Method for preparing iron-doped basic copper sulfate by recovering copper from waste lithium batteries and iron-doped basic copper sulfate

Abstract

The invention belongs to the technical field of waste lithium battery resource recovery, and particularly relates to a method for preparing iron-doped basic copper sulfate by recovering copper from waste lithium batteries and iron-doped basic copper sulfate, the method for preparing iron-doped basic copper sulfate by recovering copper from waste lithium batteries comprises the following steps: S1, adding a waste lithium battery negative electrode material into an acid solution, and stirring uniformly; after reaction, filtering to obtain a copper salt solution; s2, adding a trivalent iron salt into the copper salt solution to obtain a first solution; s3, adjusting the pH value of the first solution to 7-8 to obtain a second solution; s4, the second solution is subjected to a hydrothermal reaction, filtering, washing and drying are performed after the reaction, and iron-doped basic copper sulfate is obtained; according to the method, the iron-doped basic copper sulfate with adsorption and degradation functions on water pollution is synthesized by recovering copper from the waste lithium battery negative electrode material, so that the waste lithium battery negative electrode material is recovered and utilized, and organic matter pollution of the water is effectively removed.

Description

Technical Field

[0001] This invention belongs to the field of waste lithium battery resource recycling technology, specifically a method for preparing iron-doped basic copper sulfate from copper recovered from waste lithium batteries, and the iron-doped basic copper sulfate. Background Technology

[0002] With the rapid development of the new energy vehicle industry, the number of discarded lithium batteries is gradually increasing. If these discarded lithium batteries are not properly disposed of, they will cause enormous pollution to the environment. Discarded lithium batteries have significant resource value, with lithium having the highest potential value; therefore, the recycling of discarded lithium batteries is urgently needed.

[0003] Currently, the main methods for treating organic pollution in water bodies are: physical treatment methods: (1) screen / grid: removes large suspended solids, essential for pretreatment. (2) sedimentation / flotation: uses gravity or air bubbles to separate suspended solids, suitable for wastewater with high suspended solids. (3) adsorption (such as activated carbon): efficiently removes dissolved organic matter, but regeneration costs need to be considered. Chemical treatment methods: (1) chemical oxidation: ozone, chlorine, Fenton's reagent, etc. decompose recalcitrant organic matter, suitable for high-concentration wastewater; (2) coagulation / flocculation: coagulants such as aluminum salts and ferric salts aggregate colloids, requiring the treatment of chemical sludge. Biological treatment methods: (1) aerobic treatment (activated sludge method, biofilm method): suitable for low-concentration wastewater, requires aeration, and has high energy consumption; (2) anaerobic treatment: treats high-concentration organic wastewater, produces methane that can be recovered as energy. Ecological treatment methods: artificial wetlands / stabilization ponds, low cost, eco-friendly, suitable for areas with sufficient land, with a long treatment cycle. Deep treatment technologies: (1) Membrane separation is efficient but costly and requires pretreatment; (2) Ozone-biological activated carbon: combined oxidation and adsorption, suitable for slightly polluted water sources.

[0004] Therefore, there is an urgent need for a method that can recycle waste lithium batteries and use them to degrade organic pollutants in water. Summary of the Invention

[0005] This invention provides a method for preparing iron-doped basic copper sulfate from copper recovered from spent lithium batteries, comprising the following steps: S1. Add the waste lithium battery negative electrode material to an acidic solution, react, and then filter to obtain a copper salt solution. S2. Add ferric salt to the copper salt solution to obtain the first solution; S3. Adjust the pH of the first solution to 7-8 to obtain the second solution; S4. The second solution undergoes a hydrothermal reaction, followed by filtration, washing, and drying to obtain iron-doped basic copper sulfate; the iron-doped basic copper sulfate is (Cu 1-x Fe x )4SO4(OH)6, where 0.25≤x≤0.75.

[0006] In step S1, the acidic solution includes at least one of sulfuric acid, hydrochloric acid, and nitric acid; the solid-liquid ratio of the waste lithium battery negative electrode material to the acidic solution is (40~500) g: 1 L; and the concentration of hydrogen ions in the acidic solution is 2~4 mol / L. Step S1 also includes crushing and sieving the waste lithium battery negative electrode material. Preferably, the ratio of the waste lithium battery negative electrode material to the acidic solution is 100g:1L.

[0007] Specifically, step S1 involves adding the waste lithium battery negative electrode material to the acidic solution, reacting it at 20-70°C for 5-60 minutes, and then filtering to obtain the copper salt solution.

[0008] Step S1 further includes: adding the waste lithium battery negative electrode material to the acidic solution, then adding an oxidant, reacting and filtering to obtain the copper salt solution; the oxidant includes at least one of hydrogen peroxide, oxygen, and ozone; Furthermore, the waste lithium battery negative electrode material is stirred with the acidic solution at 20~70°C, then an oxidant is added, and the reaction is continued for 5~60 minutes. After the reaction, the copper salt solution is obtained by filtration. Preferably, the waste lithium battery negative electrode material is stirred with the acidic solution at 60°C, then an oxidant is added, and the reaction is continued for 40 minutes. After the reaction, the copper salt solution is obtained by filtration.

[0009] In step S2, the ferric salt includes at least one of ferric sulfate, ferric chloride, and ferric nitrate, and the first solution contains at least sulfate ions.

[0010] In the first solution, the molar ratio of iron ions to copper ions is (0.5~2.5):1; Furthermore, the molar ratio of iron ions to copper ions in the first solution is any one of 0.5:1, 1.0:1, 1.5:1, 2.0:1, 2.5:1, or a range between both. Preferably, the molar ratio of iron ions to copper ions in the first solution is 2:1.

[0011] Specifically, step S3 involves adjusting the pH of the first solution to 7-8 using an alkaline solution; the alkaline solution is sodium hydroxide, potassium hydroxide, or ammonia.

[0012] In step S4, the hydrothermal reaction temperature is 110~180℃ and the time is 2~8h.

[0013] The present invention also provides iron-doped basic copper sulfate, which is prepared by the above-mentioned method for preparing iron-doped basic copper sulfate from waste lithium battery copper foil.

[0014] The iron-doped basic copper sulfate is used to adsorb or photocatalyze the removal of organic pollutants from water bodies. The organic pollutants include at least one of tetracycline hydrochloride, phenol, carboxylated polystyrene, and polystyrene. The iron-doped basic copper sulfate is used to treat organic polluted water with a concentration of 25 mg / L and a pH of 3-11 at a solid-liquid ratio of 2 mg:1 mL. The removal rate of the organic pollutants is greater than or equal to 90%.

[0015] This invention synthesizes iron-doped basic copper sulfate with adsorption and degradation functions for water pollution by recovering copper foil from waste lithium battery anode materials, thereby realizing the recycling and utilization of waste lithium battery anode materials and effectively removing organic pollution from water bodies. Attached Figure Description

[0016] 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 the structures shown in these drawings without creative effort.

[0017] Figure 1 The images show the XRD patterns of iron-doped basic copper sulfate prepared in some of the examples and comparative examples.

[0018] The realization of the objective, functional features and advantages of the present invention will be further explained in conjunction with the embodiments and with reference to the accompanying drawings. Detailed Implementation

[0019] The technical solutions described below in conjunction with the embodiments will be clearly and completely described. Obviously, the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0020] This invention provides a method for preparing iron-doped basic copper sulfate from copper recovered from spent lithium batteries, comprising the following steps: S1. Add the waste lithium battery negative electrode material to an acidic solution, react, and then filter to obtain a copper salt solution. In embodiments of the present invention, the waste lithium battery negative electrode material is the negative electrode material obtained from the dismantling of waste lithium batteries or the waste negative electrode material copper foil generated during the lithium battery manufacturing process; the acidic solution includes at least one of sulfuric acid solution, hydrochloric acid solution and nitric acid solution; In a preferred embodiment of the present invention, waste lithium battery negative electrode material is added to an acidic solution, then an oxidant is added, and after reaction, a copper salt solution is obtained by filtration. The oxidant includes at least one of hydrogen peroxide, oxygen, and ozone, preferably hydrogen peroxide. The following example uses hydrogen peroxide as the oxidant to illustrate the reaction that occurs when an oxidant is added to the negative electrode material of a spent lithium battery in an acidic solution. The ionic equation is as follows: Cu + H₂O₂ + H₂ + →Cu 2+ +H2O.

[0021] S2. Add ferric salt to the copper salt solution to obtain the first solution; S3. Adjust the pH of the first solution to 7-8 to obtain the second solution; S4. The second solution undergoes a hydrothermal reaction, followed by filtration, washing, and drying to obtain iron-doped basic copper sulfate; the iron-doped basic copper sulfate is (Cu... 1-x Fe x The ionic equation is as follows: Fe(OH)3(s) + Cu(OH)2(s) + SO42-(OH)6, where 0.25 ≤ x ≤ 0.75. 2- →(Cu 1-x Fe x )4SO4(OH)6(s).

[0022] The technical solution of the present invention will be further described below with reference to specific embodiments.

[0023] In an embodiment of the present invention, the pH of the first solution is adjusted using a sodium hydroxide solution.

[0024] Example 1 Take 50g of crushed and sieved waste lithium battery negative electrode material and put it into 100mL of 2mol / L sulfuric acid solution. The solution temperature is 60℃. Stir to allow it to react. Then add 35wt% H2O2 and continue to react for 30min. After the reaction is completed, filter to obtain copper salt solution. Ferric sulfate was added to a copper salt solution to adjust the molar ratio of iron ions to copper ions to 2:1, yielding the first solution. 50 mL of the first solution was taken and its pH was adjusted to 7 using sodium hydroxide solution to obtain the second solution. The second solution was added to a hydrothermal reactor and placed in an electric blast furnace. The reaction temperature was set to 130°C for 5 hours. After the reaction was complete, the solution was cooled, filtered, washed, dried, and ground to obtain iron-doped basic copper sulfate. 0.47 Fe 0.53 )4SO4(OH)6.

[0025] Take 200 mg of iron-doped basic copper sulfate and place it in 100 ml of tetracycline hydrochloride solution with a concentration of 25 mg / L. The solution pH is 5. Stir and react in the dark for 20 min, then react under light for 60 min. Measure the absorbance of the solution before and after the reaction. It is calculated that the removal rate of tetracycline hydrochloride reaches 96.7%.

[0026] Example 2 Take 20g of crushed and sieved waste lithium battery negative electrode material and put it into 100mL of 2mol / L nitric acid solution. The solution temperature is 60℃. Stir to allow it to react. Then add 35wt% H2O2 and continue to react for 40min. After the reaction is completed, filter to obtain copper salt solution. Ferric sulfate was added to a copper salt solution to adjust the molar ratio of iron ions to copper ions to 2:1, yielding the first solution. 50 mL of the first solution was taken and its pH was adjusted to 7 using sodium hydroxide solution to obtain the second solution. The second solution was added to a hydrothermal reactor and placed in an electric blast furnace. The reaction temperature was set to 130°C for 5 hours. After the reaction was complete, the solution was cooled, filtered, washed, dried, and ground to obtain iron-doped basic copper sulfate. 0.46 Fe 0.54 )4SO4(OH)6.

[0027] Take 200 mg of iron-doped basic copper sulfate and place it in 100 ml of polystyrene (100 nm) solution with a concentration of 25 mg / L. Stir and react for 60 min. Measure the absorbance of the solution before and after the reaction. It is calculated that the removal rate of polystyrene reaches 97.9%.

[0028] Example 3 Take 5g of crushed and sieved waste lithium battery negative electrode material and put it into 100mL of 2mol / L hydrochloric acid solution. The solution temperature is 30℃. Stir to allow it to react. Then add 35wt% H2O2 and continue to react for 10min. After the reaction is completed, filter to obtain copper salt solution. Ferric sulfate was added to a copper salt solution to adjust the molar ratio of iron ions to copper ions to 2:1, yielding the first solution. 50 mL of the first solution was taken and its pH was adjusted to 7 using sodium hydroxide solution to obtain the second solution. The second solution was added to a hydrothermal reactor and placed in an electric blast furnace. The reaction temperature was set to 130°C for 5 hours. After the reaction was complete, the solution was cooled, filtered, washed, dried, and ground to obtain iron-doped basic copper sulfate. 0.36 Fe 0.64 )4SO4(OH)6.

[0029] Take 200 mg of iron-doped basic copper sulfate and place it in 100 ml of carboxylated polystyrene (100 nm) solution with a concentration of 25 mg / L. Stir and react for 60 min. Detect the absorbance of the solution before and after the reaction. Calculation shows that the removal rate of carboxylated polystyrene reaches 96.5%.

[0030] Example 4 Unlike Example 1, ferric sulfate was added to the copper salt solution to adjust the molar ratio of iron ions to copper ions in the solution to 0.5:1, thus obtaining the first solution; Iron-doped basic copper sulfate was obtained, (Cu 0.62 Fe 0.38 )4SO4(OH)6; Take 200 mg of iron-doped basic copper sulfate and place it in 100 ml of tetracycline hydrochloride solution with a concentration of 15 mg / L. The solution pH is 5. Stir and react in the dark for 20 min, then react under light for 60 min. Measure the absorbance of the solution before and after the reaction. It is calculated that the removal rate of tetracycline hydrochloride reaches 90.3%.

[0031] Example 5 Unlike Example 1, ferric sulfate was added to the copper salt solution to adjust the molar ratio of iron ions to copper ions in the solution to 1.5:1, thus obtaining the first solution; the reaction temperature was set at 110°C and the reaction time was 2 hours. Iron-doped basic copper sulfate was obtained, (Cu 0.41 Fe 0.59 )4SO4(OH)6; Take 200 mg of iron-doped basic copper sulfate and place it in 100 ml of tetracycline hydrochloride solution with a concentration of 25 mg / L. The solution pH is 5. Stir and react in the dark for 20 min, then react under light for 60 min. Measure the absorbance of the solution before and after the reaction. It is calculated that the removal rate of tetracycline hydrochloride reaches 91.2%.

[0032] Example 6 Unlike Example 1, ferric sulfate was added to the copper salt solution to adjust the molar ratio of iron ions to copper ions in the solution to 2.5:1, thus obtaining the first solution; the reaction temperature was set at 180°C and the reaction time was 8 hours. Iron-doped basic copper sulfate was obtained, (Cu 0.28 Fe 0.72 )4SO4(OH)6; Take 200 mg of iron-doped basic copper sulfate and place it in 100 ml of tetracycline hydrochloride solution with a concentration of 25 mg / L. The solution pH is 5. Stir and react in the dark for 20 min, then react under light for 60 min. Measure the absorbance of the solution before and after the reaction. It is calculated that the removal rate of tetracycline hydrochloride reaches 90.1%.

[0033] Example 7 Five 200 mg samples of iron-doped basic copper sulfate prepared in Example 1 were placed in five 100 mL tetracycline hydrochloride solutions with a concentration of 25 mg / L. The pH values ​​of the five tetracycline hydrochloride solutions were 3, 5, 7, 9, and 11, respectively. The solutions were stirred in the dark for 20 min, followed by light exposure for 60 min. The absorbance of the solutions before and after the reaction was measured. The removal rates of tetracycline hydrochloride were calculated as follows: 90.4% at pH 3.0; 96.7% at pH 5.0; 92.3% at pH 7.0; 91.8% at pH 9.0; and 90.1% at pH 11.0.

[0034] Comparative Example 1 Unlike Example 1, no iron salt was added to the copper salt solution; Iron-doped basic copper sulfate, Cu4SO4(OH)6, was obtained. 200 mg of Cu4SO4(OH)6 was placed in 100 ml of a 25 mg / L tetracycline hydrochloride solution with a pH of 5. The mixture was stirred in the dark for 20 min, followed by irradiation for 60 min. The absorbance of the solution before and after the reaction was measured. The removal rate of tetracycline hydrochloride was calculated to be 46.1%. Take 200 mg of Cu4SO4(OH)6 and place it in 100 ml of polystyrene (100 nm) solution with a concentration of 25 mg / L. Stir and react for 60 min. Measure the absorbance of the solution before and after the reaction. The polystyrene removal rate is calculated to be 22%.

[0035] Comparative Example 2 Unlike Example 1, the pH of the first solution was adjusted to 6 using sulfuric acid solution to obtain the second solution; No sediment can be obtained.

[0036] Comparative Example 3 Unlike Example 1, ferric sulfate was added to the copper salt solution to adjust the molar ratio of iron ions to copper ions in the solution to 0.1:1, thus obtaining the first solution; Iron-doped basic copper sulfate was obtained, (Cu 0.93 Fe 0.07 )4SO4(OH)6; Take 200mg (Cu) 0.93 Fe 0.07 )4SO4(OH)6 was placed in 100ml of a 25mg / L polystyrene (100nm) solution and stirred for 60min. The absorbance of the solution before and after the reaction was measured. The polystyrene removal rate was calculated to be 31%.

[0037] Comparative Example 4 Unlike Example 1, ferric sulfate was added to the copper salt solution to adjust the molar ratio of iron ions to copper ions in the solution to 3:1, thus obtaining the first solution; Iron-doped basic copper sulfate was obtained, (Cu 0.18 Fe 0.82 )4SO4(OH)6; Take 200 mg of iron-doped basic copper sulfate and place it in 100 ml of tetracycline hydrochloride solution with a concentration of 25 mg / L. The solution pH is 5. Stir in the dark for 20 min and then react under light for 60 min. Measure the absorbance of the solution before and after the reaction. It is calculated that the removal rate of tetracycline hydrochloride reaches 63%.

[0038] Comparative Example 5 Example 1 of the patent with publication number CN119824230A was used as a comparison, and its removal rate of tetracycline hydrochloride was 80%.

[0039] Comparative Example 6 Unlike Example 1, the second solution was added to a hydrothermal reactor and placed in an electric heating blower box, with the reaction temperature set at 100°C and the reaction time set at 1 hour. Iron-doped basic copper sulfate was obtained; Take 200 mg of iron-doped basic copper sulfate and place it in 100 ml of tetracycline hydrochloride solution with a concentration of 25 mg / L. The solution pH is 5. Stir and react in the dark for 20 min, then react under light for 60 min. Measure the absorbance of the solution before and after the reaction. It is calculated that the removal rate of tetracycline hydrochloride reaches 65.3%.

[0040] Comparative Example 7 Unlike Example 1, the second solution was added to a hydrothermal reactor and placed in an electric heating blower box, with the reaction temperature set at 200°C and the reaction time set at 10 hours. Iron-doped basic copper sulfate was obtained; Take 200 mg of iron-doped basic copper sulfate and place it in 100 ml of tetracycline hydrochloride solution with a concentration of 25 mg / L. The solution pH is 5. Stir in the dark for 20 min and then react under light for 60 min. Measure the absorbance of the solution before and after the reaction. It is calculated that the removal rate of tetracycline hydrochloride reaches 41.2%.

[0041] Please see Figure 1 , Figure 1 The XRD patterns of the products prepared in Example 1, Comparative Example 1, Comparative Example 4, and Comparative Example 5 are shown. The XRD diffraction peaks of the products obtained in Example 1 and Comparative Example 1 are consistent, indicating that the crystal structure of the main phase is consistent, that is, iron element replaces part of the copper element and is doped into Cu4SO4(OH)6, resulting in (Cu 1-x Fex )4SO4(OH)6. Comparative Example 4 has excessive iron doping, resulting in a product with an amorphous structure and indistinct XRD diffraction peaks. Comparative Example 5 is an iron-copper composite prepared according to the patent publication number CN119824230A. The XRD diffraction peaks of this substance are inconsistent with those of Example 1 and Comparative Example 1, indicating that it is not the same type of substance.

[0042] The above description is merely a preferred embodiment of the present invention and does not limit the patent scope of the present invention. Any equivalent structural transformations made using the contents of the present invention under the inventive concept of the present invention, or direct / indirect applications in other related technical fields, are included within the patent protection scope of the present invention.

Claims

1. A method for preparing iron-doped basic copper sulfate from copper recovered from waste lithium batteries, characterized in that, Includes the following steps: S1. Add the waste lithium battery negative electrode material to an acidic solution, react, and then filter to obtain a copper salt solution. S2. Add ferric salt to the copper salt solution to obtain the first solution; S3. Adjust the pH of the first solution to 7-8 to obtain the second solution; S4. The second solution undergoes a hydrothermal reaction, followed by filtration, washing, and drying to obtain iron-doped basic copper sulfate; the iron-doped basic copper sulfate is (Cu 1-x Fe x )4SO4(OH)6, where 0.25≤x≤0.

75.

2. The method for preparing iron-doped basic copper sulfate from copper recovered from waste lithium batteries according to claim 1, characterized in that, In step S1, the acidic solution includes at least one of sulfuric acid, hydrochloric acid, and nitric acid, the solid-liquid ratio of the waste lithium battery negative electrode material to the acidic solution is (40~500) g: 1 L, and the concentration of hydrogen ions in the acidic solution is 2~4 mol / L. Step S1 further includes crushing and sieving the waste lithium battery negative electrode material.

3. The method for preparing iron-doped basic copper sulfate from copper recovered from waste lithium batteries according to claim 2, characterized in that, Specifically, step S1 involves adding the waste lithium battery negative electrode material to the acidic solution, reacting it at 20-70°C for 5-60 minutes, and then filtering to obtain the copper salt solution.

4. The method for preparing iron-doped basic copper sulfate from copper recovered from waste lithium batteries according to claim 1, characterized in that, Step S1 further includes: adding the waste lithium battery negative electrode material to the acidic solution, then adding an oxidant, and filtering after reaction to obtain the copper salt solution; the oxidant includes at least one of hydrogen peroxide, oxygen, and ozone.

5. The method for preparing iron-doped basic copper sulfate from copper recovered from waste lithium batteries according to claim 1, characterized in that, In step S2, the ferric salt includes at least one of ferric sulfate, ferric chloride, and ferric nitrate, and the first solution contains at least sulfate ions.

6. The method for preparing iron-doped basic copper sulfate from copper recovered from waste lithium batteries according to claim 5, characterized in that, The molar ratio of iron ions to copper ions in the first solution is (0.5~2.5):

1.

7. The method for preparing iron-doped basic copper sulfate from copper recovered from waste lithium batteries according to claim 1, characterized in that, Specifically, step S3 involves adjusting the pH of the first solution to 7-8 using an alkaline solution; the alkaline solution is sodium hydroxide, potassium hydroxide, or ammonia.

8. The method for preparing iron-doped basic copper sulfate from copper recovered from waste lithium batteries according to claim 1, characterized in that, In step S4, the hydrothermal reaction temperature is 110~180℃ and the time is 2~8h.

9. Iron-doped basic copper sulfate, characterized in that, The iron-doped basic copper sulfate is prepared by the method described in any one of claims 1 to 8, which involves recovering copper from waste lithium batteries to prepare iron-doped basic copper sulfate.

10. The iron-doped basic copper sulfate according to claim 9, characterized in that, The iron-doped basic copper sulfate is used to adsorb or photocatalyze the removal of organic pollutants from water, including at least one of tetracycline hydrochloride, phenol, carboxylated polystyrene, and polystyrene. The iron-doped basic copper sulfate is used to treat organic polluted water with a concentration of 25 mg / L and a pH of 3-11 at a solid-liquid ratio of 2 mg:1 mL, and the removal rate of the organic pollutants is greater than or equal to 90%.

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