A preparation method, application and device of aluminum salt lithium ion adsorbent

Abstract

The present invention relates to a preparation method, application and device of an aluminum salt lithium adsorbent, belonging to the field of new materials and salt lake chemical technology. The preparation method comprises the following steps: washing lithium carbonate with pure water to remove water-soluble impurities, and preparing filter cake into lithium carbonate slurry in a certain proportion; introducing CO2 gas into the lithium carbonate slurry for hydrogenation reaction, and filtering the reaction slurry to obtain hydrogenated liquid; passing the hydrogenated liquid into an ion exchange resin column for refining and impurity removal to obtain a refined hydrogenated liquid; subjecting the refined hydrogenated liquid to a precipitation reaction with an aluminum salt solution, and filtering to obtain a powdered aluminum salt lithium adsorbent; mixing the powdered aluminum salt lithium adsorbent, an adhesive and a solvent in a mixing device, and obtaining the obtained product through an extrusion granulation process, and at the same time providing a method and device for preparing battery-grade lithium carbonate based on the aluminum salt lithium adsorbent. Compared with lithium salt products such as lithium chloride and lithium hydroxide, the aluminum salt lithium adsorbent provided by the present invention has a wider source of raw materials and a lower price.

Description

Technical Field

[0001] The invention relates to the technical field of new materials and salt lake chemical industry, and in particular to a preparation method, application and device of an aluminum salt lithium ion adsorbent. Background Art

[0002] With the proposal of the "carbon peak" and "carbon neutrality" development goals in my country's "14th Five-Year Plan", my country is gradually transforming from an economic model dominated by traditional fossil energy to a green and low-carbon economic model, thereby driving the vigorous development of the new energy industry, especially the promotion and application of power lithium battery technology, resulting in the demand for lithium salt products such as lithium carbonate rising year by year.

[0003] Lithium exists in nature mainly in the form of lithium ore and liquid brine, among which salt lake brine lithium resources account for more than 2 / 3 of the total lithium resources, and the value of development and utilization is huge. my country is rich in salt lake brine resources, but most salt lake types are high magnesium-lithium ratio salt lakes. Due to the similarity of magnesium and lithium in chemical properties, separation is difficult. At present, the main technologies for extracting lithium from high magnesium-lithium ratio salt lake brine include calcination leaching, solvent extraction, adsorption, membrane separation, etc. Among them, the adsorption method is generally applicable to salt lake brines with different lithium concentrations and salinities, and is suitable for the separation and extraction of lithium in the front stage of the brine lithium extraction process. The essence of the membrane separation method is a physical separation method, which does not require the introduction of chemical reagents and is suitable for the deep separation and concentration of magnesium and lithium in the back stage of the brine lithium extraction process. After years of practice and summary by salt lake experts and scholars, adsorption-coupled membrane separation will become the mainstream process for lithium extraction from salt lakes in the future.

[0004] The key to the adsorption method is to prepare an adsorbent material that has the ability to selectively adsorb lithium ions in brine. Among the many lithium-extraction adsorbent materials, aluminum salt lithium ion adsorbents have attracted much attention due to their simple preparation process, high ion selectivity, good cycle stability, and long service life. In the existing aluminum salt lithium ion adsorbent synthesis technology, water-soluble lithium salts such as lithium chloride and lithium hydroxide are mainly used as raw materials to synthesize aluminum salt lithium ion adsorbent powder by inserting it into the amorphous aluminum hydroxide structure. For example, patent CN02145583.X discloses a method for extracting lithium from salt lake brine by adsorption, using aluminum chloride solution to react with alkaline solution, first generating amorphous aluminum hydroxide microcrystals, and then inserting lithium chloride into the amorphous aluminum hydroxide structure through stirring precipitation reaction to synthesize aluminum salt lithium ion adsorbent; patent CN106076243A discloses a microporous aluminum salt lithium ion adsorbent and a preparation method thereof, wherein lithium hydroxide solution is added dropwise to a soluble aluminum salt solution (such as aluminum chloride, aluminum sulfate, aluminum nitrate, etc.) at a certain rate to form a precipitate embedded with soluble lithium, and the precipitate is removed from the soluble lithium to obtain a microporous aluminum salt lithium ion adsorbent. However, the technology of using lithium carbonate as a synthetic lithium source to prepare aluminum salt lithium ion adsorbent has not been reported. In the traditional salt lake lithium extraction process, a large amount of industrial-grade lithium carbonate, crude-grade lithium carbonate and unqualified lithium carbonate will be produced as by-products in the process of producing battery-grade lithium carbonate. Due to the high impurity content, there is basically no market share in the lithium battery industry. Therefore, using these by-products as raw materials to further synthesize aluminum salt lithium ion adsorbents is of great significance for increasing the added value of industrial-grade lithium carbonate and crude-grade lithium carbonate and improving the utilization rate of unqualified lithium carbonate. It also provides a new idea for the synthesis process of aluminum salt lithium ion adsorbents.

[0005] The technical core of membrane separation lies in the gradient combination of different membrane processes. This method uses pressure or electrical energy as the driving force, and achieves the separation of different substances through the pore size of the membrane and the electrostatic effect. Depending on the type of membrane, it is divided into nanofiltration, reverse osmosis, forward osmosis, electrodialysis, etc. For example, patent CN103074502A discloses a method for separating lithium from salt lake brine with a high magnesium-to-lithium ratio by a combined process of nanofiltration + reverse osmosis + natural evaporation concentration; patent CN109368670A discloses a method for separating and enriching lithium from salt lake brine by a combined process of nanofiltration + reverse osmosis + electrodialysis concentration. Both methods use a combined membrane process to achieve effective separation of magnesium and lithium in brine, but the above technologies have the following problems in actual application: First, the lithium extraction cycle is long, and the raw material liquid for membrane separation is old brine from salt lakes, which requires at least 1-2 years of salt pan beach drying before use; second, the water consumption is large, the nanofiltration membrane is a low-pressure operating membrane, which cannot tolerate a high-salt and high-pressure environment, and the old brine needs to be diluted 5-20 times with fresh water before use; third, the process flow is long, and it needs to undergo multi-stage nanofiltration and multi-stage reverse osmosis treatment; fourth, the maintenance cost is high, and both nanofiltration membrane and reverse osmosis membrane are pressure-driven membranes, and concentration polarization is prone to occur on the membrane surface, which seriously affects the membrane flux and the service life of the membrane. Summary of the invention

[0006] The present invention not only proposes a method for preparing an aluminum salt lithium ion adsorbent, but also verifies the separation performance of the aluminum salt lithium ion adsorbent prepared by the present invention on lithium ions in salt lake brine, and proposes a combined lithium extraction process and device of adsorption + nanofiltration + concentration + refined lithium precipitation. The present invention mainly includes three parts. The first part is a method for preparing an aluminum salt lithium ion adsorbent; the second part is a method for preparing battery-grade lithium carbonate using an aluminum salt lithium ion adsorbent; and the third part is a device for preparing battery-grade lithium carbonate using an aluminum salt lithium ion adsorbent.

[0007] The preparation method of aluminum salt lithium ion adsorbent uses lithium carbonate as a synthetic lithium source, and synthesizes a powdered aluminum salt lithium ion adsorbent by inserting it into an amorphous aluminum hydroxide structure or further prepares a granular aluminum salt lithium ion adsorbent after an extrusion granulation molding process. The material has the advantages of simple preparation process and high ion selectivity. The chemical reaction process is as follows:

[0008] Li2CO3+CO2+H2O=2LiHCO3

[0009] 6LiHCO3+2AlCl3+nH2O=LiCl·2Al(OH)3·nH2O+5LiCl+6CO2+3H2O

[0010] A method for preparing an aluminum salt lithium ion adsorbent comprises the following steps:

[0011] S1. Wash the lithium carbonate with pure water to remove water-soluble impurities, and prepare the filter cake into lithium carbonate slurry in a certain proportion;

[0012] S2, introducing CO2 gas into the lithium carbonate slurry for hydrogenation reaction, and filtering the reaction slurry to obtain a hydrogenated liquid;

[0013] S3, passing the hydrogenated liquid into an ion exchange resin column for refining and removing impurities to obtain a refined hydrogenated liquid;

[0014] S4, subjecting the refined hydrogenated liquid to a precipitation reaction with an aluminum salt solution, and filtering to obtain a powdered aluminum salt lithium ion adsorbent;

[0015] S5. Mix the powdered aluminum salt lithium ion adsorbent, the adhesive and the solvent in a mixing device according to a certain mass ratio, and obtain the granular aluminum salt lithium ion adsorbent after an extrusion granulation process.

[0016] As a further technical solution of the present invention, the lithium carbonate in S1 can be commercially available industrial-grade lithium carbonate, crude-grade lithium carbonate produced in the production process of lithium carbonate, or unqualified lithium carbonate produced in the production process of lithium carbonate. S1 is mainly used to remove soluble impurities such as sodium, potassium, boron, calcium, and magnesium in the lithium carbonate; the lithium carbonate slurry in S1 is prepared according to a mass ratio of lithium carbonate to pure water of 1:10-50.

[0017] As a further technical solution of the present invention, the CO2 gas introduction rate in the S2 is 1-5 L / min, the hydrogenation reaction time is 30-180 min, and the hydrogenation reaction temperature is 20-40°C.

[0018] As a further technical solution of the present invention, the ion exchange resin in S3 is a calcium-magnesium chelating resin and / or a boron removal resin, which is used to remove impurities such as calcium, magnesium, and boron in the hydrogenated liquid.

[0019] As a further technical solution of the present invention, the aluminum salt solution in S4 is an AlCl3 solution with a molar concentration of 0.1-3.0 mol / L, and the aluminum salt lithium ion adsorbent has a molecular formula of LiCl·2Al(OH)3·nH2O, wherein the value of n is 1-3.

[0020] As a further technical solution of the present invention, the adhesive in S5 is at least one of polyethylene, polyvinyl alcohol, polystyrene, polyvinylidene fluoride, polytetrafluoroethylene, polypropylene, polyacrylonitrile, nitrile rubber, hydrogenated nitrile rubber, polyamide, polyimide, polysulfone, polyurethane, polycarbonate, polymethyl methacrylate, epoxy resin, and phenolic resin; the solvent in S5 is at least one of chloroform, carbon tetrachloride, toluene, acetone, glycerol, tetrahydrofuran, ethyl formate, ethyl acetate, N-methylpyrrolidone, N,N-dimethylformamide, and N,N-dimethylacetamide; the mixing mass ratio of the powdered aluminum salt lithium ion adsorbent, the adhesive, and the solvent in S5 is 1:0.01-0.50:1.00-10.00; the material mixing time in S5 is 5-180 min, and the mixing equipment is at least one of a high-efficiency wet mixing granulator, a planetary mixer, a V-type mixer, and a kneader.

[0021] A method for preparing battery-grade lithium carbonate using an aluminum salt lithium ion adsorbent comprises the following steps:

[0022] Adsorption: The salt lake brine is introduced into the ion exchange resin column for adsorption to obtain the adsorption tail liquid, and then the eluent is used for elution after the adsorption is completed to obtain the analytical solution;

[0023] Nanofiltration: The analytical solution is separated by nanofiltration to obtain nanofiltration concentrated water and nanofiltration produced water;

[0024] Concentration: The nanofiltration produced water is concentrated by forward osmosis membrane and forced evaporation to obtain a high-lithium solution;

[0025] Refining and precipitating lithium: After using alkaline solution to purify and remove impurities from the high-lithium solution, pure alkali solution is added to carry out lithium precipitation reaction. The precipitate is washed and dried to obtain battery-grade lithium carbonate.

[0026] As a further technical solution of the present invention, in the adsorption, Li + The mass concentration is 0.05-5.00g / L, and the Mg content of salt lake brine is 2+ With Li + The mass percentage is 20-2000; the filling resin of the ion exchange resin column is at least one of an aluminum salt lithium ion adsorbent, a manganese lithium ion sieve adsorbent or its precursor, a titanium lithium ion sieve adsorbent or its precursor, and a lithium iron phosphate precursor; the adsorption flow rate is 0.1-10BV / h, the adsorption temperature is 10-80°C; the Li + The mass concentration is 0.1-3.0g / L, and the Mg content of the analytical solution is 2+ With Li + The mass percentage is 0.1-5.0.

[0027] As a further technical solution of the present invention, in the nanofiltration, the nanofiltration stage is one, the nanofiltration pressure is 1.0-8.0MPa, and the nanofiltration temperature is 10-80°C; Li + The mass concentration is 0.1-3.0g / L, and the Mg content of nanofiltration concentrated water is 2+ With Li + The mass percentage is 1.0-50.0; Li in nanofiltration water + The mass concentration is 0.1-3.0g / L, and the Mg content of nanofiltration water is 2+ With Li + The mass percentage is 0.01-0.10.

[0028] As a further technical solution of the present invention, in the concentration, the forward osmosis membrane concentration raw liquid is nanofiltration produced water, and its total salt content TDS is 1-200g / L, and the forward osmosis membrane concentration draw liquid is at least one of adsorption tail liquid, nanofiltration concentrated water, and salt lake brine, and its total salt content TDS is 200-600g / L; the forward osmosis membrane concentration operation mode can be parallel flow or cross flow osmosis, and the operating temperature is 10-80°C;

[0029] As a further technical solution of the present invention, forced evaporation concentration can adopt a thin film evaporator or a rotary evaporator, the evaporation temperature is 30-90°C, the evaporation vacuum is 0.01-0.10MPa; Li of high lithium solution + The mass concentration is 10.0-50.0g / L.

[0030] As a further technical solution of the present invention, in the refined lithium precipitation, the alkaline solution is at least one of 30% by mass sodium hydroxide, 30% by mass potassium hydroxide, 10% by mass lithium hydroxide, 15% by mass ammonia water, and 20% by mass sodium carbonate; the refined impurity removal mainly removes calcium and magnesium ions in the high lithium solution, and the Ca in the high lithium solution after refined impurity removal is 2+ The mass concentration is 0.01-50.00 mg / L, Mg 2+ The mass concentration is 0.01-50.00 mg / L; CO3 in pure alkali solution 2- The mass concentration is 120-150g / L, and the amount of soda ash solution added is based on the amount of Li in the refined high-lithium solution and the soda ash solution. + With CO3 2- The total mass ratio is 1:4.7-5.2; the lithium precipitation reaction temperature is 50-90°C, and the lithium precipitation reaction time is 0.5-3.0h.

[0031] A device for preparing battery-grade lithium carbonate using aluminum salt lithium ion adsorbent comprises an adsorption and analysis mechanism, a nanofiltration mechanism, a concentration mechanism, a refined lithium precipitation mechanism and a washing and drying mechanism.

[0032] As a further technical solution of the present invention, the adsorption and analysis mechanism is an ion exchange resin column, the second inlet of the ion exchange resin column is connected to the eluent storage tank, the first inlet of the ion exchange resin column is connected to the brine storage tank via a valve and a delivery pump, and the first outlet of the ion exchange resin column is connected to the forward osmosis reactor.

[0033] As a further technical solution of the present invention, the nanofiltration mechanism is a nanofiltration separator, which is connected to the first inlet of the ion exchange resin column, connected to the raw liquid side of the forward osmosis reactor, and connected to the second outlet of the ion exchange resin column.

[0034] As a further technical solution of the present invention, the concentration mechanism includes a forward osmosis reactor and a forced evaporator. The drawn liquid of the forward osmosis reactor is introduced into the drawn tail liquid storage tank after being diluted by forward osmosis, the raw liquid of the forward osmosis reactor is introduced into the forced evaporator after being concentrated by forward osmosis, the evaporated condensed water of the forced evaporator is introduced into the condensed water storage tank, and the evaporated concentrated liquid of the forced evaporator is introduced into the refining reactor.

[0035] As a further technical solution of the present invention, the refined lithium precipitation mechanism includes a refined reactor and a lithium precipitation reactor, the upper end of the refined reactor is connected to an alkali liquid tank, the lithium precipitation reactor is connected to a plate and frame filter press, the refined reactor is connected to a sediment storage tank through a belt conveyor, the upper end of the lithium precipitation reactor is connected to a soda liquid tank, and the lithium precipitation reactor is connected to an ion exchange resin column and a washing reactor through a first centrifuge.

[0036] As a further technical solution of the present invention, the washing and drying mechanism includes a washing reactor and a disc dryer, and the washing reactor is connected to the ion exchange resin column and the disc dryer through a second centrifuge.

[0037] Compared with the prior art, the present invention has the following beneficial effects:

[0038] The granular aluminum salt lithium ion adsorbent prepared by the preparation method of the aluminum salt lithium ion adsorbent has the following advantages:

[0039] First, the aluminum salt lithium ion adsorbent provided by the present invention can use commercially available industrial-grade lithium carbonate, crude lithium carbonate produced in the production process of lithium carbonate, or unqualified lithium carbonate as a synthetic lithium source. Compared with lithium salt products such as lithium chloride and lithium hydroxide, its raw material source is wider and the price is lower.

[0040] Second, the aluminum salt lithium ion adsorbent provided by the present invention utilizes the double hydrolysis reaction of bicarbonate ions in the hydrogenation reaction and aluminum ions in the aluminum salt solution. The reaction conditions are relatively mild, which is conducive to the growth of crystal nuclei. The synthesized adsorption material powder has good crystallinity and the product particle size is large, which is convenient for subsequent molding and processing.

[0041] Third, the aluminum salt lithium ion adsorbent provided by the present invention adopts a polymer as a reinforcement, and obtains a high-strength, high-toughness, and high-wear-resistant granular aluminum salt lithium ion adsorbent through an extrusion process. It is not easy to break and pulverize when loaded into a fixed fluidized bed or an adsorption reactor. The particle retention degree is good during the recycling process, which is conducive to industrial promotion and application.

[0042] The above-mentioned process and device for preparing battery-grade lithium carbonate using aluminum salt lithium ion adsorbent can be used for lithium extraction from different types of salt lake brines such as chloride, sulfate and carbonate, and can also be used for lithium extraction from salt lake raw brines with high sodium-lithium ratio and old brines with high magnesium-lithium ratio. The above content only lists the process for preparing lithium carbonate, and the processing method of the refined high-lithium solution can also be changed to produce lithium salt products such as lithium chloride and lithium hydroxide, such as using evaporation crystallization to produce lithium chloride, and using electrolysis or bipolar membrane electrodialysis to produce lithium hydroxide, so as to enrich the types of lithium products.

[0043] Compared with the prior art, the method and device for preparing battery-grade lithium carbonate using aluminum salt lithium ion adsorbent has the following advantages:

[0044] First, the process for preparing battery-grade lithium carbonate using aluminum salt lithium ion adsorbent provided by the present invention adopts an adsorption method in the front stage of the process to effectively separate lithium from other components in salt lake brine to obtain a high-lithium and low-impurity analytical solution, which is more beneficial to the subsequent membrane separation process.

[0045] Second, the process for preparing battery-grade lithium carbonate using aluminum salt lithium ion adsorbent provided by the present invention adopts a combined process of adsorption + nanofiltration + concentration + refined lithium precipitation. The analytical solution can completely separate magnesium and lithium by only one-stage nanofiltration treatment, and the osmotic pressure difference between the adsorption tail liquid and the nanofiltration separation liquid is used for forward osmosis concentration, which can basically achieve low-pressure or even pressure-free operation, with low process energy consumption, stronger membrane anti-pollution ability, and is conducive to the long-term operation of the equipment. At the same time, the solution is concentrated to a high concentration by forced evaporation, which can effectively improve the product yield of lithium carbonate. The combined process has the advantages of short production process, low production energy consumption, small production water consumption, high lithium extraction efficiency, and less production emissions, and greatly improves the quality of the final lithium salt product, which is suitable for the development and utilization of lithium resources in various types of salt lake brines.

[0046] Third, the device provided by the present invention for preparing battery-grade lithium carbonate using aluminum salt lithium ion adsorbent has a relatively mature application in the field of salt lake lithium extraction technology. It also has the characteristics of good production continuity and high degree of automation, which can significantly improve the production efficiency of the process. BRIEF DESCRIPTION OF THE DRAWINGS

[0047] Figure 1This is the XRD diagram of the powdered aluminum salt lithium ion adsorbent in this technology.

[0048] Figure 2 This is a flow chart for the preparation of granular aluminum salt lithium ion adsorbent in this technology.

[0049] Figure 3 This is a curve diagram of the static adsorption capacity change of the powdered aluminum salt lithium ion adsorbent and the granular lithium adsorption material in this technology.

[0050] Figure 4 A schematic diagram of a device for extracting lithium carbonate from salt lake brine provided by the present invention.

[0051] Among them, 1. brine storage tank; 2. valve; 3. delivery pump; 4. ion exchange resin column; 5. eluent storage tank; 6. tail liquid storage tank; 7. nanofiltration separator; 8. forward osmosis reactor; 9. forced evaporator; 10. refining reactor; 11. alkali liquid tank; 12. condensate storage tank; 13. plate and frame filter press; 14. belt conveyor; 15. sediment storage tank; 16. soda ash tank; 17. lithium precipitation reactor; 18. first centrifuge; 19. washing reactor; 20. second centrifuge; 21. disc dryer; 22. finished product warehouse. DETAILED DESCRIPTION

[0052] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0053] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0054] Example 1

[0055] The crude lithium carbonate produced in the lithium carbonate production process of a salt lake in Qinghai was used as raw material. The specific composition information is shown in Table 1.

[0056] Table 1 Chemical composition of crude lithium carbonate produced in a salt lake in Qinghai

[0057]

[0058] The crude lithium carbonate produced in the lithium carbonate production process was washed three times by adding pure water at a solid-liquid ratio of 1:2 to remove water-soluble impurities such as NaCl, KCl, and MgCl2. After filtration and separation, the filter cake was adjusted to lithium carbonate slurry at a solid-liquid ratio of 1:30. The CO2 gas rate in the hydrogenation reaction was controlled to be 2L / min, the hydrogenation reaction time was 120min, and the reaction temperature was 30°C. After the hydrogenation reaction was completed, the solution was filtered and separated to obtain a hydrogenated liquid. The hydrogenated liquid was passed into a calcium-magnesium chelate resin and a boron removal resin column to remove impurities such as calcium, magnesium, and boron by adsorption and separation to obtain a refined hydrogenated liquid. 1mol / L AlCl3 solution was added dropwise to the refined hydrogenated liquid, wherein the molar ratio of LiHCO3 to AlCl3 was 3:1, the stirring rate was 200r / min, and the reaction time was 1-2h. After the reaction was completed, it was filtered and separated to obtain a powdered aluminum salt lithium ion adsorbent, whose molecular formula was LiCl·2Al(OH)3·nH2O. 1000g of powdered aluminum salt lithium ion adsorbent was used as the adsorption material matrix, 100g of polyvinylidene fluoride (PVDF) and 400g of N,N-dimethylformamide were added and mixed in a wet mixing granulator for 30 minutes, and then the mixture was extruded and granulated in an extruder. After the extruded material was dried, crushed and sieved, a granular aluminum salt lithium ion adsorbent with a particle size of 0.5-2.0mm was obtained. The XRD pattern of the powdered aluminum salt lithium ion adsorbent prepared in this embodiment is compared with the standard spectrum of LiCl·2Al(OH)3·nH2O. Figure 1 ; The preparation process of the aluminum salt lithium ion adsorbent of the embodiment is shown in Figure 2 .

[0059] Example 2

[0060] Industrial-grade lithium carbonate produced in a salt lake in Qinghai was used as raw material. The specific composition information is shown in Table 2.

[0061] Table 2 Chemical composition of industrial-grade lithium carbonate produced in a salt lake in Qinghai

[0062]

[0063] Pure water was added at a solid-liquid ratio of 1:2 to wash the industrial-grade lithium carbonate twice to remove water-soluble impurities such as NaCl, KCl, and MgCl2. After filtration and separation, the filter cake was adjusted to lithium carbonate slurry at a solid-liquid ratio of 1:40. The CO2 gas rate in the hydrogenation reaction was controlled to be 3L / min, the hydrogenation reaction time was 90min, and the reaction temperature was 25°C. After the hydrogenation reaction was completed, the solution was filtered and separated to obtain a hydrogenated liquid, and the hydrogenated liquid was passed into a calcium-magnesium chelate resin and a boron removal resin column to remove impurities such as calcium, magnesium, and boron by adsorption and separation to obtain a refined hydrogenated liquid. A 2mol / L AlCl3 solution was added dropwise to the refined hydrogenated liquid, wherein the molar ratio of LiHCO3 to AlCl3 was 3:1, the stirring rate was 200r / min, and the reaction time was 1-2h. After the reaction was completed, it was filtered and separated to obtain a powdered aluminum salt lithium ion adsorbent, whose molecular formula was LiCl·2Al(OH)3·nH2O. 1000g of powdered aluminum salt lithium ion adsorbent is used as the adsorption material matrix, 50g of hydrogenated nitrile rubber (HNBR) and 500g of N-methylpyrrolidone are added and mixed in a kneader for 30 minutes, and then the mixture is extruded and granulated in an extruder. After the extruded material is dried, crushed and sieved, a granular aluminum salt lithium ion adsorbent with a particle size between 0.5-2.0mm is obtained.

[0064] Example 3

[0065] The static adsorption capacity of the powdered aluminum salt lithium ion adsorbent and the granular aluminum salt lithium ion adsorbent in Example 2 was verified. The experimental brine was taken from a salt lake beach in the Qaidam Basin of Qinghai. The water chemistry type was magnesium sulfate subtype and had the chemical composition shown in Table 3.

[0066] Table 3 Chemical composition of brine from a salt lake beach in the Qaidam Basin, Qinghai

[0067] Element Name <![CDATA[Li + ]]> <![CDATA[Na + ]]> <![CDATA[K + ]]> <![CDATA[Mg 2+ ]]> <![CDATA[Cl - ]]> <![CDATA[SO4 2- ]]> <![CDATA[B2O3]]> Content (mg / L) 1030 56322 16352 35412 184519 35688 3670

[0068] Weigh 50g of powdered aluminum salt lithium ion adsorbent and 50g of granular aluminum salt lithium ion adsorbent, add 500ml of experimental brine respectively, carry out stirring adsorption reaction in a beaker, the stirring speed is 200r / min, monitor the brine concentration at different time points, and obtain the relationship curve between the adsorption capacity of powdered aluminum salt lithium ion adsorbent and granular aluminum salt lithium ion adsorbent and the adsorption time, as shown in Figure 2. Figure 3 shown.

[0069] The experimental results show that the powdered aluminum salt lithium ion adsorbent and the granular aluminum salt lithium ion adsorbent prepared by the present invention are used for lithium extraction from this type of salt lake brine. After 120 minutes of adsorption time, the adsorption material basically reaches an adsorption saturation state. At this time, the static adsorption capacity of the powdered aluminum salt lithium ion adsorbent is 8.60 mg / g, and the static adsorption capacity of the granular aluminum salt lithium ion adsorbent is 4.10 mg / g, which have good adsorption capacity.

[0070] Example 4

[0071] (1) 10 kg of manganese-based lithium ion sieve adsorbent resin was filled into a 20 L ion exchange resin column for extracting lithium carbonate from salt lake brine. The experimental brine was taken from a salt lake in the Qaidam Basin of Qinghai Province and had the chemical composition shown in Table 4.

[0072] Table 4 Chemical composition of the original brine in a salt lake in the Qaidam Basin, Qinghai

[0073] Element Name <![CDATA[Li + ]]> <![CDATA[Na + ]]> <![CDATA[K + ]]> <![CDATA[Mg 2+ ]]> <![CDATA[Cl - ]]> <![CDATA[SO4 2- ]]> <![CDATA[B2O3]]> Content (mg / L) 170 82456 7886 25442 185443 32455 1420

[0074] The experimental brine was introduced into the ion exchange resin column for adsorption operation, with an adsorption flow rate of 6 BV / h and an adsorption temperature of 20 °C. + When the mass concentration is greater than 20 mg / L, the adsorption is stopped, the single adsorption time is 3h, and the brine treatment volume is 360L; 0.15mol / L hydrochloric acid solution is used as the eluent, the analysis flow rate is 8BV / h, the elution temperature is 20°C, and the analysis is stopped when the Li+ mass concentration in the tail effluent is less than 100 mg / L. The single analysis time is 0.5h, and the analysis liquid output is 80L. After 5 adsorption-analysis cycles, the cumulative output of adsorbed tail halogen is 1800L, and the analysis qualified liquid is 400L, of which the average lithium ion adsorption yield is 94.12%, the average lithium adsorption capacity is 5.76mg / g, and the average analysis yield is 100.69%. The chemical composition of the obtained analysis liquid is shown in Table 5.

[0075] Table 5 Chemical composition of manganese series lithium ion sieve adsorption analysis solution

[0076] Element Name <![CDATA[Li + ]]> <![CDATA[Na + ]]> <![CDATA[K + ]]> <![CDATA[Mg 2+ ]]> <![CDATA[Cl - ]]> <![CDATA[SO4 2- ]]> <![CDATA[B2O3]]> Content (mg / L) 725 50 24 178 4247 40 20

[0077] (2) The 400 L analytical solution in Example (1) was subjected to primary nanofiltration separation at a nanofiltration pressure of 3.0 MPa and a nanofiltration temperature of 30°C, and a total of 360 L of nanofiltration water was obtained, of which Mg 2+ With Li + The mass percentage of Mg is 0.01, and 40L of nanofiltration concentrated water is obtained. 2+ With Li + The mass percentage of Mg in the raw material solution is 2.41. 2+ The mass concentration decreased from 178mg / L to 10mg / L, SO4 2- The mass concentration decreased from 40mg / L to 5mg / L, and the mass concentration of B2O3 decreased from 20mg / L to 10mg / L. 2+The retention rate is 90.90%, the SO42- retention rate is 88.75%, the B2O3 retention rate is 64.00%, and the nanofiltration separation lithium yield is 90.62% without taking into account the recovery of lithium from nanofiltration concentrated water.

[0078] (3) Forward osmosis membrane concentration process: The nanofiltration water produced in Example (2) was used as the raw liquid, and its total salt content TDS was 5 g / L. The adsorption tail liquid was used as the draw liquid, and its total salt content TDS was 335 g / L. The membrane was concentrated by parallel flow osmosis at an operating temperature of 30°C. After forward osmosis membrane concentration treatment, Li + The mass concentration increased from 0.73g / L to 4.70g / L, and the concentration multiple was 6.44 times. A total of 55L of forward osmosis concentrate was obtained, and its total salt content TDS was 35g / L. The total salt content TDS of the tail liquid after forward osmosis membrane concentration treatment was 283g / L. The evaporation concentration process used a rotary evaporator to concentrate the forward osmosis concentrate, the evaporation temperature was 70℃, the evaporation vacuum was 0.07MPa, and the Li + The mass concentration increased from 4.70g / L to 24.50g / L, with a concentration factor of 5.21. A total of 10.5L of high-lithium solution was obtained, and about 44L of evaporated condensed water was obtained.

[0079] (4) The high-lithium solution obtained in Example (3) is refined and lithium is precipitated. The Mg in the high-lithium solution is 2+ The mass concentration is 1.02g / L, and the pH value of the solution is adjusted to 10-12 with a 30% mass fraction of sodium hydroxide solution. After the precipitation reaction for 30 minutes, it is introduced into a plate and frame filter press for solid-liquid separation. The precipitate is conveyed to the precipitate storage tank by a belt. According to the lithium content of the separated refined high-lithium solution, CO3 is added 2- 11.2L of 120g / L sodium carbonate solution was used for lithium precipitation reaction at 80℃ for 2h. The lithium precipitation slurry was filtered and separated by centrifuge to obtain Li + 21L of lithium precipitation mother liquor with a mass concentration of 1.80g / L and 1300g of wet lithium carbonate, the wet lithium carbonate is washed and dried to obtain 1080g of lithium carbonate product and Li + The washing mother liquor with a mass concentration of 1.50g / L totaled 9L. The main content of lithium carbonate in the product was 99.70%, and the trace element indicators all met the requirements of the battery-grade lithium carbonate YS / T 582-2013 standard. Without considering the recovery of lithium-containing mother liquor, the overall process lithium ion yield from salt lake brine to battery-grade lithium carbonate products was calculated to be 66.77%.

[0080] Example 5

[0081] (1) This example uses the granular aluminum salt lithium ion adsorbent prepared by the preparation method of the aluminum salt lithium ion adsorbent of the present invention to adsorb lithium from the experimental brine in Table 4. 10 kg of aluminum salt lithium ion adsorbent resin is filled into an ion exchange resin column with a volume of 20 L, and the experimental brine is introduced into the ion exchange resin column for adsorption operation. The adsorption flow rate is 3 BV / h, the adsorption temperature is 30°C, and the Li + When the mass concentration is greater than 20 mg / L, the adsorption is stopped. The single adsorption time is 2.5 h, and the brine treatment volume is 150 L. Pure water is used as the eluent, the analysis flow rate is 3 BV / h, the elution temperature is 50 ° C, and the Li in the tail effluent is analyzed. + When the mass concentration was less than 100 mg / L, the analysis was stopped, the single analysis time was 0.5 h, and the analysis solution yield was 55 L. After 10 adsorption-analysis cycles, the cumulative output of adsorbed tail halogen was 1500 L, and the analysis qualified solution was 550 L, of which the average lithium ion adsorption yield was 91.18%, the average lithium adsorption capacity was 2.33 mg / g, and the average analysis yield was 99.35%. The chemical composition of the obtained analysis solution is shown in Table 6.

[0082] Table 6 Chemical composition of the analytical solution by aluminum salt lithium ion adsorbent adsorption method

[0083] Element Name <![CDATA[Li + ]]> <![CDATA[Na + ]]> <![CDATA[K + ]]> <![CDATA[Mg 2+ ]]> <![CDATA[Cl - ]]> <![CDATA[SO4 2- ]]> <![CDATA[B2O3]]> Content (mg / L) 420 112 75 265 3350 120 60

[0084] The experimental results show that after the adsorption and analysis process, an analysis solution with a lithium concentration of 420 mg / L can be obtained. The sodium-lithium ratio in the brine is reduced from 485.04 to 0.27, the potassium-lithium ratio is reduced from 46.39 to 0.18, the magnesium-lithium ratio is reduced from 149.66 to 0.63, the sulfur-lithium ratio is reduced from 190.91 to 0.29, and the boron-lithium ratio is reduced from 8.35 to 0.14.

[0085] Comparative Example 4, the manganese-based lithium ion sieve adsorption material resin, the granular aluminum salt lithium ion adsorbent prepared by the preparation method of the aluminum salt lithium ion adsorbent of the present invention in this embodiment also has a good adsorption and analysis effect on this type of brine, and can effectively realize the separation and extraction of lithium resources in salt lake brine.

[0086] (2) The 550 L analytical solution in Example (1) was subjected to primary nanofiltration separation at a nanofiltration pressure of 3.0 MPa and a nanofiltration temperature of 35°C to obtain a total of 500 L of nanofiltration water, of which Mg 2+ With Li + The mass percentage of Mg is 0.06, and 50L of nanofiltration concentrated water is obtained. 2+ With Li + The mass percentage of Mg in the raw material solution is 6.35. 2+ The mass concentration decreased from 265mg / L to 25mg / L, SO4 2-The mass concentration decreased from 120mg / L to 10mg / L, and the mass concentration of B2O3 decreased from 60mg / L to 20mg / L. 2+ The interception rate is 91.42%, SO4 2- The rejection rate is 92.42%, the B2O3 rejection rate is 69.70%, and the lithium yield of nanofiltration separation is 90.91% without considering the recovery of lithium from nanofiltration concentrated water.

[0087] (3) Forward osmosis membrane concentration process: The nanofiltration produced water in Example (2) is used as the raw liquid, and its total salt content TDS is 4g / L. The adsorption tail liquid is used as the draw liquid, and its total salt content TDS is 335g / L. The membrane concentration is carried out by cross-flow osmosis, and the operating temperature is 30°C. After forward osmosis membrane concentration treatment, the Li+ mass concentration in the nanofiltration produced water increases from 0.42g / L to 4.60g / L, and the concentration multiple is 10.95 times. A total of 45L of forward osmosis concentrated liquid is obtained, and its total salt content TDS is 40g / L. The total salt content TDS of the draw tail liquid after forward osmosis membrane concentration treatment is 255g / L. The evaporation concentration process uses a rotary evaporator to concentrate the forward osmosis concentrated liquid. The evaporation temperature is 70°C, the evaporation vacuum is 0.07MPa, and the Li+ content in the raw liquid is 1.57g / L. + The mass concentration increased from 4.60g / L to 26.00g / L, with a concentration factor of 5.65 times. A total of 8L of high-lithium solution was obtained, and about 36L of evaporated condensed water was obtained.

[0088] (4) The high-lithium solution obtained in Example (3) is refined and lithium is precipitated. The Mg in the high-lithium solution is 2+ The mass concentration is 1.55g / L, and the pH value of the solution is adjusted to 10-12 with a 10% lithium hydroxide solution. After the precipitation reaction for 30 minutes, it is introduced into a plate and frame filter press for solid-liquid separation. The precipitate is conveyed to the precipitate storage tank by a belt. According to the lithium content of the separated refined high-lithium solution, CO3 is added 2- 9L of soda ash solution with a mass concentration of 120g / L was used for lithium precipitation reaction at 80℃ for 2h. The lithium precipitation slurry was filtered and separated by a centrifuge to obtain Li + 16.5L of lithium precipitation mother liquor with a mass concentration of 1.80g / L and 1050g of wet lithium carbonate, the wet lithium carbonate is washed and dried to obtain 850g of lithium carbonate product and Li + The washing mother liquor with a mass concentration of 1.50g / L totaled 12L. The main lithium carbonate content of the product was 99.63%, and the trace element indicators all met the requirements of the battery-grade lithium carbonate YS / T 582-2013 standard. Without considering the recovery of lithium-containing mother liquor, the overall process lithium ion yield from salt lake brine to battery-grade lithium carbonate products was calculated to be 63.06%.

[0089] (5) Mix 50 L of the nanofiltration concentrated water in Example (2), 16.5 L of the lithium precipitation mother liquor in Example (4), and 12 L of the washing mother liquor to obtain Li + 78 L of the mixed solution with a mass concentration of 0.87 g / L was adsorbed and analyzed using the adsorption device in Example (1) at an adsorption flow rate of 2 BV / h and an adsorption temperature of 30 °C. + When the mass concentration is greater than 20 mg / L, the adsorption is stopped. The single adsorption time is 2 h, and the mixed solution processing volume is 40 L. Pure water is used as the eluent, the analysis flow rate is 3 BV / h, the elution temperature is 50 ° C, and the Li in the tail effluent is analyzed. + When the mass concentration is less than 100 mg / L, the analysis is stopped. The single analysis time is 1.0 h and the analysis liquid output is 55 L. After two adsorption-analysis cycles, the cumulative output of adsorption tail liquid is 78 L and the analysis qualified liquid is 110 L, of which the average lithium adsorption yield is 98.85%, the average lithium adsorption capacity is 3.35 mg / g, and the average lithium analysis yield is 98.39%. The obtained analysis liquid Li + The mass concentration is 600 mg / L. Through the adsorption-analysis operation of the adsorption device, the recovery of lithium from nanofiltration concentrated water, lithium precipitation mother liquor, and washing mother liquor was basically completed. The overall process lithium ion yield from salt lake brine to battery-grade lithium carbonate products was calculated to be 88.95%.

[0090] The above is a specific implementation example of the present invention. It should be pointed out that for inventors in this industry field, without violating the spirit and essence of the present invention, corresponding improvements and modifications can be made based on the disclosed content of the present invention, but these corresponding improvements and modifications all fall within the scope of protection of the claims in the present invention.

[0091] The present invention not only proposes a method for preparing an aluminum salt lithium ion adsorbent, but also verifies the separation performance of the aluminum salt lithium ion adsorbent prepared by the present invention on lithium ions in salt lake brine, and proposes a combined lithium extraction process and device of adsorption + nanofiltration + concentration + refined lithium precipitation.

[0092] A device for preparing battery-grade lithium carbonate using aluminum salt lithium ion adsorbent comprises an adsorption and analysis mechanism, a nanofiltration mechanism, a concentration mechanism, a refined lithium precipitation mechanism, and a washing and drying mechanism.

[0093] The adsorption and analysis mechanism is an ion exchange resin column 4. During the adsorption process, the brine storage tank 1 is connected to the first inlet of the ion exchange resin column 4 via a valve 2 and a delivery pump 3. After the lithium-containing brine undergoes an adsorption reaction, it is connected to the forward osmosis reactor 8 via the first outlet of the ion exchange resin column 4. During the analysis process, the eluent storage tank 5 is connected to the second inlet of the ion exchange resin column 4. After the adsorption resin undergoes an analysis reaction, it is connected to the nanofiltration separator 7 via the second outlet of the ion exchange resin column 4.

[0094] The nanofiltration mechanism is a nanofiltration separator 7 , the concentrated water of the nanofiltration separator 7 is connected to the first inlet of the ion exchange resin column 4 , and the produced water of the nanofiltration separator 7 is introduced into the raw liquid side of the forward osmosis reactor 8 .

[0095] The concentration mechanism includes a forward osmosis reactor 8 and a forced evaporator 9. The drawn liquid of the forward osmosis reactor 8 is introduced into the drawn tail liquid storage tank 6 after being diluted by forward osmosis. The raw liquid of the forward osmosis reactor 8 is introduced into the forced evaporator 9 after being concentrated by forward osmosis. The evaporated condensed water of the forced evaporator 9 is introduced into the condensed water storage tank 12. The evaporated concentrated liquid of the forced evaporator 9 is introduced into the refining reactor 10.

[0096] The refined lithium precipitation mechanism includes a refined reactor 10 and a lithium precipitation reactor 17. The upper end of the refined reactor 10 is connected to an alkali liquid tank 11. The refined slurry is filtered and separated by a plate and frame filter press 13 and then introduced into the lithium precipitation reactor 17. The separated precipitate is transported to a precipitate storage tank 15 via a belt conveyor 14. At the same time, the upper end of the lithium precipitation reactor 17 is connected to a soda liquid tank 16. The lithium precipitation slurry is separated into a lithium precipitation mother liquor and wet lithium carbonate by a first centrifuge 18 after solid-liquid separation. The lithium precipitation mother liquor is introduced into an ion exchange resin column 4 for cyclic adsorption, and the wet lithium carbonate is transported to a washing reactor 19.

[0097] The washing and drying mechanism includes a washing reactor 19 and a disc dryer 21. The washing slurry is separated into solid and liquid by a second centrifuge 20 to obtain a washing mother liquor and washing lithium carbonate. The washing mother liquor is introduced into an ion exchange resin column 4 for cyclic adsorption. The washing lithium carbonate is transported to the disc dryer 21 for drying to obtain battery-grade lithium carbonate. The product is transported to a finished product warehouse 22 for storage.

[0098] During operation, lithium carbonate is subjected to washing, hydrogenation, refining and other steps, and then subjected to precipitation reaction with aluminum salt solution to obtain powdered aluminum salt lithium ion adsorbent, which is further formed and granulated to obtain granular aluminum salt lithium ion adsorbent; using the aluminum salt lithium ion adsorbent of the present invention, salt lake brine is adsorbed to achieve separation of lithium ions and other ions in the salt lake brine; the desorption liquid obtained by adsorption is subjected to the nanofiltration, concentration, refining and lithium precipitation processes of the present invention to prepare battery-grade lithium carbonate.

[0099] The preparation method of the aluminum salt lithium ion adsorbent of the present invention has the advantages of wide raw material sources, high powder crystallinity, good particle strength, and high adsorption capacity. The process of using aluminum salt lithium ion adsorbent to prepare battery-grade lithium carbonate of the present invention adopts a combined process of adsorption + nanofiltration + concentration + refined lithium precipitation. The analytical liquid can completely separate magnesium and lithium through only one-stage nanofiltration treatment, and the osmotic pressure difference between the adsorption tail liquid and the nanofiltration separation liquid is used for forward osmosis concentration, which can basically achieve low-pressure or even pressure-free operation, and has the advantages of low process energy consumption, short production process, high lithium extraction efficiency, and less production emissions. The device for preparing battery-grade lithium carbonate using aluminum salt lithium ion adsorbent of the present invention has a relatively mature application in the field of salt lake lithium extraction invention, and at the same time has the characteristics of good production continuity and high degree of automation, which can significantly improve the production efficiency of the process.

[0100] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the present invention can be implemented in other specific forms without departing from the spirit or essential features of the present invention. Therefore, the embodiments should be considered exemplary and non-restrictive in all respects, and the scope of the present invention is defined by the appended claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims be included in the present invention.

[0101] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A method for preparing an aluminum salt lithium ion adsorbent, characterized in that: The following steps are involved: S1. Wash the lithium carbonate with pure water to remove water-soluble impurities, and prepare the filter cake into lithium carbonate slurry in a certain proportion; S2, introducing CO2 gas into the lithium carbonate slurry for hydrogenation reaction, and filtering the reaction slurry to obtain a hydrogenated liquid; S3, passing the hydrogenated liquid into an ion exchange resin column for refining and removing impurities to obtain a refined hydrogenated liquid; S4, subjecting the refined hydrogenated liquid to a precipitation reaction with an aluminum salt solution, and filtering to obtain a powdered aluminum salt lithium ion adsorbent; S5. Mix the powdered aluminum salt lithium ion adsorbent, the adhesive and the solvent in a mixing device according to a certain mass ratio, and obtain the granular aluminum salt lithium ion adsorbent after an extrusion granulation process.

2. The method for preparing the aluminum salt lithium ion adsorbent according to claim 1, characterized in that: The solid-liquid ratio of pure water washing in S1 is 1:0.5-5.0, and the number of washing times is 1-3 times.

3. The method for preparing the aluminum salt lithium ion adsorbent according to claim 1, characterized in that: The lithium carbonate slurry in S1 is prepared according to a mass ratio of lithium carbonate to pure water of 1:10-50.

4. The method for preparing the aluminum salt lithium ion adsorbent according to claim 1, characterized in that: The CO2 gas introduction rate in the S2 is 1-5 L / min, the hydrogenation reaction time is 30-180 min, and the hydrogenation reaction temperature is 20-40°C.

5. The method for preparing the aluminum salt lithium ion adsorbent according to claim 1, characterized in that: The ion exchange resin in S3 is a calcium-magnesium chelating resin and / or a boron removal resin, which is used to remove impurities such as calcium, magnesium, and boron in the hydrogenated liquid.

6. The method for preparing the aluminum salt lithium ion adsorbent according to claim 1, characterized in that: The aluminum salt solution in S4 is an AlCl3 solution with a molar concentration of 0.1-3.0 mol / L, and the molecular formula of the aluminum salt lithium ion adsorbent is LiCl·2Al(OH)3·nH2O, wherein the value of n is 1-3.

7. The method for preparing the aluminum salt lithium ion adsorbent according to claim 1, characterized in that: The adhesive in S5 is at least one of polyethylene, polyvinyl alcohol, polystyrene, polyvinylidene fluoride, polytetrafluoroethylene, polypropylene, polyacrylonitrile, nitrile rubber, hydrogenated nitrile rubber, polyamide, polyimide, polysulfone, polyurethane, polycarbonate, polymethyl methacrylate, epoxy resin, and phenolic resin.

8. The method for preparing the aluminum salt lithium ion adsorbent according to claim 1, characterized in that: The solvent in S5 is at least one of chloroform, carbon tetrachloride, toluene, acetone, glycerol, tetrahydrofuran, ethyl formate, ethyl acetate, N-methylpyrrolidone, N,N-dimethylformamide, and N,N-dimethylacetamide.

9. The method for preparing the aluminum salt lithium ion adsorbent according to claim 1, characterized in that: The mixing mass ratio of the powdered aluminum salt lithium ion adsorbent, the adhesive and the solvent in S5 is 1:0.01-0.50:1.00-10.

00.

10. The method for preparing the aluminum salt lithium ion adsorbent according to claim 1, characterized in that: The material mixing time in S5 is 5-180 min, and the mixing equipment is at least one of a high-efficiency wet mixing granulator, a planetary mixer, a V-type mixer, and a kneader.

11. A method for preparing battery-grade lithium carbonate using the aluminum salt lithium ion adsorbent prepared by the method according to any one of claims 1 to 10, characterized in that: The following steps are involved: Adsorption: The salt lake brine is introduced into the ion exchange resin column for adsorption to obtain the adsorption tail liquid, and then the eluent is used for elution after the adsorption is completed to obtain the analytical solution; Nanofiltration: The analytical solution is separated by nanofiltration to obtain nanofiltration concentrated water and nanofiltration produced water; Concentration: The nanofiltration produced water is concentrated by forward osmosis membrane and forced evaporation to obtain a high-lithium solution; Refining and precipitating lithium: After using alkaline solution to purify and remove impurities from the high-lithium solution, pure alkali solution is added to carry out lithium precipitation reaction. The precipitate is washed and dried to obtain battery-grade lithium carbonate.

12. The method for preparing battery-grade lithium carbonate using aluminum salt lithium ion adsorbent according to claim 11, characterized in that: In the adsorption, Li + The mass concentration is 0.05-5.00g / L, and the Mg content of salt lake brine is 2+ With Li + The mass percentage is 20-2000.

13. The method for preparing battery-grade lithium carbonate using aluminum salt lithium ion adsorbent according to claim 11, characterized in that: In the adsorption, the filling resin of the ion exchange resin column is at least one of aluminum salt lithium ion adsorbent, manganese series lithium ion sieve adsorbent or its precursor, titanium series lithium ion sieve adsorbent or its precursor, and lithium iron phosphate precursor.

14. The method for preparing battery-grade lithium carbonate using aluminum salt lithium ion adsorbent according to claim 11, characterized in that: In the adsorption, the adsorption flow rate is 0.1-10 BV / h, and the adsorption temperature is 10-80°C.

15. The method for preparing battery-grade lithium carbonate using aluminum salt lithium ion adsorbent according to claim 11, characterized in that: In the adsorption, Li + The mass concentration is 0.1-3.0g / L, and the Mg content of the analytical solution is 2+ With Li + The mass percentage is 0.1-5.

0.

16. The method for preparing battery-grade lithium carbonate using aluminum salt lithium ion adsorbent according to claim 11, characterized in that: In the nanofiltration, the nanofiltration stage is one, the nanofiltration pressure is 1.0-8.0 MPa, and the nanofiltration temperature is 10-80°C.

17. The method for preparing battery-grade lithium carbonate using aluminum salt lithium ion adsorbent according to claim 11, characterized in that: In the nanofiltration, Li + The mass concentration is 0.1-3.0g / L, and the Mg content of nanofiltration concentrated water is 2+ With Li + The mass percentage is 1.0-50.

0.

18. The method for preparing battery-grade lithium carbonate using aluminum salt lithium ion adsorbent according to claim 11, characterized in that: In the nanofiltration, Li + The mass concentration is 0.1-3.0g / L, and the Mg content of nanofiltration water is 2+ With Li + The mass percentage is 0.01-0.

10.

19. The method for preparing battery-grade lithium carbonate using aluminum salt lithium ion adsorbent according to claim 11, characterized in that: In the concentration, the forward osmosis membrane concentration raw liquid is nanofiltration produced water, and its total salt content TDS is 1-200g / L, and the forward osmosis membrane concentration draw liquid is at least one of adsorption tail liquid, nanofiltration concentrated water, and salt lake brine, and its total salt content TDS is 200-600g / L.

20. The method for preparing battery-grade lithium carbonate using aluminum salt lithium ion adsorbent according to claim 11, characterized in that: In the concentration, the forward osmosis membrane concentration operation mode can be co-current or cross-current osmosis, and the operation temperature is 10-80°C.

21. The method for preparing battery-grade lithium carbonate using aluminum salt lithium ion adsorbent according to claim 11, characterized in that: In the concentration, the forced evaporation concentration can adopt a thin film evaporator or a rotary evaporator, the evaporation temperature is 30-90° C., and the evaporation vacuum is 0.01-0.10 MPa.

22. The method for preparing battery-grade lithium carbonate using aluminum salt lithium ion adsorbent according to claim 11, characterized in that: The concentrated, high-lithium solution Li + The mass concentration is 10.0-50.0g / L.

23. The method for preparing battery-grade lithium carbonate using aluminum salt lithium ion adsorbent according to claim 11, characterized in that: In the refined lithium precipitation, the alkaline solution is at least one of 30% by mass sodium hydroxide, 30% by mass potassium hydroxide, 10% by mass lithium hydroxide, 15% by mass ammonia water, and 20% by mass sodium carbonate.

24. The method for preparing battery-grade lithium carbonate using aluminum salt lithium ion adsorbent according to claim 11, characterized in that: In the refined lithium precipitation, the refined impurity removal mainly removes calcium and magnesium ions in the high lithium solution. 2+ The mass concentration is 0.01-50.00 mg / L, Mg 2+ The mass concentration is 0.01-50.00mg / L.

25. The method for preparing battery-grade lithium carbonate using aluminum salt lithium ion adsorbent according to claim 11, characterized in that: In the refined lithium precipitation, the CO3 2- The mass concentration is 120-150g / L, and the amount of soda ash solution added is based on the amount of Li in the refined high-lithium solution and the soda ash solution. + With CO3 2- The total mass ratio is 1:4.7-5.

2.

26. The method for preparing battery-grade lithium carbonate using aluminum salt lithium ion adsorbent according to claim 11, characterized in that: In the refined lithium precipitation, the lithium precipitation reaction temperature is 50-90° C., and the lithium precipitation reaction time is 0.5-3.0 h.

27. A device for preparing battery-grade lithium carbonate using the aluminum salt lithium ion adsorbent prepared by the method according to any one of claims 1 to 10, characterized in that: It includes an adsorption and analysis mechanism, a nanofiltration mechanism, a concentration mechanism, a refined lithium precipitation mechanism and a washing and drying mechanism.

28. The device for preparing battery-grade lithium carbonate using aluminum salt lithium ion adsorbent according to claim 27, characterized in that: The adsorption and analysis mechanism is an ion exchange resin column, the second inlet of the ion exchange resin column is connected to the eluent storage tank, the first inlet of the ion exchange resin column is connected to the brine storage tank via a valve and a delivery pump, and the first outlet of the ion exchange resin column is connected to the forward osmosis reactor.

29. The device for preparing battery-grade lithium carbonate using aluminum salt lithium ion adsorbent according to claim 28, characterized in that: The nanofiltration mechanism is a nanofiltration separator, which is connected to the first inlet of the ion exchange resin column, connected to the raw liquid side of the forward osmosis reactor, and connected to the second outlet of the ion exchange resin column.

30. The device for preparing battery-grade lithium carbonate using aluminum salt lithium ion adsorbent according to claim 27, characterized in that: The concentration mechanism comprises a forward osmosis reactor and a forced evaporator. The drawn liquid of the forward osmosis reactor is introduced into the drawn tail liquid storage tank after being diluted by forward osmosis. The raw liquid of the forward osmosis reactor is introduced into the forced evaporator after being concentrated by forward osmosis. The evaporated condensed water of the forced evaporator is introduced into the condensed water storage tank. The evaporated concentrated liquid of the forced evaporator is introduced into the refining reactor.

31. The device for preparing battery-grade lithium carbonate using aluminum salt lithium ion adsorbent according to claim 28, characterized in that: The refined lithium precipitation mechanism comprises a refined reactor and a lithium precipitation reactor, the upper end of the refined reactor is connected with an alkali liquid tank, the lithium precipitation reactor is connected with a plate and frame filter press, the refined reactor is connected with a sediment storage tank through a belt conveyor, the upper end of the lithium precipitation reactor is connected with a soda liquid tank, and the lithium precipitation reactor is connected with an ion exchange resin column and a washing reactor through a first centrifuge.

32. The device for preparing battery-grade lithium carbonate using aluminum salt lithium ion adsorbent according to claim 28, characterized in that: The washing and drying mechanism comprises a washing reaction kettle and a disc dryer, and the washing reaction kettle is connected with the ion exchange resin column and the disc dryer through a second centrifuge.

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