CN106299526A - Recycling method of strong alkali solution in waste lithium battery recycling industry - Google Patents

Abstract

The invention relates to a method for recycling strong alkali solution in the waste lithium battery recycling industry. The invention belongs to the technical field of recycling waste lithium ion batteries. Recycling and utilization methods of strong alkaline solutions in the waste lithium battery recycling industry: (1) Separation of aluminum-containing materials: mechanically crush the waste lithium batteries, add water for stirring, slurry is screened, and the material on the screen is aluminum-containing materials; (2) Dissolution of aluminum: Add aluminum-containing materials to 3-25mol/L sodium hydroxide solution, stir the reaction and pass through a sieve. The filtrate is an aluminum-containing strong alkali solution; (3) Adjustment of the ion ratio of the aluminum strong alkali solution: add sodium hydroxide Or water to adjust the sodium ion concentration in the solution to 6-25mol/L and the aluminum ion concentration to 0.001-1mol/L; (4) Utilization of aluminum-containing strong alkali solution: the obtained strong alkali solution is used as a precipitant and reacts with the target salt solution. Precursors of lithium iron phosphate and ternary material cathode materials are prepared, and then lithium iron phosphate and ternary material target cathode materials are prepared. The invention has the advantages of simple process, convenient operation, green, environmental protection, low cost, high added value and so on.

Description

A kind of recycling method of strong alkali solution in waste lithium battery recycling industry

technical field

The invention belongs to the technical field of waste lithium ion battery recycling, in particular to a method for recycling strong alkali solution in the waste lithium battery recycling industry.

Background technique

At present, with the rapid growth of the electric vehicle industry, by 2020, the cumulative scrap of electric vehicle power batteries in my country alone will reach a scale of 120,000-170,000 tons. If it cannot be properly recycled, it will cause huge damage to the environment.

Patent CN101921917B discloses a method for recovering valuable metals from waste lithium batteries. In this method, the discharged waste lithium battery is mechanically crushed, calcined at a high temperature of 350°C to 400°C to obtain a material containing cobalt, aluminum, and copper, and then a sodium hydroxide solution with a content of 5% to 10% is added to react for 2-3 hours. The lye is filtered, washed, and dried to obtain materials containing cobalt and copper. The lye contains a large amount of aluminum, and aluminum hydroxide crystals are obtained through further acid treatment, filtration and washing. The aluminum foil recycling method in this patent is currently the main recycling method for aluminum foil in the lithium ion battery recycling industry. Patents CN101217206A, CN104157926A, etc. use the same method to achieve the purpose of recycling aluminum foil. In this method, a large amount of sulfuric acid needs to be added during the acid treatment to neutralize the alkali in the lye, so as to adjust the pH value and realize the purpose of aluminum hydroxide precipitation. At this time, the filtrate contains a large amount of sodium sulfate and cannot be recycled, and the waste liquid generated needs to be treated to avoid secondary pollution to the environment. The amount of waste water to be treated is large, and a large amount of sulfuric acid is consumed during acid treatment, resulting in high cost.

Patent CN102285738B discloses a treatment method for high-salt wastewater in the waste lithium battery recycling industry. This method obtains purified water and concentrated water through reverse osmosis technology, and the concentrated water obtains salt products through natural evaporation or low-temperature crystallization or multi-stage flash evaporation. The cost of the reverse osmosis membrane used is high, the treatment efficiency is limited, and there are technical problems such as high energy consumption or extremely long treatment time in the later salt crystallization process.

Contents of the invention

In order to solve the technical problems existing in the known technology, the invention provides a method for recycling strong alkali solution in the waste lithium battery recycling industry.

The purpose of the present invention is to provide a production process with simple process and convenient operation, which can be used in the production process of precursors such as lithium iron phosphate and ternary materials, which are green, environmentally friendly, low-cost, and high-efficiency. The recycling method of the strong alkali solution in the waste lithium battery recycling industry with the characteristics of added value and so on.

The recycling method of the strong alkali solution in the waste lithium battery recycling industry of the present invention comprises a process:

⑴Separation of aluminum-containing materials: mechanically crush the fully discharged waste lithium batteries, add water for stirring to accelerate the separation of the electrode material and the current collector; pass the stirred slurry through a 60-mesh sieve, and the sieve is aluminum-containing materials;

(2) Dissolution of aluminum: Add the aluminum-containing material obtained in (1) into a 3-25mol/L sodium hydroxide solution, stir and react for 1-2 hours, then pass the slurry through a sieve, and add the filter residue to a sodium hydroxide solution of the same concentration In the same process, filter after secondary alkali leaching, the filter residue is subjected to subsequent treatment, the filtrate is merged into the first filtrate, and the filtrate is a strong alkali solution containing aluminum after repeated filtration to remove residue;

(3) Adjustment of the ion ratio of the aluminum-containing strong alkali solution: use an inductively coupled plasma emission spectrometer (ICP) to test the concentration of sodium ions and aluminum ions in (2), and add sodium hydroxide or water to adjust the concentration of the solution according to the target product composition. The sodium ion concentration is 6-25mol/L, and the aluminum ion concentration is 0.001-1mol/L;

(4) Recycling of aluminum-containing strong alkali solution: use the strong alkali solution obtained in (3) as a precipitating agent, carry out liquid phase precipitation reaction with the target salt solution, and prepare precursors of positive electrode materials such as lithium iron phosphate and ternary materials, Then, target positive electrode materials such as lithium iron phosphate and ternary materials are produced.

The technical scheme adopted by the recycling method of the strong alkali solution in the waste lithium battery recycling industry of the present invention is:

A method for recycling a strong alkali solution in the waste lithium battery recycling industry is characterized in that: the method for recycling a strong alkali solution in the waste lithium battery recycling industry includes the following process:

(1) Separation of aluminum-containing materials

The fully discharged waste lithium battery is mechanically crushed, and water is added for stirring to accelerate the separation of the electrode material and the current collector; the stirred slurry is passed through a sieve, and the material on the sieve is the aluminum-containing material;

(2) Dissolution of aluminum

Add the aluminum-containing material obtained in (1) to a 3-25mol/L sodium hydroxide solution, stir and react for 1-2h, and then pass the slurry through a 60-mesh sieve, and the filtrate is a strong alkali solution containing aluminum;

(3) Adjustment of ion ratio of aluminum strong alkali solution

According to the target product composition, add sodium hydroxide or water to adjust the sodium ion concentration in the solution to 6-25mol/L, and the aluminum ion concentration to 0.001-1mol/L;

(4) Utilization of aluminum-containing strong alkali solution

Using the strong base solution obtained in (3) as a precipitating agent, carry out a liquid phase precipitation reaction with the target salt solution to prepare the precursor of lithium iron phosphate and ternary material positive electrode materials, and then prepare lithium iron phosphate and ternary material target positive electrode materials finished product.

The recycling method of the strong alkali solution in the waste lithium battery recycling industry of the present invention can also adopt the following technical scheme:

The method for recycling the strong alkali solution in the waste lithium battery recycling industry is characterized in that during the dissolving process of aluminum, the aluminum-containing material obtained in (1) is added to a 3-25mol/L sodium hydroxide solution and stirred for reaction After 1-2 hours, after the slurry passes through the sieve, the filter residue is added to the sodium hydroxide solution of the same concentration, and the same process is carried out for the second alkali leaching and then filtered, and the filter residue is subjected to subsequent treatment, and the filtrate is incorporated into the first filtrate, and the filtrate is passed through After 2-6 times of filtering to remove slag, it is an aluminum-containing strong alkali solution.

The method for recycling the strong alkali solution in the waste lithium battery recycling industry is characterized in that: in the process of adjusting the ion ratio of the aluminum strong alkali solution, the sodium ion, The concentration of aluminum ions is tested, and then sodium hydroxide or water is added according to the target product composition to adjust the concentration of sodium ions in the solution.

The method for recycling the strong alkali solution in the waste lithium battery recycling industry is characterized in that during the utilization of the aluminum-containing strong alkali solution, the ternary materials include nickel-cobalt-manganese-lithium oxide, nickel-cobalt-aluminum-lithium oxide and corresponding doped modified material.

The method for recycling strong alkali solution in the waste lithium battery recycling industry is characterized in that: the precursor of lithium iron phosphate includes iron phosphate and corresponding doping components, and the precursor of ternary materials includes nickel hydroxide cobalt manganese or Nickel cobalt aluminum hydroxide and corresponding doping components.

The method for recycling the strong alkali solution in the waste lithium battery recycling industry is characterized in that: when ferric phosphate is prepared, the salt solution includes iron-containing solution, phosphorus-containing solution or a mixed solution of the two; when the ternary material is prepared, the salt solution includes Nickel solution, cobalt-containing solution, manganese-containing solution or any mixed solution of several kinds.

The advantages and positive effects that the present invention has are:

The recycling method of the strong alkali solution in the waste lithium battery recycling industry has adopted the brand-new technical solution of the present invention. Compared with the prior art, the present invention has the following characteristics:

(1) The process is simple: the aluminum foil in the waste lithium battery can be used as a new production raw material after being dissolved in an alkaline solution, without the subsequent processes of precipitation, washing, separation and reproduction in the prior art, which simplifies the entire recycling process;

(2) Environmental protection: no need to add a large amount of sulfuric acid for acid treatment, avoiding the generation of a large number of by-products and waste water, which not only reduces the cost of recycling strong alkali solution but also avoids secondary pollution caused by by-products;

(3) High added value: The recovered strong alkali solution is used in the preparation process of the precursor of the cathode material of lithium-ion batteries, which not only saves the investment in the recovery of lye in the existing recovery technology, but also saves the hydrogen required for the preparation of the precursor The cost of sodium oxide and aluminum salt increases the added value of the entire recycling process.

Description of drawings

Fig. 1 is the process figure of strong alkali solution recycling of the present invention;

Fig. 2 is the SEM image of the ternary material precursor obtained in Example 1 (Ni _1/3 Co _1/3 Mn _1/3 (OH) ₂ , containing Al 1200ppm);

Fig. 3 is the SEM image of the precursor of the ternary material obtained in Example 2 (Ni _0.5 Co _0.2 Mn _0.3 (OH) ₂ , containing 1500 ppm of Al);

Fig. 4 is the SEM image of the precursor of the ternary material of Example 3 (Ni _0.6 Co _0.2 Mn _0.2 (OH) ₂ , containing Al 2000ppm);

Fig. 5 is an SEM image of the precursor of the ternary material of Example 4 (Ni _0.8 Co _0.15 Al _0.05 (OH) ₂ ).

detailed description

In order to further understand the invention content, characteristics and effects of the present invention, the following examples are given, and detailed descriptions are as follows in conjunction with the accompanying drawings:

Refer to accompanying drawing 1 to Fig. 5.

Example 1

A method for recycling a strong alkali solution in the waste lithium battery recycling industry, comprising the following process:

1. Separation of aluminum-containing materials: Mechanically crush the fully discharged waste lithium batteries, add water for stirring to accelerate the separation of the electrode material and the current collector; pass the stirred slurry through a 60-mesh sieve, and the sieve is the containing aluminum material;

2. Dissolution of aluminum: Add the aluminum-containing material obtained in (1) into a 12mol/L sodium hydroxide solution, stir and react for 2 hours, then pass the slurry through a 60-mesh sieve, and add the filter residue into a sodium hydroxide solution of the same concentration , the same process is filtered after secondary alkali leaching, the filter residue is subjected to subsequent treatment, the filtrate is incorporated into the first filtrate, and the filtrate is a strong alkali solution containing aluminum after repeated filtration to remove residue;

3. Adjustment of the ion ratio of the aluminum-containing strong alkali solution: the lye obtained in (2) is tested with an inductively coupled plasma emission spectrometer (ICP), and the sodium ion concentration is 11.5mol/L, and the aluminum ion concentration is 0.1mol/L , according to the target product composition, add sodium hydroxide and water to adjust the sodium ion concentration in the solution to 6mol/L, and the aluminum ion concentration to 0.01mol/L;

4. Recycling of aluminum-containing strong alkali solution: with the strong alkali solution obtained in (3) as a precipitant, the concentration of nickel ions is 0.8mol/L, the concentration of cobalt ions is 0.8mol/L, and the concentration of manganese ions is 0.8mol/L The mixed salt solution was subjected to liquid-phase precipitation reaction to obtain the precursor of the 111-type ternary material.

Example 2

A method for recycling a strong alkali solution in the waste lithium battery recycling industry, comprising the following process:

1. Separation of aluminum-containing materials: Mechanically crush the fully discharged waste lithium batteries, add water for stirring to accelerate the separation of the electrode material and the current collector; pass the stirred slurry through a 60-mesh sieve, and the sieve is the containing aluminum material;

2. Dissolution of aluminum: Add the aluminum-containing material obtained in (1) to a 16mol/L sodium hydroxide solution, stir and react for 1.5 hours, and then pass the slurry through a 60-mesh sieve, and add the filter residue to a sodium hydroxide solution of the same concentration In the same process, filter after secondary alkali leaching, the filter residue is subjected to subsequent treatment, the filtrate is merged into the first filtrate, and the filtrate is a strong alkali solution containing aluminum after repeated filtration to remove residue;

3. The adjustment of the ion ratio of aluminum-containing strong alkali solution: test the lye obtained in (2) with an inductively coupled plasma emission spectrometer (ICP), the sodium ion concentration is 15mol/L, and the aluminum ion concentration is 0.2mol/L. According to the target product composition, add sodium hydroxide and water to adjust the sodium ion concentration in the solution to be 8mol/L, and the aluminum ion concentration to be 0.02mol/L;

4. Recycling of aluminum-containing strong alkali solution: with the strong alkali solution obtained in (3) as a precipitant, the concentration of nickel ions is 1.2mol/L, the concentration of cobalt ions is 0.48mol/L, and the concentration of manganese ions is 0.72mol/L The mixed salt solution was subjected to liquid-phase precipitation reaction to obtain the precursor of the 523-type ternary material.

Example 3

A method for recycling a strong alkali solution in the waste lithium battery recycling industry, comprising the following process:

1. Separation of aluminum-containing materials: Mechanically crush the fully discharged waste lithium batteries, add water for stirring to accelerate the separation of the electrode material and the current collector; pass the stirred slurry through a 60-mesh sieve, and the sieve is the containing aluminum material;

2. Dissolution of aluminum: Add the aluminum-containing material obtained in (1) into a 20mol/L sodium hydroxide solution, stir and react for 1 hour, and then pass the slurry through a 60-mesh sieve, and add the filter residue into a sodium hydroxide solution of the same concentration , the same process is filtered after secondary alkali leaching, the filter residue is subjected to subsequent treatment, the filtrate is incorporated into the first filtrate, and the filtrate is a strong alkali solution containing aluminum after repeated filtration to remove residue;

3. The adjustment of ion ratio of aluminum-containing strong alkali solution: test (2) gained lye with inductively coupled plasma emission spectrometer (ICP), sodium ion concentration is 19mol/L, and aluminum ion concentration is 0.4mol/L, According to the target product composition, add sodium hydroxide and water to adjust the sodium ion concentration in the solution to 10mol/L, and the aluminum ion concentration to 0.04mol/L;

4. Recycling of aluminum-containing strong alkali solution: with (3) gained strong alkali solution as a precipitant, the nickel ion concentration is 1.44mol/L, the cobalt ion concentration is 0.48mol/L, and the manganese ion concentration is 0.48mol/L The mixed salt solution was subjected to liquid-phase precipitation reaction to obtain the precursor of the 622-type ternary material.

Example 4

A method for recycling a strong alkali solution in the waste lithium battery recycling industry, comprising the following process:

1. Separation of aluminum-containing materials: Mechanically crush the fully discharged waste lithium batteries, add water for stirring to accelerate the separation of the electrode material and the current collector; pass the stirred slurry through a 60-mesh sieve, and the sieve is the containing aluminum material;

2. Dissolution of aluminum: Add the aluminum-containing material obtained in (1) into a 24mol/L sodium hydroxide solution, stir and react for 0.5h, and then pass the slurry through a 60-mesh sieve, and add the filter residue to a sodium hydroxide solution of the same concentration In the same process, filter after secondary alkali leaching, the filter residue is subjected to subsequent treatment, the filtrate is merged into the first filtrate, and the filtrate is a strong alkali solution containing aluminum after repeated filtration to remove residue;

3. The adjustment of the ion ratio of aluminum-containing strong alkali solution: test the lye obtained in (2) with an inductively coupled plasma emission spectrometer (ICP), the sodium ion concentration is 22mol/L, and the aluminum ion concentration is 3mol/L, according to Target product composition, adding sodium hydroxide and water to adjust the sodium ion concentration in the solution to 12mol/L, and the aluminum ion concentration to 0.3mol/L;

4. Recycling of aluminum-containing strong alkali solution: with the strong alkali solution obtained in (3) as a precipitant, the concentration of nickel ions is 1.92mol/L, the concentration of cobalt ions is 0.36mol/L, and the concentration of manganese ions is 0.12mol/L The mixed salt solution was subjected to liquid phase precipitation reaction to prepare the NCA type ternary material precursor.

Element content in the precursor obtained by each embodiment of table 1

content(%) Na Al Fe Cu Ca Zn Mg Example 1 0.0224 0.12 0.0037 0.0006 0.0008 0.0009 0.0031 Example 2 0.0213 0.15 0.0046 0.0006 0.0010 0.0005 0.0025 Example 3 0.0221 0.2 0.0036 0.0007 0.0005 0.0006 0.0028 Example 4 0.0245 1.48 0.0048 0.0010 0.0006 0.0014 0.0054

This embodiment has the advantages of simple process and convenient operation, and only needs to fine-tune the ion ratio, which can be used in the production process of precursors such as lithium iron phosphate and ternary materials for lithium ion batteries. It is green, environmentally friendly, low cost, and high added value. and other positive effects.

Claims (6)

1. waste lithium cell reclaims a recoverying and utilizing method for industry strong base solution, it is characterized in that: waste lithium cell reclaims row The recoverying and utilizing method of industry strong base solution includes following technical process:

(1) separation of aluminiferous material

The waste lithium cell discharged completely is carried out Mechanical Crushing, add water be stirred accelerating pole piece material and collector point From；Being sifted out by slurry after stirring, oversize is aluminiferous material；

(2) dissolving of aluminum

In in (1), gained aluminiferous material joins the sodium hydroxide solution of 3-25mol/L, stirring reaction 1-2h disposed slurry sieves Son, filtrate is containing aluminum strong base solution；

(3) adjustment of aluminum strong base solution ion ratio

According to target product composition, adding sodium hydroxide or water adjustment sodium ion in liquor concentration is 6-25mol/L, aluminium ion is dense Degree is 0.001-1mol/L；

(4) utilization containing aluminum strong base solution

With (3) gained strong base solution as precipitant, carry out liquid-phase precipitation reaction with target saline solution, prepare LiFePO4, ternary The precursor of material positive electrode, and then prepared LiFePO4, ternary material target positive electrode finished product.

Waste lithium cell the most according to claim 1 reclaims the recoverying and utilizing method of industry strong base solution, it is characterized in that: aluminum Course of dissolution in, after gained aluminiferous material in (1) is joined in the sodium hydroxide solution of 3-25mol/L stirring reaction 1-2h Slurry by, after sieve, joining in the sodium hydroxide solution of same concentration by filtering residue, and same technique carries out mistake after secondary alkali leaching Filter, filtering residue carries out subsequent treatment, and filtrate is incorporated in first time filtrate, and it is molten that filtrate is the highly basic containing aluminum after 2-6 filter cleaner Liquid.

Waste lithium cell the most according to claim 1 reclaims the recoverying and utilizing method of industry strong base solution, it is characterized in that: aluminum During the adjustment of strong base solution ion ratio, with inductive coupling plasma emission spectrograph (ICP) to sodium ion in (2), Aluminium ion concentration is tested, and then adds sodium hydroxide according to target product composition or water adjusts sodium ion in liquor concentration.

4. the recoverying and utilizing method of industry strong base solution, its feature is reclaimed according to the waste lithium cell described in claim 1,2 or 3 It is: during the utilization containing aluminum strong base solution that ternary material includes cobalt nickel oxide manganses lithium, cobalt nickel oxide aluminum lithium and mixes accordingly Miscellaneous material modified.

5. the recoverying and utilizing method of industry strong base solution, its feature is reclaimed according to the waste lithium cell described in claim 1,2 or 3 It is: the precursor of LiFePO4 includes iron phosphate and corresponding doping component, and the precursor of ternary material includes hydroxide nickel cobalt Manganese or nickel cobalt aluminum hydroxide and corresponding doping component.

6. the recoverying and utilizing method of industry strong base solution, its feature is reclaimed according to the waste lithium cell described in claim 1,2 or 3 It is: time prepared by iron phosphate, saline solution includes iron-containing liquor, solution containing phosphate or the mixed solution of the two；Time prepared by ternary material, salt is molten Liquid includes solution containing nickel, cobalt-carrying solution, manganese containing solution or the most several mixed solutions.