Method for recycling valuable metals in waste lithium batteries by using coal gangue

Abstract

The invention relates to a method for recovering valuable metals in waste lithium batteries by using coal gangue, which is characterized by comprising the following steps of: (1) ball-milling the coal gangue, filtering to obtain coal gangue particles with the particle size of 0.5-1 mu m, and drying; (2) discharging the waste lithium battery until the waste lithium battery is inactivated, disassembling, collecting a positive electrode material, and drying; (3) soaking the positive electrode material in an alkaline solution, and filtering after soaking; continuously soaking in an acid solution, and filtering after soaking to obtain a leaching solution containing valuable metal ions; (4) adding coal gangue particles, stirring, and filtering to obtain a coal gangue adsorption carrier loaded with valuable metal ions; and (5) soaking the coal gangue adsorption carrier in a mixed solution of nitric acid and hydrogen peroxide to obtain the desorption solution rich in valuable metal ions. The method has the advantages that the coal gangue is used as the adsorbent to recycle valuable metal of the waste batteries, the nickel recovery rate is larger than or equal to 70.8%, the cobalt recovery rate is larger than or equal to 71.2%, the manganese recovery rate is larger than or equal to 60.2%, and the method is environmentally friendly, low in cost and capable of being repeatedly used.

Description

Technical Field

[0001] The invention belongs to the technical field of waste lithium battery recycling and relates to a method for recycling valuable metals in waste lithium batteries by using coal gangue. Background Art

[0002] Lithium batteries are a type of battery that uses lithium metal or lithium alloy as the negative electrode material and a non-aqueous electrolyte solution. With the development of science and technology, the new energy vehicle industry has expanded rapidly, and the use of lithium batteries has also increased significantly. With the increase in the use of lithium batteries, a large number of waste lithium batteries have also been generated. If these waste lithium batteries cannot be safely and effectively handled, they will inevitably cause great pollution to the environment and endanger human life. The positive electrode materials of lithium batteries are generally lithium cobalt oxide / lithium iron phosphate / nickel cobalt manganese oxide, etc. These lithium, nickel, cobalt, and manganese metals are precious metals. If they can be recycled and reused, they will inevitably bring huge profits.

[0003] At present, there are two main methods for recovering valuable metals in waste lithium batteries: dry recovery and wet recovery. Dry recovery refers to the direct recovery of materials or valuable metals without using a medium such as a solution. The main methods used are physical sorting and high-temperature pyrolysis. The wet recovery process is to crush and dissolve the waste batteries, and then use appropriate chemical reagents to selectively separate the metal elements in the leaching solution to produce high-grade cobalt metal or lithium carbonate, etc., for direct recovery. Wet recovery is more suitable for recycling waste lithium-ion batteries with relatively simple chemical compositions. Its equipment investment cost is relatively low, and it is suitable for the recovery of small and medium-sized waste lithium-ion batteries. Therefore, this method is currently widely used. Both methods have problems such as low recovery energy consumption, cumbersome procedures, high separation consumption, and serious environmental pollution. Summary of the invention

[0004] The purpose of the present invention is to solve the problems of low energy consumption, complicated process, large separation consumption and serious environmental pollution in the existing waste lithium battery recycling, and to provide a method for recycling valuable metals in waste lithium batteries using coal gangue.

[0005] In order to achieve the above object, the technical solution adopted by the present invention is as follows: A method for recovering valuable metals from waste lithium batteries using coal gangue, characterized by comprising the following steps: (1) Place the coal gangue in a ball mill for ball milling (ball milling for 5 to 10 hours), filter to obtain coal gangue particles of 0.5 to 1 μm, and dry for later use (drying temperature is 50 to 80 ° C, time is 240 to 380 minutes); (2) Discharge the waste lithium batteries until they are inactivated, then disassemble the inactivated waste lithium batteries, collect the positive electrode materials and place them in an oven for drying (drying at 55-65°C for 8-12 hours); (3) Soaking the positive electrode material in an alkaline solution for 12 to 24 hours and filtering to obtain an active solid powder; continuing to soak the active solid powder in an acidic solution for 12 to 24 hours and filtering to obtain a leachate containing valuable metal ions (using ICP-OES to test the concentration of valuable metals in the solution); (4) Add coal gangue particles to the leaching solution, stir thoroughly for 5 to 15 hours, and filter to obtain the coal gangue adsorption carrier loaded with valuable metal ions; (5) Soak the gangue adsorption carrier in a mixture of nitric acid and hydrogen peroxide to obtain a mixture rich in valuable metal ions (Ni + 、Co 2+ , Mn 2+ ) and test its content.

[0006] Furthermore, the coal gangue is produced in Shanxi or Xinjiang.

[0007] Furthermore, the waste lithium batteries are 18650 type ternary lithium waste batteries produced by Yiwei Lithium Energy.

[0008] Furthermore, the method of discharge treatment is: placing the waste battery in a 2-5% NaCl aqueous solution and discharging for 24 hours or self-short-circuiting and discharging until it is out of power.

[0009] Furthermore, the alkaline solution is any one of sodium hydroxide, potassium hydroxide, barium hydroxide, calcium hydroxide and the like.

[0010] Furthermore, the immersion temperature in the alkaline washing solution is 50-70° C. and the pH is 8-11.

[0011] Furthermore, the acidic solution is any one of nitric acid, sulfuric acid, hydrochloric acid and glacial acetic acid.

[0012] Furthermore, the immersion temperature in the acidic solution is 50-70° C. and the pH is 2-6.

[0013] Furthermore, the mass ratio of the positive electrode material to the coal gangue particles is 1:3-8.

[0014] Furthermore, the volume fraction of hydrogen peroxide to nitric acid is 10-15%.

[0015] The present invention utilizes multiple active components of coal gangue with unique flaky structure, and there are a large number of adsorption sites and hydroxyl functional groups on the surface. Through ball milling, abundant pores and high specific surface area can be obtained. The micron-level pore size and adsorption sites on the surface of coal gangue are utilized to adsorb valuable metals in waste batteries. First, aluminum materials on the surface of waste batteries are removed by alkaline solution, and then the valuable metals in the waste batteries are dissolved by acidic solution, and then a mixed solution of valuable metals is obtained through the steps of coal gangue adsorption, enrichment, separation and the like.

[0016] Beneficial effects of the present invention: 1. The present invention uses coal gangue, a byproduct of coal mining, and uses the active sites such as hydrogen and hydroxyl groups on the surface of coal gangue to be used as an adsorbent to recover valuable metals from waste batteries. This not only solves the environmental pollution problem caused by coal gangue, but also provides a new method for recycling waste batteries, making it commercially valuable. It can be said to kill two birds with one stone (solving two substances that pollute the environment at the same time), and provides a feasible method for the waste battery recycling industry; 2. This recycling method is simple, efficient, controllable, environmentally friendly, low-cost, and has obvious advantages in large-scale recycling of waste batteries. ICP-OES (inductively coupled plasma atomic emission spectrometer) testing has confirmed that the valuable metal ions in waste batteries are efficiently recovered (nickel recovery rate ≥70.8%, cobalt recovery rate ≥71.2%, manganese recovery rate ≥60.2%) and can be reused repeatedly. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a scanning electron microscope image of coal gangue after ball milling. DETAILED DESCRIPTION

[0018] Combination Figure 1 , the present invention is further described: A method for recovering valuable metals from waste lithium batteries using coal gangue, the specific implementation steps are as follows: Example

[0019] (1) The coal gangue produced in Shanxi was placed in a ball mill for 8 h, filtered to obtain 0.8 μm coal gangue particles, and dried at 65 °C for 360 min for later use; (2) The 18650 type waste ternary lithium batteries produced by Yiwei Lithium Energy Co., Ltd. were immersed in a 4% by mass NaCl aqueous solution for discharge treatment, the waste battery shells and copper and aluminum plates were disassembled and peeled off, and the positive electrode materials were collected and placed in a 60°C oven for drying for 10 hours; (3) Place 2 g of the positive electrode material in 10 mL of sodium hydroxide aqueous solution (pH 11), heat to 50 ° C and stir for 2 h, then soak for 15 h to remove impurities such as copper and aluminum, and filter to obtain lithium nickel cobalt manganese oxide solid; (4) Place the solid lithium nickel cobalt manganese oxide in 15 mL of nitric acid solution (60°C, pH 3), stir thoroughly for 2 hours, and then soak for 15 hours. Filter to obtain the Ni-containing + 、Co 2+ , Mn 2+ The leachate (containing Ni + 95.1%,Co 2+ 97.3%, Mn 2+ 96.1 %)); (5) Add 6 g of coal gangue particles to the leaching solution, stir and vibrate for 10 h, and let stand for 5 h, then filter to obtain the coal gangue adsorption carrier loaded with valuable metal ions; (6) The gangue adsorption carrier is soaked and eluted in a mixture of nitric acid solution and hydrogen peroxide (mixed by nitric acid and hydrogen peroxide in a volume ratio of 10:1) to obtain a desorption solution rich in valuable metal ions (containing Ni + 72%,Co 2+ 69.3%, Mn 2+ 61.8 %).

[0020] The content of metal ions in the leaching solution and the desorption solution was tested by ICP-OES (inductively coupled plasma optical emission spectrometer), and the recovery rates of nickel, cobalt and manganese were calculated to be 75.8%, 71.5% and 64.4%, respectively. Example

[0021] (1) The coal gangue produced in Shanxi was placed in a ball mill for 5 h, filtered to obtain 0.5 μm coal gangue particles, and dried at 80 °C for 240 min for later use; (2) The 18650 type waste ternary lithium batteries produced by Yiwei Lithium Energy Co., Ltd. were immersed in a 3% by mass NaCl aqueous solution for discharge treatment, the waste battery shells and copper and aluminum plates were disassembled and peeled off, and the positive electrode materials were collected and placed in a 58°C oven for drying for 12 hours; (3) Place 2 g of the positive electrode material in 12 mL of potassium hydroxide aqueous solution (pH 10), heat to 60 ° C and stir for 2 h, then soak for 10 h to remove impurities such as copper and aluminum, and filter to obtain lithium nickel cobalt manganese oxide solid; (4) Place the solid lithium nickel cobalt manganese oxide in 16 mL of sulfuric acid solution (60 ° C, pH 5), stir thoroughly for 2 hours, and then soak for 18 hours. Filter to obtain the Ni-containing + 、Co 2+ , Mn 2+ The leachate (containing Ni + 93.5%,Co 2+ 94.1%, Mn 2+ 92.6 %)); (5) Add 8 g of coal gangue particles to the leaching solution, stir and vibrate for 8 h, and leave it to stand for 6 h, then filter to obtain the coal gangue adsorption carrier loaded with valuable metal ions; (6) The gangue adsorption carrier is soaked and eluted in a mixture of nitric acid solution and hydrogen peroxide (mixed by nitric acid and hydrogen peroxide in a volume ratio of 9:1) to obtain a desorption solution rich in valuable metal ions (containing Ni + 71.5%,Co 2+ 69.2%, Mn2+ 60.2 %).

[0022] The content of metal ions in the leaching solution and the desorption solution was tested by ICP-OES (inductively coupled plasma optical emission spectrometer), and the recovery rates of nickel, cobalt and manganese were calculated to be 76.5%, 73.5% and 65%, respectively. Example

[0023] (1) The coal gangue produced in Shanxi was placed in a ball mill for 8 hours, filtered to obtain 0.5 μm coal gangue particles, and dried at 55°C for 380 minutes for later use; (2) The 18650 type waste ternary lithium batteries produced by Yiwei Lithium Energy Co., Ltd. were immersed in a 5% by mass NaCl aqueous solution for discharge treatment, the waste battery shells and copper and aluminum plates were disassembled and peeled off, and the positive electrode materials were collected and placed in a 62°C oven for drying for 9 hours; (3) Place 2 g of the positive electrode material in 14 mL of a barium hydroxide aqueous solution (pH 10), heat to 50 °C and stir for 2 h, then soak for 12 h to remove impurities such as copper and aluminum, and filter to obtain a solid lithium nickel cobalt manganese oxide; (4) Place the solid lithium nickel cobalt manganese oxide in 18 mL of hydrochloric acid solution (50°C, pH 3), stir thoroughly for 2 hours, and then soak for 15 hours. Filter to obtain the Ni-containing + 、Co 2+ , Mn 2+ The leachate (containing Ni + 94.8 %,Co 2+ 93.6%, Mn 2+ 93.8 %)); (5) Add 10 g of coal gangue particles to the leaching solution, stir and vibrate for 10 h, and let it stand for 6 h, then filter to obtain the coal gangue adsorption carrier loaded with valuable metal ions; (6) The gangue adsorption carrier is soaked and eluted in a mixture of nitric acid solution and hydrogen peroxide (mixed by nitric acid and hydrogen peroxide in a volume ratio of 8:1) to obtain a desorption solution rich in valuable metal ions (containing Ni + 73.2%,Co 2+ 67.2%, Mn 2+ 61.9 %).

[0024] The content of metal ions in the leaching solution and the desorption solution was tested by ICP-OES (inductively coupled plasma optical emission spectrometer), and the recovery rates of nickel, cobalt and manganese were calculated to be 77.2%, 71.8% and 66%, respectively. Example

[0025] (1) The coal gangue produced in Xinjiang was placed in a ball mill for 8 h, filtered to obtain 1 μm coal gangue particles, and dried at 80 °C for 240 min for later use; (2) The 18650 type waste ternary lithium batteries produced by Yiwei Lithium Energy Co., Ltd. were self-short-circuited and discharged until they were out of power, and the waste battery shells and copper and aluminum plates were disassembled and peeled off. The positive electrode materials were collected and placed in a 56°C oven for drying for 11 hours; (3) Place 2 g of the positive electrode material in 16 mL of calcium hydroxide aqueous solution (pH 10), heat to 55 °C and stir for 2 h, then soak for 16 h to remove impurities such as copper and aluminum, and filter to obtain lithium nickel cobalt manganese oxide solid; (4) Place the solid lithium nickel cobalt manganese oxide in 18 mL of glacial acetic acid solution (60°C, pH 3), stir thoroughly for 2 h, and then soak for 15 h. Filter and obtain the solid lithium nickel cobalt manganese oxide containing Ni. + 、Co 2+ , Mn 2+ The leachate (containing Ni + 95.8 %,Co 2+ 96.4%, Mn 2+ 97.6 %)); (5) Add 10 g of coal gangue particles to the leaching solution, stir and vibrate for 12 h, and leave it to stand for 6 h, then filter to obtain the coal gangue adsorption carrier loaded with valuable metal ions; (6) The gangue adsorption carrier is soaked and eluted in a mixture of nitric acid solution and hydrogen peroxide (mixed by nitric acid and hydrogen peroxide in a volume ratio of 7.5:1) to obtain a desorption solution rich in valuable metal ions (containing Ni + 70.8%,Co 2+ 71.2%, Mn 2+ 68.3 %).

[0026] The content of metal ions in the leaching solution and the desorption solution was tested by ICP-OES (inductively coupled plasma optical emission spectrometer), and the recovery rates of nickel, cobalt and manganese were calculated to be 78.5%, 73.9% and 70%, respectively. Example

[0027] (1) The coal gangue produced in Xinjiang was placed in a ball mill for 7 hours, filtered to obtain coal gangue particles of 0.7 μm, and dried at 72°C for 360 minutes for later use; (2) The 18650 type waste ternary lithium batteries produced by Yiwei Lithium Energy Co., Ltd. were self-short-circuited and discharged until they were out of power, and the waste battery shells and copper and aluminum plates were disassembled and peeled off. The positive electrode materials were collected and placed in a 64°C oven for drying for 8 hours; (3) Place 2 g of the positive electrode material in 18 mL of sodium hydroxide aqueous solution (pH 9), heat to 50 ° C and stir for 2 h, then soak for 14 h to remove impurities such as copper and aluminum, and filter to obtain lithium nickel cobalt manganese oxide solid; (4) Place the solid lithium nickel cobalt manganese oxide in 20 mL of nitric acid solution (60°C, pH 3), stir thoroughly for 2 hours, and then soak for 14 hours. Filter and obtain the solid lithium nickel cobalt manganese oxide containing Ni. + 、Co 2+ , Mn 2+ The leachate (containing Ni + 95.3%,Co 2+ 95.8 %, Mn 2+ 94.6 %)); (5) Add 10 g of coal gangue particles to the leaching solution, stir and vibrate for 9 h, and let it stand for 5 h, then filter to obtain the coal gangue adsorption carrier loaded with valuable metal ions; (6) The gangue adsorption carrier is soaked and eluted in a mixture of nitric acid solution and hydrogen peroxide (mixed by nitric acid and hydrogen peroxide in a volume ratio of 7:1) to obtain a desorption solution rich in valuable metal ions (containing Ni + 76.2%,Co 2+ 72.3%, Mn 2+ 65.7 %).

[0028] The content of metal ions in the leaching solution and the desorption solution was tested by ICP-OES (inductively coupled plasma optical emission spectrometer), and the recovery rates of nickel, cobalt and manganese were calculated to be 80%, 75.5% and 69.5%.

[0029] Comparative Example 1 The same operating steps as in Example 1 are used, except that only nitric acid solution is used for soaking and eluting in step (6).

[0030] The content of metal ions in the leaching solution and the desorption solution was tested by ICP-OES (inductively coupled plasma optical emission spectrometer), and the recovery rates of nickel, cobalt and manganese were calculated to be 66.5%, 62.3% and 55.8%, respectively.

[0031] Comparative Example 2 The same operating steps as in Example 1 are adopted, except that step (3) is not performed.

[0032] The content of metal ions in the leaching solution and the desorption solution was tested by ICP-OES (inductively coupled plasma optical emission spectrometer), and the recovery rates of nickel, cobalt and manganese were calculated to be 64.8%, 68.7% and 60.6%, respectively.

[0033] The experimental results of the above embodiments and comparative examples show that coal gangue as an adsorption carrier has a significant effect on the recovery of valuable metals in waste batteries, and the adsorption effect is better under hydrogen peroxide and heating conditions.

Claims

1. A method for recovering valuable metals from waste lithium batteries using coal gangue, characterized in that The steps include: (1) Place the coal gangue in a ball mill, grind it, and filter it to obtain coal gangue particles of 0.5-1 μm, and dry it for later use; (2) Discharge the waste lithium batteries until they are inactivated, then disassemble the inactivated waste lithium batteries, collect the positive electrode materials and place them in an oven for drying; (3) Soaking the positive electrode material in an alkaline solution for 12 to 24 hours, filtering to obtain an active solid powder; continuing to soak the active solid powder in an acidic solution for 12 to 24 hours, filtering to obtain a leachate containing valuable metal ions; (4) Add coal gangue particles to the leaching solution, stir thoroughly for 5 to 15 hours, and filter to obtain the coal gangue adsorption carrier loaded with valuable metal ions; (5) Soak the gangue adsorption carrier in a mixture of nitric acid and hydrogen peroxide to obtain a desorption solution rich in valuable metal ions, and test its content.

2. The method for recovering valuable metals from waste lithium batteries using coal gangue according to claim 1, characterized in that: The coal gangue is produced in Shanxi or Xinjiang.

3. The method for recovering valuable metals from waste lithium batteries using coal gangue according to claim 1, characterized in that: The waste lithium batteries are 18650 type ternary lithium waste batteries produced by Yiwei Lithium Energy.

4. The method for recovering valuable metals from waste lithium batteries using coal gangue according to claim 1, characterized in that: The method of discharge treatment is: place the used battery in a 2~5% NaCl aqueous solution and discharge it for 24 hours or short-circuit discharge it until it is out of power.

5. The method for recovering valuable metals from waste lithium batteries using coal gangue according to claim 1, characterized in that: The alkaline solution is any one of sodium hydroxide, potassium hydroxide, barium hydroxide and calcium hydroxide.

6. The method for recovering valuable metals from waste lithium batteries using coal gangue according to claim 1, characterized in that: The immersion temperature in the alkaline washing solution is 50-70°C and the pH is 8-11.

7. The method for recovering valuable metals from waste lithium batteries using coal gangue according to claim 1, characterized in that: The acidic solution is any one of nitric acid, sulfuric acid, hydrochloric acid and glacial acetic acid.

8. The method for recovering valuable metals from waste lithium batteries using coal gangue according to claim 1, characterized in that: The immersion temperature in the acidic solution is 50-70° C., and the pH is 2-6.

9. The method for recovering valuable metals from waste lithium batteries using coal gangue according to claim 1, characterized in that: The mass ratio of the positive electrode material to the coal gangue particles is 1:3-8.

10. The method for recovering valuable metals from waste lithium batteries using coal gangue according to claim 1, characterized in that: The volume fraction of the hydrogen peroxide to the nitric acid is 10-15%.

Images