Valuable metal recovery method

Abstract

The method for recovering valuable metals according to the present invention includes the steps of (S1) extracting a sulfate solution from waste battery materials, (S2) adding a phosphorus-based compound to the sulfate solution to precipitate aluminum phosphate, and (S3) separating the aluminum phosphate from the sulfate solution by solid-liquid separation, wherein the concentration of metal sulfate contained in the sulfate solution is 90 g / L or more.

Description

[Technical Field]

[0001] The present invention relates to a method for recovering valuable metals, and more particularly to a method for recovering valuable metals from waste batteries. [Background technology]

[0002] In recent years, the demand for secondary batteries has been increasing due to the expansion of the battery electric vehicle (BEV) market. Valuable metals such as nickel, cobalt, manganese, etc. are contained in the waste battery scrap generated during the secondary battery manufacturing process, waste cathode materials, and waste secondary battery scrap discarded after use. Recently, active development of technologies to recover and recycle valuable metals in secondary batteries has been underway.

[0003] Valuable metals such as nickel, cobalt, and manganese can be recovered by dissolving secondary battery raw materials in acid and then using solvent extraction. Solvent extraction utilizes the principle of metal ions being extracted from an aqueous solution into an organic solvent. Generally, when recovering valuable metals from secondary battery raw materials using solvent extraction, a process for removing impurities contained in the secondary battery raw materials is required. Typical examples of such impurities include aluminum and copper. However, there is a problem in that the waste rate of valuable metals increases due to process by-products generated during the impurity removal process, resulting in a decrease in the recovery rate of valuable metals. Summary of the Invention [Problem to be solved by the invention]

[0004] An object of the present invention is to provide a method for recovering valuable metals from waste batteries, which can shorten the recovery time, minimize the loss rate of valuable metals, and increase the aluminum removal rate when recovering valuable metals from waste batteries. [Means for solving the problem]

[0005] The method for recovering valuable metals according to the present invention includes a step (S1) of extracting a sulfate solution from waste battery materials, a step (S2) of adding a phosphorus-based compound to the sulfate solution to precipitate aluminum phosphate, and a step (S3) of performing solid-liquid separation of the aluminum phosphate from the sulfate solution, wherein the concentration of metal sulfate contained in the sulfate solution is 90 g / L or more.

[0006] In the valuable metal recovery method according to the present invention, the concentration of aluminum contained in the sulfate solution may be 1 g / L or more.

[0007] In the valuable metal recovery method according to the present invention, the metal sulfate may be one or more sulfates selected from the group consisting of nickel, cobalt, manganese, lithium, copper, and aluminum.

[0008] In the valuable metal recovery method according to the present invention, the step (S1) may include a step of calcining the shredded waste batteries without solvent treatment, and a step of recovering lithium using deionized water without carbon dioxide.

[0009] In the step (S2) of the valuable metal recovery method according to the present invention, the amount of the phosphorus-based compound added may be 0.1 wt % to 7.0 wt % based on the weight of the sulfate solution.

[0010] In the valuable metal recovery method according to the present invention, the molar ratio of phosphorus contained in the added phosphorus-based compound to aluminum contained in the sulfate solution (P / Al molar ratio) may be 0.92 to 1.72.

[0011] In the valuable metal recovery method according to the present invention, the phosphorus-based compound may be sodium phosphate.

[0012] In the valuable metal recovery method according to the present invention, step (S2) may last for 2 to 8 hours and may be performed at 25° C. to 95° C. In step (S2), the sulfate solution may have a pH of 2.0 to 5.0.

[0013] In the valuable metal recovery method according to the present invention, 96.0% or more of the aluminum contained in the sulfate solution may be precipitated and removed as the aluminum phosphate, on a weight basis.

[0014] The method for recovering valuable metals according to the present invention may further include a step (S4) of removing phosphorus contained in the sulfate solution, wherein the pH of the sulfate solution in step (S4) may be 5.0 or higher. [Effects of the Invention]

[0015] In recent years, there has been a trend toward reducing the process of separating and separating aluminum thin films from waste batteries in order to increase the recovery rate of valuable metals contained in batteries. As a result, battery material raw materials extracted from waste batteries contain high concentrations of aluminum, which is considered an impurity. Conventionally, aluminum has been removed by reacting aluminum contained in a leachate of the battery material raw materials with a hydroxide salt source, resulting in the precipitation of aluminum hydroxide as a process by-product. However, when the leachate contains a high concentration of aluminum, the valuable metal to be recovered precipitates in the form of hydroxide salt upon addition of the hydroxide salt source, resulting in a problem of reduced recovery rate of the valuable metal.

[0016] To solve these problems, the present invention adds a phosphorus-based compound instead of a hydroxide salt source to a sulfate solution containing a metal sulfate at a concentration of 90 g / L or more, thereby minimizing the loss rate of the metal to be recovered, increasing the aluminum removal rate, and reducing the time required for the aluminum removal process, even when the battery material raw material contains a high concentration of aluminum.As a result, the present invention ensures a variety of treatable battery material raw materials, making it applicable to waste battery treatment technology for medium- to large-sized batteries in packs, and has the advantage of being usable in fields such as electric vehicles. [Brief explanation of the drawings]

[0017] [Figure 1]FIG. 1 is a flow chart of the valuable metal recovery method according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0018] Hereinafter, specific contents for implementing the present disclosure will be described in detail with reference to the accompanying drawings. However, in the following description, specific descriptions of well-known functions and configurations will be omitted if they may obscure the gist of the present disclosure.

[0019] In the accompanying drawings, identical or corresponding components are denoted by the same reference numerals. In addition, in the following description of the embodiments, repeated descriptions of identical or corresponding components may be omitted. However, omission of a description of a component does not mean that such a component is not included in the embodiment.

[0020] The terms used in this disclosure will be briefly explained, and the disclosed embodiments will be specifically described. The terms used in this specification are currently commonly used and generally selected as much as possible, taking into consideration the function of the present disclosure. However, this may change depending on the intentions of engineers in the relevant field, precedents, or the emergence of new technology. In addition, in certain cases, the applicant may arbitrarily select terms, and in such cases, the meanings of these terms will be described in detail in the relevant description of the invention. Therefore, the terms used in this disclosure should be defined based on the meanings of the terms and the overall content of this disclosure, rather than simply by the names of the terms.

[0021] In this disclosure, the singular expression also includes the plural expression unless the context clearly specifies otherwise, and the plural expression also includes the singular expression unless the context clearly specifies otherwise.

[0022] In this disclosure, when a part includes one component, this does not mean that it excludes other components, but that it may further include other components, unless otherwise specified.

[0023] In this disclosure, the phrase "A and / or B" means A, or B, or A and B.

[0024] The advantages and features of the disclosed embodiments, as well as methods for achieving them, will become apparent from the following examples, taken in conjunction with the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below, and may be embodied in various other forms. The embodiments are provided solely to ensure that this disclosure will be complete and to fully convey the scope of the invention to those skilled in the art.

[0025] The method for recovering valuable metals according to the present invention includes a step (S1) of extracting a sulfate solution from waste battery materials, a step (S2) of adding a phosphorus-based compound to the sulfate solution to precipitate aluminum phosphate, and a step (S3) of performing solid-liquid separation of the aluminum phosphate from the sulfate solution, wherein the concentration of metal sulfate contained in the sulfate solution is 90 g / L or more.

[0026] Hereinafter, each step of the valuable metal recovery method according to the present invention will be described in more detail with reference to the drawings. Figure 1 is a process diagram of the valuable metal recovery method according to the present invention. As shown in Figure 1, the valuable metal recovery method includes a step (S1) of extracting a sulfate solution from waste battery material, a step (S2) of adding a phosphorus-based compound to the sulfate solution to precipitate aluminum phosphate, and a step (S3) of performing solid-liquid separation of the aluminum phosphate from the sulfate solution, and may further include a step (S4) of removing phosphorus contained in the sulfate solution.

[0027] Step S1: Leaching sulfate solution from waste battery material

[0028] The valuable metal recovery method according to the present invention begins with step (S1) of extracting a sulfate solution from waste battery materials. For example, step (S1) may be a step of extracting a sulfate solution from recovered waste battery materials. Alternatively, step (S1) may be a step of extracting a sulfate solution from one or more materials selected from the group consisting of nickel ore, nickel MHP (Mixed Hydroxide Precipitate), and nickel oxide, instead of the waste battery materials.

[0029] The waste battery material may be recovered by a pre-treatment process for waste batteries, which may include a discharging process, a dismantling process, a crushing / pulverizing process, a drying process, and a firing process.

[0030] The discharging process is a process of discharging power stored in the waste batteries to prevent the waste batteries from exploding during subsequent processes. The discharging process may be performed by mechanical discharging using a discharger or saltwater discharging using saltwater.

[0031] The dismantling process is a process of dismantling a pack-shaped waste battery into modules and / or cells. The dismantling process may be performed after the discharging process, but is not limited thereto. The dismantling process may be performed first, and then the discharging process. The dismantling process may be performed using, for example, automated dismantling equipment.

[0032] The crushing / pulverization process is a process in which disassembled waste batteries are crushed and pulverized to produce crushed powder. The crushing / pulverization process may be performed while spraying water under a nitrogen atmosphere to prevent sparks and explosions. After crushing and pulverization, the sprayed water and electrolyte that has leaked from the waste batteries may be removed. For example, the water and electrolyte may be removed by centrifugation in a rotary barrel.

[0033] The drying step is a step for removing water and electrolytes remaining after the crushing / grinding step. For example, the drying step may be carried out by adding nitrogen gas heated to about 50°C or higher to a dryer in which the crushed powder is placed.

[0034] The firing process is a process of roasting shredded / pulverized batteries. Generally, to improve battery performance, firing, metal oxide addition, binder addition, and the like are performed during the process of manufacturing cathode materials. As a result, waste battery materials, including cathode materials, may contain valuable metals and impurities in the form of various oxides, which can hinder the recovery of valuable metals by recycling waste batteries. High-temperature firing can be performed to remove such impurities. The firing process can be a process of reducing and firing shredded / pulverized batteries in an inert gas atmosphere (IAR: Inert Atmospheric Roaster). For example, in the firing process, shredded / pulverized batteries can be reduced and fired in a nitrogen atmosphere at a temperature of 800°C to 900°C for 1 hour to 3 hours.

[0035] The firing process of the present invention may omit a separate solvent treatment for removing binders contained in waste battery materials. The firing process can be simplified because the binder can be removed by firing the waste batteries in a reducing atmosphere without a separate solvent treatment. Furthermore, the firing process of the present invention may reduce metallic substances in the form of oxides that are bonded to oxygen in the waste batteries. Specifically, during the reduction firing of the shattered / pulverized batteries, some high oxides (MeO, Me=Ni, Co, Mn) may be reduced to low oxides (MeO, Me=Ni, Co, Mn). As a result, the amount of auxiliary materials (H2O2, hydrogen peroxide) used during the sulfate solution leaching process may be reduced.

[0036] Meanwhile, the waste battery material may be, but is not limited to, waste battery scrap, black mass obtained by converting waste batteries into raw materials through a recycling process, waste cathode material generated during the manufacturing process of cathode material, or a combination thereof.

[0037] The waste battery material may contain one or more metal oxides, for example, the metal oxide contained in the waste battery material may be one or more selected from the group consisting of lithium cobalt oxide (LiCoO), lithium nickel cobalt manganese oxide (LiNiCoMnO), lithium manganese oxide (LiMnO), and lithium iron phosphate (LiFePO).

[0038] In step (S1), the sulfate solution may be extracted from the waste battery material through a wet process. For example, the sulfate solution may be leached from the waste battery material recovered through the pretreatment process described above. During the leaching of the sulfate solution, a small amount of a reducing agent may be added to improve the dissolution rate of the cake. In this case, hydrogen peroxide (H2O2) may be used as the reducing agent.

[0039] According to one embodiment of the present invention, step (S1) may be carried out by a pre-separation process and a leaching process.

[0040] The pre-separation process involves adding water to shredded / crushed waste batteries to leach and separate lithium (Li). For example, in the lithium pre-separation process, shredded and crushed batteries are dissolved in water, and the lithium (Li) solution is leached at 10°C to 30°C for 1 to 3 hours to produce a lithium carbonate (Li2CO3) solution, from which a cake can be separated. When a sulfate solution is leached from the cake after lithium has been pre-separated from the waste battery material, the amount of auxiliary materials such as hydrogen peroxide used can be minimized, enabling stable process control in a continuous process. In the pre-separation process of the present invention, lithium can be recovered using deionized water without carbon dioxide (CO2). Recovering lithium using only deionized water without using carbon dioxide (CO2) reduces process costs and reduces the carbon footprint.

[0041] The leaching process is a process in which the sulfate solution is leached from the cake produced in the preliminary separation process. Specifically, in the leaching process, the cake produced in the preliminary separation process is subjected to reduction leaching with sulfuric acid and hydrogen peroxide (H2O2) at 80 to 85°C for 1 to 8 hours.

[0042] On the other hand, the metal sulfate contained in the sulfate solution may be one or more sulfates selected from the group consisting of nickel, cobalt, manganese, lithium, copper, and aluminum.

[0043] The concentration of the metal sulfate contained in the sulfate solution may be 90 g / L or more, specifically 90 g / L to 140 g / L, more specifically 90 g / L to 120 g / L. If the metal sulfate concentration is less than 90 g / L, the reaction efficiency of the metal sulfate decreases when removing impurities contained in the sulfate solution, and the loss rate of valuable metals to be recovered from the metal sulfate decreases. However, the relatively low metal sulfate concentration reduces the amount of valuable metals recovered, which increases the time required to recover a certain amount of valuable metals through waste battery recycling.

[0044] The concentration of aluminum contained in the sulfate solution may be 1 g / L or more, specifically 3 g / L or more, more specifically 3 g / L to 10 g / L. When aluminum is contained in the sulfate solution at a high concentration within this range, adding a hydroxide salt source to remove the aluminum can result in the valuable metal to be recovered being precipitated in the form of a hydroxide salt, resulting in a decrease in the recovery rate of the valuable metal. However, adding a phosphorus-based compound instead of a hydroxide salt source to remove the aluminum, as in step (S2) described below, can increase the removal rate of aluminum while minimizing the loss rate of the valuable metal to be recovered.

[0045] Step S2: Precipitating aluminum phosphate by adding a phosphorus compound to the sulfate solution.

[0046] Step (S2) is a process for removing aluminum (Al) as an impurity from the leached sulfate solution. Specifically, in step (S2), a phosphorus-based compound is added to the leached sulfate solution to precipitate aluminum phosphate.

[0047] The amount of the phosphorus-based compound added may be 0.1 wt% to 7.0 wt%, specifically 0.3 wt% to 5.0 wt%, more specifically 0.3 wt% to 4.8 wt%, based on the weight of the sulfate solution. When the weight ratio of the phosphorus-based compound added to the sulfate solution is within this range, it is possible to prevent problems such as reduced process efficiency and cost-effectiveness due to an increase in the amount of phosphorus-based compound added and an increase in the overall process liquid volume, which leads to an increase in the scale of process equipment.

[0048] The molar ratio of phosphorus (P) contained in the added phosphorus-based compound to aluminum (Al) contained in the sulfate solution (P / Al molar ratio) may be 0.92 to 1.72, specifically 0.92 to 1.49, more specifically 1.15 to 1.49. When the molar ratio of phosphorus to aluminum satisfies this range, the phosphorus (P) concentration in the sulfate solution after the precipitation reaction can be reduced to 5 ppm or less.

[0049] The phosphorus-based compound may be at least one selected from the group consisting of sodium phosphate (Na3PO4) and phosphoric acid (H3PO4), but is not limited thereto. Preferably, the phosphorus-based compound according to the present invention may be sodium phosphate. When sodium phosphate is added to remove aluminum contained in a sulfate solution, free acid is not generated in the aluminum phosphate precipitation reaction, so the amount of neutralizing agent required can be significantly reduced. In addition, sodium phosphate is less expensive than other phosphorus-based compounds. As a result, applying the valuable metal recovery method of the present invention to waste battery recycling technology can significantly reduce process time and costs.

[0050] In step (S2), aluminum can be precipitated as aluminum phosphate (AlPO4) compound by the following reaction such as [Reaction Scheme 1] or [Reaction Scheme 2].

[0051] [Reaction Scheme 1] Al2(SO4)3+2Na3PO4->2AlPO4↓+3Na2SO4

[0052] [Reaction Scheme 2] Al2(SO4)3+2H3PO4+6NaOH->2AlPO4↓+3Na2SO4+6H2O

[0053] Step (S2) may last for 2 to 8 hours, specifically 2 to 6 hours, and more specifically 2 to 4 hours. When the duration of step (S2) is within the above range, the loss rate of valuable metals in the sulfate solution can be reduced, while the removal rate of aluminum as an impurity can be increased.

[0054] Step (S2) may be performed at 25°C to 95°C, specifically 45°C to 95°C, more specifically 60°C to 90°C. When the temperature in step (S2) is within the above range, the aluminum removal rate can be increased to a level that does not increase the loss rate of valuable metals in the sulfate solution.

[0055] The pH of the sulfate solution in step (S2) may be 2.0 to 5.0, specifically 2.0 to 3.5, more specifically 2.5 to 3.5. When the pH of the sulfate solution in step (S2) is within this range, the aluminum removal rate can be increased while preventing the problem of increased nickel loss due to the precipitation of nickel in the sulfate solution as a compound.

[0056] In step (S2), 96.0% or more, specifically 97.0% or more, more specifically 98.0% or more of the aluminum contained in the sulfate solution can be removed by precipitation as aluminum phosphate, thereby sufficiently removing aluminum from the sulfate solution and significantly reducing the impurity content in the recovered valuable metals.

[0057] Step (S3) of separating the aluminum phosphate from the sulfate solution.

[0058] Step (S3) is a step of separating the aluminum phosphate precipitated in step (S2) from the sulfate solution. Specifically, step (S3) can recover the precipitated aluminum phosphate and separate the sulfate solution by distribution. The sulfate solution separated and recovered in step (S3) may be a solution from which aluminum has been removed and which contains the valuable metals to be recovered.

[0059] The sulfate solution filtered in step (S3) may be sent to a phosphorus removal step (for example, step (S4)), and the precipitated aluminum phosphate may be discarded or stored separately.

[0060] Step S4: Removing phosphorus from the sulfate solution

[0061] Step (S4) is a step for removing phosphorus (P) remaining in the sulfate solution. Specifically, step (S4) is a process of adding aluminum sulfate (Al2(SO4)3) to the sulfate solution that has been subjected to steps (S1) to (S3) to remove phosphorus. For example, by adding aluminum sulfate and sodium hydroxide (NaOH) to the sulfate solution, adjusting the pH to 5.0 or higher, specifically to pH 5 to 6, and reacting at 50 to 70°C for 4 to 8 hours, phosphorus contained in the sulfate solution can be precipitated and removed, and iron (Fe) and other impurities can also be co-precipitated and removed.

[0062] Some of the valuable metals to be recovered will precipitate as residue in the (S4) stage, but by re-injecting this precipitate into the waste battery material in the (S1) stage, there will be no loss of valuable metals in the (S4) stage.

[0063] In step (S4), the pH of the sulfate solution may be 5 or more, specifically 5 to 6, more specifically 5.5 to 6. When the pH of the sulfate solution in step (S4) is within the above range, aluminum (Al) added in excess relative to phosphorus (P) is converted into aluminum hydroxide (Al(OH)). )3 ) can be precipitated and removed.

[0064] Meanwhile, in the present invention, after the steps (S1), (S2), and (S3), and further step (S4), valuable metals can be recovered from the sulfate solution using a conventional method such as solvent extraction.

[0065] The present invention may be embodied in various different forms and should not be construed as being limited to the embodiments set forth herein, but the present invention may be practiced in various different forms and should not be construed as being limited to the embodiments set forth herein.

[0066] Examples and Comparative Examples

[0067] Example 1

[0068] In Example 1, valuable metals were recovered from waste batteries through the above-mentioned steps. Detailed conditions for each step are as follows:

[0069] (S1) stage

[0070] The waste battery material was recovered through a pre-treatment process that included discharging, dismantling, crushing / pulverization, drying, and calcination. A sulfate solution was extracted from the recovered waste battery material through a wet process. The wet process consisted of a pre-separation process and a leaching process. In the pre-separation process, water at 25°C was added to the waste battery material that had been calcined, and leaching was carried out for two hours. In the leaching process, lithium was pre-separated in the pre-separation process, and sulfuric acid and 30% hydrogen peroxide (H2O2) were added to the resulting cake, and leaching was carried out for eight hours at 80°C with a pH of 3.0. The concentration of metal sulfates in the leached sulfate solution was 90g / L, and the concentration of aluminum was 1g / L.

[0071] (S2) Stage

[0072] Sodium phosphate (Na3PO4) was added to the sulfate solution leached through step (S1), and sodium hydroxide (NaOH) was added to adjust the pH. The amount of sodium phosphate added was 2.5 wt% based on the weight of the sulfate solution. The mixture was then reacted at 85°C for 4 hours, with the pH of the sulfate solution at 3, to precipitate aluminum phosphate.

[0073] (S3) Stage

[0074] The aluminum phosphate precipitated in step (S2) and the sulfate solution were separated using a solid-liquid separator or a centrifuge.

[0075] Example 2

[0076] Valuable metals were recovered in the same manner as in Example 1, except that the concentration of aluminum contained in the sulfate solution was 8 g / L.

[0077] Example 3

[0078] Valuable metals were recovered in the same manner as in Example 1, except that the concentration of aluminum contained in the sulfate solution was 8 g / L and the pH of the sulfate solution was 4.

[0079] Example 4

[0080] Valuable metals were recovered in the same manner as in Example 1, except that the concentration of aluminum contained in the sulfate solution was 8 g / L and the pH of the sulfate solution was 5.

[0081] Example 5

[0082] Valuable metals were recovered in the same manner as in Example 1, except that phosphoric acid (H3PO4) was added to the sulfate solution instead of sodium phosphate (Na3PO4).

[0083] Example 6

[0084] Valuable metals were recovered in the same manner as in Example 1, except that phosphoric acid (H3PO4) was added to the sulfate solution instead of sodium phosphate (Na3PO4), and the concentration of aluminum contained in the sulfate solution was 8 g / L.

[0085] Comparative Example 1

[0086] Valuable metals were recovered in the same manner as in Example 1, except that only sodium hydroxide (NaOH) was added to the sulfate solution instead of sodium phosphate (Na3PO4) and sodium hydroxide (NaOH), and the pH of the sulfate solution was 5.

[0087] Comparative Example 2

[0088] Valuable metals were recovered in the same manner as in Comparative Example 1, except that the concentration of aluminum contained in the sulfate solution was 3 g / L.

[0089] Comparative Example 3

[0090] Valuable metals were recovered in the same manner as in Comparative Example 1, except that the concentration of aluminum contained in the sulfate solution was 5 g / L.

[0091] Comparative Example 4

[0092] Valuable metals were recovered in the same manner as in Comparative Example 1, except that the concentration of aluminum contained in the sulfate solution was 8 g / L.

[0093] Comparative Example 5

[0094] Valuable metals were recovered in the same manner as in Example 1, except that the concentration of metal sulfates contained in the sulfate solution was 60 g / L, the concentration of aluminum was 5 g / L, and the pH of the sulfate solution was 3.

[0095] Experimental Example 1: Measurement of loss rate / recovery rate and reaction time at S2 stage

[0096] At each S2 stage of the Examples and Comparative Examples, the loss rate of valuable metals (Ni, Co, Mn), the recovery rate of impurities (Al), and the reaction time were measured and are shown in Tables 1 and 2 below.

[0097] The loss rate of valuable metals and the recovery rate of impurities are calculated by excluding losses during the recovery of target metals (e.g., Ni) in a compatible form (e.g., NiSO4). The weight of the raw material (and slag) containing the target metals was measured using a balance, and the concentration of the leached compound metals was measured using ICP-AES spectroscopy, and the loss rate of each metal and the recovery rate of impurities were then calculated.

[0098] The reaction time for the S2 stage was measured as the time elapsed from the time the charge was added to the sulfate solution until no further precipitation reaction occurred.

[0099] [Table 1]

[0100] [Table 2]

[0101] Tables 1 and 2 show that in Examples 1 to 6, where the concentration of metal sulfates in the sulfate solution was 90 g / L or more and a phosphorus-based compound was added, the loss rates of nickel, cobalt, and manganese were lower, the aluminum recovery rate (removal rate) was higher, and the time required for step (S2) was reduced compared to Comparative Examples 1 to 4, where a hydroxide salt source was added instead of a phosphorus-based compound. Furthermore, in Examples 1 to 6, the time required for step (S2) was significantly reduced compared to Comparative Example 5, where the concentration of metal sulfates was less than 90 g / L.

[0102] Although the present invention has been described herein with reference to certain embodiments, it will be apparent that various modifications and variations that would be apparent to one of ordinary skill in the art to which the present invention pertains can be made without departing from the spirit and scope of the present invention, and such modifications and variations are to be considered to fall within the scope of the appended claims.

[0103] A person having ordinary knowledge in the field of technology to which the present invention pertains may make various substitutions, modifications and changes within the scope of the technical concept of the present invention, and the present invention is not limited to the above-described embodiments and the accompanying drawings.

Claims

1. (S1) leaching a sulfate solution from waste battery materials; (S2) adding a phosphorus-based compound to the sulfate solution to precipitate aluminum phosphate; (S3) subjecting the aluminum phosphate to solid-liquid separation from the sulfate solution; A method for recovering valuable metals, wherein the concentration of metal sulfates contained in the sulfate solution is 90 g / L or more.

2. 2. The method for recovering valuable metals according to claim 1, wherein the concentration of aluminum contained in the sulfate solution is 1 g / L or more.

3. 2. The method for recovering valuable metals according to claim 1, wherein the metal sulfate is one or more sulfates selected from the group consisting of nickel, cobalt, manganese, lithium, copper, and aluminum.

4. The step (S1) The method for recovering valuable metals according to claim 1, further comprising a step of calcining the shredded waste batteries without solvent treatment.

5. The step (S1) 10. The method for recovering valuable metals according to claim 1, comprising recovering lithium using deionized water without carbon dioxide.

6. In the step (S2), 2. The method for recovering valuable metals according to claim 1, wherein the amount of the phosphorus-based compound added is 0.1% by weight to 7.0% by weight based on the weight of the sulfate solution.

7. 2. The method for recovering valuable metals according to claim 1, wherein a molar ratio of phosphorus contained in the added phosphorus-based compound to aluminum contained in the sulfate solution (P / Al molar ratio) is 0.92 to 1.

72.

8. 2. The method for recovering valuable metals according to claim 1, wherein the phosphorus-based compound is sodium phosphate.

9. 2. The method for recovering valuable metals according to claim 1, wherein the step (S2) lasts for 2 to 8 hours.

10. The method of claim 1, wherein step (S2) is performed at 25°C to 95°C.

11. 2. The method of claim 1, wherein in step (S2), the sulfate solution has a pH of 2.0 to 5.

0.

12. 2. The method for recovering valuable metals according to claim 1, wherein 96.0% or more of the aluminum contained in the sulfate solution is precipitated and removed as the aluminum phosphate on a weight basis.

13. The method for recovering valuable metals according to claim 1, further comprising the step of (S4) removing phosphorus contained in the sulfate solution.

14. The method for recovering valuable metals according to claim 13, wherein in step (S4), the pH of the sulfate solution is 5.0 or more.

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