CN115786711A

CN115786711A - Method for recovering waste residues generated by wet recovery of lithium battery anode powder

Info

Publication number: CN115786711A
Application number: CN202211491653.5A
Authority: CN
Inventors: 任伟阳; 苑晓凯; 朱亚超; 石茹冰; 郭梦凡; 毕瑞; 胡延强; 贾重阳
Original assignee: Sinochem Hebei Lithium Battery Technology Co Ltd
Current assignee: Sinochem Hebei Lithium Battery Technology Co Ltd
Priority date: 2022-11-25
Filing date: 2022-11-25
Publication date: 2023-03-14

Abstract

The invention provides a method for recovering waste residues generated by wet recovery of lithium battery anode powder. The recovery method comprises the following steps: dissolving the first metal-containing waste residue by using a sulfuric acid aqueous solution, heating and leaching to obtain a first solution, diluting the first solution by using a diluent to obtain a first solution diluent, and dissolving the second metal-containing waste residue and the third metal-containing waste residue by using a first solution diluent respectively to obtain a second solution and a third solution; and finally, mixing the second solution and the third solution to obtain a mixed solution, adding an initiator into the mixed solution to trigger a fluorination reaction, and obtaining the nickel-cobalt-manganese-lithium-containing recovered solution. The method skillfully combines the treatment of three main waste residues generated by hydrometallurgy, solves the problem that the waste residues generated in the hydrometallurgy recovery process are difficult to treat through cooperative treatment, realizes the maximum possibility recovery of valuable metals by using very low cost, is simple and easy to implement, is more practical to fit, and is easy to realize scientific, reasonable and efficient industrial application.

Description

Method for recovering waste residues generated by wet recovery of lithium battery anode powder

Technical Field

The invention relates to the technical field of lithium battery recovery, in particular to a method for recovering waste residues generated by wet recovery of lithium battery anode powder.

Background

At present, most of waste lithium batteries are mainly treated by a wet recovery process route, wherein the wet recovery process route comprises the steps of discharging, crushing, sorting, screening and the like of the waste lithium batteries to obtain anode powder, leaching nickel, cobalt, manganese and lithium metal from the anode powder by using acid and a reducing agent, adding a reagent to remove iron, aluminum, copper and calcium and magnesium to obtain a refined nickel, cobalt, manganese and sulfate solution, and then, the refined nickel, cobalt, manganese and sulfate solution can be used for synthesizing an anode precursor material.

The prior art has no complete and effective solution for the waste residue generated by recovering the anode powder by wet metallurgy. Generally, as shown in fig. 1, in the first step of the hydrometallurgical process, valuable metals (nickel-cobalt-manganese-lithium) are extracted in a free state by using an acid leaching method (including inorganic acid and organic acid), and a reducing agent is added to improve the recovery rate of the valuable metals, so that part of the valuable metals cannot be extracted at one time regardless of the acid and the reducing agent, and the first waste residue, namely the first metal-containing waste residue, is generated in the hydrometallurgy. In order to increase the recovery rate of valuable metals and to improve the economy, the first metalliferous waste residue needs to be subjected to secondary leaching. The first metal-containing waste residue is characterized in that the content of the binder and the conductive agent is high, the conductive agent is generally conductive carbon black, acetylene black, ketjen black and the like, the substances generally have the characteristics of strong hydrophobicity and low density, the treatment is difficult, and no good solution exists in the market at present. When the secondary leaching is carried out according to the primary leaching method, the phenomenon of material flushing is particularly easy to cause when a reducing agent is added, in addition, the working procedure of adding the reducing agent is more complicated, and the process cost is increased.

In the second step, the removal of the ferro-aluminium impurities from the leach solution is generally carried out by adding a pH adjusting agent for neutralization and hydrolysis, and separating the iron and aluminium elements from other ions in the form of hydroxide precipitates, which is the second slag, the second metal-containing slag, produced by hydrometallurgy. When the pH is adjusted, the local solution is easy to precipitate nickel, cobalt and manganese through over-alkali when the pH adjusting agent is added, and then the nickel, cobalt and manganese are dissolved more slowly along with the increase of the pH, so that part of nickel, cobalt and manganese are precipitated together in the process of adjusting the pH. Meanwhile, aluminum and iron are easy to form amorphous colloid in the continuous precipitation-dissolution-precipitation process, the water content is high, the filtration is difficult, and valuable metals such as nickel, cobalt, manganese, lithium and the like are easy to adsorb, so that the recovery is not thorough. Because the second contains a large amount of amorphous aluminium hydroxide of metal waste, so adsorbed material is more, contains partial hydroxide because local alkali produces moreover, so when handling second contains metal waste alone, need separate the aluminium element of iron, does not have fine processing scheme at present, and it is not good to handle second containing metal waste alone effect, and the effect that alkali handled second containing metal waste is not good, causes aluminium element and other valuable metallic element to separate unsatisfactory, and the iron element can't separate. When the aluminum content in the solution for removing iron and aluminum is 5000ppm, the loss rate of nickel, cobalt, manganese and lithium is about 15 percent, and the treatment of the second metal-containing waste residue is very necessary, especially under the condition that the aluminum content in the anode powder is higher.

And thirdly, removing copper by using soluble sulfides (sodium sulfide, ammonium sulfide, potassium sulfide and the like), selectively and deeply removing copper, generating a small amount of waste residues, directly treating the waste residues to obtain a solution containing iron, aluminum and copper, adding sodium hydroxide into the solution to separate nickel, cobalt and manganese in a precipitation form from lithium ions, and washing and dissolving the nickel, cobalt and manganese precipitate to obtain the solution to be subjected to calcium and magnesium removal.

Fourthly, generally, when the calcium and magnesium content in the calcium and magnesium removing solution is below 300ppm, fluoride (manganese fluoride and nickel fluoride) is generally added into the solution after copper removal to precipitate calcium and magnesium, and when a large amount of nickel and cobalt ions are contained in the solution, the fluorine ions and the nickel and cobalt ions form complex fluoride [ NiF ₆ ] ^4- And [ CoF ₆ ] ^4- And the like, the fluoride complex ion is difficult to eliminate. In addition, in the process of removing calcium and magnesium by adding fluoride, the content of calcium and magnesium ions in the solution can be reduced to the requirement of the solution required for producing qualified products because the addition amount of fluoride is far greater than the theoretical amount due to the interference of background metal ions. Therefore, in order to deeply remove calcium and magnesium, the addition amount of the fluoride is required to be 2-7% of the mass fraction of the calcium and magnesium solution to be removed, the specific addition amount can be determined according to the content of calcium and magnesium, and more waste residues are generated. This is the third slag produced by hydrometallurgy, the third metal-containing slag. When the third metal-containing waste residue is treated separately, although calcium fluoride and magnesium fluoride can be separated from nickel fluoride or manganese fluoride by using an acid, the resulting solution containing a large amount of fluorine ions is difficult to treat.

Patent CN 110373545A discloses the use of alkali solution to treat the second metal-containing slag, but this method cannot separate iron from nickel, cobalt and manganese. Usually, multiple alkali dissolution is needed to change the aluminum element into the metaaluminate ions, the obtained alkali dissolution slag needs to be dissolved by adding acid again, and the obtained sodium metaaluminate needs to be additionally treated. CN 114214517A needs to prepare an aluminum-containing defluorinating agent in addition to achieve the purpose of defluorinating, thereby increasing the process flow and other costs. In the CN 111455175A patent, nickel fluoride or manganese fluoride is used for removing calcium and magnesium in the impurity removal process, other impurities are not introduced, but other generated waste residues are rarely mentioned, and a solution of the waste residues is not given.

Disclosure of Invention

The invention mainly aims to provide a method for recovering waste residues generated by wet recovery of lithium battery positive electrode powder, so as to solve the problem that the waste residues generated by wet metallurgy recovery of the lithium battery positive electrode powder in the prior art are difficult to recover.

In order to achieve the above object, according to one aspect of the present invention, there is provided a method for recovering waste residues generated by wet recovery of lithium battery anode powder, the waste residues including a first metal-containing waste residue, a second metal-containing waste residue and a third metal-containing waste residue, the first metal-containing waste residue containing nickel, cobalt, manganese and lithium elements; the second metal-containing waste residue contains iron, aluminum, nickel, cobalt, manganese and lithium elements; the third metal-containing waste residue contains fluorine, calcium, magnesium, nickel and manganese elements; the recovery method comprises the following steps: step S1, dissolving first metal-containing waste residue by using a sulfuric acid aqueous solution, and heating and leaching to obtain a first dissolved solution; s2, diluting the first solution with a diluent to obtain a first solution diluent; dissolving the second metal-containing waste residue by using the first solution diluent to obtain a second solution; dissolving the third metal-containing waste residue by using the first solution diluent to obtain a third solution; s3, mixing the second solution and the third solution to obtain a mixed solution; adding an initiator into the mixed solution to adjust the pH of the mixed solution to 4.5-5.1, and triggering a fluorination reaction to obtain the nickel-cobalt-manganese-lithium-containing recovered solution.

Further, in the step S1, the mass concentration of the sulfuric acid aqueous solution is 30-50%; preferably, the mass ratio of the sulfuric acid aqueous solution to the first metal-containing waste residue is (10-20): 1.

Further, in the step S1, the temperature of the heating leaching is 80-90 ℃, and the time is 1-3 h.

Further, in step S2, the diluent is water or a mixed solution of water and hydrogen peroxide.

In step S2, the volume ratio of the diluent to the first solution is (0.5-1): 1.

Further, in step S2, the pH of the second solution is less than 1, and the pH of the third solution is less than 2.

Further, the second solution includes aluminum, the third solution includes fluorine, and in step S3, the second solution and the third solution are mixed according to the ratio of aluminum: the molar ratio of fluorine is 1 (5.5-6.1).

Further, in step S3, the initiator includes one or more of a first initiator, a second initiator and a third initiator; wherein the first initiator comprises sodium hydroxide and/or sodium carbonate, the second initiator comprises potassium hydroxide and/or potassium carbonate, and the third initiator comprises ammonia and/or ammonium carbonate.

Further, the wet recovery uses a pH regulator to remove iron and aluminum, wherein the pH regulator comprises one or more of a first pH regulator, a second pH regulator and a third pH regulator; wherein the first pH regulator comprises one or more of sodium hydroxide, sodium carbonate and sodium bicarbonate, the second pH regulator comprises one or more of potassium hydroxide, potassium carbonate and potassium bicarbonate, and the third pH regulator comprises one or more of ammonia, ammonium carbonate and ammonium bicarbonate; wherein, when the pH regulator is a first pH regulator, the initiator is a first initiator; and/or when the pH regulator is a second pH regulator, the initiator is a second initiator; and/or when the pH adjuster is a third pH adjuster, the initiator is a third initiator.

Further, the step S3 also comprises the step of stirring the fluorination reaction finished solution for 1 to 2 hours and then aging for 2 to 6 hours to obtain the nickel-cobalt-manganese-lithium-containing recovered solution.

By applying the technical scheme of the invention, the treatment of three main waste residues generated by wet metallurgy is skillfully combined with each other, and the problem that the waste residues generated in the wet metallurgy recovery process are difficult to treat is solved through synergistic treatment, and the maximum possibility of recovering valuable metals is realized by using very low cost. In addition, special reagents such as a defluorinating agent and the like do not need to be added, the effect of synchronously removing iron, aluminum and fluorine can be achieved by using a simple initiator, the impurity removal selectivity is strong, and the separation effect is good. The recovery method can well separate the impurity element substances from the valuable metal elements, realizes the recovery of all elements, is simple and easy to implement, is more practical, and is easy to realize scientific, reasonable and efficient industrial application.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate embodiments of the invention and, together with the description, serve to explain the invention and not to limit the invention. In the drawings:

FIG. 1 shows a flow chart of a process for recovering lithium battery positive electrode powder by hydrometallurgy; and

FIG. 2 shows a flowchart of a slag recovery process according to example 1 of the present invention.

Detailed Description

It should be noted that the embodiments and features of the embodiments in the present application may be combined with each other without conflict. The present invention will be described in detail below with reference to the embodiments with reference to the attached drawings.

It should be noted that, as described in the background art, the first metal-containing waste residue of the present invention refers to acid-leaching waste residue of lithium battery positive electrode powder, wherein the acid-leaching waste residue mainly contains unleached nickel, cobalt, manganese and lithium, and also contains a large amount of binder and conductive agent; the second metal-containing waste residue is iron and aluminum removing waste residue of lithium battery anode powder, wherein the iron and aluminum removing waste residue mainly comprises amorphous iron hydroxide, aluminum hydroxide, partial precipitated nickel, cobalt and manganese and adsorbed lithium ions; the third metal-containing waste residue is calcium and magnesium-removed waste residue of lithium battery anode powder, wherein the calcium and magnesium-removed waste residue mainly comprises manganese nickel fluoride and calcium magnesium fluoride. Unless otherwise specified, the first metal-containing waste residue, the second metal-containing waste residue and the third metal-containing waste residue of the present invention are all referred to as a dry residue basis.

Interpretation of terms:

liquid-solid ratio: mass ratio of solution to solid material.

As mentioned in the background of the invention, the problem that the waste residue generated by recovering the lithium battery anode powder by hydrometallurgy is difficult to recover exists in the prior art. In order to solve the above problems, in an exemplary embodiment of the present invention, a method for recovering waste residues generated by wet recovery of lithium battery anode powder is provided, where the waste residues include a first metal-containing waste residue, a second metal-containing waste residue, and a third metal-containing waste residue, and the first metal-containing waste residue contains nickel, cobalt, manganese, and lithium elements; the second metal-containing waste residue contains iron, aluminum, nickel, cobalt, manganese and lithium elements; the third metal-containing waste residue contains fluorine, calcium, magnesium, nickel and manganese elements; the recovery method comprises the following steps: step S1, dissolving first metal-containing waste residue by using a sulfuric acid aqueous solution, and heating and leaching to obtain a first dissolved solution; s2, diluting the first solution with a diluent to obtain a first solution diluent; dissolving the second metal-containing waste residue by using the first solution diluent to obtain a second solution; dissolving the third metal-containing waste residue by using the first solution diluent to obtain a third solution; s3, mixing the second solution and the third solution to obtain a mixed solution; adding an initiator into the mixed solution to adjust the pH of the mixed solution to 4.5-5.1, and triggering a fluorination reaction to obtain the nickel-cobalt-manganese-lithium-containing recovered solution.

As described above, the first metal-containing waste residue mainly contains unleached nickel-cobalt-manganese-lithium, a binder and a conductive agent, and aiming at the characteristics of the first metal-containing waste residue, the first metal-containing waste residue is dissolved by using a sulfuric acid aqueous solution, the first metal-containing waste residue is heated and leached, the nickel-cobalt-manganese-lithium unleached at one time is leached into the sulfuric acid aqueous solution in a free state at a higher temperature, a first dissolved solution is obtained, the first dissolved solution mainly contains a sulfuric acid solution containing nickel, cobalt, manganese and lithium ions, and the binder and the conductive agent with strong hydrophobicity and low density enter filter residue for separation; and then diluting the first solution with a diluent to obtain a first solution diluent, dissolving the second metal-containing waste residue with the first solution diluent, and completely extracting amorphous ferric hydroxide, aluminum hydroxide, part of precipitated nickel, cobalt and manganese and adsorbed lithium ions into the solution to obtain a second solution, wherein the second solution is mainly a solution containing iron, aluminum, nickel, cobalt, manganese and lithium ions.

And dissolving the third metal-containing waste residue by using the first solution diluent, and extracting fluorine, nickel and manganese in the third metal-containing waste residue into a solution to obtain a third solution, wherein calcium fluoride and magnesium fluoride in the third metal-containing waste residue are slightly soluble in the diluted sulfuric acid solution, so that calcium and magnesium can be separated out in a precipitation form after the third metal-containing waste residue is completely dissolved, only a small amount of calcium and magnesium enters the third solution in an ion form, and the third solution is mainly a solution containing fluorine, nickel and manganese ions or a complex thereof.

And finally, mixing the second solution and the third solution to obtain a mixed solution, wherein the mixed solution contains more nickel complex fluoride, manganese complex fluoride and free fluoride ions after the two solutions are mixed with each other, an initiator is added into the mixed solution to trigger the fluorination reaction, the pH of the solution can be increased, the pH of the reaction solution is 4.5-5.1 at the moment, the fluorination reaction is more favorably carried out, after precipitation and filtration are carried out, the filtrate is the recovered solution containing nickel, cobalt, manganese and lithium, and the filter residue is mainly a fluoroaluminate compound and part of ferric hydroxide precipitate. Because fluoride ions have excellent selectivity on aluminum ions, nickel, cobalt, manganese and lithium cannot be adsorbed or precipitated, the fluoride reaction mainly generates fluoroaluminate, the fluoroaluminate has better crystallinity and is easier to filter, and iron in the solution is hydrolyzed due to the increase of pH to form ferric hydroxide precipitate for removal, so that the effects of removing fluorine and iron and aluminum at the same time can be achieved at one time, the impurity removal selectivity is strong, the separation effect is good, special reagents such as a fluorine removal agent and the like are not required to be added, other impurities are not introduced, and the maximum recovery of nickel, cobalt, manganese and lithium is realized. The aluminum content in the recovery liquid containing nickel, cobalt, manganese and lithium is below 30ppm, the fluorine content is below 50ppm, and the recovery liquid can be incorporated into the subsequent hydrometallurgy leaching liquid for further recovery of nickel, cobalt, manganese and lithium.

The invention skillfully combines the treatment of three main waste residues generated by wet metallurgy, solves the problem that the waste residues generated in the wet metallurgy recovery process are difficult to treat through cooperative treatment, and uses a simple chemical method and non-harsh chemical conditions to ensure that the recovery method becomes simple and easy, realizes the maximum possibility recovery of valuable metals by using very low cost, can well separate the impurity element substances from the valuable metal elements, realizes the recovery of all elements, is simple and easy to implement, is more practical to fit, and is easy to realize scientific, reasonable and efficient industrial application.

In a preferred embodiment, in step S1, the mass concentration of the aqueous sulfuric acid solution is 30 to 50%; preferably, the mass ratio of the sulfuric acid aqueous solution to the first metal-containing waste residue is (10-20): 1. The concentrated sulfuric acid solution and the large liquid-solid ratio are beneficial to leaching the valuable metals left in the first metal waste residue, the valuable metal recovery rate is further increased, and the leached sulfuric acid can be used in other procedures.

Higher temperatures also increase the leaching rate of the valuable metals, and in a preferred embodiment, the temperature for the heat leaching in step S1 is 80-90 ℃ for 1-3 h.

In a preferred embodiment, in step S2, the diluent is water or a mixed solution of water and hydrogen peroxide, preferably a mixed solution of water and hydrogen peroxide, and the amount of hydrogen peroxide added is adjusted as required, and a small amount of hydrogen peroxide is added to increase the leaching rate of nickel, cobalt and manganese, so that the hydrogen peroxide can dilute and play a role of an oxidant, thereby facilitating subsequent dissolution of waste slag.

Specifically, in a preferred embodiment, in step S2, the volume ratio of the diluent to the first dissolved solution is (0.5-1): 1, and the obtained first dissolved solution is diluted in the above ratio, so that the first dissolved solution can be more conveniently used for dissolving the second metal-containing waste residue and the third metal-containing waste residue, and the leaching rate is improved.

In the step S2, the mass ratio of the first solution diluent to the second metal-containing waste residue and the third metal-containing waste residue is adaptively adjusted according to the content of metal in the waste residue in the actual treatment process. For the purpose of further reducing material waste and cost while completely dissolving the second and third metal-containing wastes, in a preferred embodiment, the pH of the second solution is less than 1, the pH of the third solution is less than 2, the pH of the solutions is related to the contents of the wastes and the amount of the diluent added to the first solution, and controlling the pH of the solutions to the above range can further extract all the amorphous iron hydroxide, aluminum hydroxide, and partially precipitated nickel-cobalt-manganese and adsorbed lithium ions in the second metal-containing wastes into the solution, while further reducing the calcium and magnesium in the third solution to be dissolved in the solution, and the effect of removing calcium and magnesium is better.

In a preferred embodiment, the second solution includes aluminum, the third solution includes fluorine, and in step S3, the second solution and the third solution are mixed in a ratio of aluminum: the molar ratio of fluorine is 1 (5.5-6.1), and the aluminum impurities in the final recovery liquid can be further reduced to a lower content, and the impurity removal effect is better.

As described above, in the present application, a simple initiator is used without preparing a fluorine removal agent, so as to achieve the effect of removing iron, aluminum and fluorine simultaneously, and in order to further enhance the selectivity of the fluorination reaction and improve the separation effect, in a preferred embodiment, in step S3, the initiator includes one or more of a first initiator, a second initiator and a third initiator; the first initiator comprises sodium hydroxide and/or sodium carbonate, the second initiator comprises potassium hydroxide and/or potassium carbonate, and the third initiator comprises ammonia water and/or ammonium carbonate.

In order to avoid introducing more impurities in the recovery process, in a preferred embodiment, the wet recovery uses a pH regulator for removing iron and aluminum, wherein the pH regulator comprises one or more of a first pH regulator, a second pH regulator and a third pH regulator; wherein the first pH regulator comprises one or more of sodium hydroxide, sodium carbonate and sodium bicarbonate, the second pH regulator comprises one or more of potassium hydroxide, potassium carbonate and potassium bicarbonate, and the third pH regulator comprises one or more of ammonia, ammonium carbonate and ammonium bicarbonate; when the pH regulator is a first pH regulator, the initiator is a first initiator; and/or when the pH regulator is a second pH regulator, the initiator is a second initiator; and/or when the pH adjustor is a third pH adjustor, the initiator is a third initiator. The purpose of the pH regulator and the initiator are the same metal salt is that the precipitation product obtained after the fluorination reaction is the same fluoroaluminate, and the generated product is purer, so that the further separation of the impurity element substance and the valuable metal element is realized, and the separation and recovery of all elements are better realized.

In a preferred embodiment, the step S3 further comprises a step of stirring the fluorination reaction completion solution for 1 to 2 hours and then aging for 2 to 6 hours to obtain the nickel-cobalt-manganese-lithium-containing recovery solution. The occurrence of the fluorination reaction can be further promoted, so that the fluorine, the iron and the aluminum in the solution can be more fully removed.

The present application is described in further detail below with reference to specific examples, which should not be construed as limiting the scope of the invention as claimed.

Example 1

The components of the cathode powder recovered in example 1 are shown in table 1, the flow chart of the cathode powder hydrometallurgy recovery process is shown in fig. 1, and the flow chart of the generated waste residue recovery process is shown in fig. 2.

TABLE 1

Content of elements/%)	Nickel (II)	Cobalt	Manganese oxide	Lithium ion source	Iron	Aluminium	Copper (Cu)	Calcium carbonate	Magnesium alloy
										Positive electrode powder	8.66	8.80	25.29	4.05	0.05	2.74	0.11	0.06	0.02

(1) Treatment of the first metal-containing waste residue: stirring a sulfuric acid water solution with the mass fraction of 45% and the first metal-containing waste residue according to the mass ratio of 10 to 1 at 85 ℃ for 2 hours, filtering, washing filter residues with a proper amount of water, and drying to measure the content of valuable metals; part of the filtrate, namely the first solution, returns to the heating leaching process, and part of the filtrate is used for dissolving the second metal-containing waste residue and the third metal-containing waste residue;

(2) And (3) treating the second metal-containing waste residue: adding 1 time of water and hydrogen peroxide mixed solution to dilute the first solution, dissolving the second metal-containing waste residue until the second metal-containing waste residue is completely dissolved, and filtering to obtain filtrate, namely a second solution, wherein the pH value of the second solution is below 1, and the content of aluminum in the second solution is 5.8g/L;

(3) And (3) treating the third metal-containing waste residue: adding 1 time of the mixed solution of water and hydrogen peroxide to dilute the first solution, dissolving the third metal-containing waste residue until the third metal-containing waste residue is completely dissolved, and filtering to obtain a filtrate, namely a third solution, wherein the pH of the third solution is below 2, the fluorine content in the third solution is 2.7g/L, and filter residues mainly comprise calcium fluoride and magnesium fluoride;

(4) In the main flow of hydrometallurgy, a pH regulator is sodium hydroxide, and an initiator is 10wt% of sodium hydroxide aqueous solution; and (3) under stirring, mixing the second solution and the third solution according to the ratio of aluminum: mixing the materials according to the molar ratio of fluorine of 1. Finally, the aluminum content of the nickel-cobalt-manganese-lithium containing filtrate is 25mg/L, the iron content is 28mg/L, and the fluorine content is 34mg/L.

The content of valuable metals in the first metal-containing waste residue before and after leaching is shown in table 2; the overall recovery of each valuable metal is shown in table 3.

TABLE 2

Content of elements/%)	Nickel (II)	Cobalt	Manganese oxide	Lithium ion source
					Before treatment	0.70	0.61	15.04	0.86
After treatment	0.026	0.006	0.026	0.004

TABLE 3

Item	Nickel (II)	Cobalt	Manganese oxide	Lithium ion source	Aluminium	Iron
							Percent recovery%	99.95	99.97	99.84	99.74	99.88	99.75

Example 2

The composition of the cathode powder recovered in example 2 is shown in table 4.

TABLE 4

Content of elements/%)	Nickel (II)	Cobalt	Manganese oxide	Lithium ion source	Iron	Aluminium	Copper (Cu)	Calcium carbonate	Magnesium alloy
										Positive electrode powder	26.74	10.37	14.82	5.94	0.013	1.02	1.13	0.028	0.001

Example 2 treatment of only the first metalliferous waste residue: stirring the sulfuric acid water solution with the mass fraction of 35% and the first metal-containing waste residue for 2 hours at 85 ℃ according to the mass ratio of 15.

TABLE 5

Content of elements/%)	Nickel (II)	Cobalt	Manganese oxide	Lithium ion source
					Before treatment	4.66	1.48	2.20	0.99
After treatment	0.028	0.009	0.013	0.004

Example 3

The composition of the cathode powder recovered in example 3 is shown in table 6.

TABLE 6

Content of elements/%)	Nickel (II)	Cobalt	Manganese oxide	Lithium ion source	Iron	Aluminium	Copper (Cu)	Calcium carbonate	Magnesium alloy
										Positive electrode powder	6.51	6.98	28.63	3.31	0.056	3.25	0.174	0.174	0.036

(1) Treatment of the first metal-containing waste residue: stirring a sulfuric acid water solution with the mass fraction of 45% and first metal-containing waste residue for 2 hours at 85 ℃ according to the mass ratio of 10; part of the filtrate, namely the first solution, returns to the heating leaching process, and part of the filtrate is used for dissolving the second metal-containing waste residue and the third metal-containing waste residue;

(2) And (3) treating the second metal-containing waste residue: adding 1 time of water and hydrogen peroxide mixed solution to dilute the first solution, dissolving the second metal-containing waste residue until the second metal-containing waste residue is completely dissolved, and filtering to obtain filtrate, namely a second solution, wherein the pH value of the second solution is below 1, and the aluminum content in the second solution is 6.4g/L;

(3) And (3) treating the third metal-containing waste residue: adding 1 time of the mixed solution of water and hydrogen peroxide to dilute the first dissolved solution, dissolving the third metal-containing waste residue until the third metal-containing waste residue is completely dissolved, and filtering to obtain a filtrate, namely a third dissolved solution, wherein the pH of the third dissolved solution is below 2, the fluorine content in the third dissolved solution is 4.9g/L, and filter residues mainly comprise calcium fluoride and magnesium fluoride;

(4) In the main flow of hydrometallurgy, a pH regulator is potassium carbonate, and an initiator is a 15wt% potassium carbonate aqueous solution; and (3) mixing the second solution and the third solution according to the ratio of aluminum: and (2) mixing the materials according to the molar ratio of fluorine of 1. The aluminum content of the final filtrate containing nickel, cobalt, manganese and lithium is 18mg/L, the iron content is 13mg/L, the fluorine content is 44mg/L, and the overall recovery rate of each valuable metal is shown in Table 7.

TABLE 7

Item	Nickel (II)	Cobalt	Manganese oxide	Lithium ion source	Aluminium	Iron (II)
							Percent recovery%	99.89	99.93	99.89	99.84	99.79	99.85

Example 4

The composition of the cathode powder recovered in example 4 is shown in table 8.

TABLE 8

Content of elements/%)	Nickel (II)	Cobalt	Manganese oxide	Lithium ion source	Iron	Aluminium	Copper (Cu)	Calcium carbonate	Magnesium alloy
										Positive electrode powder	13.45	11.64	16.37	4.89	0.021	2.17	0.11	0.036	0.009

(1) Treatment of the first metal-containing waste residue: stirring a sulfuric acid solution with the mass fraction of 35% and the first metal-containing waste residue according to the mass ratio of 10 to 1 at 85 ℃ for 2 hours, filtering, washing filter residues with a proper amount of water, and drying to measure the content of valuable metals; part of the filtrate, namely the first solution, returns to the heating leaching process, and part of the filtrate is used for dissolving the second metal-containing waste residue and the third metal-containing waste residue;

(2) And (3) treating the second metal-containing waste residue: adding 0.5 times of the mixed solution of water and hydrogen peroxide to dilute the first solution, dissolving the second metal-containing waste residue until the second metal-containing waste residue is completely dissolved, and filtering to obtain a filtrate, namely a second solution, wherein the pH value of the second solution is below 1, and the aluminum content in the second solution is 3.7g/L;

(3) And (3) treating the third metal-containing waste residue: adding 0.5 times of the mixed solution of water and hydrogen peroxide to dilute the first solution, dissolving the third metal-containing waste residue until the third metal-containing waste residue is completely dissolved, filtering to obtain a filtrate, namely a third solution, wherein the pH of the third solution is below 2, the fluorine content in the third solution is 3.2g/L, and filter residues mainly comprise calcium fluoride and magnesium fluoride;

(4) In the main flow of hydrometallurgy, a pH adjusting agent is ammonia water, and an initiator is 10wt% of ammonia water; and (3) under stirring, mixing the second solution and the third solution according to the ratio of aluminum: and (3) mixing the materials according to the molar ratio of fluorine of 1. The aluminum content of the final filtrate containing nickel, cobalt, manganese and lithium is 13mg/L, the iron content is 24mg/L, the fluorine content is 14mg/L, and the overall recovery rate of each valuable metal is shown in Table 9.

TABLE 9

Item	Nickel (II)	Cobalt	Manganese oxide	Lithium ion source	Aluminium	Iron
							Percent recovery%	99.79	99.86	99.91	99.76	99.90	99.73

Example 5

The composition of the cathode powder recovered in example 5 was the same as in example 1.

(1) Treatment of the first metal-containing waste residue: stirring a sulfuric acid aqueous solution with the mass fraction of 30% and first metal-containing waste residue for 3 hours at the temperature of 80 ℃ according to the mass ratio of 20; part of the filtrate, namely the first solution, returns to the heating leaching process, and part of the filtrate is used for dissolving the second metal-containing waste residue and the third metal-containing waste residue;

(4) In the main flow of hydrometallurgy, a pH regulator is sodium hydroxide, and an initiator is 10wt% of sodium hydroxide aqueous solution; and (3) under stirring, mixing the second solution and the third solution according to the ratio of aluminum: and (2) mixing the materials according to the molar ratio of fluorine of 1. The aluminum content of the final filtrate containing nickel, cobalt, manganese and lithium is 27mg/L, the iron content is 30mg/L and the fluorine content is 15mg/L.

The content of valuable metals in the first metal-containing waste residue before and after leaching is shown in Table 10; the overall recovery of each valuable metal is shown in Table 11.

Watch 10

Content of elements/%)	Nickel (II)	Cobalt	Manganese oxide	Lithium ion source
					Before treatment	0.70	0.61	15.04	0.86
After treatment	0.029	0.008	0.028	0.026

TABLE 11

Item	Nickel (II)	Cobalt	Manganese oxide	Lithium ion source	Aluminium	Iron
							Percent recovery%	99.92	99.95	99.83	99.71	99.85	99.73

Example 6

The composition of the recovered positive electrode powder of example 6 was the same as that of example 1.

(1) Treatment of the first metal-containing waste residue: stirring a sulfuric acid water solution with the mass fraction of 50% and first metal-containing waste residue for 1 hour at the temperature of 90 ℃ according to the mass ratio of 10; part of the filtrate, namely the first solution, returns to the heating leaching process, and part of the filtrate is used for dissolving the second metal-containing waste residue and the third metal-containing waste residue;

(4) In the main flow of hydrometallurgy, a pH regulator is sodium hydroxide, and an initiator is 10wt% of sodium hydroxide aqueous solution; and (3) under stirring, mixing the second solution and the third solution according to the ratio of aluminum: mixing the materials according to the molar ratio of fluorine of 1. Finally, the aluminum content of the nickel-cobalt-manganese-lithium containing filtrate is 28mg/L, the iron content is 29mg/L, and the fluorine content is 36mg/L.

The content of valuable metals in the first metal-containing waste residue before and after leaching is shown in Table 12; the overall recovery of each valuable metal is shown in Table 13.

TABLE 12

Content of elements/%)	Nickel (II)	Cobalt	Manganese oxide	Lithium ion source
					Before treatment	0.70	0.61	15.04	0.86
After treatment	0.028	0.009	0.030	0.027

Watch 13

Item	Nickel (II)	Cobalt	Manganese (Mn)	Lithium ion source	Aluminium	Iron
							Percent recovery%	99.91	99.94	99.84	99.70	99.84	99.75

Comparative example 1

The second metal-containing waste residue in example 1 was treated with 80g/L aqueous sodium hydroxide solution at a liquid-to-solid ratio of 10, the temperature of mixing was controlled at 90 ℃ with stirring, the reaction was carried out for 3 hours, then filtration was carried out, and ICP-AES detection was carried out on the filter residue. The dissolution rate of the aluminum element is only 74.43 percent, the lithium solubility in the filtrate is 54.3 percent in a conversion mode, the nickel, the cobalt, the manganese and the iron are in the filter residue, and undissolved lithium is adsorbed on the surface of the filter residue.

From the above, it can be seen that, compared with the comparative example, the treatment of the three main waste residues generated by hydrometallurgy is skillfully combined with each other in each embodiment of the invention, and the problem that the waste residues generated in the hydrometallurgy recovery process are difficult to treat is solved through synergistic treatment, and the maximum possible recovery of valuable metals is realized at very low cost. In addition, special reagents such as a defluorinating agent and the like do not need to be added, the effect of synchronously removing iron, aluminum and fluorine can be achieved by using a simple initiator, the impurity removal selectivity is strong, the separation effect is good, impurity element substances and valuable metal elements can be well separated, the recovery of all elements is realized, and the method is simple and easy to implement and is more practical. In addition, it can be seen that the impurity removal effect and the recovery rate of valuable metals are better when the recovery process parameters are all within the preferred ranges of the present invention.

The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention, and various modifications and changes may be made by those skilled in the art. Any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for recovering waste residues generated by wet recovery of lithium battery anode powder comprises the steps of enabling the waste residues to comprise first metal-containing waste residues, second metal-containing waste residues and third metal-containing waste residues, wherein the first metal-containing waste residues contain nickel, cobalt, manganese and lithium elements; the second metal-containing waste residue contains iron, aluminum, nickel, cobalt, manganese and lithium; the third metal-containing waste residue contains fluorine, calcium, magnesium, nickel and manganese elements; the recovery method is characterized by comprising the following steps:

step S1, dissolving the first metal-containing waste residue by using a sulfuric acid aqueous solution, and heating and leaching to obtain a first dissolved solution;

s2, diluting the first dissolved solution with a diluent to obtain a first dissolved solution diluent; dissolving the second metal-containing waste residue by using the first dissolving solution diluent to obtain a second dissolving solution; dissolving the third metal-containing waste residue by using the first solution diluent to obtain a third solution;

s3, mixing the second solution and the third solution to obtain a mixed solution; and adding an initiator into the mixed solution to adjust the pH of the mixed solution to 4.5-5.1, and triggering a fluorination reaction to obtain the nickel-cobalt-manganese-lithium-containing recovered solution.

2. The recovery method according to claim 1, wherein in the step S1, the mass concentration of the sulfuric acid aqueous solution is 30 to 50%; preferably, the mass ratio of the sulfuric acid aqueous solution to the first metal-containing waste residue is (10-20): 1.

3. The recycling method according to claim 1 or 2, wherein the temperature of the heat leaching in the step S1 is 80-90 ℃ for 1-3 h.

4. The recovery method according to any one of claims 1 to 3, wherein in the step S2, the diluent is water or a mixed solution of water and hydrogen peroxide.

5. The recovery method according to any one of claims 1 to 4, wherein the volume ratio of the diluent to the first solution in step S2 is (0.5 to 1): 1.

6. The recovery method according to any one of claims 1 to 5, wherein in the step S2, the pH of the second solution is < 1, and the pH of the third solution is < 2.

7. A recovery method, according to any one of claims 1 to 6, characterized in that said second dissolution liquid comprises aluminium,

the third solution includes fluorine, and in step S3, the second solution and the third solution are mixed in a ratio of aluminum: the molar ratio of fluorine is 1 (5.5-6.1).

8. The recycling method according to any one of claims 1 to 7, wherein in the step S3, the initiator includes one or more of a first initiator, a second initiator, and a third initiator;

wherein the first initiator comprises sodium hydroxide and/or sodium carbonate, the second initiator comprises potassium hydroxide and/or potassium carbonate, and the third initiator comprises ammonia and/or ammonium carbonate.

9. The recovery method according to claim 8, wherein the wet recovery is performed for removing iron and aluminum using a pH adjuster including one or more of a first pH adjuster, a second pH adjuster, and a third pH adjuster; wherein the first pH adjusting agent comprises one or more of sodium hydroxide, sodium carbonate and sodium bicarbonate, the second pH adjusting agent comprises one or more of potassium hydroxide, potassium carbonate and potassium bicarbonate, and the third pH adjusting agent comprises one or more of aqueous ammonia, ammonium carbonate and ammonium bicarbonate;

wherein, when the pH regulator is the first pH regulator, the initiator is the first initiator; and/or when the pH adjuster is the second pH adjuster, the initiator is the second initiator; and/or when the pH adjuster is the third pH adjuster, the initiator is the third initiator.

10. The recovery method according to any one of claims 1 to 9, further comprising a step of stirring the fluorination reaction completion solution for 1 to 2 hours and then aging the fluorination reaction completion solution for 2 to 6 hours to obtain the nickel-cobalt-manganese-lithium-containing recovery solution in step S3.