Method for recovering metal from battery leachate by using molecular sieve

Abstract

The invention belongs to the field of resource regeneration, and relates to a method for recovering metal from a battery leachate by using a molecular sieve, which comprises the following steps: S1, adsorbing the battery leachate by using a molecular sieve A, and filtering to obtain a lithium-containing filtrate and a molecular sieve B, s2, the molecular sieve B is subjected to low-temperature desorption in a saturated sodium salt solution and then filtered, the low-temperature desorption temperature is 20 DEG C or below, and manganese-containing filtrate and a molecular sieve C are obtained; s3, the molecular sieve C is subjected to high-temperature desorption in a saturated sodium salt solution and then filtered, the high-temperature desorption temperature is 70 DEG C or above, and cobalt-containing filtrate and a molecular sieve D are obtained. By adopting the method provided by the invention, Li < + >, Co < 2 + > and Mn < 2 + > can be effectively recovered, and the yield and purity of the recovered product are high.

Description

Technical Field

[0001] This invention belongs to the field of resource recycling, and specifically relates to a method for recovering metals from battery leachate. Background Technology

[0002] Waste lithium-ion batteries are rich in important valuable metals such as lithium, cobalt, and manganese, with mass fractions reaching 5-10 wt%, 5-20 wt%, and 10-15 wt%, respectively, far exceeding the grades of similar natural ores. The indiscriminate disposal of waste lithium batteries not only results in a serious waste of strategic metal resources but also causes environmental pollution and ecological risks, posing potential threats to human health and the living environment. Lithium, cobalt, and manganese are key metals with limited global reserves, and their extraction is energy-intensive and highly polluting. With the rapid growth of the lithium-ion battery market, the demand for these metals is constantly increasing, leading to a growing shortage of these resources. It is estimated that by 2040, recycling waste lithium-ion batteries alone could meet more than 50% of the world's demand for cobalt, lithium, manganese, and nickel. Therefore, the recycling of waste lithium-ion batteries is not only a crucial step in achieving sustainable battery resource management but also...

[0003] Methods for recovering metals from leachate of spent lithium-ion batteries include dry recovery, wet recovery, and biological recovery. Compared to dry and biological recovery, wet recovery has advantages such as high metal recovery rate, high product purity, and strong process adaptability. Wet recovery typically includes leaching, purification, and separation steps. Due to its high leaching efficiency and scalability, it is widely used for recovering valuable metals from spent lithium-ion batteries. Specifically, wet recovery generally begins by acid leaching to break down the crystal lattice of the cathode material in the spent lithium-ion battery, converting metal oxides into metal ions. Valuable metal components are then recovered through solvent extraction, ion exchange, and chemical precipitation. Molecular sieves, as a commonly used ion exchange material, are mainly used to capture Li- ions in battery leachate. + For example, CN117101599A discloses a novel lithium-based molecular sieve adsorbent that can directly capture Li from waste lithium battery recycling liquid. + However, the above method can only be used for Li. + Recovery is not possible, but other valuable metal ions (such as Co) in the leachate cannot be recovered. 2+ Mn 2+ ) for recycling. Summary of the Invention

[0004] The purpose of this invention is to overcome the limitations of existing methods, which can only recover Li from spent lithium-ion batteries. + However, it is impossible to achieve Li + Co 2+ Mn 2+ To address the shortcomings of simultaneous recovery, a method is provided that can simultaneously recover Li from battery leachate.+ Co 2+ Mn 2+ The method.

[0005] Specifically, the present invention provides a method for recovering metals from battery leaching solutions containing Li. + Co 2+ and Mn 2+ The method includes the following steps: S1. The battery leachate is adsorbed by molecular sieve A and then filtered. The molecular sieve A is a low-silica molecular sieve with a SiO2 / Al2O3 molar ratio of less than 6, to obtain lithium-containing filtrate and molecular sieve B. S2. Molecular sieve B is desorbed in a saturated sodium salt solution at low temperature and then filtered. The low temperature of the desorption is below 20°C, to obtain a manganese-containing filtrate and molecular sieve C. S3. Molecular sieve C is desorbed at high temperature in a saturated sodium salt solution and then filtered. The high temperature of the desorption is above 70°C, to obtain a cobalt-containing filtrate and molecular sieve D.

[0006] During the research process, this invention surprisingly discovered that by using a low-silica molecular sieve (molecular sieve A) with a SiO2 / Al2O3 molar ratio of less than 6 to adsorb battery leachate, and then subjecting the adsorbed molecular sieve to sequential low-temperature and high-temperature desorption, lithium, manganese, and cobalt can be recovered stepwise. The reason for this is speculated to be that: low-silica molecular sieves with a SiO2 / Al2O3 molar ratio of less than 6 have a high negative charge in their framework, making them more susceptible to electrostatic attraction with cations; on the other hand, Co... 2+ Ni 2+ Mn 2+ With Li + There is competitive adsorption, and divalent cations (Co) are involved. 2+ Ni 2+ Mn 2+ Due to their high charge density, the electrostatic attraction between them and the molecular sieve framework is significantly stronger than that between Li and Li. + Electrostatic attraction between the cation and the molecular sieve framework will preferentially lead to adsorption by the molecular sieve, and divalent cations (Co) will be adsorbed. 2+ Ni 2+ Mn 2+ Compared to Li + It has a stronger ion exchange capacity, if some Li + Ni² adsorbed onto the surface or pore size of the molecular sieve + Co² + Mn² + It will remove the Li already adsorbed by the molecular sieve + Displaced when the molecular sieve adsorption sites are replaced by Co 2+ Ni 2+ Mn 2+ Completely occupy, Li+ Li will not be adsorbed or in very small amounts + Adsorbed; Co 2+ Ni 2+ Mn 2+ There is competitive adsorption between Mn² + Due to its relatively low hydration energy, Mn²⁺ readily loses some water molecules, resulting in a rapid diffusion rate. + It can rapidly diffuse to the surface or channels of the molecular sieve, occupy adsorption sites, and be preferentially adsorbed; Co² + Because of its slow diffusion rate, after dehydration, it occupies the untouched Mn²⁺ due to its smaller radius advantage. + It occupies the adsorption sites and adsorbs at a relatively fast rate, but slightly lower than that of Mn². + ;and Ni² + The high hydration energy of Mn² makes dehydration difficult, resulting in a slow rate of entry into the pores. Mn² can only gradually occupy the remaining sites in the later stages, therefore the adsorption priority order is Mn². + Co² + >Ni² + On the other hand, molecular sieves for Mn² + Co² + and Ni² + The adsorption thermodynamic parameter enthalpy change (ΔH) 0 The values ​​of ΔH are all positive, indicating that the adsorption process is an endothermic reaction, and increasing the temperature can significantly promote adsorption; 0 The absolute value follows Ni² + Co² + >Mn² + The order explains Ni² + The interaction with the molecular sieve framework is the strongest, while Mn² + The interaction between the two is the weakest, so temperature is the key factor for the ion exchange selectivity in the solution of this metal ion. Manganese can be preferentially desorbed at low temperature, and cobalt can be desorbed at high temperature.

[0007] Compared with the prior art, the main advantages of this invention are: (1) Li + Co 2+ Mn 2+ (1) It can be effectively recycled, and the yield and purity of the recycled products are high; (2) The whole process is simple to operate, low in cost, requires little equipment investment, and is easy to use on a large scale; (3) The whole process is short, the reagents used are environmentally friendly, the conditions are mild, and there is no secondary pollution. Attached Figure Description

[0008] Figure 1 A flowchart for recovering metals from battery leachate provided by the present invention; Figure 2The scanning electron microscope (SEM) image and X-ray diffraction (XRD) pattern of the metal recovered using the method of Example 1, wherein, (a) Li + X-ray diffraction pattern of the recycled product Li₂CO₃; (b) Li + Scanning electron microscope image of the regenerated product Li2CO3; (c) Mn 2+ X-ray diffraction pattern of the regenerated product MnO2; (d) Mn 2+ Scanning electron microscope image of the recycled product MnO2; (e)Co 2+ X-ray diffraction pattern of the recycled product Co3O4; (f) Co 2+ Scanning electron microscope image of the recycled product Co3O4. Detailed Implementation

[0009] See Figure 1 The method for recovering metals from battery leachate provided by the present invention includes the following steps: S1. The battery leachate is adsorbed by molecular sieve A and then filtered to obtain lithium-containing filtrate (filtrate B') and molecular sieve B; S2. Molecular sieve B is desorbed in a saturated sodium salt solution at low temperature and then filtered to obtain a manganese-containing filtrate (filtrate C') and molecular sieve C; S3. Molecular sieve C is desorbed at high temperature in a saturated sodium salt solution and then filtered to obtain a cobalt-containing filtrate (filtrate D') and molecular sieve D.

[0010] In the above-mentioned process of recovering metals from battery leaching solution, the battery leaching solution is a lithium-ion battery leaching solution. The lithium-ion battery can be a spent lithium-ion battery or a defective lithium-ion battery generated during the production process; there is no particular limitation. The lithium-ion battery leaching solution is typically obtained by crushing spent or defective lithium-ion batteries into battery powder, then reacting and leaching the battery powder in an acid solution to remove impurities such as copper, iron, and aluminum. During the leaching process, the solid-liquid ratio (i.e., the ratio of the mass of battery powder to the volume of acid solution) is generally 5~500 g / L, such as 5, 8, 10, 12, 15, 18, 20, 22, 25, 28, 30, 32, 35, 38, 40, 42, 45, 48, 50, 60, 70, 80, 90, 100, 120, 150, 180, 200, 250, 300, 350, 400, 450, 500, or any value between them. The acid solution can be at least one of hydrochloric acid solution, phosphoric acid solution, sulfuric acid solution, and nitric acid solution. The concentration of the acid solution can be 0.5~10 mol / L, such as 0.5, 1, 2, 4, 6, 8, 10 mol / L, or any value between them. The preferred leaching conditions for the battery powder include a temperature of 25°C to 80°C, such as 25°C, 30°C, 35°C, 40°C, 45°C, 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, or any value between them; and a leaching time of 10 min to 60 min, such as 10 min, 15 min, 20 min, 25 min, 30 min, 35 min, 40 min, 45 min, 50 min, 55 min, 60 min, or any value between them. Furthermore, the leaching is typically carried out under stirring conditions, and the stirring speed is preferably 100 rpm to 600 rpm, such as 100 rpm, 150 rpm, 200 rpm, 250 rpm, 300 rpm, 350 rpm, 400 rpm, 450 rpm, 500 rpm, 550 rpm, 600 rpm, or any value between them.

[0011] In the above-described process of recovering metals from the battery leaching solution, the battery leaching solution contains Li. + Co 2+ and Mn 2 + In addition to these three metal ions, it may also contain nickel ions (Ni). 2+ That is, containing Li + Co 2+ Mn 2+ and Ni 2+ When the battery leachate contains only Li + Co 2+ and Mn 2+ At that time, molecular sieve A adsorbs Co2+ and Mn 2+ Li + It remains in the leachate and adsorbs Co. 2+ and Mn 2+ Molecular sieve A (also known as molecular sieve B) undergoes low-temperature desorption in a saturated sodium salt solution, Mn 2+ It is desorbed into the leachate, while Co 2+ It will continue to remain on the molecular sieve, adsorbing Co. 2+ Molecular sieve A (also known as molecular sieve C) undergoes high-temperature desorption in a saturated sodium salt solution, and Co... 2+ The metal ions adsorbed on molecular sieve A are desorbed into the leachate, at which point all metal ions are desorbed and can be reused in step S1. When the battery leachate contains Li... + Co 2+ Mn 2+ and Ni 2+ At that time, molecular sieve A adsorbs Co 2+ Mn 2+ and Ni 2+ Li + It remains in the leachate and adsorbs Co. 2+ Mn 2+ and Ni 2+ Molecular sieve A (also known as molecular sieve B) undergoes low-temperature desorption in a saturated sodium salt solution, Mn 2+ It is desorbed into the leachate, while Co 2+ and Ni 2+ It will continue to remain on the molecular sieve, adsorbing Co. 2+ and Ni 2+ Molecular sieve A (also known as molecular sieve C) undergoes high-temperature desorption in a saturated sodium salt solution, and Co... 2+ It is desorbed into the leachate, while Ni 2+ They will continue to remain on the molecular sieve, and at this point, only Ni remains of the metal ions adsorbed on molecular sieve A. 2+ Ni adsorbed 2+ The molecular sieve A can be reused in step S1. Furthermore, the Li in the battery leachate... + The concentration can be 0.02~0.5 mol / L, such as 0.02, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.4, 0.45, 0.5 mol / L or any value between them; Co 2+ The concentration can be 0.01~0.3 mol / L, such as 0.01, 0.02, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3 mol / L or any value between them; Mn 2+The content can be 0.01~0.3 mol / L, such as 0.01, 0.02, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3 mol / L or any value between them; Ni 2+ The concentration can be 0.01~0.3 mol / L, such as 0.01, 0.02, 0.05, 0.1, 0.15, 0.2, 0.25, 0.3 mol / L or any value between them.

[0012] In the process of recovering metal from the battery leachate described above, in step S1, the preferred ratio of molecular sieve A to battery leachate is (5~125) g:1L, such as 5g:1L, 10g:1L, 15g:1L, 20g:1L, 25g:1L, 30g:1L, 35g:1L, 40g:1L, 45g:1L, 50g:1L, 55g:1L, 60g:1L, 65g:1L, 70g:1L, 75g:1L, 80g:1L, 85g:1L, 90g:1L, 95g:1L, 100g:1L, 105g:1L, 110g:1L, 115g:1L, 120g:1L, 125g:1L, or any value between them.

[0013] In the process of recovering metals from the battery leachate described above, in step S1, the adsorption conditions preferably include a temperature of 25℃~90℃, such as 25℃, 30℃, 35℃, 40℃, 45℃, 55℃, 60℃, 65℃, 70℃, 75℃, 80℃, 85℃, 90℃ or any value between them; a pH value of 2~7, such as 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, 7 or any value between them; and a time of 1h~30h, such as 1h, 2h, 4h, 6h, 8h, 10h, 12h, 14h, 16h, 18h, 20h, 22h, 24h, 26h, 28h, 30h or any value between them.

[0014] In the process of recovering metals from the battery leachate described above, in step S1, the SiO2 / Al2O3 molar ratio of the molecular sieve A is 6, specifically it can be 6, 5.8, 5.6, 5.4, 5.2, 5, 4.8, 4.6, 4.4, 4.2, 4, 3.8, 3.6, 3.4, 3.2, 3, 2.8, 2.6, 2.4, 2.2, 2, 1.8, 1.6, 1.4, 1.2, 1, 0.8, 0.6, 0.4, 0.2 or any value between them. Furthermore, the pore size of the molecular sieve A is preferably below 1 nm, such as 1 nm, 0.95 nm, 0.9 nm, 0.85 nm, 0.8 nm, 0.75 nm, 0.7 nm, 0.65 nm, 0.6 nm, 0.55 nm, 0.5 nm, 0.45 nm, 0.42 nm, 0.4 nm, 0.38 nm, 0.35 nm, 0.32 nm, 0.3 nm, 0.28 nm, 0.25 nm, 0.22 nm, 0.2 nm, 0.18 nm, 0.15 nm, 0.12 nm, 0.11 nm, 0.1 nm, 0.08 nm, 0.05 nm, or any value between them. Controlling the pore size of the molecular sieve A within the above preferred range is more conducive to improving the yield and purity of the recovered product. Furthermore, the molecular sieve A is preferably selected from at least one of type A, type X, type P molecular sieves, and molecular sieves modified from them with a SiO2 / Al2O3 molar ratio of 6 or less.

[0015] In the above process of recovering metals from battery leachate, step S2, the low-temperature desorption, needs to be carried out in a saturated sodium salt solution at a temperature below 20°C. The saturated sodium salt solution can reduce the activity coefficient of metal ions, weakening their electrostatic attraction and coordination bonding with the molecular sieve. Below 20°C, Mn... 2+ The coordination bonds with molecular sieves are weaker, resulting in a faster desorption rate than Co. 2+ That is, Mn 2+ Below 20℃, it will preferentially desorb from the molecular sieve, yielding a manganese-containing solution. The preferred low-temperature desorption temperature is -5℃ to 20℃, at which point Mn can be desorbed. 2+ It desorbs from molecular sieve B at a relatively fast rate into the saturated sodium salt solution, while Co, which has a more stable coordination with the molecular sieve,... 2+ And optional Ni 2+The molecules then continue to adhere to the molecular sieve. Specifically, the temperature for low-temperature desorption can be -5℃, -4℃, -2℃, 0℃, 2℃, 4℃, 6℃, 8℃, 10℃, 12℃, 14℃, 16℃, 18℃, 20℃, or any value between them. The preferred time for low-temperature desorption is 20h to 150h, such as 20h, 30h, 40h, 50h, 60h, 70h, 80h, 90h, 100h, 110h, 120h, 130h, 140h, 150h, or any value between them.

[0016] In the above-described process of recovering metals from battery leachate, step S3, the high-temperature desorption, needs to be carried out in a saturated sodium salt solution at a temperature above 70°C. The saturated sodium salt solution can reduce the activity coefficient of metal ions, weakening their electrostatic attraction and coordination bonding with the molecular sieve. At temperatures above 70°C, it can increase the activity of Co. 2+ The thermal energy of the molecules breaks their strong coordination bonds with the molecular sieve, promoting the release of Co. 2+ Desorption yields a cobalt-containing solution. The preferred temperature for this high-temperature desorption is 70℃~110℃, at which temperature allows Co to... 2+ It desorbs from molecular sieve C at a relatively fast rate into the saturated sodium salt solution, while other metal ions, such as Ni, which have a more stable coordination with the molecular sieve, are absorbed. 2+ The molecules continue to adhere to the molecular sieve, ensuring the stability of the molecular sieve structure. Specifically, the high-temperature desorption temperature can be 70℃, 75℃, 80℃, 85℃, 90℃, 95℃, 100℃, 105℃, 110℃, or any value between them. The preferred high-temperature desorption time is 0.5h to 10h, such as 0.5h, 1h, 1.5h, 2h, 2.5h, 3h, 3.5h, 4h, 4.5h, 5h, 5.5h, 6h, 6.5h, 7h, 7.5h, 8h, 8.5h, 9h, 9.5h, 10h, or any value between them.

[0017] In the process of recovering metals from battery leachate described above, the saturated sodium salt solutions in steps S2 and S3 may be the same or different, and the saturated sodium salts are preferably each independently selected from at least one of sodium sulfate, sodium nitrate, sodium chloride and sodium acetate.

[0018] The method for recovering metals from battery leachate provided by this invention preferably further includes regenerating lithium-containing, manganese-containing, and cobalt-containing filtrates respectively to obtain lithium carbonate, manganese dioxide, and cobalt tetroxide. The regeneration method can be carried out using various existing methods without particular limitation. For example, for lithium-containing filtrate, the regeneration method may include first adding a precipitant to the lithium-containing filtrate to precipitate lithium ions, then filtering and washing the precipitate with deionized water to remove impurities, and drying the washed precipitate to obtain lithium carbonate. For manganese-containing and cobalt-containing filtrates, the regeneration method may include first adding a precipitant to the manganese-containing and cobalt-containing filtrates respectively to precipitate metal ions, then filtering and washing the precipitate with deionized water to remove impurities, and then drying and calcining the washed precipitate to finally convert it into manganese dioxide and cobalt tetroxide. For lithium-containing filtrate, sodium carbonate can be used as the precipitant. For manganese-containing filtrate, the precipitant can be at least one of sodium hypochlorite, potassium permanganate, and ammonium persulfate. For cobalt-containing filtrate, the solution is adjusted to a weakly alkaline state (pH range of 7.5-9) using ammonia or sodium hydroxide, and the precipitant can be at least one of hydrogen peroxide, sodium hypochlorite, and sodium persulfate.

[0019] The method for recovering metals from battery leachate provided by the present invention preferably further includes recycling molecular sieve D as molecular sieve A to step S1.

[0020] In this invention, the terms "molecular sieve A", "molecular sieve B" and "molecular sieve C" are merely used to distinguish molecular sieves introduced at different locations for ease of description, and have no other special meaning.

[0021] The present invention will be described in detail below through examples.

[0022] In the following examples and comparative examples, the concentration of metal ions in the leachate of waste lithium-ion batteries was determined using an inductively coupled plasma optical emission spectrometer (ICP-OES, model iCAP PRO X).

[0023] Example 1 This embodiment illustrates the method for recovering metals from leachate of spent lithium-ion batteries provided by the present invention.

[0024] S1. Add 1000mL of leachate from spent lithium-ion batteries (the leachate from spent lithium-ion batteries is Li...) + Mn 2+ Co 2+ and Ni 2+ A mixed solution of Li + The content is 0.05 mol / L, Mn 2+ The content was 0.025 mol / L, Co2+ The content is 0.025 mol / L, Ni 2+ After adjusting the pH to 4.5, 85g of molecular sieve A (NaA molecular sieve, purchased from Xiamen Luyuan Fine Chemical Co., Ltd., grade 4A, pore size 0.4nm, SiO2 / Al2O3 molar ratio 2.0) was added. The adsorption treatment was carried out at 80℃ for 2h. The resulting leachate was then filtered to obtain a lithium-containing filtrate and molecular sieve B. Under stirring, 3g of precipitant (sodium carbonate) was added to the lithium-containing filtrate to precipitate lithium ions. The precipitate was then filtered, and the precipitate was washed with deionized water to remove impurities. The washed precipitate was dried at 100℃ for 10h to finally obtain 1.74g of lithium carbonate, with a lithium recovery rate of 94.3%.

[0025] S2. Molecular sieve B was soaked in a saturated sodium sulfate aqueous solution at 0℃ for 72 hours to achieve low-temperature desorption, followed by vacuum filtration to obtain a manganese-containing filtrate and molecular sieve C. 7.2 g of ammonium persulfate was added to the manganese-containing filtrate, and the mixture was reacted at 90℃ for 1 hour to precipitate manganese ions. The precipitate was then filtered, and the precipitate was washed with deionized water to remove impurities. The washed precipitate was dried at 105℃ for 10 hours to finally obtain 2.0 g of manganese dioxide, with a manganese recovery rate of 92.2%.

[0026] S3. Molecular sieve C was soaked in a saturated sodium sulfate aqueous solution at 90℃ for 1 hour to achieve high-temperature desorption, followed by vacuum filtration to obtain a cobalt-containing filtrate and molecular sieve C. The pH of the solution was adjusted to 8.0 with sodium hydroxide, and 4 mL of 20% hydrogen peroxide was added to the cobalt-containing filtrate to precipitate cobalt ions. The precipitate was then filtered, and the precipitate was washed with deionized water to remove impurities. The washed precipitate was dried at 105℃ for 10 hours to finally obtain 1.9 g of cobalt tetroxide, with a cobalt recovery rate of 94.5%. Molecular sieve C is a NaA molecular sieve adsorbed with Ni and can be recycled.

[0027] Scanning electron microscope (SEM) images and XRD patterns of the recovered lithium carbonate, manganese dioxide, and cobalt tetroxide are shown below. Figure 2 As shown. From Figure 2 XRD analysis showed that the purity of lithium carbonate, manganese dioxide, and cobalt tetroxide was over 98%.

[0028] Example 2 This embodiment illustrates the method for recovering metals from leachate of spent lithium-ion batteries provided by the present invention.

[0029] S1. Add 800 mL of leachate from spent lithium-ion batteries (the leachate from spent lithium-ion batteries is Li...) + Mn 2+ Co 2+ and Ni2+ A mixed solution of Li + The content is 0.05 mol / L, Mn 2+ The content was 0.02 mol / L, Co 2+ The content is 0.025 mol / L, Ni 2+ After adjusting the pH to 4.5, 100g of molecular sieve A (CaA molecular sieve, purchased from Xiamen Luyuan Fine Chemical Co., Ltd., grade 5A, pore size 0.5nm, SiO2 / Al2O3 molar ratio 2.0) was added. The adsorption treatment was carried out at 70℃ for 3h. The resulting leachate was then filtered to obtain a lithium-containing filtrate and molecular sieve B. Under stirring, 2.5g of precipitant (sodium carbonate) was added to the lithium-containing filtrate to precipitate lithium ions. The precipitate was then filtered, and the precipitate was washed with deionized water to remove impurities. The washed precipitate was dried at 100℃ for 10h to finally obtain 1.43g of lithium carbonate, with a lithium recovery rate of 96.7%.

[0030] S2. Molecular sieve B was soaked in a saturated sodium nitrate aqueous solution at 10℃ for 80 hours to achieve low-temperature desorption, followed by vacuum filtration to obtain a manganese-containing filtrate and molecular sieve C. 4.2 g of ammonium persulfate was added to the manganese-containing filtrate, and the mixture was reacted at 90℃ for 1 hour to precipitate manganese ions. The precipitate was then filtered, and the precipitate was washed with deionized water to remove impurities. The washed precipitate was dried at 100℃ for 10 hours to finally obtain 1.30 g of manganese dioxide, with a manganese recovery rate of 96.3%.

[0031] S3. Molecular sieve C was soaked in a saturated sodium nitrate aqueous solution at 80℃ for 1 hour to achieve high-temperature desorption, followed by vacuum filtration to obtain a cobalt-containing filtrate and molecular sieve C. The pH of the solution was adjusted to 8.0 with sodium hydroxide, and 4.0 mL of 20% hydrogen peroxide was added to the cobalt-containing filtrate to precipitate cobalt ions. The precipitate was then filtered, and the precipitate was washed with deionized water to remove impurities. The washed precipitate was dried at 100℃ for 10 hours to finally obtain 1.50 g of cobalt tetroxide, with a cobalt recovery rate of 93.2%. Molecular sieve C is a CaA molecular sieve adsorbed with Ni and can be recycled.

[0032] XRD analysis of the recovered lithium carbonate, manganese dioxide, and cobalt tetroxide showed that the purity was over 98%.

[0033] Example 3 This embodiment illustrates the method for recovering metals from leachate of spent lithium-ion batteries provided by the present invention.

[0034] S1. Add 500 mL of leachate from spent lithium-ion batteries (the leachate from spent lithium-ion batteries is Li...) + Mn 2+Co 2+ and Ni 2+ A mixed solution of Li + The content is 0.1 mol / L, Mn 2+ The content is 0.1 mol / L, Co 2+ The content is 0.05 mol / L, Ni 2+ After adjusting the pH to 5, 50g of molecular sieve A (NaX molecular sieve, purchased from Xiamen Luyuan Fine Chemical Co., Ltd., grade 13X, pore size 0.96nm, SiO2 / Al2O3 molar ratio 2.6) was added. The adsorption treatment was carried out at 80℃ for 2h. The resulting leachate was then filtered to obtain a lithium-containing filtrate and molecular sieve B. Under stirring, 2.85g of precipitant (sodium carbonate) was added to the lithium-containing filtrate to precipitate lithium ions. The precipitate was then filtered, and the precipitate was washed with deionized water to remove impurities. The washed precipitate was dried at 90℃ for 10h to finally obtain 1.8g of lithium carbonate, with a lithium recovery rate of 97.3%.

[0035] S2. Molecular sieve B was soaked in a saturated sodium chloride aqueous solution at 0℃ for 50 hours to achieve low-temperature desorption. Then, vacuum filtration was performed to obtain a manganese-containing filtrate and molecular sieve C. 4.0 g of sodium hypochlorite was added to the manganese-containing filtrate, and the mixture was reacted at 80℃ for 1 hour to precipitate manganese ions. The precipitate was then filtered, and the precipitate was washed with deionized water to remove impurities. The washed precipitate was dried at 90℃ for 10 hours, finally yielding 4.2 g of manganese dioxide. The manganese recovery rate was 96.6%.

[0036] S3. Molecular sieve C was soaked in a saturated sodium chloride aqueous solution at 80℃ for 1 hour to achieve high-temperature desorption, followed by vacuum filtration to obtain a cobalt-containing filtrate and molecular sieve C. The pH of the solution was adjusted to 7.5 using ammonia water, and 6 mL of 10% hydrogen peroxide was added to the cobalt-containing filtrate to precipitate cobalt ions. The precipitate was then filtered, and the precipitate was washed with deionized water to remove impurities. The washed precipitate was dried at 90℃ for 10 hours, finally yielding 1.90 g of cobalt tetroxide, with a cobalt recovery rate of 94.5%. Molecular sieve C is a NaX molecular sieve adsorbed with Ni and can be recycled.

[0037] XRD analysis of the recovered lithium carbonate, manganese dioxide, and cobalt tetroxide showed that the purity was over 98%.

[0038] Example 4 This embodiment illustrates the method for recovering metals from leachate of spent lithium-ion batteries provided by the present invention.

[0039] S1. Add 1000mL of leachate from spent lithium-ion batteries (the leachate from spent lithium-ion batteries is Li...) + Mn2+ and Co 2+ A mixed solution of Li + The content is 0.1 mol / L, Mn 2+ The content is 0.1 mol / L, Co 2+ After adjusting the pH to 2, 85g of molecular sieve A (GIS molecular sieve, purchased from Xiamen Luyuan Fine Chemical Co., Ltd., grade P zeolite, pore size 0.74nm, SiO2 / Al2O3 molar ratio 2.0) was added. The adsorption treatment was carried out at 70℃ for 3h. The resulting leachate was then filtered to obtain a lithium-containing filtrate and molecular sieve B. Under stirring conditions, 7.0g of precipitant (sodium carbonate) was added to the lithium-containing filtrate to precipitate lithium ions. The precipitate was then filtered, and the precipitate was washed with deionized water to remove impurities. The washed precipitate was dried at 100℃ for 10h to finally obtain 3.6g of lithium carbonate, with a lithium recovery rate of 97.6%.

[0040] S2. Molecular sieve B was soaked in a saturated sodium acetate aqueous solution at -5℃ for 80 hours to achieve low-temperature desorption. Then, vacuum filtration was performed to obtain a manganese-containing filtrate and molecular sieve C. 9.0 g of sodium hypochlorite was added to the manganese-containing filtrate, and the mixture was reacted at 80℃ for 1 hour to precipitate manganese ions. The precipitate was then filtered, and the precipitate was washed with deionized water to remove impurities. The washed precipitate was dried at 100℃ for 10 hours, finally yielding 8.5 g of manganese dioxide, with a manganese recovery rate of 97.8%.

[0041] S3. Molecular sieve C was soaked in a saturated sodium acetate aqueous solution at 80℃ for 1 hour to achieve high-temperature desorption, followed by vacuum filtration to obtain a cobalt-containing filtrate and molecular sieve C. The pH was adjusted to 8.5 with sodium hydroxide solution, and 2.0 g of sodium hypochlorite was added to the cobalt-containing filtrate to precipitate cobalt ions. The precipitate was then filtered, and the precipitate was washed with deionized water to remove impurities. The washed precipitate was dried at 100℃ for 10 hours, finally yielding 7.60 g of cobalt tetroxide, with a cobalt recovery rate of 94.6%. Molecular sieve C was NaY molecular sieve.

[0042] XRD analysis of the recovered lithium carbonate, manganese dioxide, and cobalt tetroxide showed that the purity was over 98%.

[0043] Example 5 This embodiment illustrates the method for recovering metals from leachate of spent lithium-ion batteries provided by the present invention.

[0044] S1. Add 2000 mL of leachate from spent lithium-ion batteries (the leachate from spent lithium-ion batteries is Li...) + Mn 2+ and Co 2+ A mixed solution of Li+ The content is 0.2 mol / L, Mn 2+ The content is 0.1 mol / L, Co 2+ After adjusting the pH to 6, 150g of molecular sieve A (NaA molecular sieve, purchased from Xiamen Luyuan Fine Chemical Co., Ltd., grade 4A, pore size 0.4nm, SiO2 / Al2O3 molar ratio 2.0) was added. The adsorption treatment was carried out at 50℃ for 10h. The resulting leachate was then filtered to obtain a lithium-containing filtrate and molecular sieve B. Under stirring, 12g of precipitant (sodium carbonate) was added to the lithium-containing filtrate to precipitate lithium ions. The precipitate was then filtered, and the precipitate was washed with deionized water to remove impurities. The washed precipitate was dried at 100℃ for 20h to finally obtain 7.1g of lithium carbonate, with a lithium recovery rate of 96.1%.

[0045] S2. Molecular sieve B was soaked in a saturated sodium sulfate aqueous solution at 10℃ for 120 h to achieve low-temperature desorption, followed by vacuum filtration to obtain a manganese-containing filtrate and molecular sieve C. 7.5 g of potassium permanganate was added to the manganese-containing filtrate, and the mixture was reacted at 70℃ for 2 h to precipitate manganese ions. The precipitate was then filtered, and the precipitate was washed with deionized water to remove impurities. The washed precipitate was dried at 100℃ for 20 h to finally obtain 11.6 g of manganese dioxide, with a manganese recovery rate of 95.3%.

[0046] S3. Molecular sieve C was soaked in a saturated sodium chloride aqueous solution at 100℃ for 0.5 h to achieve high-temperature desorption, followed by vacuum filtration to obtain a cobalt-containing filtrate and molecular sieve C. The pH of the solution was adjusted to 7.5 with ammonia, and 4 mL of 30% hydrogen peroxide was added to the cobalt-containing filtrate to precipitate cobalt ions. The precipitate was then filtered, and the precipitate was washed with deionized water to remove impurities. The washed precipitate was dried at 100℃ for 20 h to finally obtain 3.8 g of cobalt tetroxide, with a cobalt recovery rate of 94.7%. Molecular sieve C was NaA molecular sieve.

[0047] XRD analysis of the recovered lithium carbonate, manganese dioxide, and cobalt tetroxide showed that the purity was over 98%.

[0048] Example 6 This embodiment illustrates the method for recovering metals from leachate of spent lithium-ion batteries provided by the present invention.

[0049] S1. Add 3000 mL of leachate from spent lithium-ion batteries (the leachate from spent lithium-ion batteries is Li...) + Mn 2+ and Co 2+ A mixed solution of Li + The content is 0.05 mol / L, Mn 2+The content was 0.2 mol / L, Co 2+ After adjusting the pH to 4, 200g of molecular sieve A (KA molecular sieve, purchased from Xiamen Luyuan Fine Chemical Co., Ltd., grade 3A, pore size 0.3nm, SiO2 / Al2O3 molar ratio 2.0) was added. The adsorption treatment was carried out at 60℃ for 20h. The resulting leachate was then filtered to obtain a lithium-containing filtrate and molecular sieve B. Under stirring, 10g of precipitant (sodium carbonate) was added to the lithium-containing filtrate to precipitate lithium ions. The precipitate was then filtered, and the precipitate was washed with deionized water to remove impurities. The washed precipitate was dried at 100℃ for 20h, finally yielding 5.2g of lithium carbonate, with a lithium recovery rate of 93.8%.

[0050] S2. Molecular sieve B was soaked in a saturated sodium sulfate aqueous solution at -5℃ for 150 h to achieve low-temperature desorption, followed by vacuum filtration to obtain a manganese-containing filtrate and molecular sieve C. 140 g of ammonium persulfate was added to the manganese-containing filtrate, and the mixture was reacted at 60℃ for 2 h to precipitate manganese ions. The precipitate was then filtered, and the precipitate was washed with deionized water to remove impurities. The washed precipitate was dried at 100℃ for 20 h to finally obtain 48.5 g of manganese dioxide, with a manganese recovery rate of 93.0%.

[0051] S3. Molecular sieve C was soaked in a saturated sodium chloride aqueous solution at 100℃ for 1 hour to achieve high-temperature desorption. Then, vacuum filtration was performed to obtain a cobalt-containing filtrate and molecular sieve C. The pH of the solution was adjusted to 9, and 32 mL of 30% hydrogen peroxide was added to the cobalt-containing filtrate to precipitate cobalt ions. The precipitate was then filtered, and the precipitate was washed with deionized water to remove impurities. The washed precipitate was dried at 100℃ for 20 hours, finally yielding 45.6 g of cobalt tetroxide, with a cobalt recovery rate of 96.7%. Molecular sieve C was a KA molecular sieve.

[0052] XRD analysis of the recovered lithium carbonate, manganese dioxide, and cobalt tetroxide showed that the purity was over 98%.

[0053] Example 7 Metals were recovered from the leachate of spent lithium-ion batteries according to the method in Example 1, except that the NaA molecular sieve was replaced with the same parts by weight of NaA molecular sieve (purchased from Zhangzhou Yandan Additives Co., Ltd., grade 4A, pore size 0.4 nm, SiO2 / Al2O3 molar ratio 1.97). All other conditions were the same as in Example 1, yielding lithium carbonate, manganese dioxide, and cobalt tetroxide with purities of 98.5%, 97.2%, and 98.8%, respectively. The recovery rates were 94.1% for lithium, 93.2% for manganese, and 95.1% for cobalt.

[0054] Comparative Example 1 Metals were recovered from the leachate of spent lithium-ion batteries according to the method in Example 1, except that the NaA molecular sieve was replaced with the same weight of ZSM-5 molecular sieve (purchased from Xiamen Luyuan Fine Chemical Co., Ltd., grade ZSM-5, pore size 0.55 nm, SiO2 / Al2O3 molar ratio 30). All other conditions were the same as in Example 1, yielding lithium carbonate, manganese dioxide, and cobalt tetroxide with purities of 22.3%, 80.6%, and 76.3%, respectively. The recovery rates were 15.5% for lithium, 18.2% for manganese, and 20.5% for cobalt.

[0055] Comparative Example 2 Metals were recovered from the leachate of spent lithium-ion batteries using the method described in Example 1, except that the low-temperature desorption temperature was controlled at 40°C, while the other conditions remained the same as in Example 1. This yielded lithium carbonate, manganese dioxide, and cobalt tetroxide with purities of 98.0%, 67.2%, and 97.8%, respectively. The recovery rates were 94.3% for lithium, 91.4% for manganese, and 64.2% for cobalt.

[0056] Comparative Example 3 Metals were recovered from the leachate of spent lithium-ion batteries according to the method of Example 1, except that the high-temperature desorption temperature was controlled at 50°C, while the other conditions were the same as in Example 1. Lithium carbonate, manganese oxide, and cobalt oxide were obtained with purities of 98.9%, 98.4%, and 98.6%, respectively. The recovery rates were 94.2% for lithium, 91.8% for manganese, and 47.8% for cobalt.

[0057] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention without departing from the principles and spirit of the present invention.

Claims

1. A method for recovering metals from battery leaching solutions, wherein the battery leaching solution contains Li + Co 2+ and Mn 2+ Its characteristics are, The method includes the following steps: S1. The battery leachate is adsorbed by molecular sieve A and then filtered. The molecular sieve A is a low-silica molecular sieve with a SiO2 / Al2O3 molar ratio of less than 6, to obtain lithium-containing filtrate and molecular sieve B. S2. Molecular sieve B is desorbed in a saturated sodium salt solution at low temperature and then filtered. The low temperature of the desorption is below 20°C, to obtain a manganese-containing filtrate and molecular sieve C. S3. Molecular sieve C is desorbed at high temperature in a saturated sodium salt solution and then filtered. The high temperature of the desorption is above 70°C, to obtain a cobalt-containing filtrate and molecular sieve D.

2. The method for recovering metals from battery leaching solution according to claim 1, characterized in that, In step S1, the ratio of molecular sieve A to battery leaching solution is (5~125) g: 1 L.

3. The method for recovering metals from battery leachate according to claim 1, characterized in that, In step S1, the adsorption conditions include a temperature of 25℃~90℃, a pH value of 2~7, and a time of 1h~30h.

4. The method for recovering metals from battery leachate according to claim 1, characterized in that, In step S1, the molecular sieve A is selected from at least one of type A, type X, type P molecular sieves, and molecular sieves modified from them with a SiO2 / Al2O3 molar ratio of less than 6.

5. The method for recovering metals from battery leachate according to claim 1, characterized in that, In step S2, the conditions for low-temperature desorption include a temperature of -5℃ to 20℃ and a time of 20h to 150h.

6. The method for recovering metals from battery leaching solution according to claim 1, characterized in that, In step S2, the saturated sodium salt in the saturated sodium salt solution is selected from at least one of sodium sulfate, sodium nitrate, sodium chloride, and sodium acetate.

7. The method for recovering metals from battery leachate according to claim 1, characterized in that, In step S3, the conditions for high-temperature desorption include a temperature of 70℃~110℃ and a time of 0.5h~10h.

8. The method for recovering metals from battery leachate according to claim 1, characterized in that, In step S3, the saturated sodium salt in the saturated sodium salt solution is selected from at least one of sodium sulfate, sodium nitrate, sodium chloride, and sodium acetate.

9. The method for recovering metals from battery leachate according to any one of claims 1 to 8, characterized in that, The method also includes regenerating the lithium-containing filtrate, manganese-containing filtrate, and cobalt-containing filtrate respectively to obtain their respective lithium carbonate, manganese dioxide, and cobalt tetroxide.

10. The method for recovering metals from battery leachate according to any one of claims 1 to 8, characterized in that, The method also includes recycling molecular sieve D as molecular sieve A to step S1.

Images