WO2022041845A1

WO2022041845A1 - Recovery method for removing fluorine from nickel-cobalt-manganese solution

Info

Publication number: WO2022041845A1
Application number: PCT/CN2021/093182
Authority: WO
Inventors: 何芳; 谌志新; 陈若葵; 阮丁山; 李长东
Original assignee: 湖南邦普循环科技有限公司; 广东邦普循环科技有限公司; 湖南邦普汽车循环有限公司
Priority date: 2020-08-24
Filing date: 2021-05-12
Publication date: 2022-03-03
Also published as: CN112079371A

Abstract

The present invention relates to a recovery method for removing fluorine from a nickel-cobalt-manganese solution, comprising the following steps: after carrying out acid leaching and impurity removal on battery powder, obtaining a fluorine-containing nickel-cobalt-manganese solution; mixing the obtained fluorine-containing nickel-cobalt-manganese solution with a fluorine removing agent to obtain a mixed slurry; adjusting the pH of the obtained mixed slurry to 2-5, and passing through filtering to obtain a first-stage defluorinated filtrate and first-stage fluorine-containing filter residue; and after washing the first-stage fluorine-containing filter residue, adding same into an alkali liquid, heating and stirring same, and passing same through filtering to obtain fluorine-containing filtrate and nickel-cobalt-manganese-containing filter residue. The method of the embodiments of the present invention has a relatively good fluorine removal effect in a front-section nickel-cobalt-manganese solution. Meanwhile, other impurities are not introduced, the obtained fluorine-containing filter residue may meet industrial cryolite product requirements after being purified, and the method has relatively large economic benefits.

Description

A kind of recovery method of removing fluorine in nickel-cobalt-manganese solution

technical field

The invention belongs to the technical field of lithium ion battery recycling, and in particular relates to a method for removing fluorine from a nickel-cobalt-manganese sulfate solution after acid leaching of battery waste powder.

Background technique

Lithium-ion batteries have been widely used in various electronic products and electric vehicles and other industries. According to statistics, my country's lithium-ion battery production and output accounted for more than 50% of the world's total, and the output in 2019 was 15.72 billion. The rapid expansion of lithium-ion battery production capacity also means In recent years, there will be a large number of lithium-ion batteries that need to be scrapped and recycled. Improper handling will cause environmental pollution and waste of resources. Therefore, the recycling of lithium-ion batteries is imminent, which is important for environmental protection and sustainable development of resources. significance.

At present, used lithium-ion batteries are mainly disassembled, crushed, and screened to obtain positive electrode powder and other components. For the recovery of positive electrode powder, the method of inorganic acid leaching is mainly used to transfer the valuable metal from the solid powder to the solution and effectively separate it from carbon black and organic binders. The fluorine introduced will enter the solution, which will affect the process of wet recovery of nickel, cobalt and manganese, which mainly includes: 1) affecting the product quality of the nickel-cobalt-manganese ternary precursor; 2) fluorine removal in the subsequent wastewater treatment process section The pressure is high, and the current fluorine removal process is difficult to meet the wastewater discharge requirements, and the treatment cost is high; 3) The fluorine in the wet system will be corrosive to the equipment, shortening the service life of the equipment; 4) It is easy to cause pipeline blockage.

SUMMARY OF THE INVENTION

Aiming at the shortcomings and deficiencies of the current back-stage wastewater defluorination process, a method for recovering fluorine removal in a nickel-cobalt-manganese solution is provided according to an embodiment of the present invention. The method of the embodiment of the present invention has a good fluorine removal effect in the nickel-cobalt-manganese solution in the first stage, without introducing other impurities, and the obtained fluorine-containing filter residue can meet the requirements of industrial cryolite products after being purified, and has a relatively large economy. benefit.

In view of this, the embodiment of the present invention provides a recovery method for removing fluorine in a nickel-cobalt-manganese solution, comprising the following steps:

After acid leaching and impurity removal of the battery powder, a fluorine-containing nickel-cobalt-manganese solution is obtained;

Mixing the obtained fluorine-containing nickel-cobalt-manganese solution with a defluorination agent to obtain a mixed slurry;

The pH of the obtained mixed slurry is adjusted to 2-5, and a section of defluorinated filtrate and a section of fluorine-containing filter residue are obtained by filtration;

A section of the fluorine-containing filter residue is washed and then added to the alkaline solution, heated and stirred, and filtered to obtain a fluorine-containing filtrate and a nickel-cobalt-manganese-containing filter residue.

According to an embodiment of the present invention, the battery powder can be obtained by pulverizing battery waste. According to an embodiment of the present invention, the battery waste can be selected from waste positive electrode materials obtained by dismantling waste lithium batteries or waste positive electrode materials generated during the manufacturing process of lithium batteries. In some embodiments, the removal of impurities includes removal of impurities such as iron, aluminum, and the like using processes known in the art.

In some embodiments, the resulting fluorine-containing nickel-cobalt-manganese solution contains a high concentration of fluorine. Specifically, according to certain embodiments, in the obtained fluorine-containing nickel-cobalt-manganese solution, the nickel-cobalt-manganese concentration is 40-100 g/L, and the fluorine concentration is 1-5 g/L. According to an embodiment of the present invention, the fluorine removing agent is a solid fluorine removing agent. In some embodiments, the fluorine removing agent includes, but is not limited to, one or more of aluminum oxide, aluminum hydroxide and soluble aluminum salts. Among them, the soluble aluminum salts include single salts, such as aluminum sulfate, and double salts, such as sodium alum. Optionally, the fluorine removing agent can be selected from natural and inexpensive materials whose main components are one or more of alumina, aluminum hydroxide and soluble aluminum salts, such as bauxite. In some implementations of the present invention, the mass ratio of the volume of the nickel-cobalt-manganese solution to the defluorination agent is 50-300:1; preferably, 100-200:1. The applicant of the present invention has found and verified through previous research that the amount of fluorine removal agent added can be calculated according to the fluorine content in the nickel-cobalt-manganese solution, so that the minimum and appropriate amount of fluorine removal can be used on the premise of ensuring good fluorine removal effect. The agent reacts with fluorine to generate and preferentially generates sodium fluoroaluminate to avoid the generation of other impurity compounds.

According to the embodiment of the present invention, the pH of the obtained mixed slurry is adjusted to 2-5 with dilute acid. The dilute acid includes, but is not limited to, at least one of dilute sulfuric acid, dilute hydrochloric acid, and dilute nitric acid. Preferably, the dilute acid is dilute sulfuric acid. Specifically, the dilute acid concentration is 5-50%.

In some embodiments of the present invention, the pH value of the obtained mixed slurry is adjusted to reduce to facilitate the conversion of aluminum in the fluorine scavenger into aluminum ions, which react with fluorine in the mixed slurry to generate sodium fluoroaluminate. In the embodiment of the present invention, the total reaction time of controlling the obtained mixed slurry to adjust pH to 2-5 is 0.5-2h. By controlling the speed and reaction time of adjusting pH value, it helps to form high-purity sodium fluoroaluminate precipitate and avoid the accumulation of new waste residue.

According to the embodiment of the present invention, the main component of a section of fluorine-containing filter residue obtained by filtration is sodium fluoroaluminate.

According to an embodiment of the present invention, after obtaining a section of defluorinated filtrate and a section of fluorine-containing filter residue, the method further comprises: mixing the obtained section of defluorinated filtrate with a defluorinating agent, adjusting the pH to 2-5, and filtering to obtain a second section of defluorinated filtrate and The second-stage fluorine-containing filter residue. In some embodiments, the fluorine content of the obtained second-stage defluorination filtrate is reduced to 20 mg/L or less, the second-stage fluorine-containing filter residue contains a small amount of nickel, cobalt, and manganese, and the second-stage fluorine-containing filter residue is returned to the acid leaching process. Under the inspiration of the embodiments of the present invention, those skilled in the art can obviously according to the actual production needs, after obtaining the N-stage defluorination filtrate and the N-stage fluorine-containing filter residue, the N-stage defluorination filtrate is further mixed with a defluorinating agent, adjusting The pH reaches 2-5, and N+1 stage defluorination filtrate and N+1 fluorine-containing filter residue are obtained by filtration. Among them, the second-stage fluorine-containing filter residue, ..., the N-stage fluorine-containing filter residue and the N+1 fluorine-containing filter residue are returned to the acid leaching process. In this paper, N is greater than 1.

According to the embodiment of the present invention, after obtaining the second-stage defluorination filtrate and the second-stage fluorine-containing filter residue, the method further includes: adjusting the pH of the second-stage defluorination filtrate to 5-6.5, and performing subsequent extraction to obtain nickel-cobalt-manganese products. Under the inspiration of the embodiments of the present invention, those skilled in the art can obviously according to the actual production needs, after obtaining the N-stage defluorination filtrate and the N-stage fluorine-containing filter residue, the N-stage defluorination filtrate is subjected to subsequent extraction to obtain Nickel Cobalt Manganese product. In this paper, N is greater than 1.

Under the inspiration of the embodiments of the present invention, on the premise that a section of fluorine-containing filter residue is not reconstituted, those skilled in the art can also easily imagine that the obtained section of fluorine-removing filtrate is mixed with a fluorine-removing agent, and the pH is first adjusted to 2-5 , and then adjust the pH to 5-6.5, and obtain the second-stage defluorination filtrate and the second-stage fluorine-containing filter residue after filtration. At this time, the second-stage defluorination filtrate can be subjected to subsequent extraction without adjusting the pH to obtain nickel-cobalt-manganese products.

According to an embodiment of the present invention, the pH is adjusted to 5-6.5 with a neutralizing agent. The neutralizing agent includes but is not limited to one or more of sodium carbonate, potassium carbonate, sodium hydroxide, and potassium hydroxide. Preferably, the neutralizer is a 10-30% concentration neutralizer solution.

According to an embodiment of the present invention, the alkali solution includes but is not limited to sodium hydroxide and potassium hydroxide solution. Preferably, the concentration of the lye solution is 5-30%. The ratio of the molar amount of the alkaline compound in the alkaline solution to the theoretical molar amount of sodium fluoroaluminate in the first-stage fluorine-containing filter residue is 0.9-1.5; preferably, the ratio is 1.0-1.4; more preferably, the ratio is is 1.1-1.3.

According to the embodiment of the present invention, a section of fluorine-containing filter residue is washed and then added to alkali solution, heated to 50-80° C., stirred for 0.5-2 h, and filtered to obtain fluorine-containing filtrate and nickel-cobalt-manganese-containing filter residue.

According to an embodiment of the present invention, after obtaining the fluorine-containing filtrate and the nickel-cobalt-manganese-containing filter residue, it also includes:

The obtained nickel-cobalt-manganese-containing filter residue is returned to the acid leaching process;

The obtained fluorine-containing filtrate is passed into carbon dioxide to react, and the cryolite product is obtained after filtering, washing and drying.

Preferably, carbon dioxide is introduced into the reaction for 2-8h.

The method of the embodiment of the present invention has the following advantages and beneficial effects:

The method of the embodiment of the present invention has a good defluorination effect in the nickel-cobalt-manganese solution in the first stage, and the loss of nickel-cobalt-manganese in the fluorine-containing filter residue is small; at the same time, the process of the embodiment of the present invention does not introduce other impurities, and the obtained fluorine-containing filter residue After the fluorine filter residue is purified, it can meet the requirements of industrial cryolite products, improve the added value of recycled raw materials, and have greater economic benefits.

Description of drawings

1 is a flow chart of a method for removing fluorine in a nickel-cobalt-manganese solution according to an embodiment of the present invention.

detailed description

The present invention will be described in further detail below with reference to the examples, but the embodiments of the present invention are not limited thereto.

Referring to Fig. 1, specifically, a kind of recovery method of removing fluorine in nickel-cobalt-manganese solution, comprises the following steps:

(1) Pulverize and sieve the battery waste to obtain battery powder;

(2) after the battery powder is subjected to acid leaching and impurity removal, a fluorine-containing nickel-cobalt-manganese solution is obtained;

(3) by volume to mass ratio of 50-300:1, the obtained fluorine-containing nickel-cobalt-manganese solution is mixed with a defluorinating agent to obtain a mixed slurry;

(4) adjusting the pH of the obtained mixed slurry to 2-5 with 5-50% dilute acid, the reaction time is controlled at 0.5-2h, and a section of defluorinated filtrate and a section of fluorine-containing filter residue are obtained by filtration;

(5) the gained one-stage defluorination filtrate is mixed with a defluorinating agent, and step (4) is repeated to obtain a second-stage defluorination filtrate and a second-stage fluorine-containing filter residue; the second-stage fluorine-containing filter residue is returned to the acid leaching process;

(6) adjusting the pH of the second-stage defluorination filtrate to 5-6.5 with a 10-30% neutralizer, and carrying out subsequent extraction to obtain a nickel-cobalt-manganese product;

(7) After washing a section of fluorine-containing filter residue, add it to the alkaline solution, heat to 50-80 ° C, stir for 0.5-2 h, and obtain fluorine-containing filtrate and nickel-cobalt-manganese-containing filter residue by filtration; The obtained nickel-cobalt-manganese-containing filter residue is returned to acid leaching process;

(8) Passing the obtained fluorine-containing filtrate into carbon dioxide to react for 2-8h, filtering, washing and drying to obtain a cryolite product.

The present invention will be further described in detail below with reference to the embodiments, so as to facilitate the understanding of the present invention by those skilled in the art. It is necessary to point out that the embodiments are only used to further illustrate the present invention, and should not be construed as limiting the scope of protection of the present invention. Those skilled in the art make non-essential improvements and The adjustment should still belong to the protection scope of the present invention. At the same time, the raw materials mentioned below are all commercially available products; the concentrations of metal ions in the following examples are all obtained by atomic absorption spectrometry (AAS) or inductively coupled plasma atomic emission spectrometry (ICP-AES) ) determination; the fluoride ion concentration is determined by the fluorine electrode potentiometric method; the process steps or preparation methods not mentioned in detail are the process steps or preparation methods known to those skilled in the art.

Example 1

The present embodiment proposes a recovery method for removing fluorine in a nickel-cobalt-manganese solution, comprising the following steps:

(1) Pulverize and sieve the waste ternary battery waste to obtain ternary battery powder;

(2) After the ternary battery powder is subjected to acid leaching and impurity removal, a nickel-cobalt-manganese solution with a fluorine content of 4.03 g/L is obtained;

(3) 1L fluorine-containing nickel-cobalt-manganese solution is mixed with 10g bauxite and stirred to obtain mixed slurry;

(4) using 30% dilute sulfuric acid to adjust the pH value of the mixed slurry obtained in step (3) to about 4, adjusting the pH within 1 h, and filtering to obtain a section of defluorination filtrate and a section of fluorine-containing filter residue, wherein a section of defluorination filtrate contains Fluorine is 34.6 mg/L, and (Ni+Co+Mn) in a fluorine-containing filter residue is 0.029% (by weight);

(5) adding 10g of bauxite to the one-stage defluorination filtrate obtained in step (4), repeating step (4), and filtering to obtain a second-stage defluorination filtrate and a second-stage fluorine-containing filter residue, wherein the second-stage defluorination filtrate contains fluorine 20.7mg/L, the (Ni+Co+Mn) in the second-stage fluorine-containing filter residue is 0.905%, the second-stage fluorine-containing filter residue is returned to acid leaching; the second-stage defluorination filtrate is adjusted to about 5.7 with 15% sodium carbonate solution, and the subsequent Extraction to obtain nickel-cobalt-manganese products;

(6) Add a 30% sodium hydroxide solution with 1.1 times the theoretical molar weight of sodium fluoroaluminate to the fluorine-containing filter residue obtained in step (4), heat and stir in a water bath at 80° C. for 1 h, and filter to obtain fluorine-containing filtrate and nickel-cobalt-containing filtrate. Manganese filter residue, nickel-cobalt-manganese filter residue is returned to acid leaching;

(7) Passing the fluorine-containing filtrate obtained in step (6) into carbon dioxide for 4 h, filtering, washing and drying to obtain a cryolite product with a purity of 98.2%.

Example 2

(1) pulverizing and sieving the waste of lithium cobalt oxide battery to obtain lithium cobalt oxide battery powder;

(2) after the lithium cobalt oxide battery powder is subjected to acid leaching and impurity removal, a nickel-cobalt-manganese solution with a fluorine content of 4.54 g/L is obtained;

(3) 1L of fluorine-containing nickel-cobalt-manganese solution is mixed with 5g of aluminum hydroxide and stirred to obtain a mixed slurry;

(4) using 20% dilute sulfuric acid to adjust the pH value of the mixed slurry obtained in step (3) to about 3, adjusting the pH within 1 hour, and filtering to obtain a section of defluorination filtrate and a section of fluorine-containing filter residue, wherein a section of defluorination filtrate contains Fluorine is 37.4mg/L, and (Ni+Co+Mn) in the first-stage fluorine-containing filter residue is 0.033% (by weight);

(5) adding 5g of aluminum hydroxide to the first-stage defluorination filtrate obtained in step (4), repeating step (4), and filtering to obtain a second-stage defluorination filtrate and a second-stage fluorine-containing filter residue, wherein the second-stage defluorination filtrate contains fluorine 20.3mg/L, the (Ni+Co+Mn) in the second-stage fluorine-containing filter residue is 0.967%, the second-stage fluorine-containing filter residue is returned to acid leaching; the second-stage defluorination filtrate is adjusted to about 6.1 with 15% sodium carbonate solution, and the subsequent Extraction to obtain nickel-cobalt-manganese products;

(6) Add a 25% sodium hydroxide solution with 1.2 times the theoretical molar weight of sodium fluoroaluminate to the fluorine-containing filter residue obtained in step (4), heat and stir in a water bath at 75° C. for 2 hours, and filter to obtain fluorine-containing filtrate and nickel-cobalt-containing filtrate. Manganese filter residue, nickel-cobalt-manganese filter residue is returned to acid leaching;

(7) Passing the fluorine-containing filtrate obtained in step (6) into carbon dioxide for 6 h, filtering, washing and drying to obtain a cryolite product with a purity of 98.1%.

Example 3

(1) Pulverize and sieve the pole piece waste to obtain pole piece powder;

(2) after the pole piece powder is subjected to acid leaching and impurity removal, obtaining a nickel-cobalt-manganese solution with a fluorine content of 2.65 g/L;

(3) 1L of fluorine-containing nickel-cobalt-manganese solution is mixed with 10g of sodium alum and stirred to obtain mixed slurry;

(4) using 10% dilute sulfuric acid to adjust the pH value of the mixed slurry obtained in step (3) to about 2, adjusting the pH within 1 h, and filtering to obtain a section of defluorination filtrate and a section of fluorine-containing filter residue, wherein a section of defluorination filtrate contains Fluorine is 52.6 mg/L, and (Ni+Co+Mn) in the first-stage fluorine-containing filter residue is 0.041% (by weight);

(5) adding 10g of sodium alum to the first-stage defluorination filtrate obtained in step (4), repeating step (4), and filtering to obtain a second-stage defluorination filtrate and a second-stage fluorine-containing filter residue, wherein the second-stage defluorination filtrate contains 19.6% fluorine mg/L, the (Ni+Co+Mn) in the second-stage fluorine-containing filter residue is 0.915%, the second-stage fluorine-containing filter residue is returned to acid leaching; the second-stage defluorination filtrate is adjusted to pH 5.5 with 10% sodium carbonate solution, and the subsequent extraction is carried out , to obtain nickel-cobalt-manganese products;

(6) Add a 25% sodium hydroxide solution with 1.3 times the theoretical molar weight of sodium fluoroaluminate to the fluorine-containing filter residue obtained in step (4), heat and stir in a water bath at 70° C. for 3 hours, and filter to obtain fluorine-containing filtrate and nickel-cobalt-containing filtrate. Manganese filter residue, nickel-cobalt-manganese filter residue is returned to acid leaching;

(7) The fluorine-containing filtrate obtained in step (6) was passed into carbon dioxide for 8h, filtered, washed and dried to obtain a cryolite product with a purity of 97.8%.

Compared with the related art, the nickel-cobalt-manganese solution is defluorinated by the method of the embodiment of the present invention, and the fluorine content in the nickel-cobalt-manganese solution can be reduced to 20 mg/L or less, and the nickel-cobalt in the fluorine-containing filter residue can be reduced. Manganese content <1%, less loss. In the reaction of removing fluorine from nickel-cobalt-manganese solution in the embodiment of the present invention, the reaction conditions are wide, the reagents and raw materials used are cheap and easy, and the effect of removing fluorine is good. , the added value of the recovered raw materials is improved, and the valuable metals entrained in the defluorination residue are effectively recovered. According to the embodiment of the present invention, there is no waste water and waste residue in the process system. The process of the embodiment of the present invention is simple, no other impurities are introduced or generated, and the purity of cryolite obtained after treatment and purification of the fluorine-containing filter residue can reach more than 98%, which meets the requirements of industrial cryolite products and has considerable economic benefits.

The above-mentioned embodiments are preferred embodiments of the present invention, but the embodiments of the present invention are not limited by the above-mentioned embodiments, and any other changes, modifications, substitutions, combinations, The simplification should be equivalent replacement manners, which are all included in the protection scope of the present invention.

Claims

A recovery method for removing fluorine in a nickel-cobalt-manganese solution, comprising the following steps:

After acid leaching and impurity removal of the battery powder, a fluorine-containing nickel-cobalt-manganese solution is obtained;

Mixing the obtained fluorine-containing nickel-cobalt-manganese solution with a defluorination agent to obtain a mixed slurry;

The pH of the obtained mixed slurry is adjusted to 2-5, and a section of defluorinated filtrate and a section of fluorine-containing filter residue are obtained by filtration;

A section of the fluorine-containing filter residue is washed and then added to the alkaline solution, heated and stirred, and filtered to obtain a fluorine-containing filtrate and a nickel-cobalt-manganese-containing filter residue.
The recovery method according to claim 1, wherein the defluorinating agent is a solid defluorinating agent.
The recovery method according to claim 1, wherein the fluorine removing agent comprises one or more of alumina, aluminum hydroxide and soluble aluminum salts.
The recovery method according to claim 1, wherein the mass ratio of the volume of the nickel-cobalt-manganese solution to the defluorinating agent is 50-300:1.
The recovery method according to claim 1, wherein the obtained mixed slurry is adjusted to pH 2-5 with dilute acid.
The recovery method according to claim 1 is characterized in that, after obtaining a section of defluorinated filtrate and a section of fluorine-containing filter residue, the method further comprises: mixing the obtained section of defluorinated filtrate with a defluorinating agent, adjusting pH to 2-5, and filtering The second-stage defluorination filtrate and the second-stage fluorine-containing filter residue are obtained.
The recovery method according to claim 6, characterized in that, after obtaining the second-stage defluorination filtrate and the second-stage fluorine-containing filter residue, further comprising: adjusting the pH of the second-stage defluorination filtrate to 5-6.5 for extraction to obtain nickel cobalt manganese product.
The recovery method according to claim 6, characterized in that, after obtaining the N-stage defluorination filtrate and the N-stage fluorine-containing filter residue, the method further comprises: mixing the N-stage defluorination filtrate with a defluorinating agent, and adjusting the pH to 2-5 , and N+1 stage fluoride removal filtrate and N+1 fluorine-containing filter residue are obtained by filtration, wherein N is greater than 1.
The recovery method according to claim 1, wherein the ratio of the molar amount of the alkaline compound in the alkaline solution to the theoretical molar amount of the sodium fluoroaluminate in the first-stage fluorine-containing filter residue is 0.9-1.5.
recovery method according to claim 1, is characterized in that, after obtaining fluorine-containing filtrate and nickel-cobalt-manganese-containing filter residue, also comprises:

The obtained nickel-cobalt-manganese-containing filter residue is returned to the acid leaching process;

The obtained fluorine-containing filtrate is passed into carbon dioxide to react, and the cryolite product is obtained after filtering, washing and drying.