A method for loading aluminum-based lithium adsorbents into anionic macroporous resins

Abstract

This method for loading aluminum-based lithium adsorbents onto anionic macroporous resins belongs to the field of lithium adsorbent preparation technology. The anionic macroporous resin is immersed in a NaAlO2 solution to adsorb AlO2. ‑ Anionic macroporous resin was placed in a gas-solid reaction apparatus, wetted with deionized water, and CO2 was introduced from bottom to top to obtain macroporous resin loaded with Al(OH)3; the anionic macroporous resin was then placed in LiCl and LiOH solutions for Li... + The insertion reaction was followed by washing with deionized water to obtain a macroporous resin loaded with aluminum-based lithium adsorbent; after adsorption of lithium in lithium solution by anionic macroporous resin, Li was desorbed using deionized water. + The aluminum-based lithium adsorbent of this invention uses inexpensive and readily available raw materials, exhibits a fast adsorption rate, is suitable for the flow adsorption of large quantities of brine, and demonstrates good magnesium-lithium separation performance. The adsorption-desorption process of the aluminum-based lithium adsorbent is reversible, it can be regenerated by washing with water, is low-cost, and environmentally friendly.

Description

Technical Field

[0001] This invention relates to a method for loading an aluminum-based lithium adsorbent into an anionic macroporous resin, belonging to the field of lithium adsorbent preparation technology. Background Technology

[0002] Lithium and its compounds are widely used in new energy, nuclear energy industries, and other fields, and are known as "important elements driving the world forward." Lithium resources are mainly found in lithium ore and salt lake brines. Low-grade brines often have a high magnesium-to-lithium ratio, making extraction difficult. Chemical adsorption, characterized by high selectivity and low environmental pollution, can selectively adsorb lithium ions in high-magnesium-to-lithium salt lake brines, achieving efficient lithium extraction.

[0003] Aluminum-based lithium adsorbents are currently industrially applied brine lithium adsorbents, developed from the aluminum salt precipitation lithium extraction method. They are composed of Li·Al2(OH)7·2H2O. Their preparation involves inserting Li+ ions into the crystal structure layers of Al(OH)3, with Cl- ions acting as balancing anions in the interlayer, resulting in Li·Al2(OH)7·2H2O. Subsequently, some Li+ is removed from the crystal. + This forms a crystal structure with hole defects, and the hole is just enough to accommodate Li. + The radius of the bare ion, this crystal structure tends to trap Li + The bare ions form a more stable original structure. Common interfering ions in brine include Na+. + K + Due to its large radius, Mg cannot enter the cavities of the adsorbent due to steric hindrance. 2+ In the brine, hydrated ions [Mg(H2O)6] are present. 2+ It exists, and its radius is greater than Li. + Bare ions, although Mg 2+ The bare ionic radius is smaller than that of Li. + Bare ions, but [Mg(H2O)6] 2+ The free energy of hydration is much greater than that of Li. + Mg 2+ The difficulty in entering the adsorbent in the form of bare ions is the reason why aluminum-based lithium adsorbents can selectively adsorb lithium ions in salt lake brines with a high magnesium-to-lithium ratio.

[0004] Compared to manganese-based and titanium-based adsorbents, aluminum-based lithium adsorbents have a reversible adsorption-desorption process, can be regenerated by washing with water, use inexpensive and readily available raw materials, are environmentally friendly, have a faster adsorption rate, and good selectivity, and can effectively extract lithium ions even in brines with a high magnesium-to-lithium ratio.

[0005] Patent applications US4116856 and US4221767 synthesized the aluminum salt lithium adsorbent LiOH·2Al(OH)3 in macroporous anion exchange resin using AlCl3 as the aluminum source, ammonia precipitation, and LiOH insertion. During cyclic adsorption, Li… + The adsorption capacity did not decrease significantly. However, the Al in its synthesis raw materials... 3+ It is difficult for this material to enter anionic macroporous resins, and the preservation of ammonia water is also difficult, which limits the industrial application of the lithium-ion adsorption performance and synthesis method of this material.

[0006] Patent application CN108722372A directly uses Al(OH)3, LiCl, and lower alcohols and sugars to synthesize spherical aluminum salt lithium adsorbent LiCl·2Al(OH)3·nH2O primary particles through high-temperature calcination. The particles agglomerate into secondary particles under saccharification, but the high-temperature calcination process results in higher costs.

[0007] Patent application CN110918047A involves mixing lithium aluminum salt adsorbent with hot melt adhesive, molding it, and then cutting it into adsorbent materials of a set size, which is a complicated process. Summary of the Invention

[0008] Finding more environmentally friendly and safer synthetic raw materials and suitable carriers or appropriate granulation methods for aluminum-based lithium adsorbents can further enhance their practical application value. This invention addresses the technical problems existing in the prior art, thereby providing a method for loading aluminum-based lithium adsorbents into anionic macroporous resins.

[0009] The existing technical problems are solved by the following technical solutions:

[0010] A method for loading an aluminum-based lithium adsorbent into an anionic macroporous resin includes the following steps:

[0011] Step 1) Immerse the resin in a NaAlO2 solution to adsorb AlO2. - .

[0012] Step 2) Place the resin in a gas-solid reaction apparatus, wet it with deionized water, and then introduce CO2 from bottom to top to obtain a macroporous resin loaded with Al(OH)3.

[0013] Step 3) Place the above resin in a LiCl and LiOH solution for Li + The insertion reaction was followed by washing with deionized water to obtain a macroporous resin loaded with aluminum-based lithium adsorbent.

[0014] Step 4) After adsorption in lithium solution, deionized water is used to desorb Li. + .

[0015] Further optimization is made in step 1), where the concentration of the NaAlO2 solution is 0.1–1 M.

[0016] Alternatively, in step 1), the volume of the NaAlO2 solution is 5–50 mL / g resin.

[0017] Alternatively, in step 1), the macroporous resin is soaked in NaAlO2 solution for 12–24 h at a reaction temperature of 25–30 °C.

[0018] Further optimization of step 3) is that the concentrations of LiCl and LiOH in the solution are 5–30 g / L.

[0019] Alternatively, in step 3), the LiCl and LiOH solutions may be further optimized. + The insertion time is 6 to 24 hours, and the insertion temperature is 35 to 90℃.

[0020] Alternatively, in step 3), the elution time of deionized water is 6–18 h.

[0021] Alternatively, in step 3), the elution temperature of the deionized water is 35–90°C.

[0022] In further optimization step 4), the adsorption temperature is 25-30℃.

[0023] Alternatively, in step 4), the desorption temperature of the deionized water is 35–90°C.

[0024] The advantages of this invention are:

[0025] Anionic macroporous resins have a large specific surface area and low mass transfer resistance during flow adsorption. Among them, the raw materials for the preparation of in-situ synthesized aluminum-based lithium adsorbents are inexpensive, readily available, safe, and easy to store.

[0026] NaAlO2 was selected as the aluminum source for the aluminum-based lithium adsorbent. Its loading capacity on the anionic macroporous resin is greater than that of AlCl3, and the process of generating Al(OH)3 by introducing CO2 is easier to control.

[0027] Synthetic H x Li 1-x Al2(OH)7·2H2O has a fast adsorption rate and good magnesium-lithium separation effect. The adsorption-desorption process is reversible and can be regenerated by washing with water, making it environmentally friendly.

[0028] The aluminum-based lithium adsorbent of this invention uses inexpensive and readily available raw materials, exhibits a fast adsorption rate, is suitable for the flow adsorption of large quantities of brine, and demonstrates good magnesium-lithium separation performance. The adsorption-desorption process of the aluminum-based lithium adsorbent is reversible, can be regenerated by water washing, is low-cost, and environmentally friendly. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. As shown in the figures:

[0030] Figure 1 The image shows the XRD pattern of the aluminum-based lithium adsorbent of the present invention. Detailed Implementation

[0031] The present invention will be further described below with reference to the accompanying drawings and embodiments. The technical solutions in the embodiments of the present invention will be clearly and completely described. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0032] Example 1: As Figure 1 As shown, a method for loading an aluminum-based lithium adsorbent onto an anionic macroporous resin is described. The macroporous resin has a large specific surface area and low mass transfer resistance during flow adsorption. NaAlO2 is selected as the aluminum source for the aluminum-based lithium adsorbent, as its loading capacity on the anionic macroporous resin is greater than that of AlCl3. The process of generating Al(OH)3 by introducing CO2 is easily controlled. The synthesized H... x Li 1-x Al2(OH)7·2H2O has a fast adsorption rate and good magnesium-lithium separation effect. The adsorption-desorption process is reversible and can be regenerated by washing with water, making it environmentally friendly.

[0033] A method for loading an aluminum-based lithium adsorbent into an anionic macroporous resin includes the following steps:

[0034] Step 1) Immerse the resin in a NaAlO2 solution to adsorb AlO2. - ;

[0035] Step 2) Place the resin in a gas-solid reaction apparatus, wet it with deionized water, and then introduce CO2 from bottom to top to obtain a macroporous resin loaded with Al(OH)3.

[0036] Step 3) The above resin is placed in LiCl and LiOH solutions to carry out the Li+ insertion reaction, and then washed with deionized water to obtain the supported aluminum-based lithium adsorbent H. x Li 1-x Macroporous resin of Al2(OH)7·2H2O.

[0037] Step 4) Add brine or lithium-containing solution for adsorption.

[0038] Step 5) Use deionized water to desorb Li + .

[0039] Alternatively, in step 1), the NaAlO2 solution concentration is 0.25M.

[0040] Alternatively, in step 1), the volume of the NaAlO2 solution is 10 mL / g resin.

[0041] Alternatively, in step 1), the macroporous resin is soaked in NaAlO2 solution for 24 hours and the reaction temperature is 25℃.

[0042] Alternatively, in step 2), the CO2 is introduced for 4 hours.

[0043] Alternatively, in step 3), the concentration of LiCl and LiOH solutions is 15 g / L.

[0044] Alternatively, in step 3), the volume of the LiCl and LiOH solutions is 100 mL / g resin.

[0045] Or in step 3), the LiCl and LiOH solutions contain Li + The insertion time is 6 to 24 hours.

[0046] Or in step 3), the LiCl and LiOH solutions contain Li + The insertion temperature is 35–90℃.

[0047] Alternatively, in step 3), the volume of deionized water is 50 mL / g resin.

[0048] Alternatively, in step 3), the elution time for deionized water is 6–18 hours.

[0049] Alternatively, in step 3), the elution temperature of the deionized water is 35–90°C.

[0050] Alternatively, in step 4), the volume of the brine or lithium-containing solution is 100 mL / g resin.

[0051] Alternatively, in step 4), the adsorption temperature of the adsorption experiment is 50℃, and the adsorption is carried out until saturation.

[0052] Alternatively, in step 4), the volume of deionized water is 50 mL / g resin.

[0053] Alternatively, in step 4), the desorption time of deionized water is 24 hours.

[0054] Alternatively, in step 4), the desorption temperature of deionized water is 35–90°C.

[0055] Example 2: A method for loading an aluminum-based lithium adsorbent into an anionic macroporous resin, comprising the following steps:

[0056] Prepare a 0.25M NaAlO2 solution, immerse 1g of D301 resin in 10mL of 0.25M NaAlO2 solution at 25℃ for 24h, and then dry it in an oven at 60℃.

[0057] 0.5g was exchanged for AlO2 - The resin was placed in a solid-gas reaction apparatus, and 1 mL of deionized water was added to wet the resin.

[0058] Pass 5L of CO2 into it and let it stand for 4 hours.

[0059] The resin was then placed in 50 mL of 15 g / L LiCl and LiOH solution in a water bath at 50 °C for 24 h to obtain a resin loaded with the adsorbent precursor.

[0060] The resin was soaked in 25 mL of deionized water and desorbed at 50 °C for 12 h to obtain the resin loaded with the adsorbent.

[0061] A certain mass of resin loaded with adsorbent was placed in 1800 mg / L LiCl solution and adsorbed in a water bath at 50 °C for a sufficient time.

[0062] Desorb using 25 mL of deionized water in a 50°C water bath for 24 hours.

[0063] The desorption of Li from the macroporous resin supported on aluminum-based lithium adsorbent was measured to be 0.7102 mg / L. + .

[0064] Example 3: A method for loading an aluminum-based lithium adsorbent into an anionic macroporous resin, comprising the following steps:

[0065] Prepare a 0.25M NaAlO2 solution, immerse 1g of D301 resin in 10mL of 0.25M NaAlO2 solution at 25℃ for 24h, and then dry it in an oven at 60℃.

[0066] 0.5g was exchanged for AlO2 - The resin was placed in a solid-gas reaction apparatus, and 1 mL of deionized water was added to wet the resin. 5 L of CO2 was then introduced into the apparatus, and the mixture was allowed to stand for 4 hours.

[0067] The resin was then placed in 50 mL of 200 mg / L LiCl solution and bathed in a water bath at 35 °C for 12 h to obtain a resin loaded with the adsorbent precursor.

[0068] The resin was soaked in 25 mL of deionized water and desorbed at 35 °C for 12 h to obtain the resin loaded with the adsorbent.

[0069] A certain mass of resin loaded with adsorbent was placed in a 13.25 mg / L LiCl solution and adsorbed in an oil bath at 35°C for a sufficient time.

[0070] Desorb using 25 mL of deionized water in a 50°C water bath for 24 hours.

[0071] The desorption of Li from the macroporous resin supported on aluminum-based lithium adsorbent was measured to be 0.0512 mg / L. + .

[0072] Figure 1 The paper shows the synthesized adsorbent precursor Li·Al2(OH)7·2H2O and adsorbent H x Li 1-x The XRD patterns of Al2(OH)7·2H2O, the adsorbent after lithium adsorption, and the adsorbent after lithium desorption prove that the corresponding adsorbent has been synthesized. The diffraction peaks correspond well with the standard card PDF#51-0355, and the crystal structure of the adsorbent is stable before and after adsorption.

[0073] The various embodiments in the specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.

[0074] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. The above descriptions are merely individual embodiments of the present invention and are not intended to limit the invention in any way. Any simple modifications, equivalent variations, and alterations made to the above embodiments based on the technical essence of the present invention shall still fall within the protection scope of the present invention.

[0075] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A method for loading an aluminum-based lithium adsorbent into an anionic macroporous resin, characterized in that, Includes the following steps: Step 1) Immerse the anionic macroporous resin in NaAlO2 solution to adsorb AlO2. - ; Step 2) Place the anionic macroporous resin in a gas-solid reaction apparatus, wet it with deionized water, and then introduce CO2 from bottom to top to obtain a macroporous resin loaded with Al(OH)3. Step 3) Place the anion exchange macroporous resin in a LiCl and LiOH solution for Li... + The insertion reaction was followed by washing with deionized water to obtain a macroporous resin loaded with aluminum-based lithium adsorbent. Step 4) After the anion-modifying macroporous resin adsorbs Li+ in the lithium solution, deionized water is used to desorb Li+. In step 1), the concentration of the NaAlO2 solution is 0.1–1 M. In step 1), the volume of the NaAlO2 solution is 5–50 mL / g resin. In step 1), the macroporous resin is soaked in NaAlO2 solution for 12–24 h, and the reaction temperature is 25–30 °C. In step 3), the concentrations of LiCl and LiOH in the solution are 5–30 g / L. In step 3), the LiCl and LiOH solutions contain Li + The insertion time is 6–24 h, and the insertion temperature is 35–90 ℃. In step 3), the elution time for deionized water is 6–18 hours. In step 3), the elution temperature of the deionized water is 35–90 °C. In step 4), the adsorption temperature is 25–30 °C. In step 4), the desorption temperature of deionized water is 35–90 °C.

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