CN116216797A - A method for dismantling black powder and positive electrode powder from waste lithium batteries to prepare positive electrode materials for lithium ion batteries - Google Patents

Abstract

The invention discloses a method for preparing lithium ion battery anode material by reclaiming waste lithium power dismantling black powder and anode powder, which belongs to the field of comprehensive reclaiming of lithium ion batteries, wherein raw materials to be reclaimed are placed into a container, acid leaching is carried out on the raw materials, filtering is carried out on the raw materials after reaction, iron and aluminum removal and calcium and magnesium removal are carried out on filter residues, the processed raw materials are sequentially subjected to ultrafiltration, defluorination and ratio adjustment, after the raw materials are subjected to the processing, the raw materials are put into mixed alkali liquid of sodium hydroxide and ammonium hydroxide, protective gas is introduced, meanwhile, mixed sulfuric acid solution of nickel, cobalt and manganese, mixed alkali liquid of sodium hydroxide and ammonium hydroxide are added, EDTA is added, the pH value is controlled to carry out a primary sedimentation process, after the primary sedimentation reaction is finished, a primary sedimentation reaction solution is sent into a reaction container, protective gas is introduced and stirred, saturated ammonium bicarbonate solution is then added, filter residues are obtained after the reaction is finished, and finally the filter residues are washed, dried, calcined and finely ground and washed.

Description

A kind of waste lithium battery dismantling black powder and positive electrode powder recycling to prepare lithium ion battery positive electrode material method of feeding

technical field

The invention relates to the field of comprehensive recovery of lithium-ion batteries, in particular to a method for dismantling black powder from waste lithium batteries and recycling positive-electrode powder to prepare lithium-ion battery positive-electrode materials.

Background technique

The black powder of waste lithium battery dismantling is the product of lithium ion battery dismantling process, black solid powder, which is mainly a mixture of lithium battery positive electrode (such as nickel cobalt lithium manganese oxide), negative electrode (such as graphite) and a small amount of aluminum powder and copper powder . Lithium battery waste positive electrode powder is the solid powder broken into the positive electrode materials and substandard products scrapped by the lithium battery positive electrode material factory, scrap products, scraps, pole pieces, etc. produced by the battery factory, mainly a mixture of nickel cobalt lithium manganese oxide and a small amount of aluminum powder. Lithium-ion battery cathode material is generally nickel-cobalt-manganese lithium manganese oxide, which is calcined by nickel-cobalt-manganese mixed hydroxide (commonly known as ternary precursor) and lithium salt, black powder disassembled from waste lithium batteries and waste lithium battery cathode powder Contains a large amount of heavy metals, among which heavy metals have adverse effects on the environment; at the same time, the waste lithium battery dismantling black powder and the lithium battery waste positive electrode powder contain metals such as nickel, cobalt, manganese, lithium, etc., which have great recycling value; the waste lithium battery dismantling black powder Cobalt, nickel, manganese, and lithium in waste lithium battery cathode powder and lithium battery waste cathode powder are important strategic metals, which need to be imported in large quantities. Recycling is an important source supplement. Therefore, it is necessary to disassemble the waste lithium battery black powder and lithium battery waste cathode powder. Recycle.

The ternary precursor is a co-precipitation produced under the control of nickel, cobalt, manganese sulfate and alkali under certain conditions. It is a mixed hydroxide; lithium salt is generally lithium carbonate or lithium hydroxide, and lithium salt mainly comes from ore refining and containing Recycling of crude lithium products and waste. At present, the positive electrode materials of lithium-ion batteries must go through the above two processes, and then mix the ternary precursor and lithium salt in a certain proportion and then calcined.

In the patent "A Short-process Resource Recycling Method for Ternary Cathode Materials of Waste Lithium-ion Batteries" with the application number 2022110511099, the recycled waste lithium-ion battery ternary cathode materials are used as raw materials, and the raw materials are subjected to chemical oxidation treatment and chemical vulcanization After processing, the vulcanized ternary composite oxide is added with appropriate amount of functional additives to prepare the positive electrode of the alkaline secondary battery and assemble it into the alkaline secondary battery. The raw materials of this patent have great limitations, and are not suitable for raw materials containing carbon powder, copper, aluminum, etc., and the application of the prepared alkaline secondary battery positive electrode is very limited, and it is not suitable for most lithium ion batteries. This patent has strong applicability to raw materials, and the scope of application includes dismantling black powder of waste lithium batteries and waste positive electrode powder of lithium batteries.

In the patent "A Method for Recovering Cobalt, Nickel and Manganese from Waste Lithium Batteries" with the application number 2021113864929, the waste lithium batteries are discharged and then disassembled to obtain positive electrode materials, which are then mixed with iron sulfate in a certain proportion and roasted. Leach with deionized water and filter to obtain nickel-cobalt-manganese-lithium mixed solution. Due to the addition of a large amount of iron sulfate in this patent, a large amount of iron-containing slag will be produced after leaching, and the treatment is difficult. The resulting mixture is high in impurities and requires further processing of several metals. The amount of slag produced by adding materials in this patent is less, and the prepared product is a ternary positive electrode material that can be directly used for ternary lithium batteries.

In the patent "A Method for Recovering Valuable Metals from Waste Lithium-ion Batteries" with application number 2012100048069, a kind of recovery of valuable metals from waste lithium-ion batteries is nickel, cobalt, manganese, copper, and iron. . The method uses waste lithium-ion batteries as raw materials, and recovers nickel-cobalt-manganese-copper-iron and other valuable metals through steps such as drying, sieving, magnetic separation, leaching, impurity removal, and crystallization. The final product of this patent is a mixture of one or more sulfates, and the recovery capacity of lithium in the raw material is not enough. In this patent, nickel, cobalt, manganese and lithium as raw materials are all recovered and recycled, and the prepared product is a ternary positive electrode material that can be directly used for ternary lithium batteries.

In the patent "A Treatment Method for Recycling Waste Lithium-ion Batteries" with the application number of 2021104607475, the waste lithium-ion batteries are discharged, disassembled, and sorted to obtain positive and negative electrode mixed powder. Roasting the mixed powder of the positive and negative electrodes to obtain a roasted product, adding water to the roasted product, adding sulfuric acid for leaching reaction, and separating the leaching liquid and leaching residue; removing impurities from the leaching liquid to obtain a decontamination liquid; decontamination liquid Add sulfuric acid and ammonium sulfate to react, evaporate and crystallize, and separate to obtain nickel-cobalt-manganese-ammonium sulfate mixed salt and mixed solution; nickel-cobalt-manganese-ammonium sulfate mixed salt is thermally decomposed to obtain nickel-cobalt-manganese sulfate mixed salt; Ammonium hydrogen and ammonia water carry out precipitation reaction, separate and obtain lithium carbonate and heavy lithium mother liquor. This patent only recycles nickel, cobalt, manganese and lithium in raw materials into crude products respectively. In this patent, nickel-cobalt-manganese-lithium is comprehensively recovered and processed. Adding materials in the process does not increase impurity elements. The prepared product is a ternary positive electrode material that can be directly used for ternary lithium batteries.

It can be seen from the above that in the traditional method of obtaining lithium-ion battery cathode materials, the procedures and processes are relatively long, and the risk of process loss and pollution is high. In particular, the amount of scrapped lithium-ion batteries is increasing at present, and it is basically necessary to go through the above-mentioned complicated process to obtain the positive electrode materials required by lithium-ion batteries. This patent is to directly restore the dismantled black powder of waste lithium batteries and the waste positive electrode powder of lithium batteries to produce positive electrode materials of lithium ion batteries.

Contents of the invention

In view of the above technical problems, the present invention discloses a method for dismantling black powder and positive electrode powder of waste lithium batteries to recycle and prepare positive electrode materials for lithium ion batteries, including the following steps:

S1: First fill the reaction container with the prepared acid solution, put the raw materials to be recovered into the reaction container, then raise the temperature of the reaction container to T1, and then carry out the reaction. The reaction time is t1. After the reaction, the reduction The reagent is put into the reaction container for reaction, and the reaction time is t2. After the reaction, the pH value of the solution is adjusted to a.

S2: After the reaction, the raw materials are filtered, and then the filter residue is treated to remove iron, aluminum and calcium and magnesium.

S3: The processed raw materials are subjected to ultrafiltration, fluorine removal and ratio adjustment in sequence.

S4: Put the treated raw materials into the mixed lye of sodium hydroxide and ammonium hydroxide, and pass through the protective gas, stir at the same time and add the mixed solution of nickel-cobalt-manganese-sulfuric acid, sodium hydroxide and hydroxide Ammonia is mixed with lye and EDTA, and the pH value is controlled to 11~12, and the temperature is controlled at 25-45°C during the reaction.

S5: After the above reaction is completed, send the reaction solution into the reaction container, pass through the protective gas and stir the reaction solution, then raise the temperature of the reaction container to T2, and the stirring time is t3, then add saturated ammonium bicarbonate solution and continue Introduce protective gas, and stir during this process, and the stirring time is t4.

S6: After the reaction is completed, the filter residue is obtained, and finally the filter residue is washed and dried, calcined, and finely ground and washed.

Further, the acid solution in S1 is a dilute sulfuric acid solution with a concentration of 2-3 mol/L, the mass ratio of the dilute sulfuric acid solution to the raw material is 0.15-0.35:1, and the T1 is 75°C-95°C, The t1 is 120-140 minutes, the t2 is 60-120 minutes, the a is 1.0-1.5, and the reducing agent is ferrous sulfide.

Further, the process of removing iron and aluminum in the described S2 comprises the following steps:

S31: After leaching the filtrate, add it into the reactor, raise the temperature of the reaction vessel to 75° C., and then add hydrogen peroxide. The amount of hydrogen peroxide added is 10-20 kg per cubic volume.

S32: After adding hydrogen peroxide, react for 30-60 minutes, then add nickel carbonate to adjust the pH value to 2.0-2.5, and then add manganese powder.

S33: The mass ratio of the amount of manganese powder added to the copper content in the solution is 1:1.1-1.8, continue to react for 60-90 minutes after adding the manganese powder, and filter after the reaction to obtain filtrate and filter residue.

Further, the decalcification and magnesium process in the described S2 comprises the following steps:

S41: Add the filtrate after removing iron and aluminum into the reactor for removing calcium and magnesium, and raise the temperature to 90°C.

S42: The content of calcium and magnesium in the solution can be analyzed and detected by an atomic absorption instrument. According to the amount of calcium and magnesium, 10 to 15 times the theoretical amount of lithium fluoride is added. The lithium fluoride is in a slurry colloidal state, and the reaction is 240 to After 360 minutes, the reaction was completed and filtered to obtain calcium-magnesium slag and filtrate.

Further, the ultrafiltration process in the described S3 comprises the following steps:

S51: Filtrate the filtrate treated by removing calcium, magnesium and iron and aluminum through a microporous membrane filter for two times, and the filter pore size of the first microporous membrane filter is selected to be 0.5 μm.

S52: The filtrate after calcium and magnesium removal and iron and aluminum removal contains ultrafine and suspended particles, including silicate, calcium fluoride, and magnesium fluoride, and the second microporous membrane filter has a filter pore size The selection is 0.1μm, the purpose is to filter the ultrafine and suspended particles in the solution.

Further, the fluoride removal process in S3 is as follows: the ultrafiltered solution is treated with a special resin for fluoride removal, and the concentration of fluoride ions in the solution is controlled within a range of 0.3-1 mg/L.

Further, the adjustment process in the described S3 comprises the following steps:

S71: The pre-precipitation ratio is based on the various specifications and models of the ternary cathode material to adjust the combined amount of nickel, cobalt and manganese in the solution. The total molar concentration of nickel, cobalt and manganese is 1.5-2.4mol/L.

S72: Add complexing agent EDTA in an amount of 0.1-0.2 g/L. The adjustment ratio before calcination is to adjust the ratio of nickel-cobalt-manganese to lithium, and adjust the ratio of lithium to 1.05-1.2 of the theoretical amount according to the content of nickel-cobalt-manganese.

Further, the concentration of sodium hydroxide in S4 is: 25%-27%, the concentration of ammonia water is: 5-7mol/L, and the volume ratio of sodium hydroxide to ammonia water is (4-6): 1, protecting The rate of gas feeding is 3-5m ³ /h, and the amount of EDTA added is 100-200g/m ³ . The total flow rate of each liquid added is 1/10-1/20 of the volume of the reactor.

Further, in the S5, the T2 is 75-90°C, the input rate of the protective gas is 3-5m ³ /h, the t3 is 30-60 minutes, and the saturated bicarbonate The amount of ammonium solution to be added is 1.1 to 1.4 times the theoretical value of lithium ion precipitation, and the flow rate is: reactor empty volume/(2 to 3) hours. After the addition of ammonium bicarbonate is completed, the flow rate of the protective gas remains unchanged. The t4 is 60-90 minutes. Filtrate and filter residue can be obtained by filtering after the reaction is completed, and the filter residue is a mixture of nickel-cobalt-manganese co-precipitated hydroxide and lithium carbonate.

Further, the washing and drying in S6 needs to control the moisture content in the reactants within 1-2%.

In said S6, the dried mixture is adjusted and reacted in a calciner at 600-700° C. for 120-240 minutes, and then reacted at 800-1000° C. for 120-240 minutes.

The calcined material in S6 is wet finely ground, the liquid-solid ratio of the finely ground is (3-5): 1, and the finely ground particle size is 100% over 400 mesh. After finely grinding, the slurry is filtered and then press The mass-liquid-solid ratio is (3-5):1, washed once, filtered and dried to obtain the ternary positive electrode material.

The beneficial effects of the present invention compared with the prior art are: (1) The method adopts ferrous sulfide as a reducing agent, fully utilizes it to react with sulfuric acid to generate reducing substances, plays a reducing role at the same time, and can also achieve the purpose of controlling acidity (2) This method uses slurry colloidal lithium fluoride as a calcium and magnesium remover, which can remove calcium and magnesium ions on the one hand, and can also reduce free fluorine ions in the solution; (3) use nickel carbonate and manganese powder to remove Impurity agent, which can remove copper, iron, cadmium, aluminum and other impurities at one time; (4) Adopt two-stage precipitation reaction to realize mixed precipitation of nickel, cobalt, manganese and lithium, shorten the process flow and reduce the process; (4) Precipitation process Oxygen barrier atmosphere control is adopted, and the complexation and dispersion of ammonia ions are fully utilized to achieve synergistic effect under the condition of adding a complexing agent, which effectively inhibits the oxidation of cobalt and manganese during the precipitation process, thereby affecting co-precipitation.

Description of drawings

Figure 1 is a schematic diagram of the overall structure of the present invention.

Fig. 2 is a table of analysis results of ternary cathode materials in Example 1 of the present invention.

Fig. 3 is a table of analysis results of ternary cathode materials in Example 2 of the present invention.

Fig. 4 is a table of analysis results of ternary cathode materials in Example 3 of the present invention.

Fig. 5 is a table of analysis results of ternary cathode materials in Example 4 of the present invention.

Implementation

The technical solutions of the present invention will be further described below in conjunction with specific embodiments.

Example 1

This case is the recovery of black powder from lithium battery dismantling to prepare NCM523 lithium ion battery cathode material.

Add 350kg of concentrated sulfuric acid into the reactor to prepare a 2.3mol/L dilute sulfuric acid solution. Then put in a lithium battery to disassemble 1000kg of black powder, raise the temperature to 85°C, and react for 180 minutes. After the reaction was completed, 40 kg of ferrous sulfide was added, and the reaction was continued for 90 minutes, and the terminal pH value was 1.3. After the reaction is completed, filter to obtain a filtrate and a filter residue.

Take 2000L of the above-mentioned filtrate and add it into the reactor, after raising the temperature to 75°C, add 40kg of hydrogen peroxide, and react for 45 minutes. First add nickel carbonate to adjust the pH value to 2.2, then add 15.2 kg of manganese powder (the filtrate contains 5.12 g/L copper), and continue the reaction for 75 minutes. Filtration to obtain filtrate and filter residue.

Take 2000L of the above-mentioned filtrate and add it to the reactor, heat up to 90°C, add 23.7kg of lithium fluoride (the filtrate detects calcium 0.63g/L, magnesium 0.27g/L), react for 300 minutes and filter to obtain the filter residue and filtrate. After the filtrate is ultra-filtered twice, it is defluorinated by a special resin for defluorination, and the solution contains 0.67mg/L of fluorine.

Take the defluoridated solution, add cobalt sulfate, nickel sulfate, and manganese sulfate to adjust the total concentration to 2mol/L, and the contents of nickel, cobalt, and manganese in the solution are: 58.71g/L, 23.49g/L, and 32.82g/L, respectively. Add EDTA at the same time, the addition amount is 0.2g/L.

Prepare sodium hydroxide and ammonium hydroxide mixed lye, the concentration of liquid alkali is 27%, the concentration of ammonia water is 7mol/L, and the volume ratio of alkali and ammonia is 5:1. Nitrogen gas is introduced into the reactor at a flow rate of 5m ³ /h. After starting the stirring, control the temperature to 27°C, and at the same time add a well-adjusted nickel-cobalt-manganese mixed sulfuric acid solution, sodium hydroxide and ammonium hydroxide mixed lye, and EDTA. The pH value is controlled to be 11.2, and the addition amount of EDTA is 200g/m ³ . The total flow rate of each liquid added is 134L/hour, and the effective volume of the reactor is 2000L. When the reactor volume is full, keep feeding, and the reaction slurry overflows into the double sedimentation reactor. In the secondary settling reactor, the protective gas nitrogen is introduced at a flow rate of 5m ³ /h. Raise the temperature to 80°C, stir for 45 minutes, then add saturated ammonium bicarbonate solution, the amount added is 1.4 times the theoretical value of lithium ion precipitation, the flow rate of addition is 800L/hour, and the effective volume of the reactor is 2000L. After the addition of ammonium bicarbonate was completed, the protective gas flow rate was kept constant and the reaction was stirred for another 60 minutes. After the reaction is completed, the filtrate and the filter residue can be obtained by filtering, and the filter residue is a mixture of nickel-cobalt-manganese co-precipitated hydroxide and lithium carbonate.

The secondary precipitation filter residue was washed with pure water and then dried, with a water content of 1.07%. According to the amount of nickel, cobalt and manganese, adjust the ratio of lithium to 1.1 of the theoretical amount, then react in the calciner at 670°C for 240 minutes, and then react at 900°C for 240 minutes. The calcined material is wet finely ground with a liquid-solid ratio of 3:1 and a particle size of 100% over 400 mesh. After fine grinding, the slurry is filtered and then washed once according to the mass-liquid-solid ratio of 3:1. After filtering, it is dried to obtain the ternary positive electrode material.

Example 2

In this case, lithium batteries were dismantled and black powder was recovered to prepare NCM622 lithium-ion battery cathode materials.

Add 350 kg of concentrated sulfuric acid into the reactor to prepare a 2.0 mol/L dilute sulfuric acid solution. Then put in a lithium battery to disassemble 1000kg of black powder, heat up to 85°C, and react for 120 minutes. After the reaction was completed, 50 kg of ferrous sulfide was added, and the reaction was continued for 120 minutes, and the terminal pH value was 1.2. After the reaction is completed, filter to obtain a filtrate and a filter residue.

Take 2000L of the above-mentioned filtrate and add it into the reactor, after raising the temperature to 75°C, add 35kg of hydrogen peroxide, and react for 60 minutes. First add nickel carbonate to adjust the pH value to 2.5, then add 13.5 kg of manganese powder (the filtrate contains 3.85 g/L copper), and continue the reaction for 90 minutes. Filtration to obtain filtrate and filter residue.

Take 2000L of the above-mentioned filtrate into the reactor, heat up to 90°C, add 16.5kg of lithium fluoride (the filtrate detects calcium 0.44g/L, magnesium 0.13g/L), react for 360 minutes and then filter to obtain the filter residue and filtrate. After the filtrate is ultra-filtered twice, it is defluorinated by a special resin for defluorination, and the solution contains 0.38mg/L of fluorine.

Take the defluoridated solution, add cobalt sulfate, nickel sulfate, and manganese sulfate to adjust the total concentration to 1.5mol/L. The contents of nickel, cobalt, and manganese in the solution are: 53.07g/L, 17.55g/L, and 16.61g/L, respectively. Add EDTA at the same time, the addition amount is 0.15g/L.

Prepare sodium hydroxide and ammonium hydroxide mixed lye, the concentration of liquid alkali is 25%, the concentration of ammonia water is 7mol/L, and the volume ratio of alkali and ammonia is 6:1. Nitrogen gas is introduced into the reactor at a flow rate of 5m ³ /h. After starting the stirring, control the temperature to 27°C, and at the same time add a well-adjusted nickel-cobalt-manganese mixed sulfuric acid solution, sodium hydroxide and ammonium hydroxide mixed lye, and EDTA. The pH value is controlled to be 11.7, and the addition amount of EDTA is 170g/m ³ . The total flow rate of each liquid added is 117L/hour, and the effective volume of the reactor is 2000L. When the reactor volume is full, keep feeding, and the reaction slurry overflows into the double sedimentation reactor. In the secondary settling reactor, the protective gas nitrogen is introduced at a flow rate of 3m ³ /h. Raise the temperature to 80°C, stir for 45 minutes and then add saturated ammonium bicarbonate solution, the amount added is 1.3 times the theoretical value of lithium ion precipitation, the flow rate of addition is 800L/hour, and the effective volume of the reactor is 2000L. After the addition of ammonium bicarbonate was completed, the protective gas flow rate was kept constant and the reaction was stirred for another 60 minutes. After the reaction is completed, the filtrate and the filter residue can be obtained by filtering, and the filter residue is a mixture of nickel-cobalt-manganese co-precipitated hydroxide and lithium carbonate.

Secondary sedimentation filter residue was washed with pure water and then dried, with a water content of 1.83%. According to the content of nickel, cobalt and manganese, the ratio of lithium is adjusted to be 1.1 of the theoretical amount, and then the reaction is carried out at 630° C. for 240 minutes in the calciner, and then at 1000° C. for 240 minutes. The calcined material is wet finely ground with a liquid-solid ratio of 3:1 and a particle size of 100% over 400 mesh. After fine grinding, the slurry is filtered and then washed once according to the mass-liquid-solid ratio of 3:1. After filtering, it is dried to obtain the ternary positive electrode material.

Example 3

A method for preparing NCM111 type lithium ion battery cathode material by recycling waste cathode powder of lithium batteries.

Add 300 kg of concentrated sulfuric acid into the reactor to prepare a 3.0 mol/L dilute sulfuric acid solution. Then put in a lithium battery to disassemble 1000kg of black powder, heat up to 85°C, and react for 120 minutes. After the reaction was completed, 40 kg of ferrous sulfide was added, and the reaction was continued for 120 minutes, and the terminal pH value was 1.5. After the reaction is completed, filter to obtain a filtrate and a filter residue.

Take 2000L of the above-mentioned filtrate and add it into the reactor, after raising the temperature to 75°C, add 35kg of hydrogen peroxide, and react for 60 minutes. First add nickel carbonate to adjust the pH value to 2.5, then add 15.3 kg of manganese powder (the filtrate contains 4.33 g/L copper), and continue the reaction for 90 minutes. Filtration to obtain filtrate and filter residue.

Take 2000L of the above-mentioned filtrate into the reactor, heat up to 90°C, add 22.8kg of lithium fluoride (the filtrate detects calcium 0.39g/L, magnesium 0.41g/L), react for 360 minutes and then filter to obtain the filter residue and filtrate. After the filtrate is ultra-filtered twice, it is defluorinated by a special resin for defluorination, and the solution contains 0.55 mg/L of fluorine.

Take the defluoridated solution, add cobalt sulfate, nickel sulfate, and manganese sulfate to adjust the total concentration to 2.4mol/L. The contents of nickel, cobalt, and manganese in the solution are: 47.09g/L, 46.91g/L, and 44.10g/L, respectively. Add EDTA at the same time, the addition amount is 0.2g/L.

Prepare sodium hydroxide and ammonium hydroxide mixed lye, the concentration of liquid alkali is 25%, the concentration of ammonia water is 7mol/L, and the volume ratio of alkali and ammonia is 5:1. Nitrogen gas is introduced into the reactor at a flow rate of 5m ³ /h. After starting the stirring, control the temperature to 27°C, and at the same time add a well-adjusted nickel-cobalt-manganese mixed sulfuric acid solution, sodium hydroxide and ammonium hydroxide mixed lye, and EDTA. The pH value is controlled to be 10.8, and the addition amount of EDTA is 190g/m ³ . The total flow rate of each liquid added is 120L/hour, and the effective volume of the reactor is 2000L. When the reactor volume is full, keep feeding, and the reaction slurry overflows into the double sedimentation reactor. In the secondary sedimentation reactor, the protective gas nitrogen is introduced into the flow rate of 5m3/h. Raise the temperature to 80°C, stir for 45 minutes and then add saturated ammonium bicarbonate solution, the amount added is 1.3 times the theoretical value of lithium ion precipitation, the flow rate of addition is 800L/hour, and the effective volume of the reactor is 2000L. After the addition of ammonium bicarbonate was completed, the protective gas flow rate was kept constant and the reaction was stirred for another 60 minutes. After the reaction is completed, the filtrate and the filter residue can be obtained by filtering, and the filter residue is a mixture of nickel-cobalt-manganese co-precipitated hydroxide and lithium carbonate.

The secondary precipitation filter residue was washed with pure water and then dried, with a water content of 1.42%. According to the amount of nickel, cobalt and manganese, adjust the ratio of lithium to 1.2 of the theoretical amount, then react in the calciner at 700°C for 240 minutes, and then react at 900°C for 240 minutes. The calcined material is wet finely ground with a liquid-solid ratio of 3:1 and a particle size of 100% over 400 mesh. After fine grinding, the slurry is filtered and then washed once according to the mass-liquid-solid ratio of 3:1. After filtering, it is dried to obtain the ternary positive electrode material.

Example 4

In this case, the method for preparing NCM811 type lithium ion battery cathode material by recycling waste cathode powder of lithium battery.

Add 300 kg of concentrated sulfuric acid into the reactor to prepare a 3.0 mol/L dilute sulfuric acid solution. Then put in a lithium battery to disassemble 1000kg of black powder, heat up to 85°C, and react for 120 minutes. After the reaction was completed, 35 kg of ferrous sulfide was added, and the reaction was continued for 120 minutes, and the terminal pH value was 1.4. After the reaction is completed, filter to obtain a filtrate and a filter residue.

Take 2000L of the above-mentioned filtrate and add it into the reactor, after raising the temperature to 75°C, add 35kg of hydrogen peroxide, and react for 60 minutes. First add nickel carbonate to adjust the pH value to 2.5, then add 5.5 kg of manganese powder (the filtrate contains 1.73 g/L copper), and continue the reaction for 90 minutes. Filter to obtain filtrate and filter residue.

Take 2000L of the above-mentioned filtrate into the reactor, heat up to 90°C, add 24kg of lithium fluoride (calcium 0.20g/L, magnesium 0.61g/L in the filtrate), react for 360 minutes and filter to obtain the filter residue and filtrate. After the filtrate is ultra-filtered twice, it is defluorinated by a special resin for defluorination, and the solution contains 0.40 mg/L of fluorine.

Take the defluoridated solution, add cobalt sulfate, nickel sulfate, and manganese sulfate to adjust the total concentration to 2.2mol/L. The contents of nickel, cobalt, and manganese in the solution are: 103.33g/L, 12.83g/L, and 12.14g/L, respectively. Add EDTA at the same time, the addition amount is 0.2g/L.

Prepare sodium hydroxide and ammonium hydroxide mixed lye, the concentration of liquid alkali is 25%, the concentration of ammonia water is 7mol/L, and the volume ratio of alkali and ammonia is 5:1. Nitrogen gas is introduced into the reactor at a flow rate of 5m ³ /h. After starting the stirring, control the temperature to 27°C, and at the same time add a well-adjusted nickel-cobalt-manganese mixed sulfuric acid solution, sodium hydroxide and ammonium hydroxide mixed lye, and EDTA. Control pH value 11.5, EDTA addition is 200g/m3. The total flow rate of each liquid added is 120L/hour, and the effective volume of the reactor is 2000L. When the reactor volume is full, keep feeding, and the reaction slurry overflows into the double sedimentation reactor. In the secondary sedimentation reactor, the protective gas nitrogen is introduced into the flow rate of 5m3/h. Raise the temperature to 80°C, stir for 45 minutes and then add saturated ammonium bicarbonate solution, the amount added is 1.3 times the theoretical value of lithium ion precipitation, the flow rate of addition is 800L/hour, and the effective volume of the reactor is 2000L. After the addition of ammonium bicarbonate was completed, the protective gas flow rate was kept constant and the reaction was stirred for another 60 minutes. After the reaction is completed, the filtrate and the filter residue can be obtained by filtering, and the filter residue is a mixture of nickel-cobalt-manganese co-precipitated hydroxide and lithium carbonate.

The secondary precipitation filter residue was washed with pure water and then dried, with a water content of 0.93%. According to the amount of nickel, cobalt and manganese, adjust the ratio of lithium to 1.2 of the theoretical amount, then react in the calciner at 650°C for 240 minutes, and then react at 900°C for 240 minutes. The calcined material is wet finely ground with a liquid-solid ratio of 3:1 and a particle size of 100% over 400 mesh. After fine grinding, the slurry is filtered and then washed once according to the mass-liquid-solid ratio of 3:1. After filtering, it is dried to obtain the ternary positive electrode material.

Claims (10)

1. A method for preparing a lithium ion battery anode material by recycling waste lithium electricity dismantling black powder and anode powder is characterized by comprising the following steps: the method comprises the following steps:

s1: firstly filling a reaction container with a prepared acid solution, putting raw materials to be recovered into the reaction container, then raising the temperature of the reaction container to T1, then carrying out reaction for T1, putting a reducing agent into the reaction container for reaction for T2 after the reaction is finished, and adjusting the ph value of the solution to be a after the reaction is finished;

s2: filtering raw materials after the reaction, and then carrying out process treatment of removing iron, aluminum, calcium and magnesium on filter residues;

s3: sequentially carrying out ultrafiltration, defluorination and ratio-regulating process treatment on the treated raw materials;

s4: adding the treated raw materials into mixed alkali liquor of sodium hydroxide and ammonium hydroxide, introducing protective gas, stirring and adding mixed solution of nickel, cobalt and manganese and sulfuric acid, mixed alkali liquor of sodium hydroxide and ammonium hydroxide and EDTA, controlling the pH value to 11-12, and controlling the temperature at 25-45 ℃ in the reaction process;

s5: after the reaction is finished, sending a reaction solution into a reaction container, introducing protective gas and stirring the reaction solution, heating the reaction container to T2, stirring for T3, adding saturated ammonium bicarbonate solution and continuously introducing the protective gas, and stirring for T4 in the process;

s6: and (3) obtaining filter residues after the reaction is finished, and finally washing, drying, calcining and finely grinding the filter residues.

2. The method for preparing the lithium ion battery anode material by recycling the waste lithium battery dismantling black powder and the anode powder according to claim 1, which is characterized in that: the acid solution in the S1 is a dilute sulfuric acid solution with the concentration of 2-3 mol/L, and the mass ratio of the dilute sulfuric acid solution to the raw materials is 0.15-0.35: 1, wherein T1 is 75-95 ℃, T1 is 120-140 minutes, T2 is 60-120 minutes, a is 1.0-1.5, and the reducing agent is ferrous sulfide.

3. The method for preparing the lithium ion battery anode material by recycling the waste lithium battery dismantling black powder and the anode powder according to claim 2, which is characterized in that: the iron and aluminum removing process in the step S2 comprises the following steps of:

s31: leaching filtrate, adding the filtrate into a reactor, heating the reaction vessel to 75 ℃, and adding hydrogen peroxide with the addition amount of 10-20 kg per cubic volume;

s32: adding hydrogen peroxide, reacting for 30-60 minutes, adding nickel carbonate, adjusting the pH value to 2.0-2.5, and then adding manganese powder;

s33: the mass ratio of the addition amount of the manganese powder to the copper content in the solution is 1:1.1 to 1.8, continuing to react for 60 to 90 minutes after the manganese powder is added, and filtering after the reaction is finished to obtain filtrate and filter residues.

4. The method for preparing the lithium ion battery anode material by recycling the waste lithium battery dismantling black powder and the anode powder according to claim 3, which is characterized in that: the calcium and magnesium removal process in the step S2 comprises the following steps:

s41: adding filtrate after iron and aluminum removal into a calcium and magnesium removal reactor, and heating to 90 ℃;

s42: the content of calcium and magnesium in the solution can be analyzed and detected by an atomic absorber, lithium fluoride with the theoretical dosage of 10-15 times is added according to the amount of calcium and magnesium, the lithium fluoride is in a slurried colloid state, the reaction is carried out for 240-360 minutes, and calcium and magnesium slag and filtrate are obtained after the reaction is finished.

5. The method for preparing the lithium ion battery anode material by recycling the waste lithium battery dismantling black powder and the anode powder according to claim 1, which is characterized in that: the ultrafiltration process in the step S3 comprises the following steps:

s51: filtering the filtrate subjected to calcium, magnesium and iron and aluminum removal treatment by using a microporous membrane filter twice, wherein the filtering pore diameter of the microporous membrane filter for the first time is 0.5 mu m;

s52: the filtrate after the treatment of removing calcium, magnesium and iron and aluminum contains superfine and suspended particles, wherein the superfine and suspended particles comprise silicate, calcium fluoride and magnesium fluoride, and the filter pore diameter of the second microporous membrane filter is selected to be 0.1 mu m, so that the superfine and suspended particles in the solution are filtered cleanly.

6. The method for preparing the lithium ion battery anode material by recycling the waste lithium battery dismantling black powder and the anode powder according to claim 5, which is characterized in that: the defluorination process in the step S3 is as follows: treating the ultrafiltered solution with a fluorine-removing special resin, and controlling the concentration range of fluorine ions in the solution to be as follows: 0.3-1 mg/L.

7. The method for preparing the lithium ion battery anode material by recycling the waste lithium battery dismantling black powder and the anode powder according to claim 6, which is characterized in that: the ratio regulating process in the step S3 comprises the following steps:

s71: the precipitation front adjustment ratio is to adjust the content of nickel, cobalt and manganese in the solution by using sulfate of nickel, cobalt and manganese according to each specification and model of the ternary positive electrode material, and the total molar concentration of nickel, cobalt and manganese is 1.5-2.4 mol/L;

s72: adding complexing agent EDTA with the addition amount of 0.1-0.2 g/L; the calcination front adjusting ratio is to adjust the ratio of nickel, cobalt and manganese to lithium, and the ratio of lithium is adjusted to be 1.05-1.2 of theoretical quantity according to the content of nickel, cobalt and manganese.

8. The method for preparing the lithium ion battery anode material by recycling the waste lithium battery dismantling black powder and the anode powder according to claim 7, which is characterized in that: the concentration of sodium hydroxide in the S4 is as follows: 25% -27%, the concentration of ammonia water is: 5-7 mol/L, and the volume ratio of sodium hydroxide to ammonia water is (4-6): 1, the introducing rate of the protective gas is 3-5 m ³ And/h, the addition amount of EDTA is 100-200 g/m ³ . The total flow rate of each liquid is 1/10-1/20 of the volume of the reactor.

9. The method for preparing the lithium ion battery anode material by recycling the waste lithium battery dismantling black powder and the anode powder according to claim 8, which is characterized in that: in the S5, the T2 is 75-90 ℃, and the input rate of the introduced protective gas is 3-5 m ³ And/h, wherein t3 is 30-60 minutes, the addition amount of the saturated ammonium bicarbonate solution is 1.1-1.4 times of the theoretical value of lithium ion precipitation, and the addition flow rate is as follows: the idle volume/(2-3) of the reactor is kept unchanged after the addition of the ammonium bicarbonate is completed, and the flow rate of the protective gas is kept unchanged, wherein t4 is 60-90 minutes. Filtering after the reaction is finished to obtain filtrate and filter residues, wherein the filter residues are a mixture of nickel cobalt manganese coprecipitation hydroxide and lithium carbonate.

10. The method for preparing the lithium ion battery anode material by recycling the waste lithium battery dismantling black powder and the anode powder according to claim 9, which is characterized in that: the washing and drying in the step S6 is required to control the water content in the reactant to be within 1-2 percent;

in the step S6, the dried mixture is subjected to mixing ratio and then reacts for 120-240 minutes at 600-700 ℃ in a calcining furnace, and then reacts for 120-240 minutes at 800-1000 ℃;

the calcined material in the step S6 is subjected to wet fine grinding, and the mass liquid-solid ratio of the fine grinding is (3-5): 1, fine grinding with granularity of 100% and 400 meshes, filtering the slurry after fine grinding, and then mixing the slurry with the slurry according to the mass liquid-solid ratio of (3-5): 1, washing once, filtering and drying to obtain the ternary anode material.

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