Method for recovering valuable metals

Abstract

A method for recovering valuable metals according to the present disclosure comprises the following steps: (S1) leaching a sulfate solution from a waste battery material; (S2) adding a phosphorus 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 sulfate solution contains a metal sulfate at a concentration of 90 g / L or more.

Description

Technical Field

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

[0002] With the recent expansion of the battery electric vehicle (BEV) market, demand for secondary batteries has continued to increase. Defective battery waste and waste cathode materials generated during secondary battery manufacturing, as well as discarded secondary battery waste after use, contain valuable metals such as nickel, cobalt, and manganese. Technologies are being actively developed to recover and recycle these valuable metals from secondary batteries.

[0003] Valuable metals such as nickel, cobalt, and manganese can be recovered by dissolving the material of the secondary battery in acid and then using solvent extraction. Solvent extraction is based on the principle of extracting metal ions from an aqueous solution into an organic solvent. Generally, when solvent extraction is used to recover valuable metals from secondary battery materials, a method for removing impurities contained in the secondary battery materials is required. Typical examples of such impurities include aluminum or copper. However, the process byproducts produced during the impurity removal process may result in a high waste rate of the valuable metals, thereby reducing the recovery rate of the valuable metals. Summary of the Invention

[0004] Technical problems to be solved

[0005] The object of the present disclosure is to provide a method for recovering valuable metals from waste batteries, thereby minimizing the loss rate of valuable metals while increasing the removal rate of aluminum and reducing the recovery time.

[0006] Solutions to technical problems

[0007] According to the present disclosure, a method for recovering valuable metals includes the following steps: (S1) leaching a sulfate solution from waste battery material; (S2) adding a phosphorus compound to the sulfate solution to precipitate aluminum phosphate; and (S3) separating aluminum phosphate from the sulfate solution by solid-liquid separation, wherein the sulfate solution contains metal sulfate at a concentration of 90 g / L or more.

[0008] In the method for recovering valuable metals according to the present disclosure, the sulfate solution contains aluminum at a concentration of 1 g / L or more.

[0009] In the method for recovering valuable metals according to the present disclosure, the metal sulfate may be at least one sulfate selected from the group consisting of nickel, cobalt, manganese, lithium, copper, and aluminum.

[0010] In the method for recovering valuable metals according to the present disclosure, step (S1) may include baking the crushed waste batteries without solvent treatment. Step (S1) may include recovering lithium using deionized water without carbon dioxide.

[0011] In step (S2) of the method for recovering valuable metals according to the present disclosure, the phosphorus compound may be added in an amount of 0.1 wt% to 7.0 wt% based on the weight of the sulfate solution.

[0012] In the method for recovering valuable metals according to the present disclosure, a molar ratio of phosphorus contained in the added phosphorus compound to aluminum contained in the sulfate solution (P / Al molar ratio) may be 0.92 to 1.72.

[0013] In the method for recovering valuable metals according to the present disclosure, the phosphorus compound may be sodium phosphate.

[0014] In the method for recovering valuable metals according to the present disclosure, step (S2) may last for 2 to 8 hours. Step (S2) may be performed at a temperature of 25° C. to 95° C. The pH of the sulfate solution in step (S2) may be 2.0 to 5.0.

[0015] In the method for recovering valuable metals according to the present disclosure, at least 96.0 wt % of aluminum contained in the sulfate solution can be precipitated and removed as aluminum phosphate.

[0016] The method for recovering valuable metals according to the present disclosure may further include a step (S4) of removing phosphorus contained in the sulfate solution. The pH of the sulfate solution in step (S4) is 5.0 or higher.

[0017] Effects of the Invention

[0018] Recently, there has been a trend to reduce the separation and sorting methods of aluminum foil from waste batteries in order to improve the recovery rate of valuable metals contained in the batteries. Consequently, battery materials extracted from waste batteries contain high concentrations of aluminum, which is considered an impurity. Traditionally, aluminum contained in the leachate of the battery material is reacted with a hydroxide source to precipitate and remove the aluminum byproduct as aluminum hydroxide. However, when the leachate contains high concentrations of aluminum, the addition of a hydroxide source causes the valuable metals to precipitate as hydroxides, thereby reducing the recovery rate of the valuable metals.

[0019] To address this issue, the present disclosure adds a phosphate compound, instead of a hydroxide source, to a sulfate solution containing a metal sulfate at a concentration of 90 g / L or higher. This minimizes the loss of recovered metal, improves aluminum removal efficiency, and reduces the time required for aluminum removal, even when the battery material contains high concentrations of aluminum. Therefore, the present disclosure ensures a diverse range of battery materials that can be processed, thus finding advantageous applications in waste battery processing technologies for medium- to large-sized battery packs, as well as in the electric vehicle field. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a flow chart of a method for recovering valuable metals according to the present disclosure. DETAILED DESCRIPTION

[0021] Hereinafter, specific contents for implementing the present disclosure will be described in detail with reference to the accompanying drawings. However, in the following description, if there is a risk of unnecessarily obscuring the main points of the present disclosure, detailed descriptions of well-known functions or configurations will be omitted.

[0022] In the accompanying drawings, identical or corresponding components are given the same reference symbols. In addition, in the description of the following embodiments, repeated description of identical or corresponding components may be omitted. However, even if the description of components is omitted, it is not intended that these components are not included in any embodiment.

[0023] The terms used in the present disclosure will be briefly described, and the disclosed embodiments will be described in detail. While taking into account the functions in the present disclosure, the terms used in this specification have been selected as common terms that are currently widely used as much as possible, but these terms may change according to the intentions of those skilled in the art or precedents, the emergence of new technologies, etc. In addition, in specific cases, there are terms arbitrarily selected by the applicant, and in this case, their meanings will be described in detail in the description of the corresponding disclosure. Therefore, the terms used in the present disclosure should be defined based on the meaning of the terms and the content of the present disclosure as a whole, rather than based on the simple names of the terms.

[0024] In the present disclosure, singular expressions include plural expressions unless the context clearly indicates the singular. In addition, plural expressions include singular expressions unless the context clearly indicates the plural.

[0025] Throughout the present disclosure, when a part “includes” a certain component, unless otherwise specified, it means that other components may be further included, rather than excluding other components.

[0026] “A and / or B” mentioned in this specification means A or B, or A and B.

[0027] The advantages and features of the disclosed embodiments and methods of achieving the same will become apparent with reference to the embodiments described below with reference to the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed below, but can be implemented in a variety of different forms, and only the embodiments are complete and provide the scope of the present invention to those skilled in the art. This scope is provided for complete information only as a reference.

[0028] According to the present disclosure, a method for recovering valuable metals includes the following steps: (S1) leaching a sulfate solution from waste battery material; (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 sulfate solution contains metal sulfate at a concentration of 90 g / L or more.

[0029] Hereinafter, each step of the method for recovering valuable metals according to the present disclosure will be described in more detail with reference to the accompanying drawings. Figure 1 Flowchart of the method for recovering valuable metals according to the present disclosure. Figure 1 As shown, a method for recovering valuable metals includes the following steps: (S1) leaching a sulfate solution from waste battery materials; (S2) adding a phosphate compound to the sulfate solution to precipitate aluminum phosphate; and (S3) separating the aluminum phosphate from the sulfate solution by solid-liquid separation, and optionally further including the step (S4) of removing phosphorus contained in the sulfate solution.

[0030] Step (S1) of leaching sulfate solution from waste battery material

[0031] The method for recovering valuable metals according to the present disclosure begins with a step (S1) of leaching a sulfate solution from a waste battery material. For example, step (S1) may be a step of recovering the waste battery material to leach the sulfate solution. Alternatively, step (S1) may be a method of leaching the sulfate solution from at least one selected from the group consisting of nickel ore, nickel MHP (Mixed Hydroxide Precipitate, MHP), and nickel oxide, rather than from the waste battery material.

[0032] Waste battery materials can be recycled through waste battery pretreatment methods. This pretreatment may include discharging methods, disassembly methods, crushing / pulverizing methods, drying methods, and baking methods.

[0033] Discharging is a process that discharges the accumulated charge in spent batteries to prevent any explosion during subsequent processes. Discharging can be accomplished through mechanical discharge using a discharger or saltwater discharge using brine.

[0034] Disassembly involves breaking down the packaged waste batteries into modules and / or cells. This can occur after, but is not limited to, discharging. Disassembly can also occur before discharging. For example, automated disassembly equipment can be used.

[0035] The crushing / pulverization method involves crushing and pulverizing disassembled discarded batteries. To prevent sparks and explosions, the crushing / pulverization method can be performed under a nitrogen atmosphere while spraying water. After the crushing and pulverization, the sprayed water and electrolyte flowing out of the battery can be removed, for example, using centrifugal separation in a rotary barrel.

[0036] The drying process is to remove the water and electrolyte remaining after the crushing / pulverizing process. For example, the drying process can be performed by heating the crushed material to about 50° C. or above using nitrogen in a dryer.

[0037] Baking method is a method of baking the battery of crushing / crushing. Generally, in the manufacture of positive electrode materials, processes such as baking, adding metal oxides and adding adhesives are carried out to enhance battery performance. Therefore, the waste battery materials comprising positive electrode materials may include oxides and impurities of various valuable metals, which may hinder the recycling of waste batteries to recover valuable metals. To eliminate these obstacles, high temperature baking can be performed. The baking method can be an inert atmosphere roaster (inert atmospheric roaster, IAR) method, in which the crushed / crushed battery is reduced and baked in an inert gas atmosphere. For example, in the baking method, the crushed / crushed battery can be reduced and baked at a temperature of 800°C to 900°C under a nitrogen atmosphere for 1 hour to 3 hours.

[0038] The baking method disclosed herein can omit a separate solvent treatment for removing binders contained in waste battery materials. By calcining the waste batteries in a reducing atmosphere without a separate solvent treatment, the binders can be removed, thereby simplifying the baking method. Furthermore, the baking method disclosed herein can reduce the amount of metal materials in the form of oxides that bind to oxygen within the waste batteries. Specifically, during the reduction baking method of crushed / pulverized batteries, some higher-order oxides (Me2O3, where Me=Ni, Co, Mn) can be reduced to lower-order oxides (MeO, where Me=Ni, Co, Mn), thereby reducing the amount of reagents (H2O2, hydrogen peroxide) required during the sulfate solution leaching process.

[0039] Examples of waste battery materials include, but are not limited to, waste battery waste, black matter processed from waste batteries through a recycling method, waste cathode materials generated in a cathode material manufacturing process, or a combination thereof.

[0040] 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 (LiCoO2), lithium nickel cobalt manganese oxide (LiNiCoMnO2), lithium manganese oxide (LiMnO2), and lithium iron phosphate (LiFePO4).

[0041] In step (S1), a sulfate solution can be extracted from the waste battery material using a wet process. For example, the sulfate solution can be leached from the waste battery material recovered by the pretreatment method described above. To improve the solubility of the filter cake during the sulfate solution leaching process, a small amount of a reducing agent can be added. In this regard, hydrogen peroxide (H2O2) can be used as the reducing agent.

[0042] According to an embodiment of the present disclosure, step (S1) may be performed by a pre-separation method and a leaching method.

[0043] The pre-separation method involves adding water to crushed / pulverized waste batteries to leach and pre-separate lithium (Li). For example, in the lithium pre-separation method, the crushed batteries can be dissolved in water and leached at 10°C to 30°C for 1 to 3 hours to produce a lithium carbonate (Li2CO3) solution and separate the filter cake. When the sulfate solution is leached from the filter cake remaining after pre-separation of lithium from the waste battery material, the use of reagents such as hydrogen peroxide can be minimized, and stable process management in continuous operation can be achieved. In the pre-separation method of the present disclosure, deionized water can be used to recover lithium without the use of carbon dioxide (CO2). Recovering lithium using only deionized water that does not contain CO2 can reduce method costs and reduce carbon footprint.

[0044] The leaching method is a method of leaching a sulfate solution from the filter cake produced by the pre-separation method. Specifically, in the leaching method, the filter cake produced in the pre-separation method can be reduction-leached with sulfuric acid and hydrogen peroxide (H2O2) at 80°C to 85°C for 1 hour to 8 hours.

[0045] The metal sulfate contained in the sulfate solution may be at least one sulfate selected from the group consisting of nickel, cobalt, manganese, lithium, copper, and aluminum.

[0046] The concentration of the metal sulfate in the sulfate solution can be 90 g / L or higher, specifically between 90 g / L and 140 g / L, and more specifically between 90 g / L and 120 g / L. If the concentration of the metal sulfate is less than 90 g / L, the efficiency of the impurity removal reaction in the sulfate solution is reduced, thereby reducing the loss rate of the valuable metals intended for recovery from the metal sulfate. However, due to the relatively low concentration of the metal sulfate, the amount of valuable metals recovered is reduced, resulting in a longer time required to recover a large amount of valuable metals through waste battery recycling.

[0047] The concentration of aluminum contained in the sulfate solution can be 1 g / L or more, specifically 3 g / L or more, and even more specifically between 3 g / L and 10 g / L. When the concentration of aluminum in the sulfate solution is high, as described above, adding a hydroxide source to remove aluminum will cause the valuable metals to precipitate in the form of hydroxides, thereby reducing the recovery rate of the valuable metals. Conversely, as described in the subsequent step (S2), adding a phosphorus compound instead of a hydroxide source to remove aluminum can minimize the loss rate of the valuable metals while increasing the aluminum removal rate.

[0048] Step (S2) of adding a phosphorus compound to a sulfate solution to precipitate aluminum phosphate

[0049] Step (S2) is a method for removing aluminum (Al) impurities from the leached sulfate solution. Specifically, in step (S2), a phosphorus compound may be added to the leached sulfate solution to precipitate aluminum phosphate.

[0050] The amount of the phosphorus compound added relative to the weight of the sulfate solution can be between 0.1% and 7.0% by weight, more specifically between 0.3% and 5.0% by weight, and even more specifically between 0.3% and 4.8% by weight. If the weight ratio of the added phosphorus compound to the sulfate solution falls within these ranges, the problem of increased process volume and process equipment size due to the addition of the phosphorus compound can be prevented, which may reduce the efficiency and economy of the process.

[0051] The molar ratio of phosphorus (P) to aluminum (Al) contained in the sulfate solution (P / Al molar ratio) may be between 0.92 and 1.72, more specifically between 0.92 and 1.49, and even more specifically between 1.15 and 1.49. If the molar ratio of phosphorus to aluminum satisfies these ranges, the phosphorus (P) concentration in the sulfate solution after the precipitation reaction can be reduced to 5 ppm or less.

[0052] The phosphorus compound may be one or more selected from the group consisting of, but not limited to, sodium phosphate (Na3PO4) and phosphoric acid (H3PO4). Preferably, the phosphorus compound of the present disclosure may be sodium phosphate. When sodium phosphate is added to remove aluminum contained in the sulfate solution, no free acid is produced during the aluminum phosphate precipitation reaction, significantly reducing the amount of neutralizing agent required. Furthermore, sodium phosphate is relatively inexpensive compared to other phosphorus compounds. Therefore, applying the disclosed method for recovering valuable metals to waste battery recycling technology can significantly reduce process time and costs.

[0053] In step (S2), aluminum may be precipitated as an aluminum phosphate (AlPO 4 ) compound through a reaction such as [Reaction Formula 1] or [Reaction Formula 2].

[0054] [Reaction formula 1]

[0055] Al2(SO4)3+2Na3PO4→2AlPO4↓+3Na2SO4

[0056] [Reaction formula 2]

[0057] Al2(SO4)3+2H3PO4+6NaOH→2AlPO4↓+3Na2SO4+6H2O

[0058] Step (S2) can last for 2 to 8 hours, specifically 2 to 6 hours, and more specifically 2 to 4 hours. When the duration of step (S2) falls within these ranges, the removal rate of impurities such as aluminum can be increased while minimizing the loss rate of valuable metals in the sulfate solution.

[0059] Step (S2) can be performed at a temperature range of 25° C. to 95° C., specifically 45° C. to 95° C., and more specifically 60° C. to 90° C. When the temperature in step (S2) satisfies these ranges, the aluminum removal rate can be increased without increasing the loss rate of valuable metals in the sulfate solution.

[0060] During step (S2), the pH of the sulfate solution may be between 2.0 and 5.0, specifically 2.0 and 3.5, and more specifically 2.5 and 3.5. If the pH of the sulfate solution in step (S2) satisfies these ranges, the aluminum removal rate can be increased while preventing the problem of an increased nickel loss rate due to precipitation as a compound.

[0061] In step (S2), the aluminum contained in the sulfate solution can be precipitated at 96.0% by weight or more, specifically 97.0% by weight or more, and more specifically 98.0% by weight or more, and removed as aluminum phosphate. Therefore, sufficient removal of aluminum from the sulfate solution can significantly reduce the impurity content in the recovered valuable metals.

[0062] Step (S3) of separating aluminum phosphate from sulfate solution by solid-liquid separation

[0063] Step (S3) is to separate the aluminum phosphate precipitated in step (S2) from the sulfate solution. Specifically, step (S3) is suitable for recovering the precipitated aluminum phosphate and separating the sulfate solution by decantation. The sulfate solution recovered by separation in step (S3) can be a solution containing the target valuable metal, from which aluminum has been removed.

[0064] The sulfate solution filtered in step (S3) can be transferred to a phosphorus removal process (e.g., step (S4)), and the precipitated aluminum phosphate can be disposed of or stored separately.

[0065] Step (S4) of removing phosphorus contained in sulfate solution

[0066] Step (S4) removes residual phosphorus (P) from the sulfate solution. Specifically, step (S4) involves adding aluminum sulfate (Al2(SO4)3) to the sulfate solution treated through steps (S1) to (S3) to remove phosphorus. For example, by adding aluminum sulfate and sodium hydroxide (NaOH) to adjust the pH to 5.0 or higher, specifically 5 to 6, and reacting at 50°C to 70°C for 4 to 8 hours, phosphorus contained in the sulfate solution can be precipitated and removed along with iron (Fe) and other impurities.

[0067] Although some target valuable metals may be precipitated as residue in step (S4), reintroducing this residual precipitate into the spent battery material in step (S1) can prevent the loss of valuable metals in step (S4).

[0068] The pH of the sulfate solution in step (S4) may be 5 or more, specifically 5 to 6, and more specifically 5.5 to 6. When the pH of the sulfate solution in step (S4) satisfies these ranges, aluminum (Al) introduced in excess relative to phosphorus (P) may be precipitated and removed as aluminum hydroxide (Al(OH) 3).

[0069] After undergoing steps (S1), (S2), and (S3), and optionally step (S4), valuable metals can be recovered from the sulfate solution by conventional methods such as solvent extraction.

[0070] Hereinafter, the embodiments of the present disclosure will be described in detail so that those skilled in the art can easily perform the present disclosure. However, the present disclosure can be implemented in many different forms and is not limited to the embodiments set forth herein.

[0071] Examples and Comparative Examples

[0072] Example 1

[0073] In Example 1, valuable metals were recovered from waste batteries through the above steps. The detailed conditions of each step are as follows:

[0074] Step (S1)

[0075] According to the pretreatment method, the waste battery material is recovered by discharging, disassembling, crushing / pulverizing, drying, and baking methods. A sulfate solution is extracted from the recovered waste battery material by a wet method. The wet method is performed in the order of a preliminary separation method and a leaching method. In the preliminary separation method, water at 25°C is added to the baked waste battery material, and leaching is performed for 2 hours. In the leaching method, sulfuric acid and 30% hydrogen peroxide (H2O2) are added to the filter cake produced after the preliminary separation of lithium, and leaching is performed at 80°C and a pH of 3.0 for 8 hours. The concentration of metal sulfate in the leached sulfate solution is 90g / L, and the concentration of aluminum is 1g / L.

[0076] Step (S2)

[0077] Sodium phosphate (Na3PO4) was added to the sulfate solution leached in step (S1), and sodium hydroxide (NaOH) was added to adjust the pH. The amount of sodium phosphate was 2.5% by weight based on the weight of the sulfate solution. The mixture was then reacted in the sulfate solution at a pH of 3 and 85°C for 4 hours to precipitate aluminum phosphate.

[0078] Step (S3)

[0079] The aluminum phosphate precipitated in step (S2) and the sulfate solution are separated using a solid-liquid separator or a centrifuge.

[0080] Example 2

[0081] Valuable metals were recovered in the same manner as in Example 1, except that the concentration of aluminum in the sulfate solution was 8 g / L.

[0082] Example 3

[0083] Valuable metals were recovered in the same manner as in Example 1, except that the pH of the sulfate solution was 4 and the aluminum concentration was 8 g / L.

[0084] Example 4

[0085] Valuable metals were recovered in the same manner as in Example 1, except that the pH of the sulfate solution was 5 and the aluminum concentration was 8 g / L.

[0086] Example 5

[0087] Valuable metals were recovered in the same manner as in Example 1, except that phosphoric acid (H 3 PO 4 ) was added to the sulfate solution instead of sodium phosphate (Na 3 PO 4 ).

[0088] Example 6

[0089] 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 aluminum concentration was 8 g / L.

[0090] Comparative Example 1

[0091] Valuable metals were recovered in the same manner as in Example 1, except that only hydroxide (NaOH) was added to the sulfate solution instead of sodium phosphate (Na 3 PO 4 ) and sodium hydroxide (NaOH), and the pH was 5.

[0092] Comparative Example 2

[0093] Valuable metals were recovered in the same manner as in Example 1, except that the sulfate solution contained aluminum at a concentration of 3 g / L.

[0094] Comparative Example 3

[0095] Valuable metals were recovered in the same manner as in Example 1, except that the sulfate solution contained aluminum at a concentration of 5 g / L.

[0096] Comparative Example 4

[0097] Valuable metals were recovered in the same manner as in Example 1, except that the sulfate solution contained aluminum at a concentration of 8 g / L.

[0098] Comparative Example 5

[0099] Valuable metals were recovered in the same manner as in Example 1, except that the sulfate solution contained a metal sulfate concentration of 60 g / L and an aluminum concentration of 5 g / L, and had a pH of 3.

[0100] Experimental Example 1: Measurement of Loss Rate / Recovery Rate and Reaction Time in Step S2

[0101] In each step S2 of Examples and Comparative Examples, the loss rate of valuable metals (Ni, Co, and Mn) and the recovery rate of impurities (Al) as well as the reaction time were measured and are shown in Tables 1 and 2 below.

[0102] The loss rate of valuable metals and the recovery rate of impurities are calculated after excluding losses during the recovery of the target metal (e.g., Ni) in a commercial form (e.g., NiSO4). The metal loss rate and impurity recovery rate are calculated by measuring the weight of the material (and slag) containing the target metal using a scale and measuring the metal concentration in the form of leached compounds using ICP-AES spectroscopy.

[0103] The reaction time of step S2 is measured as the time elapsed from the addition of the reagent to the sulfate solution to the point at which no further precipitation reaction occurs.

[0104] Table 1

[0105]

[0106] Table 2

[0107]

[0108]

[0109] As can be understood from the data in Tables 1 and 2, lower nickel, cobalt, and manganese loss rates, higher aluminum recovery (removal) rates, and reduced reaction times for step S2 were observed in Examples 1-6, wherein the concentration of the metal sulfate in the sulfate solution was 90 g / L or higher and a phosphorus compound was added, compared to Comparative Example 1-4 in which a hydroxide source was added. Furthermore, a significant reduction in the reaction time for step S2 was observed in Examples 1-6, compared to Comparative Example 5 in which the concentration of the metal sulfate was less than 90 g / L.

[0110] The technical concepts of the present disclosure have been described so far with reference to certain embodiments and examples shown in the accompanying drawings. However, it should be understood that various substitutions, modifications, and variations may be made without departing from the technical concepts and scope of the present disclosure as would be understood by one of ordinary skill in the art. Furthermore, it should be understood that such substitutions, modifications, and variations are within the scope of the appended claims.

[0111] A person skilled in the art to which the present disclosure pertains may make various substitutions, modifications, and changes without departing from the technical spirit of the present disclosure. Therefore, the present disclosure is not limited to the above-described embodiments and drawings.

Claims

1. A method for recovering valuable metals, comprising the following steps: (S1) leaching a sulfate solution from waste battery materials; (S2) adding a phosphorus compound to the sulfate solution to precipitate aluminum phosphate; as well as (S3) separating the aluminum phosphate from the sulfate solution by solid-liquid separation, The sulfate solution contains metal sulfate at a concentration of 90 g / L or more.

2. The method according to claim 1, wherein The sulfate solution contains aluminum at a concentration of 1 g / L or more.

3. The method according to claim 1, wherein The metal sulfate is at least one sulfate selected from the group consisting of nickel, cobalt, manganese, lithium, copper and aluminum.

4. The method according to claim 1, wherein The step (S1) includes the step of baking the crushed waste batteries without solvent treatment.

5. The method according to claim 1, wherein The step (S1) includes the step of recovering lithium using deionized water that does not contain carbon dioxide.

6. The method according to claim 1, wherein The phosphorus compound in the step (S2) is added in an amount of 0.1 wt% to 7.0 wt% based on the weight of the sulfate solution.

7. The method according to claim 1, wherein The molar ratio of phosphorus contained in the added phosphorus compound to aluminum contained in the sulfate solution (P / Al molar ratio) is 0.92 to 1.

72.

8. The method according to claim 1, wherein The phosphorus compound is sodium phosphate.

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

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

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

0.

12. The method according to claim 1, wherein At least 96.0 wt % of the aluminum contained in the sulfate solution is precipitated and removed as the aluminum phosphate.

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

14. The method according to claim 13, wherein The pH of the sulfate solution in the step (S4) is 5.0 or higher.

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