium adsorbent provided by this invention solves the problem of low product purity in the engineering application of rubidium adsorbent, which is beneficial for extracting high-purity rubidium chloride products.

[0118] In a preferred embodiment, the method for extracting rubidium from salt lakes includes the following steps:

[0119] The rubidium adsorbent of this invention adsorbs rubidium ions from salt lake brine, and then undergoes desorption via a regeneration solution to obtain Rb-containing... + The eluent containing Rb was taken. + The eluent was subjected to precipitation to obtain precipitate RbB(C6H5)4;

[0120] The precipitate RbB(C6H5)4 was pulped with ammonium chloride solution and then subjected to solid-liquid separation to obtain a filtrate containing RbCl and a filter cake containing NH4B(C6H5)4. The filtrate containing RbCl was then evaporated to obtain RbCl.

[0121] After the rubidium adsorbent is saturated with rubidium ions, the rubidium ions need to be eluted. Current methods for purifying rubidium ions in the eluent are difficult to obtain high-purity rubidium chloride (RbCl) products. However, the method for extracting rubidium from salt lakes in this invention, through the synergistic cooperation of each step, solves the problem of obtaining low-purity products from rubidium adsorbents in engineering applications, and achieves the goal of extracting high-purity rubidium chloride products.

[0122] In a preferred embodiment, the regeneration solution includes, but is not limited to, LiCl solution.

[0123] After the rubidium adsorbent is saturated with rubidium ions, LiCl solution is used as the regeneration solution; one method utilizes lithium ions (Li... + The advantages of small size and high migration rate allow for rapid replacement of rubidium ions on the rubidium adsorbent sites, thereby improving the desorption efficiency; secondly, lithium ions (Li) in the desorption solution... + ) and rubidium ions (Rb + When rubidium ions (Rb) coexist, it is easier to achieve rubidium ion (Rb) + ) precipitation separation.

[0124] In a preferred embodiment, Rb is included. + The precipitating agents used when precipitating the eluent include, but are not limited to, LiB(C6H5)4.

[0125] Lithium tetraphenylboron (LiB(C6H5)4) was used as the precipitant for rubidium ions. [B(C6H5)4]- can react with Rb. + The precipitate RbB(C6H5)4, which is sparingly soluble in water, is formed, thereby enabling the efficient separation and precipitation of rubidium ions from the eluent, while the eluent can be recycled.

[0126] The production of RbCl from RbB(C6H5)4 involves soaking and pulping solid RbB(C6H5)4 with a saturated ammonium chloride solution. This process converts solid RbB(C6H5)4 into solid NH4B(C6H5)4. After solid-liquid separation, solid NH4B(C6H5)4 and a solution containing RbCl and NH4Cl are obtained. This method provides a simple and efficient way to produce RbCl from RbB(C6H5)4. + It changes from a solid state to a solution state.

[0127] In a preferred embodiment, the solid-liquid separation method includes, but is not limited to, plate and frame filtration.

[0128] After plate and frame filtration, a filtrate containing RbCl and NH4Cl is obtained. This filtrate can be dehydrated by triple-effect evaporation to obtain solid RbCl and NH4Cl. Meanwhile, since solid ammonium chloride (NH4Cl) is easily decomposed by heat, a negative pressure heater can be used to thermally decompose the ammonium chloride, thereby obtaining a high-purity solid RbCl product. The entire process is not only simple to operate, but also yields a high-purity RbCl product.

[0129] In a preferred embodiment, the NH4B(C6H5)4 filter cake obtained after plate and frame filtration is pulped, and then LiOH solution is added to react and obtain LiB(C6H5)4 solution, which can be reused for Rb-containing applications. + In the step of precipitation of the eluent.

[0130] A typical method for rubidium extraction from salt lakes, see... Figure 2 This includes the following steps:

[0131] Rubidium ion adsorption process: Rubidium adsorbent Li2Zn3Fe2(CN) is packed into the adsorption column. 12 Using 9H2O-PVB microspheres, rubidium-containing brine from a salt lake is pumped from bottom to top into an adsorption column at a flow rate of 5 BV / h to 10 BV / h for an adsorption time of 10 to 20 hours. The following chemical reaction occurs during this process: Li2Zn3Fe2(CN). 12 ·9H2O-PVB+xRb + =Rb x Li 2-x Zn3Fe2(CN) 12 ·9H2O-PVB+xLi + The brine from the salt lake, after adsorbing rubidium ions, is then discharged back into the salt lake.

[0132] The rubidium ion removal process involves using a LiCl solution with a concentration of 4 mol / L to 8 mol / L as the regenerator, pumped from top to bottom into the adsorption column at a flow rate of 2 BV / h to 4 BV / h. The removal time is 3 to 5 hours. The following chemical reaction occurs during this process: Rb x Li 2-x Zn3Fe2(CN) 12 ·9H2O-PVB+xLi + =Li₂Zn₃Fe₂(CN) 12 ·9H2O-PVB+xRb + The eluent is stored in an eluent tank, and the eluent mainly contains rubidium ions (Rb). + ) and lithium ion (Li + );

[0133] Rubidium precipitation separation process: A lithium tetraphenylborate (LiB(C6H5)4) solution with a molar concentration of 0.5 mol / L-1 mol / L is added to the eluent tank (containing RbCl+LiCl) until no more RbB(C6H5)4 precipitate appears in the supernatant of the eluent. The following chemical reaction occurs during this process: Rb + +LiB(C6H5)4=RbB(C6H5)4 precipitate +Li + ;

[0134] The mixture containing RbB(C6H5)4 and LiCl was subjected to plate and frame filter press filtration and the filter cake was washed to obtain RbB(C6H5)4 solid filter cake with a water content of 40% to 50% and a reusable LiCl solution.

[0135] Precipitation conversion and RbCl product extraction process: RbB(C6H5)4 solid filter cake with a water content of 40% to 50% is slurried with saturated ammonium chloride solution. The mass ratio of RbB(C6H5)4 solid filter cake to saturated ammonium chloride solution can be 1:2 to 1:3. After stirring for 1 to 4 hours, the slurry is then subjected to plate and frame filter press and the filter cake is washed to obtain a filtrate containing RbCl and NH4Cl and an NH4B(C6H5)4 solid filter cake. The chemical reaction that occurs in this process is: RbB(C6H5)4 (solid) + NH4Cl = NH4B(C6H5)4 (solid) + RbCl.

[0136] The filtrate containing RbCl and NH4Cl was subjected to triple-effect evaporation to obtain a solid mixture of RbCl and NH4Cl. Since ammonium chloride (NH4Cl) solid is easily decomposed by heat, the solid mixture of RbCl and NH4Cl was placed in a negative pressure heater at 200℃~300℃ and heated for 1h~3h to obtain a high-purity RbCl product. The chemical reaction that occurs in this process is: NH4Cl=NH3(gas)+HCl(gas); NH3(gas) and HCl react to obtain solid NH4Cl, which can be reused in the NH4Cl solution.

[0137] The NH4B(C6H5)4 solid filter cake is pulped with pure water, and then a saturated LiOH solution is slowly added to the pulp to obtain a LiB(C6H5)4 solution, which can be reused in the rubidium precipitation step (i.e., realizing the recycling of LiB(C6H5)4 solution). The chemical reaction that occurs in this process is: NH4B(C6H5)4 (solid) + LiOH = LiB(C6H5)4 (solution) + NH3 (gas) + H2O.

[0138] In summary, this invention utilizes rubidium adsorbents for rubidium extraction from salt lakes. Through the synergistic coordination of each step and its process parameters, it solves the problem of low product purity in the engineering application of rubidium adsorbents, and achieves the goal of extracting high-purity rubidium chloride products.

[0139] It should be noted that the slurry and solution involved in this invention are prepared by the following method:

[0140] Preparation of Na4Fe(CN)6-PVB-ethanol-glycerol slurry: In a ball mill, first add 300kg-450kg of Na4Fe(CN)6 powder with a particle size of 0.5μm-10μm, then add the organic binder polyvinyl butyral (PVB) powder (which accounts for 7%-14% of the mass of Na4Fe(CN)6 powder), then add anhydrous ethanol (which accounts for 100%-150% of the mass of Na4Fe(CN)6 powder), and finally add glycerol (which accounts for 15%-40% of the mass of Na4Fe(CN)6 powder). Then ball mill at room temperature and pressure for 3h-10h to obtain a Na4Fe(CN)6-PVB-ethanol-glycerol slurry with a viscosity of 2000mPa·s-5000mPa·s.

[0141] Preparation of ZnCl2-RbCl-ethanol-H2O solution: In a stainless steel container, first add 900 kg to 1500 kg of deionized water, then add anhydrous ethanol (20% to 35% of the water mass), then add ZnCl2 powder (150% to 250% of the Na4Fe(CN)6 powder mass) and RbCl powder (100% to 150% of the Na4Fe(CN)6 powder mass), and stir for 1 to 3 hours to obtain the ZnCl2-RbCl-ethanol-H2O solution.

[0142] RbCl solution preparation: In a stainless steel container, first add RbCl powder, then add deionized water and stir for 1 to 3 hours to obtain an RbCl solution with a molar concentration of 1 mol / L to 2 mol / L.

[0143] Preparation of LiCl solution: In a stainless steel container, first add LiCl powder, then add deionized water and stir for 1 to 3 hours to obtain a LiCl solution with a molar concentration of 4 mol / L to 8 mol / L.

[0144] Preparation of LiB(C6H5)4 solution: In a stainless steel container, first add equal amounts of HB(C6H5)4·H2O powder and LiOH powder, then add deionized water and stir for 1 to 3 hours to obtain a LiB(C6H5)4 solution with a molar concentration of 0.5 mol / L to 1 mol / L.

[0145] The present invention will be further illustrated by the following examples. Unless otherwise specified, the materials in the examples are prepared according to existing methods or purchased directly from the market.

[0146] Example 1

[0147] A method for preparing a rubidium adsorbent includes the following steps:

[0148] (1) Preparation of slurry and solution:

[0149] Preparation of Na4Fe(CN)6-PVB-ethanol-glycerol slurry: In a ball mill, add 300 kg of Na4Fe(CN)6 powder with a particle size of 0.5 μm to 10 μm, then add the organic binder polyvinyl butyral (PVB) powder (7% of the Na4Fe(CN)6 powder mass), followed by anhydrous ethanol (100% of the Na4Fe(CN)6 powder mass), and finally add glycerol (15% of the Na4Fe(CN)6 powder mass). Ball mill at room temperature and pressure for 3 h to obtain a Na4Fe(CN)6-PVB-ethanol-glycerol slurry with a viscosity of 2000 mPa·s.

[0150] Preparation of ZnCl2-RbCl-ethanol-H2O solution: In a stainless steel container, add 900 kg of deionized water, then add anhydrous ethanol (20% of the water mass), add ZnCl2 powder (150% of the Na4Fe(CN)6 powder mass) and RbCl powder (100% of the Na4Fe(CN)6 powder mass), stir for 1 h to obtain ZnCl2-RbCl-ethanol-H2O solution;

[0151] RbCl solution preparation: Add RbCl powder to a stainless steel container, add deionized water, and stir for 1 hour to obtain 1 mL of solution. 3 A 1 mol / L RbCl solution;

[0152] Preparation of LiCl solution: Add LiCl powder to a stainless steel container, add deionized water, and stir for 1 hour to obtain 1 mL of solution. 3 A LiCl solution with a molar concentration of 4 mol / L;

[0153] Preparation of LiB(C6H5)4 solution: In a stainless steel container, add equal amounts of HB(C6H5)4·H2O powder and LiOH powder, add deionized water and stir for 1 hour to obtain 1m 3 A LiB(C6H5)4 solution with a molar concentration of 0.5 mol / L;

[0154] (2) Synthesis of rubidium adsorbent:

[0155] Na x Rb 2-x Zn3Fe2(CN) 12 Synthesis of 9H2O-PVB microspheres (dropping microspheres - phase inversion - coprecipitation):

[0156] Na4Fe(CN)6-PVB-ethanol-glycerol slurry was pumped into a dropper with 500 orifices and 1 mm diameter. The Na4Fe(CN)6-PVB-ethanol-glycerol slurry was then dripped into a ZnCl2-RbCl-ethanol-H2O solution through a 1 mm orifice. After standing for 12 hours, the reaction was achieved. x Rb 2-x Zn3Fe2(CN) 12 The preparation of 9H2O powder and the granulation of powder were carried out simultaneously to obtain Na. x Rb 2-x Zn3Fe2(CN) 12 ·9H2O-PVB hard microspheres;

[0157] Rb2Zn3Fe2(CN) 12 Synthesis of 9H2O-PVB microspheres (ion imprinting - lattice perfection):

[0158] Will Na x Rb 2-x Zn3Fe2(CN) 12 ·9H2O-PVB hard spheres were added to a 1 mol / L RbCl solution prepared above, and the RbCl solution was heated to 80℃ and reacted at a constant temperature for 3 h to obtain Rb2Zn3Fe2(CN). 12 ·9H2O-PVB microspheres;

[0159] Li2Zn3Fe2(CN) 12 Synthesis of 9H2O-PVB microspheres (lithium replacement):

[0160] Rb2Zn3Fe2(CN) 12 ·9H2O-PVB microspheres were added to a 4 mol / L LiCl solution prepared above, and the mixture was allowed to stand at room temperature for 12 h to obtain Li2Zn3Fe2(CN). 12 The 9H2O-PVB microsphere product is a rubidium adsorbent.

[0161] The rubidium adsorbent in this embodiment is Li2Zn3Fe2(CN). 12 • See the physical image and scanning electron microscope image of the 9H2O-PVB microspheres. Figure 3 As shown in the figure, the rubidium adsorbent microspheres have a very uniform particle size of about 1 mm. The rubidium adsorbent powder is coated with PVB resin to prevent the rubidium adsorbent powder from falling off. At the same time, it can be seen from the figure that the PVB resin forms a porous structure. The extensive network of pores is conducive to the adsorption and elution of rubidium ions, thereby improving the ion exchange efficiency.

[0162] Li2Zn3Fe2(CN) 12 After pulverizing the 9H2O-PVB microspheres, the powder was subjected to XRD analysis, and the XRD pattern is shown below. Figure 4 As can be seen from the XRD pattern, the crystal structure of the rubidium adsorbent is consistent with that of the standard card pattern Na2Zn3Fe2(CN). 12 The crystal structures of 9H2O are very similar.

[0163] Example 2

[0164] A method for extracting rubidium from salt lakes, utilizing the rubidium adsorbent of Example 1, includes the following steps:

[0165] Adsorption of rubidium ions: The adsorption column was packed with Li2Zn3Fe2(CN) obtained in Example 1. 12 The 9H2O-PVB microsphere product involves pumping rubidium-containing brine from the bottom up into an adsorption column at a flow rate of 5 BV / h for 10 hours. The brine after adsorbing rubidium ions is then discharged back into the brine.

[0166] Rubidium ion removal process: A 4 mol / L LiCl solution was used as the regenerator and pumped into the adsorption column from top to bottom at a flow rate of 2 BV / h. The removal time was 3 h. The resulting eluent was stored in an eluent tank, and the eluent mainly contained rubidium ions (Rb). + and lithium ion Li + ;

[0167] Rubidium precipitation separation process: A 0.5 mol / L lithium tetraphenylborone LiB(C6H5)4 solution is added to the eluent tank (containing RbCl and LiCl) until no more RbB(C6H5)4 precipitate appears in the supernatant of the eluent, resulting in a mixed feed of RbB(C6H5)4 and LiCl. The mixture is then subjected to plate and frame filtration and the filter cake is washed to obtain a solid filter cake of RbB(C6H5)4 with a water content of 40% and a reusable LiCl solution.

[0168] Precipitation conversion and RbCl product extraction process: The above RbB(C6H5)4 solid filter cake with a water content of 40% was pulped with saturated ammonium chloride solution. The mass ratio of RbB(C6H5)4 solid filter cake to saturated ammonium chloride solution was 1:2. The mixture was stirred for 1 hour, and then plate and frame filtration and filter cake washing were performed to obtain filtrate containing RbCl and NH4Cl and NH4B(C6H5)4 solid filter cake.

[0169] The filtrate containing RbCl and NH4Cl was subjected to triple-effect evaporation to obtain a solid mixture of RbCl and NH4Cl. Since ammonium chloride solid is easily decomposed by heat, the solid mixture of RbCl and NH4Cl was heated in a negative pressure heater at 200℃ for 1 hour to obtain RbCl product.

[0170] The NH4B(C6H5)4 solid filter cake is pulped with pure water, and then a saturated LiOH solution is slowly added to the pulp to obtain a LiB(C6H5)4 solution, which can be recycled.

[0171] Figure 5 The rubidium adsorbent is Li₂Zn₃Fe₂(CN). 12 The adsorption capacity curve of 9H2O-PVB microspheres during rubidium extraction from real salt lake brine is shown in the figure. As can be seen from the figure, the adsorption capacity of the rubidium adsorbent is very stable during the rubidium extraction process. The rubidium ion concentration in the brine influent is about 10 mg / L to 15 mg / L. During 50 cycles, the adsorption capacity basically did not decrease and remained stable at about 4 g / L. This proves that the rubidium adsorbent can meet the engineering requirements of rubidium extraction from salt lake brine. At the same time, it has the advantages of large adsorption capacity and stable adsorption performance, and is expected to achieve large-scale application.

[0172] Figure 6 The figure shows the purity of RbCl products obtained by extracting rubidium from salt lake brine using rubidium adsorbent. As can be seen from the figure, the purity of the obtained RbCl products is greater than 99%, and the purity fluctuation is very small. This proves that the rubidium adsorbent can meet the engineering requirements for rubidium extraction from salt lake brine. It also has the advantages of high product purity and stable product purity, and is expected to achieve large-scale application.

[0173] Example 3

[0174] A method for preparing a rubidium adsorbent includes the following steps:

[0175] (1) Preparation of slurry and solution:

[0176] Preparation of Na4Fe(CN)6-PVB-ethanol-glycerol slurry: In a ball mill, add 450 kg of Na4Fe(CN)6 powder with a particle size of 0.5 μm to 10 μm, then add the organic binder polyvinyl butyral (PVB) powder (accounting for 14% of the Na4Fe(CN)6 powder mass), followed by anhydrous ethanol (accounting for 150% of the Na4Fe(CN)6 powder mass), and finally add glycerol (accounting for 40% of the Na4Fe(CN)6 powder mass). Ball mill for 10 h at room temperature and pressure to obtain a Na4Fe(CN)6-PVB-ethanol-glycerol slurry with a viscosity of 5000 mPa·s.

[0177] Preparation of ZnCl2-RbCl-ethanol-H2O solution: In a stainless steel container, add 1500 kg of deionized water, then add anhydrous ethanol (35% of the water mass), add ZnCl2 powder (250% of the Na4Fe(CN)6 powder mass) and RbCl powder (150% of the Na4Fe(CN)6 powder mass), stir for 3 h to obtain ZnCl2-RbCl-ethanol-H2O solution;

[0178] RbCl solution preparation: Add RbCl powder to a stainless steel container, add deionized water, and stir for 3 hours to obtain 1.5 mL of solution. 3 A 2 mol / L RbCl solution;

[0179] Preparation of LiCl solution: Add LiCl powder to a stainless steel container, add deionized water, and stir for 3 hours to obtain 1.5 mL of solution. 3 A LiCl solution with a molar concentration of 8 mol / L;

[0180] Preparation of LiB(C6H5)4 solution: In a stainless steel container, add equal amounts of HB(C6H5)4·H2O powder and LiOH powder, add deionized water, and stir for 3 hours to obtain 1.5m 3 A LiB(C6H5)4 solution with a molar concentration of 1 mol / L;

[0181] (2) Synthesis of rubidium adsorbent:

[0182] Na x Rb 2-x Zn3Fe2(CN) 12 Synthesis of 9H2O-PVB microspheres:

[0183] Na4Fe(CN)6-PVB-ethanol-glycerol slurry was pumped into a dropper with 1000 orifices and a diameter of 1.5 mm. The slurry was then dripped into a ZnCl2-RbCl-ethanol-H2O solution through a 1.5 mm orifice. After standing for 24 hours, Na4Fe(CN)6-PVB-ethanol-glycerol slurry was obtained. x Rb 2-x Zn3Fe2(CN) 12 ·9H2O-PVB hard microspheres;

[0184] Rb2Zn3Fe2(CN) 12 Synthesis of 9H2O-PVB microspheres:

[0185] Will Na x Rb 2-x Zn3Fe2(CN) 12·9H2O-PVB hard microspheres were added to a 2 mol / L RbCl solution prepared above, and the RbCl solution was heated to 95℃ and reacted at a constant temperature for 6 h to obtain Rb2Zn3Fe2(CN). 12 ·9H2O-PVB microspheres;

[0186] Li2Zn3Fe2(CN) 12 Synthesis of 9H2O-PVB microspheres:

[0187] Rb2Zn3Fe2(CN) 12 ·9H2O-PVB microspheres were added to an 8 mol / L LiCl solution prepared above, and the mixture was allowed to stand at room temperature for 24 h to obtain Li2Zn3Fe2(CN). 12 The 9H2O-PVB microsphere product is a rubidium adsorbent.

[0188] The rubidium adsorbent in this embodiment is Li2Zn3Fe2(CN). 12 • See the physical image and scanning electron microscope image of the 9H2O-PVB microspheres. Figure 7 As shown in the figure, the rubidium adsorbent microspheres have a very uniform particle size, approximately 1 mm to 1.5 mm. The rubidium adsorbent powder is coated with PVB resin to prevent it from falling off. At the same time, it can be seen from the figure that the PVB resin forms a porous structure. The extensive network of pores is conducive to the adsorption and elution of rubidium ions, thus improving the ion exchange efficiency.

[0189] Li2Zn3Fe2(CN) 12 After pulverizing the 9H2O-PVB microspheres, the powder was subjected to XRD analysis, and the XRD pattern is shown below. Figure 8 As can be seen from the XRD pattern, the crystal structure of the rubidium adsorbent is consistent with that of the standard card pattern Na2Zn3Fe2(CN). 12 The crystal structures of 9H2O are very similar.

[0190] Example 4

[0191] A method for extracting rubidium from salt lakes, utilizing the rubidium adsorbent of Example 3, includes the following steps:

[0192] Adsorption of rubidium ions: The adsorption column was packed with Li2Zn3Fe2(CN) obtained in Example 3. 12 The 9H2O-PVB microsphere product involves pumping rubidium-containing brine from the bottom up into an adsorption column at a flow rate of 10 BV / h for 20 hours. The brine after adsorbing rubidium ions is then discharged back into the brine.

[0193] Rubidium ion removal process: An 8 mol / L LiCl solution was used as the regenerator and pumped into the adsorption column from top to bottom at a flow rate of 4 BV / h. The removal time was 5 h. The resulting eluent was stored in an eluent tank, and the eluent mainly contained rubidium ions (Rb). + and lithium ion Li + ;

[0194] Rubidium precipitation separation process: A 1 mol / L lithium tetraphenylborone LiB(C6H5)4 solution is added to the eluent tank (containing RbCl and LiCl) until no more RbB(C6H5)4 precipitate appears in the supernatant of the eluent, resulting in a mixed feed of RbB(C6H5)4 and LiCl. The mixture is then subjected to plate and frame filtration and the filter cake is washed to obtain a solid filter cake of RbB(C6H5)4 with a water content of 50% and a reusable LiCl solution.

[0195] Precipitation transformation and RbCl product extraction process: The above RbB(C6H5)4 solid filter cake with a water content of 50% was pulped with saturated ammonium chloride solution. The mass ratio of RbB(C6H5)4 solid filter cake to saturated ammonium chloride solution was 1:3. After stirring for 4 hours, plate and frame filtration and filter cake washing were performed to obtain filtrate containing RbCl and NH4Cl and NH4B(C6H5)4 solid filter cake.

[0196] The filtrate containing RbCl and NH4Cl was subjected to triple-effect evaporation to obtain a solid mixture of RbCl and NH4Cl. Since ammonium chloride solid is easily decomposed by heat, the solid mixture of RbCl and NH4Cl was heated in a negative pressure heater at 300℃ for 3 hours to obtain RbCl product.

[0197] The NH4B(C6H5)4 solid filter cake is pulped with pure water, and then a saturated LiOH solution is slowly added to the pulp to obtain a LiB(C6H5)4 solution, which can be recycled.

[0198] Figure 9 The rubidium adsorbent is Li₂Zn₃Fe₂(CN). 12 The adsorption capacity curve of 9H2O-PVB microspheres during rubidium extraction from real salt lake brine is shown in the figure. As can be seen from the figure, the adsorption capacity of the rubidium adsorbent is very stable during the rubidium extraction process. The rubidium ion concentration in the brine influent is about 10 mg / L to 15 mg / L. During 50 cycles, the adsorption capacity basically did not decrease and remained stable at about 4.1 g / L. This proves that the rubidium adsorbent can meet the engineering requirements of rubidium extraction from salt lake brine. At the same time, it has the advantages of large adsorption capacity and stable adsorption performance, and is expected to achieve large-scale application.

[0199] Figure 10The figure shows the purity of RbCl products obtained by extracting rubidium from salt lake brine using rubidium adsorbent. As can be seen from the figure, the purity of the obtained RbCl products is greater than 99%, and the purity fluctuation is very small. This proves that the rubidium adsorbent can meet the engineering requirements for rubidium extraction from salt lake brine. It also has the advantages of high product purity and stable product purity, and is expected to achieve large-scale application.

[0200] Example 5

[0201] A method for preparing a rubidium adsorbent includes the following steps:

[0202] (1) Preparation of slurry and solution:

[0203] Preparation of Na4Fe(CN)6-PVB-ethanol-glycerol slurry: In a ball mill, add 375 kg of Na4Fe(CN)6 powder with a particle size of 0.5 μm to 10 μm, then add the organic binder polyvinyl butyral (PVB) powder (10.5% of the Na4Fe(CN)6 powder mass), followed by anhydrous ethanol (125% of the Na4Fe(CN)6 powder mass), and finally add glycerol (27.5% of the Na4Fe(CN)6 powder mass). Ball mill at room temperature and pressure for 6.5 h to obtain a Na4Fe(CN)6-PVB-ethanol-glycerol slurry with a viscosity of 3500 mPa·s.

[0204] Preparation of ZnCl2-RbCl-ethanol-H2O solution: In a stainless steel container, add 1200 kg of deionized water, then add anhydrous ethanol (27.5% of the water mass), add ZnCl2 powder (200% of the Na4Fe(CN)6 powder mass) and RbCl powder (125% of the Na4Fe(CN)6 powder mass), stir for 2 h to obtain ZnCl2-RbCl-ethanol-H2O solution;

[0205] RbCl solution preparation: Add RbCl powder to a stainless steel container, add deionized water, and stir for 2 hours to obtain 1.25 mg / L solution. 3 A 1.5 mol / L RbCl solution;

[0206] Preparation of LiCl solution: Add LiCl powder to a stainless steel container, add deionized water, and stir for 2 hours to obtain 1.25 mL of solution. 3 A LiCl solution with a molar concentration of 6 mol / L;

[0207] Preparation of LiB(C6H5)4 solution: In a stainless steel container, add equal amounts of HB(C6H5)4·H2O powder and LiOH powder, add deionized water, and stir for 2 hours to obtain 1.25m 3A LiB(C6H5)4 solution with a molar concentration of 0.75 mol / L;

[0208] (2) Synthesis of rubidium adsorbent

[0209] Na x Rb 2-x Zn3Fe2(CN) 12 Synthesis of 9H2O-PVB microspheres:

[0210] Na4Fe(CN)6-PVB-ethanol-glycerol slurry was pumped into a dropper with 750 orifices and a diameter of 1.25 mm. The slurry was then dripped into a ZnCl2-RbCl-ethanol-H2O solution through a 1.25 mm orifice. After standing for 18 hours, Na4Fe(CN)6-PVB-ethanol-glycerol slurry was obtained. x Rb 2-x Zn3Fe2(CN) 12 ·9H2O-PVB hard microspheres;

[0211] Rb2Zn3Fe2(CN) 12 Synthesis of 9H2O-PVB microspheres:

[0212] Will Na x Rb 2-x Zn3Fe2(CN) 12 ·9H2O-PVB hard spheres were added to a 1.5 mol / L RbCl solution prepared above, and the RbCl solution was heated to 87.5℃ and reacted at a constant temperature for 4.5 h to obtain Rb2Zn3Fe2(CN). 12 ·9H2O-PVB microspheres;

[0213] Li2Zn3Fe2(CN) 12 Synthesis of 9H2O-PVB microspheres:

[0214] Rb2Zn3Fe2(CN) 12 ·9H2O-PVB microspheres were added to a 6 mol / L LiCl solution prepared above, and the mixture was allowed to stand at room temperature for 18 h to obtain Li2Zn3Fe2(CN). 12 The 9H2O-PVB microsphere product is a rubidium adsorbent.

[0215] The rubidium adsorbent in this embodiment is Li2Zn3Fe2(CN). 12 • See the physical image and scanning electron microscope image of the 9H2O-PVB microspheres. Figure 11As shown in the figure, the rubidium adsorbent microspheres have a very uniform particle size, approximately 1 mm to 1.5 mm. The rubidium adsorbent powder is coated with PVB resin to prevent it from falling off. At the same time, it can be seen from the figure that the PVB resin forms a porous structure. The extensive network of pores is conducive to the adsorption and elution of rubidium ions, thus improving the ion exchange efficiency.

[0216] Li2Zn3Fe2(CN) 12 After pulverizing the 9H2O-PVB microspheres, the powder was subjected to XRD analysis, and the XRD pattern is shown below. Figure 12 As can be seen from the XRD pattern, the crystal structure of the rubidium adsorbent is consistent with that of the standard card pattern Na2Zn3Fe2(CN). 12 The crystal structures of 9H2O are very similar.

[0217] Example 6

[0218] A method for extracting rubidium from salt lakes, utilizing the rubidium adsorbent of Example 5, includes the following steps:

[0219] Adsorption of rubidium ions: The adsorption column was packed with Li2Zn3Fe2(CN) obtained in Example 5. 12 The 9H2O-PVB microsphere product involves pumping rubidium-containing brine from the bottom up into an adsorption column at a flow rate of 7.5 BV / h for 15 hours. The brine after adsorbing rubidium ions is then discharged back into the brine.

[0220] Rubidium ion removal process: A 6 mol / L LiCl solution was used as the regenerator and pumped into the adsorption column from top to bottom at a flow rate of 3 BV / h. The removal time was 4 h. The resulting eluent was stored in an eluent tank, and the eluent mainly contained rubidium ions (Rb). + and lithium ion Li + ;

[0221] Rubidium precipitation separation process: A lithium tetraphenylborone (LiB(C6H5)4) solution with a molar concentration of 0.75 mol / L is added to the eluent tank (containing RbCl and LiCl) until no more RbB(C6H5)4 precipitate appears in the supernatant of the eluent, resulting in a mixed feed of RbB(C6H5)4 and LiCl. The mixture is then subjected to plate and frame filtration and the filter cake is washed to obtain a solid filter cake of RbB(C6H5)4 with a water content of 45% and a reusable LiCl solution.

[0222] Precipitation conversion and RbCl product extraction process: The above RbB(C6H5)4 solid filter cake with a water content of 45% was pulped with saturated ammonium chloride solution. The mass ratio of RbB(C6H5)4 solid filter cake to saturated ammonium chloride solution was 1:2.5. After stirring for 2.5 hours, plate and frame filtration and filter cake washing were performed to obtain filtrate containing RbCl and NH4Cl and NH4B(C6H5)4 solid filter cake.

[0223] The filtrate containing RbCl and NH4Cl was subjected to triple-effect evaporation to obtain a solid mixture of RbCl and NH4Cl. Since ammonium chloride solid is easily decomposed by heat, the solid mixture of RbCl and NH4Cl was heated in a negative pressure heater at 250°C for 2 hours to obtain the RbCl product.

[0224] The NH4B(C6H5)4 solid filter cake is pulped with pure water, and then a saturated LiOH solution is slowly added to the pulp to obtain a LiB(C6H5)4 solution, which can be recycled.

[0225] Figure 13 The rubidium adsorbent is Li₂Zn₃Fe₂(CN). 12 The adsorption capacity curve of 9H2O-PVB microspheres during rubidium extraction from real salt lake brine is shown in the figure. As can be seen from the figure, the adsorption capacity of the rubidium adsorbent is very stable during the rubidium extraction process. The rubidium ion concentration in the brine influent is about 10 mg / L to 15 mg / L. During 50 cycles, the adsorption capacity basically did not decrease and remained stable at about 4.1 g / L. This proves that the rubidium adsorbent can meet the engineering requirements of rubidium extraction from salt lake brine. At the same time, it has the advantages of large adsorption capacity and stable adsorption performance, and is expected to achieve large-scale application.

[0226] Figure 14 The figure shows the purity of RbCl products obtained by extracting rubidium from salt lake brine using rubidium adsorbent. As can be seen from the figure, the purity of the obtained RbCl products is greater than 99%, and the purity fluctuation is very small. This proves that the rubidium adsorbent can meet the engineering requirements for rubidium extraction from salt lake brine. It also has the advantages of high product purity and stable product purity, and is expected to achieve large-scale application.

[0227] Comparative Example 1

[0228] This comparative example provides a method for preparing a rubidium adsorbent, which differs from Example 1 in that, in the Na... x Rb 2-x Zn3Fe2(CN) 12 The synthesis method used in the synthesis of 9H2O-PVB microspheres is as follows:

[0229] 1 L of 3 mol / L Na4Fe(CN)6 solution was prepared using Na4Fe(CN)6 powder with a particle size of 0.5 μm to 10 μm;

[0230] Prepare 1 L of ZnCl2-RbCl solution using ZnCl2 powder (150% of the amount of Na4Fe(CN)6 powder) and RbCl powder (100% of the amount of Na4Fe(CN)6 powder);

[0231] Under mechanical stirring, 1 L of Na₄Fe(CN)₆ solution was added dropwise to 1 L of ZnCl₂-RbCl solution, and the reaction was carried out by centrifugation to obtain Na. x Rb 2-x Zn3Fe2(CN) 12 ·9H2O solid, dried at 80℃, pulverized to obtain Na x Rb 2-x Zn3Fe2(CN) 12 ·9H2O powder;

[0232] All Na x Rb 2-x Zn3Fe2(CN) 12 The 9H2O powder was placed in a stirrer, then 64g of polyvinyl butyral (PVB) powder (7% of the Na4Fe(CN)6 powder mass) was added, followed by 912g of anhydrous ethanol (100% of the Na4Fe(CN)6 powder mass), and finally 137g of glycerol (15% of the Na4Fe(CN)6 powder mass). The mixture was ball-milled for 3 hours at room temperature and pressure to obtain Na4Fe(CN)6. x Rb 2-x Zn3Fe2(CN) 12 ·9H2O-PVB-ethanol-glycerol slurry;

[0233] Will Na x Rb 2-x Zn3Fe2(CN) 12 The 9H₂O-PVB-ethanol-glycerol slurry was pumped into a dropper with 500 holes and 1 mm diameter. The slurry was then dripped into an aqueous solution through a 1 mm orifice. After standing for 12 hours, Na was obtained. x Rb 2- x Zn3Fe2(CN) 12 ·9H2O-PVB hard microspheres;

[0234] The remaining steps and process parameters are the same as in Example 1, and rubidium adsorbent is obtained.

[0235] Compared with the rubidium adsorbent obtained in Example 1, the rubidium adsorbent obtained in this comparative example has the following drawbacks: low adsorption capacity and poor cycling stability. The initial adsorption capacity decreased from 4 g / L of the rubidium adsorbent in Example 1 to 2.5 g / L (the rubidium ion concentration in the brine inlet of the salt lake is approximately 10 mg / L to 15 mg / L), with an initial adsorption capacity reduction rate of 37.5%. Furthermore, during 50 cycles, the adsorption capacity gradually decreased from the initial 2.5 g / L to 1.6 g / L (the rubidium ion concentration in the brine inlet of the salt lake is approximately 10 mg / L to 15 mg / L), with an adsorption capacity reduction rate of 36% over 50 cycles. This demonstrates that the method of synthesizing rubidium adsorbent by first preparing powder and then molding has the disadvantages of low adsorption capacity and poor cycling stability.

[0236] Comparative Example 2

[0237] This comparative example provides a method for preparing a rubidium adsorbent, which differs from Example 1 in that a CuCl2-RbCl-ethanol-H2O solution is used instead of a ZnCl2-RbCl-ethanol-H2O solution.

[0238] The remaining steps and process parameters are the same as in Example 1, and rubidium adsorbent is obtained.

[0239] Compared with the rubidium adsorbent obtained in Example 1, the rubidium adsorbent obtained in this comparative example has the following drawbacks: low adsorption capacity, poor cycling stability, and low purity of the obtained RbCl product. The initial adsorption capacity decreased from 4 g / L of the rubidium adsorbent in Example 1 to 1.8 g / L (the rubidium ion concentration in the brine influent of the salt lake is approximately 10 mg / L to 15 mg / L), representing a 55% decrease in initial adsorption capacity. Furthermore, during 50 cycles, the adsorption capacity gradually decreased from the initial 1.8 g / L to 1.1 g / L (the concentration of rubidium ions in the brine influent of the salt lake is approximately 10 mg / L to 15 mg / L), a decrease of 55%. The rubidium ion concentration in the lake brine influent was approximately 10 mg / L to 15 mg / L. The adsorption capacity decreased by 39% after 50 cycles. During the 50 cycles, the purity of the obtained RbCl product ranged from 67% to 75%, which was 24% to 32% lower than the 99% purity of the RbCl product purified from the rubidium adsorbent in Example 1. This demonstrates that the method of synthesizing rubidium adsorbent by replacing ZnCl2 with CuCl2 has disadvantages such as low adsorption capacity, poor cycle stability, and low purity of RbCl product.

[0240] Comparative Example 3

[0241] This comparative example provides a method for preparing a rubidium adsorbent, which differs from Example 1 in that a ZnCl2-RbCl-polyethylene glycol 400-H2O solution is used instead of a ZnCl2-RbCl-ethanol-H2O solution.

[0242] The remaining steps and process parameters are the same as in Example 1, and rubidium adsorbent is obtained.

[0243] Compared with the rubidium adsorbent obtained in Example 1, the rubidium adsorbent obtained in this comparative example has the following drawbacks: low adsorption capacity and poor cycling stability. The initial adsorption capacity decreased from 4 g / L of the rubidium adsorbent in Example 1 to 0.9 g / L (the rubidium ion concentration in the brine inlet of the salt lake is approximately 10 mg / L to 15 mg / L), with an initial adsorption capacity reduction rate of 77.5%. Furthermore, during 50 cycles, the adsorption capacity gradually decreased from the initial 0.9 g / L to 0.3 g / L (the rubidium ion concentration in the brine inlet of the salt lake is approximately 10 mg / L to 15 mg / L), with an adsorption capacity reduction rate of 66.7% over 50 cycles. This demonstrates that the method of synthesizing rubidium adsorbent by replacing ethanol with polyethylene glycol 400 has the disadvantages of low adsorption capacity and poor cycling stability.

[0244] Comparative Example 4

[0245] This comparative example provides a method for preparing a rubidium adsorbent, which differs from Example 1 in that sodium replacement is used instead of lithium replacement.

[0246] The remaining steps and process parameters are the same as in Example 1, and rubidium adsorbent is obtained.

[0247] Compared with the rubidium adsorbent obtained in Example 1, the rubidium adsorbent obtained in this comparative example has the following drawbacks: its adsorption capacity is very low and its cycle stability is very poor. Compared with lithium ions, sodium ions are larger in size and have a too low migration rate in solution, making it unable to quickly enter Rb2Zn3Fe2(CN). 12 Ion exchange within the 9H₂O-PVB lattice resulted in a very low adsorption capacity for the sodium-substituted rubidium adsorbent. The initial adsorption capacity decreased from 4 g / L in Example 1 to 0.4 g / L (the rubidium ion concentration in the brine inlet of the salt lake is approximately 10 mg / L to 15 mg / L), representing a 90% decrease. This fails to meet the high adsorption capacity requirements for engineered rubidium extraction. Furthermore, the adsorption capacity gradually decreased over 50 cycles, from an initial 0.4 g / L to 0.05 g / L (the rubidium ion concentration in the brine inlet of the salt lake is approximately 10 mg / L to 15 mg / L), representing an 87.5% decrease. This also fails to meet the high cycling stability requirements for engineered rubidium extraction. This demonstrates that the method of synthesizing rubidium adsorbents by replacing lithium substitution with sodium substitution suffers from low adsorption capacity and poor cycling stability.

[0248] Therefore, this invention not only solves the technical problem of low selectivity of rubidium adsorbent adsorption sites for rubidium ions, but also solves the technical problems of low adsorption performance and low production efficiency caused by first preparing adsorbent powder and then granulating it through a specific preparation method. Furthermore, it solves the problem of low product purity obtained by rubidium adsorbent in engineering applications through a specific rubidium extraction process. It achieves the technical effects of high selectivity for rubidium ions, simultaneous completion of adsorbent powder and powder granulation, high production efficiency, good economy, and obtaining high-purity rubidium chloride products from salt lake brine.

[0249] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A rubidium adsorbent, characterized in that, It includes a porous resin and an adsorbent body encapsulated in the porous resin; The adsorbent matrix has the following chemical formula: Li2Zn3Fe2(CN) 12 ∙9H2O; The method for preparing the rubidium adsorbent includes the following steps: The first slurry containing Na4Fe(CN)6 and resin was dropped onto a ball containing Zn. 2+ and Rb + In the second slurry, phase inversion and co-precipitation reactions occur to obtain resin-encapsulated Na. x Rb 2-x Zn3Fe2(CN) 12 ∙9H2O; Will Na x Rb 2-x Zn3Fe2(CN) 12 ∙Na in 9H2O + Replace with Rb + Then Rb + Replace with Li + The rubidium adsorbent was obtained.

2. The rubidium adsorbent according to claim 1, characterized in that, The porous resin includes PVB resin.

3. The rubidium adsorbent according to claim 1, characterized in that, The rubidium adsorbent has a particle size of 1 mm to 1.5 mm.

4. The rubidium adsorbent according to claim 1, characterized in that, The amount of resin added is 7% to 14% of the mass of Na4Fe(CN)6; The solvent used in the first slurry includes at least one of ethanol and glycerol; The amount of ethanol added is 100%~150% of the mass of Na4Fe(CN)6; The amount of glycerol added is 15% to 40% of the mass of Na4Fe(CN)6; The viscosity of the first slurry is 2000 mPa∙s to 5000 mPa∙s.

5. The rubidium adsorbent according to claim 1, characterized in that, The method of dripping the ball includes using a ball-drip device to drip the ball; The diameter of the circular hole in the dropper is 1mm to 1.5mm; The number of holes in the ball dropper is 500 to 1000.

6. The rubidium adsorbent according to claim 1, characterized in that, The Zn 2+ The sources include ZnCl2.

7. The rubidium adsorbent according to claim 6, characterized in that, The amount of ZnCl2 added is 150% to 250% of the amount of Na4Fe(CN)6.

8. The rubidium adsorbent according to claim 1, characterized in that, The Rb + The sources include RbCl.

9. The rubidium adsorbent according to claim 8, characterized in that, The amount of RbCl added is 100% to 150% of the amount of Na4Fe(CN)6.

10. The rubidium adsorbent according to claim 1, characterized in that, The solvent used in the second slurry includes at least one of ethanol and water.

11. The rubidium adsorbent according to claim 10, characterized in that, The solvents used in the second slurry are ethanol and water.

12. The rubidium adsorbent according to claim 1, characterized in that, The total time for the phase transformation and coprecipitation reaction is 12h~24h; The Na + Replace with Rb + The reaction temperature is 80℃~95℃, and the reaction time is 3h~6h; The Rb + Replace with Li + The reaction time is 12h~24h.

13. The application of the rubidium adsorbent according to any one of claims 1-12 in rubidium extraction from salt lakes.

14. The application according to claim 13, characterized in that, The method for extracting rubidium from salt lakes includes the following steps: After the rubidium adsorbent adsorbs rubidium ions from the salt lake brine, it is then analyzed using the regenerated solution to obtain Rb-containing... + The eluent, containing Rb + The eluent was subjected to precipitation to obtain precipitate RbB(C6H5)4; The precipitate RbB(C6H5)4 was pulped with ammonium chloride solution and then subjected to solid-liquid separation to obtain a filtrate containing RbCl and a filter cake containing NH4B(C6H5)4. The filtrate containing RbCl was then evaporated to obtain RbCl.

15. The application according to claim 14, characterized in that, The regenerated solution includes a LiCl solution; The Rb-containing + The precipitant used when precipitating the eluent includes LiB(C6H5)4; The solid-liquid separation method includes plate and frame filtration.

16. The application according to claim 14, characterized in that, The method for extracting rubidium from salt lakes also includes the following steps: The NH4B(C6H5)4 filter cake was pulped, and then LiOH solution was added to react and obtain LiB(C6H5)4 solution, which was then reused for Rb-containing applications. + In the step of precipitation of the eluent.

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