Valuable metal recovery alloy and method for recovering valuable metal

Abstract

The present invention relates to a valuable metal recovery alloy, a valuable metal recovery composition, and a method for recovering valuable metal. The valuable metal recovery alloy comprises 45 wt% or more of a valuable metal and the balance of impurities, on the basis of 100 wt% of the total composition of the alloy, and satisfies equation 1 below: <Equation 1> 5.0 ≤ Cu / Ni ≤ 15.0

Description

Valuable metal recovery alloy and method for recovering valuable metal

[0001] This relates to waste batteries, and to a valuable metal recovery alloy and a method for recovering valuable metals from waste batteries.

[0002] As global demand for electric vehicles grows, the disposal of waste batteries generated from these vehicles is emerging as a social issue. Lithium secondary batteries, the primary raw material for these waste batteries, contain organic solvents, explosive materials, and heavy metals such as nickel, cobalt, manganese, and iron. However, nickel, cobalt, manganese, and lithium are valuable metals with high scarcity value. Therefore, the recovery and recycling processes for discarded lithium secondary batteries are emerging as a key research area.

[0003] Specifically, a lithium secondary battery is mainly composed of copper and aluminum used as a current collector, Li, Ni, Co, Mn-containing oxides constituting a positive electrode material, and graphite used as an anode material, and includes a separator separating the positive electrode material and the negative electrode material, and an electrolyte injected into the separator. The solvent used as a solvent and salt constituting the electrolyte is mainly a mixture of carbonate organic substances such as ethylene carbonate and propylene carbonate, and for example, LiPF6 is used.

[0004] In this way, lithium secondary batteries are composed of heavy metal materials such as Ni-Co-Mn-Fe, carbon, and other electrolyte materials, among which Ni, Co, Mn, and Li are valuable as precious metals.

[0005] Recycling for battery raw material recovery typically involves battery disassembly, discharging, crushing, heat treatment, recovery, and wet processes to recover valuable metals. During this process, saltwater discharging is performed, and substances such as sodium, potassium, magnesium, calcium, and chloride (Ca) that enter the recovered raw material are included as impurities.

[0006] After heat treatment, the recovered material forms different products depending on the heat treatment temperature. When heat treated at a temperature below 600 ℃, it is called black powder and is a powder form in which the oxide of Ni-Co-Mn-Li and carbon of the negative electrode material are mixed. Since Al and Cu are removed in advance, they may be included in extremely small amounts.

[0007] When the above black powder is heat-treated at a high temperature of 1,000°C or higher, the metal oxide is reduced and alloyed by the carbon of the negative electrode material, and a black alloy containing the alloy components, carbon, and other substances is obtained. From the black alloy thus obtained, materials such as valuable metal alloys, lithium oxide, and graphite can be recovered by material. At this time, the valuable metal alloy in the form of a metal is coated with lithium aluminate or lithium oxide, and the black alloys are finally converted into raw materials through additional processes such as leaching.

[0008] At this time, the content of components in the recovered precious metal alloy is controlled to increase the efficiency of the subsequent wet smelting process and reduce the cost of the process.

[0009] The technical problem to be solved by the present invention is to provide a valuable metal recovery alloy that can increase the efficiency of the process and reduce the cost of the process when the valuable metal alloy raw material obtained from a spent battery is input into a wet refining process using acid or base.

[0010] Another technical problem to be solved by the present invention is to provide a method for recovering valuable metals for producing a valuable metal recovery alloy having the aforementioned advantages.

[0011] According to one embodiment of the present invention, a valuable metal recovery alloy comprises 45 wt% or more of valuable metal based on 100 wt% of the total composition of the alloy, the remainder being impurities, and satisfies the following equation 1.

[0012] <Formula 1>

[0013] 5.0 ≤ [Cu] / [Ni] ≤ 15.0 %

[0014] (In the above formula 1, [Cu] and [Ni] represent the contents of Cu and Ni in the valuable metal recovery alloy, respectively)

[0015] In one embodiment, the metal recovery alloy satisfies the following equation 2.

[0016] <Formula 2>

[0017] 30.0 ≤ [Cu] / [Mn] ≤ 55.0 %

[0018] (In the above formula 2, [Cu] and [Mn] represent the contents of Cu and Mn in the valuable metal recovery alloy, respectively)

[0019] In one embodiment, the metal recovery alloy satisfies the following equation 3.

[0020] <Formula 3>

[0021] 50.0 ≤ [Cu] / [C] ≤ 200.0 %

[0022] (In the above formula 3, [Cu] and [C] represent the contents of Cu and C in the valuable metal recovery alloy, respectively)

[0023] In one embodiment, the valuable metal recovery alloy comprises a CuNi alloy. In one embodiment, the valuable metal recovery alloy may have at least one diffraction peak having an XRD peak value of 2θ = 44 °± 1 °, 2θ = 51.5 °± 1.5 °, and 2θ = 75.5 °± 1.5 °.

[0024] In one embodiment, the alloy may include copper (Cu) in an amount of 0.02 to 5.00 wt% based on 100 wt% of the valuable metal recovery alloy. In one embodiment, the alloy may include carbon (C) in an amount of 5.0 wt% or less based on 100 wt% of the valuable metal recovery alloy.

[0025] According to another embodiment of the present invention, a method for recovering valuable metals may include the steps of preparing a battery or battery shreds in cell units, performing a dry heat treatment at a temperature range of 1,150 to 1,400° C. without going through a melting step of the battery or the shreds, and recovering a valuable metal recovery alloy having magnetism by magnetic separation of the resultant product of the dry heat treatment with a magnetic strength of 800 to 4,500 G.

[0026] In one embodiment, the dry heat treatment step may be performed in an atmosphere with an oxygen content of 5% or less. In one embodiment, the dry heat treatment step may include a step performed in multiple stages, and the step performed in multiple stages may include a preliminary heat treatment step and a high-temperature heat treatment step performed at a temperature higher than the preliminary heat treatment step.

[0027] In one embodiment, the preparatory heat treatment step is performed at a temperature of 900°C or less, and the temperature increase rate of the preparatory heat treatment step may be performed at 5 to 15°C / min. In one embodiment, the high-temperature heat treatment step is performed at 900°C or more, and the temperature increase rate of the high-temperature heat treatment step may be performed at 2.5 to 7.5°C / min.

[0028] In one embodiment, a method for recovering valuable metals comprises a cooling step after the high-temperature heat treatment step, wherein the cooling step is performed at a cooling rate of 20°C / min or more. The high-temperature heat treatment step may be performed at 900°C or more. In one embodiment, the step of recovering the valuable metal recovery alloy by magnetic separation may be performed in a wet manner.

[0029] In one embodiment, the step of recovering the valuable metal recovery alloy by magnetic separation may be performed at a concentration of the solids content in the range of 10 to 50%. In one embodiment, the result obtained from the dry heat treatment step may separate a lithium compound bound to a portion of the surface of the valuable metal recovery alloy by an external force.

[0030] In one embodiment, the step of preparing the cell-unit battery or battery shreds may include the step of preprocessing the cell-unit battery or battery shreds.

[0031] According to one embodiment of the present invention, a valuable metal recovery alloy controls the content of Cu and Ni components, thereby allowing the alloy particles to be easily crushed by external force in a subsequent wet refining process, thereby reducing the diameter of the alloy and simultaneously increasing the specific surface area, thereby enhancing the reactivity against sulfuric acid leaching. In addition, a carbon layer is disposed on the surface or interior of the valuable metal alloy, thereby facilitating the selective leaching of lithium from lithium oxide on the alloy surface.

[0032] According to another embodiment of the present invention, a method for recovering valuable metals can provide a method for producing a valuable metal recovery alloy having the aforementioned advantages by controlling heat treatment and cooling conditions.

[0033] FIG. 1 is an SEM photograph of a composition for recovering valuable metals according to one embodiment of the present invention.

[0034] FIG. 2a and FIG. 2b show XRD analysis results of a composition for recovering valuable metals according to one embodiment.

[0035] FIG. 3 shows the results of XRD analysis on the change in state of Cu in a composition for recovering valuable metals according to one embodiment.

[0036] Figures 4a and 4b show the melting process of copper foil (Cu foil) in the heat treatment step of the battery shredder of the present invention.

[0037] The terms first, second, and third, etc., are used to describe, but are not limited to, various parts, components, regions, layers, and / or sections. These terms are used solely to distinguish one part, component, region, layer, or section from another part, component, region, layer, or section. Accordingly, a first part, component, region, layer, or section described below may be referred to as a second part, component, region, layer, or section without departing from the scope of the present invention.

[0038] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the present invention. As used herein, the singular forms "singular" and "comprising" include plural forms as well, unless the context clearly dictates otherwise. The word "comprising" as used herein specifies a particular feature, region, integer, step, operation, element, and / or component, but does not exclude the presence or addition of other features, regions, integers, steps, operations, elements, and / or components.

[0039] When a part is referred to as being "on" or "over" another part, it can be directly on or over the other part, or there may be other parts intervening. Conversely, when a part is referred to as being "directly on" another part, there are no other parts intervening.

[0040] Additionally, % in this specification means weight % unless otherwise specified.

[0041] Although not defined otherwise, all terms, including technical and scientific terms, used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which the present invention pertains. Terms defined in commonly used dictionaries are further interpreted to have meanings consistent with the relevant technical literature and the present disclosure, and are not to be construed as ideal or overly formal unless otherwise defined.

[0042] Hereinafter, embodiments of the present invention will be described in detail. However, these are presented as examples and the present invention is not limited thereto, and the present invention is defined only by the scope of the claims set forth below.

[0043] According to one embodiment of the present invention, a valuable metal alloy may include 45 wt% or more of a valuable metal and the remainder being impurities, based on 100 wt% of the total composition of the alloy. The valuable metal recovery alloy may include at least one of a valuable metal such as nickel (Ni), cobalt (Co), manganese (Mn), lithium (Li), carbon (C), aluminum (Al), and copper (Cu) and the remainder being impurities. In the present specification, a valuable metal may mean an expensive metal component included in a battery, and may mean nickel, cobalt, manganese, aluminum, copper, and lithium. In one embodiment, the valuable metal may be 70 wt% or more.

[0044] In one embodiment, the metal recovery alloy may satisfy the following equation 1.

[0045] <Formula 1>

[0046] 5.0 ≤ [Cu] / [Ni] ≤ 15.0 %

[0047] (In the above formula 1, [Cu] and [Ni] represent the contents of Cu and Ni in the valuable metal recovery alloy, respectively)

[0048] The above formula 1 means the content of copper to nickel in the valuable metal recovery alloy expressed as a percentage, and the value of the above formula 1 can be 5.0 to 15.0%. Specifically, the above formula 1 can be 5 to 15%, and more specifically, 10 to 14.5%. Since the above formula 1 satisfies the above-mentioned range, there is an advantage in that the time and process cost required for removing impurities in the wet refining process can be reduced, and the recovery rate of Ni recovered as a magnetic body can be maximized.

[0049] If the above equation 1 exceeds the upper limit of the aforementioned range, problems such as increased reaction temperature during high-temperature reduction reaction, increased process costs for maintaining the temperature, and increased time and cost for Cu removal during the process of leaching the alloy and removing impurities may occur. On the other hand, there is a problem that some NCN alloys cannot be recovered due to the weak magnetic strength during magnetic separation.

[0050] If the above equation 1 is outside the lower limit of the aforementioned range, the reaction temperature may be low during high-temperature reduction, so NCM may not be completely reduced and may remain in the form of an oxide. In addition, since NCM oxide is a non-magnetic substance, the Ni weight % of the NCM alloy recovered as a magnetic product increases, but there is a problem that the recovery rate decreases. On the other hand, due to the excessively strong magnetic force of the magnetic separator, not only the ferromagnetic NCM alloy but also paramagnetic and weakly magnetic substances are recovered, so there is a problem that the impurity content of the magnetic substance recovered as the NCM alloy increases.

[0051] In one embodiment, the metal recovery alloy may satisfy the following equation 2.

[0052] <Formula 2>

[0053] 30.0 ≤ [Cu] / [Mn] ≤ 55.0 %

[0054] (In the above formula 2, [Cu] and [Mn] represent the contents of Cu and Mn in the valuable metal recovery alloy, respectively)

[0055] The above formula 2 means that the content of copper to manganese in the valuable metal recovery alloy is expressed as a percentage, and the value of the above formula 2 can be 30.0 to 55.0%. Specifically, the above formula 2 can be 35.0 to 48.0%, and more specifically, 40.0 to 46.0%. Since the above formula 2 satisfies the above-mentioned range, there is an advantage in that the recovery rate of Mn can be maximized as a magnetic product recovered through magnetic separation.

[0056] When the above equation 2 exceeds the upper limit of the above-mentioned range, there is a problem that the recovery rate of Mn decreases. When the above equation 2 exceeds the lower limit of the above-mentioned range, the weight percent grade of Mn increases, but, similar to Cu / Ni in equation 1, there is a problem that the recovery rate of Mn decreases and the impurity content increases.

[0057] In one embodiment, the metal recovery alloy may satisfy the following equation 3.

[0058] <Formula 3>

[0059] 50.0 ≤ [Cu] / [C] ≤ 200.0 %

[0060] (In the above formula 3, [Cu] and [C] represent the contents of Cu and C in the valuable metal recovery alloy, respectively)

[0061] The above formula 3 means the content of copper to carbon in the valuable metal recovery alloy expressed as a percentage, and the value of the above formula 3 can be 50.0 to 200.0%. Specifically, the above formula 3 can be 85 to 150%, more specifically, 100 to 150%, and even more specifically, 108 to 142%. Since the above formula 3 satisfies the above-mentioned range, there is an advantage in that the NCM alloy can be stably recovered with a high recovery rate and quality.

[0062] If the above equation 3 is outside the upper limit of the above-mentioned range, the problem of increased process costs occurs when the reaction temperature is very high during high-temperature reduction if the Cu content is too high. On the other hand, if the C content is too low, the reaction temperature is very low during high-temperature reduction, which means that C is not carburized into the grain boundaries of NCM. In this case, NCM is not completely reduced and some of it remains as oxide, which causes a problem of reduced recovery rate of the NCM alloy. If the above equation 3 is outside the lower limit of the above-mentioned range, the opposite problem to the case where it is outside the upper limit described above may occur.

[0063] In one embodiment, the precious metal recovery alloy may contain copper (Cu) in an amount of 0.02 wt% to 5.00 wt%, based on 100 wt% of the precious metal alloy. Specifically, the precious metal recovery alloy may contain copper in an amount of 0.1 wt% to 15 wt%.

[0064] If the content of the copper is outside the upper limit of the above range, there is a problem of process cost due to an increase in the amount of CuSO4 precipitation in leaching and solvent extraction, and if the content of the copper is outside the lower limit of the above range, there is a problem of an increase in the amount of unreacted material due to difficulty in producing low-melting-point Ni-Co-Mn.

[0065] In one embodiment, the valuable metal recovery alloy may include aluminum (Al) in a range of 0.25 to 30 wt%. Specifically, the aluminum (Al) may be 1.0 to 15.0 wt%, and more specifically, 8.0 to 9.5 wt%. If the content of aluminum is outside the upper limit of the range, there is a problem of reduced Ni and Co recovery rates during the leaching and solvent extraction processes, and if the content of aluminum is outside the lower limit of the range, it is difficult to produce LiAlO2, and there is a problem of reduced Li recovery rates.

[0066] In one embodiment, the valuable metal recovery alloy may include carbon (C) in an amount of 5.0 wt% or less. Specifically, it may include 2.80 to 4.0 wt%, and more specifically, 2.96 to 3.84 wt%. By satisfying the above-described carbon content, a carburized layer is formed within the valuable metal alloy, and pulverization is facilitated in a subsequent process, thereby providing an advantage in that the recovery rate of the valuable metal can be increased.

[0067] If the carbon content exceeds the upper limit of the aforementioned range, there is a problem in that the carbon is difficult to separate in a post-process. If the carbon content exceeds the lower limit of the aforementioned range, there is a problem in that it is difficult to form a carburized layer, making it difficult to separate carbon from the alloy.

[0068] In one embodiment, the valuable metal alloy may include a Cu-Ni alloy. Specifically, the valuable metal alloy may include an alloy combining copper and nickel.

[0069] In one embodiment, the valuable metal recovery alloy may include at least one of XRD peak intensity values ​​of 51.5°±1.5° and 75.5±1.5°. The peak intensity value may be exhibited by including a Cu-Ni alloy, and the Cu-Ni may be exhibited as copper is melted and remains in the valuable metal alloy during the high-temperature heat treatment step in the valuable metal recovery method, and simultaneously combines with nickel to form an alloy.

[0070] FIG. 1 is a SEM photograph of a metal recovery composition comprising a metal recovery composition according to one embodiment of the present invention.

[0071] In one embodiment, the valuable metal recovery composition (100) may include a core portion (110) containing a valuable metal and a shell portion (120) disposed on at least a portion of the core portion (110). Specifically, the valuable metal recovery composition (100) may be composed of a metal such as a valuable metal such as Ni, Co, or Mn in the core portion (110), and an oxide including lithium may be bonded and disposed on the core portion (110).

[0072] The core portion (110) includes a valuable metal recovery alloy, and the valuable metal recovery alloy may include 45 wt% or more of the valuable metal and the remainder being impurities, based on 100 wt% of the total composition of the alloy. The valuable metal recovery alloy may include at least one of valuable metals such as nickel (Ni), cobalt (Co), manganese (Mn), lithium (Li), carbon (C), aluminum (Al), and copper (Cu) and the remainder being impurities. In the present specification, the valuable metal may mean an expensive metal component included in a battery, and may mean nickel, cobalt, manganese, aluminum, copper, and lithium. In one embodiment, the valuable metal may be 70 wt% or more. For a detailed description of the valuable metal recovery alloy of the core portion, reference may be made to the above.

[0073] In one embodiment, the lithium in the metal recovery composition (100) is not reduced to form an alloy, unlike Ni, Co, and Mn, and can combine with the Al component in the battery to form lithium oxide.

[0074] In one embodiment, the metal recovery composition (100) may include a shell portion (120) disposed on a core portion (110). The shell portion (120) may be lithium oxide disposed on the core portion (110).

[0075] The lithium oxide may include, for example, lithium-aluminum oxide. The lithium-aluminum oxide may be a lithium-aluminum compound. The lithium-aluminum oxide may be formed by combining lithium and aluminum contained in the composition into an oxide through physical or chemical bonding.

[0076] In one embodiment, the lithium oxide may include LiAlO2, Li5AlO4, Li2CO3, and LiF. The LiAlO2, Li5AlO4, and Li2CO3 correspond to lithium oxides reacted during the high-temperature reduction reaction of the battery shreds, and LiF may be a lithium oxide detected by the electrolyte residual amount depending on the degree of pretreatment.

[0077] In one embodiment, the lithium compound may include XRD peaks having 2θ of at least one of 20.5 to 21.5°, 29.0 to 29.5°, 31.5 to 32.0°, 32.2 to 33.0°, 60.5 to 61.5°, 70.0 to 72.0°, 19.5 to 20.2°, 21.6 to 22.2°, 24.0 to 26.0°, 27.0 to 29.0°, 34.0 to 36.0°, 37.0 to 39.0°, 38.2 to 39.5°, 44.0 to 46.0°, 64.5 to 66.5°, and 77.77 to 79.77°.

[0078] In one embodiment, LiAlO2 can include XRD peaks of at least one of 20.5 to 21.5°, 29.0 to 29.5°, 31.5 to 32.0°, 32.2 to 33.0°, 60.5 to 61.5°, and 70.0 to 72.0°. Li5AlO4 can include XRD peaks of at least one of 19.5 to 20.2° and 21.6 to 22.2°.

[0079] The Li2CO3 composition may include at least one of XRD peaks from 24.0 to 26.0°, from 27.0 to 29.0°, from 34.0 to 36.0°, and from 37.0 to 39.0°. The LiF composition may include at least one of XRD peaks from 38.2 to 39.5°, from 44.0 to 46.0°, from 64.5 to 66.5°, and from 77.77 to 79.77°.

[0080] As described above, the precious metal recovery composition (100) has an XRD peak value of at least one of LiAlO2, Li5AlO4, Li2CO3, and LiF, and it can be confirmed that a lithium compound is attached and arranged on a core portion including the precious metal.

[0081] In one embodiment, the lithium compound partially bonded to the surface of the valuable metal recovery alloy can be separated using a wet process. In another embodiment, the lithium compound can be separated from the valuable metal recovery alloy by mechanical or physical external force. In this way, not only can the valuable metal recovery alloy be recovered from the valuable metal recovery composition (100), but the lithium compound can also be separated simultaneously, thereby increasing the lithium recovery rate and reducing the amount of lithium lost.

[0082] In one embodiment, the composition for recovering valuable metals (100) may contain 1 to 30 wt% of aluminum (Al). Specifically, the aluminum may contain 1.1 to 15.0 wt%. By satisfying the above range of content of aluminum, a lithium compound can be formed through physical or chemical bonding with lithium, and as the lithium compound is separated in the future, there is an advantage in that the yield of lithium can be increased.

[0083] If the content of the above aluminum exceeds the upper limit of the above range, there is a problem of increased cost of Ni, Co solvent extraction and crystallization process and decreased Ni, Co recovery rate due to excessive generation of Al2(SO4)3 in the leaching and solvent extraction process. If the content of the above aluminum exceeds the lower limit of the above range, there is a problem of inferior formation of Li-Al-O oxide due to insufficient aluminum content.

[0084] In one embodiment, the valuable metal recovery composition (100) includes aluminum (Al), and the aluminum (Al) may have a concentration gradient that gradually increases from the interface between the core portion (110) and the shell portion (120) toward the shell portion (120). The concentration gradient of aluminum (Al) increases toward the shell portion (120) because an oxide including aluminum is attached to the core portion (110) including the valuable metal alloy.

[0085] In one embodiment, a method for recovering valuable metals may include the steps of preparing battery shreds, dry heat treating the shreds, and recovering a valuable metal alloy from the heat-treated resultant. The method may be for producing an alloy having a high concentration of valuable metals, particularly a method for producing an alloy having a higher concentration of valuable metals compared to a black powder that has undergone an initial crushing step. Furthermore, the method may be the same as the method for recovering valuable metals produced through the above-described production method, as long as it does not contradict the aforementioned FIG. 1.

[0086] The step of preparing battery shredder is a step of preparing the parent material of the battery shredder by shredding it, or a step of preparing the shredded material itself. The parent material of the battery shredder may include waste batteries that have reached the end of their useful life, scrap constituting the waste batteries, positive electrode materials such as jelly rolls and slurry, defective products generated during the manufacturing process, residues within the manufacturing process, and waste materials generated during the manufacturing process, for example, waste materials from the manufacturing process of lithium ion batteries. The shredded material itself may be a shredded product itself, such as black powder.

[0087] In one embodiment, the step of preparing a battery or battery shredder in units of cells may include, when preparing the material that serves as the parent material of the battery shredder by crushing the material, the material serving as the parent material of the battery shredder. The parent material of the battery shredder may be crushed to obtain a pulverized product using a crusher. Non-limiting examples of the crushing may include, but are not limited to, crushing the waste battery by applying physical or mechanical force and pulverizing the waste battery into fine powder.

[0088] The above shredding step can separate some large impurities, such as aluminum (Al), copper (Cu), iron (Fe), and plastic, from the components contained in the waste battery. The state in which the large impurities are separated is called black powder, and the above shredding step can produce battery shreds such as black powder.

[0089] In one embodiment, the battery shredder may include aluminum (Al), manganese (Mn), lithium (Li), copper (Cu), cobalt (Co), nickel (Ni), carbon (C) and residual impurities. In one embodiment, the black powder includes 5 to 40 wt% of nickel (Ni), 1 to 20 wt% of cobalt (Co), 1 to 15 wt% of manganese (Mn), 0.5 to 5 wt% of lithium (Li), 10 to 70 wt% of carbon (C), 0.0001 to 20 wt% of aluminum (Al), and 0.0001 to 20 wt% of copper (Cu), and the sum of impurities such as iron (Fe) and phosphorus (P) may be less than 10 wt%. The components of the above black powder may vary depending on the ratio of nickel, cobalt, and manganese, and the nickel, cobalt, and manganese may be controlled by the positive electrode oxide in the lithium secondary battery when the lithium secondary battery is crushed.

[0090] In one embodiment, the step of crushing the material that becomes the parent material of the battery shredder may be a crushing method utilizing at least one of shear, compression, and tensile force. Specifically, the crushing may be performed by, for example, at least one of a hammer mill, a ball mill, and a stirred ball mill. The hammer mill may perform at least one of disintegration, punching, and milling, and it is clear that the crushing may be performed using various types of crushing or crushing devices, such as an industrial crusher, as a non-limiting example.

[0091] In one embodiment, the particle size of the battery shredder may be within 50 mm, specifically within 30 mm. A particle size larger than the above range would require more energy to be supplied in the heat treatment step described below, which is uneconomical.

[0092] In one embodiment, prior to the step of crushing the parent material of the battery shredder, a pretreatment step may be further included to prevent explosion or render the parent material of the battery shredder harmless. By including the pretreatment step, potentially explosive substances, such as electrolytes, within the parent material are removed, and the parent material, such as waste batteries, is discharged, thereby enhancing safety during the crushing step and increasing the recovery and productivity of valuable metals.

[0093] The step of dry heat treating the above-mentioned crushed material may involve placing the crushed material in a heating furnace capable of raising the temperature to a temperature higher than the melting point. The step of dry heat treating the above-mentioned crushed material may involve heat treatment conditions that perform a high-temperature reduction reaction without going through a melting step.

[0094] In one embodiment, the heat treatment conditions may involve heat treatment conditions in the range of 1,150 to 1,400° C. Specifically, the range may be performed in the range of 1,200 to 1,300° C., and more specifically, 1,200 to 1,300° C. As the heat treatment is performed in the above-described temperature range, copper in the battery shreds is melted and remains in the valuable metal alloy, so that it is advantageous in that it can be easily sorted and recovered by the magnetic sorting step, which is a subsequent process, and the reduction reaction can be performed in a state where carbon in the battery shreds is minimally burned and carbon dioxide is generated with almost no generation.

[0095] If the upper limit of the above range is exceeded, there is a problem of loss due to lithium vaporization, and if the lower limit of the above range is exceeded, there is a problem of sintering and reduction of alloy elements not proceeding.

[0096] In one embodiment, the step of dry heat treating the shredded material may be performed in a gas atmosphere of at least one of an inert gas, carbon dioxide, carbon monoxide, and a hydrocarbon gas. The inert gas may include, for example, at least one of argon and nitrogen. By performing the reduction reaction of the shredded material in the gas atmosphere, a valuable metal recovery alloy comprising the valuable metal contained in the shredded material as a component can be effectively recovered.

[0097] In one embodiment, a portion of the gaseous atmosphere may contain impurities containing residual oxygen. If the oxygen content among the impurities is high, it may combine with the components of the shredded material during the reduction reaction to form carbon dioxide, which may then be gasified together with the lithium, making recovery difficult.

[0098] In one embodiment, the oxygen content in the dry heat treatment step may be 5% or less by volume. Specifically, the oxygen content may be 1% or less, and more specifically, 0.05% or less. Specifically, when the partial pressure of the oxygen is higher than the above value, there is a problem of lithium loss and large amounts of carbon dioxide being generated in a local high-temperature state. When the partial pressure of the oxygen is lower than the lower limit of the above range, there is a problem of a decrease in the Li recovery rate due to the inferiority of LiAlO2 production.

[0099] In one embodiment, the dry heat treatment step may be performed in multiple stages. Specifically, the multiple stages may include a preliminary heat treatment step and a high-temperature heat treatment step. Specifically, the high-temperature heat treatment step may be performed at a higher temperature than the preliminary heat treatment step.

[0100] In one embodiment, the preheat treatment step may be a step of preheating the battery shreds at 900° C. or lower. Specifically, the preheat treatment step may be a step of preheating at a temperature lower than the melting point of copper.

[0101] In one embodiment, the preheat treatment step may be performed at a heating rate of 5 to 15 °C / min. Specifically, the preheat treatment step may be performed at a heating rate of 8 to 12 °C / min, and more specifically, the preheat treatment step may be performed at a heating rate of 9 to 11 °C / min.

[0102] In one embodiment, the high-temperature heat treatment step may be performed at 900° C. or higher. Specifically, the high-temperature heat treatment may involve heating at a temperature higher than the melting point of copper, such that the copper in the valuable metal recovery composition is controlled to partially melt and form a valuable metal alloy, and a carbon layer may be included in the valuable metal alloy.

[0103] In one embodiment, the heating rate of the high temperature heat treatment step may be performed at a temperature rise rate of 2.5 to 7.5 °C / min. Specifically, the heating rate may be 3.5 to 6.5 °C / min, and more specifically, 4 to 6 °C / min.

[0104] In one embodiment, the heating rate of the high-temperature heat treatment step is controlled to be lower than the heating rate of the preliminary heat treatment step, so that copper in the valuable metal recovery composition is partially melted and formed in the valuable metal alloy, and a carbon layer is controlled to be included in the valuable metal alloy, so that it can be easily introduced into a post-process.

[0105] By performing the above dry heat treatment step, a valuable metal recovery alloy comprising components such as nickel, cobalt, manganese and lithium-containing oxides in the crushed material, a valuable metal recovery composition comprising a lithium compound, copper and graphite disposed on at least a portion of the surface of the valuable metal recovery alloy or produced separately from the valuable metal recovery alloy can be obtained. The valuable metal recovery composition can include, for example, aluminum (Al), manganese (Mn), lithium (Li), copper (Cu), cobalt (Co), nickel (Ni), carbon (C) and the remainder of impurities, and the detailed description thereof is the same as the aforementioned valuable metal recovery composition to the extent that it does not contradict.

[0106] The above-described metal recovery composition may include a lithium compound, and the lithium compound may be prepared by the reduction reaction. For example, the lithium compound may be lithium aluminate (2LiAlO2), and the reaction formula thereof is as follows.

[0107] [Reaction Formula 1]

[0108] Li2O+Al2O3= 2LiAlO2

[0109] In one embodiment, the dry heat treatment step may include adding a stirring process within the heat treatment furnace. The stirring process may, for example, utilize a rotating body or gas to promote the reaction within the heat treatment furnace, which is a high-temperature reduction furnace, and ensure uniformity of the internal temperature. The valuable metal recovery composition may be recovered by the reduction reaction of the black powder within the heat treatment furnace.

[0110] The step of recovering a valuable metal alloy from the heat-treated product can be performed by separating the heat-treated fragments, for example, the valuable metal alloy, through magnetic separation. The magnetic separation method utilizes a magnetic material to separate particles through contact with the magnetic material, and various types of magnetic separation methods can be applied.

[0111] In one embodiment, the magnetic separation may be a step of magnetically separating and recovering a valuable metal recovery alloy having a magnetic strength of 800 to 4,500 G. Specifically, the magnetic strength may be 1,000 to 4,000 G, and more specifically, 2,000 to 3,000 G. When the magnetic strength satisfies the above-described range, the content of copper in the recovered valuable metal alloy satisfies Equations 1 to 3 described above, thereby improving the efficiency of the wet smelting process in the subsequent process and reducing the process cost.

[0112] In one embodiment, the magnetic separation may be performed dry. Specifically, the magnetic separation may be performed using either a dry drum-type magnetic separator or a dry conveyor belt-type magnetic separator.

[0113] In another embodiment, the magnetic separation may be performed wet. Specifically, the magnetic separation may be performed by immersing the battery shreds in a tank or a liquid material-containing batch, and then magnetically separating the shredded battery using a magnet. Specifically, the wet magnetic separation may be performed under conditions where the pulp density, which indicates the concentration of the solid content, is 10 to 50%. Specifically, the pulp density may be performed at 20 to 40%. The wet magnetic separation has the advantage of improved sorting efficiency compared to the dry magnetic separation.

[0114] In one embodiment, prior to the step of preparing the battery shredder, a step of pretreating the battery may be included. The pretreating step may be a step of discharging and stabilizing the battery.

[0115] In one embodiment, the step of discharging and stabilizing the battery may be a step of performing a salt water discharge or an electric discharge. The step of discharging and stabilizing the battery may be a step of performing a salt water discharge or an electric discharge to lower and stabilize the voltage of the battery.

[0116] In one embodiment, the step of preprocessing the battery may include freezing the battery. Directly crushing the battery may result in an explosion or fire due to the electrolyte contained within the battery. Specifically, when a certain pressure is applied to the battery, the separator may be physically crushed, resulting in a short circuit that generates a high current, generating a spark. This spark may ignite the electrolyte, potentially resulting in a fire.

[0117] The step of freezing the battery is to freeze the battery to suppress ignition of the liquid electrolyte contained within the battery, and then perform the crushing process, so that no problem due to ignition of the electrolyte occurs.

[0118] In one embodiment, the step of freezing the battery may be performed by cooling it to a temperature in the range of -150°C to -60°C. If the temperature exceeds the upper limit of the above temperature range, the voltage remaining inside the battery may not decrease to 0 V, which may cause a battery reaction due to a short circuit, and the electrolyte may not be completely frozen, which is not suitable.

[0119] When the temperature exceeds the lower limit of the above temperature range, the electrolyte is sufficiently frozen, the internal voltage of the battery is also lowered to 0 V, and even if a short circuit occurs in which the positive and negative electrodes are in direct contact, no battery reaction occurs, so the battery temperature does not increase, and gas generation and combustion of the electrolyte do not occur. In addition, since the electrolyte is in a frozen state, the mobility of lithium ions is very low, so that the conduction characteristics according to lithium ion movement may be significantly reduced, and since vaporization of the electrolyte does not occur, flammable gases such as ethylene, propylene, and hydrogen may not be generated.

[0120] In the step of freezing the battery, if the temperature exceeds the upper limit of the above-mentioned temperature range, the voltage remaining inside the battery may not decrease to 0 V, which may result in a battery reaction due to a short circuit, and the electrolyte may not be completely frozen, which is not appropriate. If the temperature exceeds the lower limit of the above-mentioned temperature range, a large amount of energy must be invested for freezing, which is uneconomical.

[0121] In one embodiment, the step of freezing the battery may be performed by cooling the battery to a temperature range of -60 to -20°C under a vacuum atmosphere of 100 torr or less. The step of freezing the battery may be performed at a temperature range capable of suppressing the evaporation of the electrolyte. The vacuum atmosphere may be, for example, an inert gas, carbon dioxide, nitrogen, water, or a combination thereof.

[0122] Since the process is performed by controlling the pressure to a vacuum atmosphere of 100 torr or less, the supply of oxygen is suppressed, thereby preventing the electrolyte from reacting with oxygen, preventing an explosion caused by this, and suppressing the vaporization of the electrolyte, thereby preventing the generation of flammable gases such as ethylene, propylene, and hydrogen.

[0123] In the step of freezing the above battery, if it is performed in an air atmosphere or at a pressure exceeding 100 torr, there is a problem that voltage may remain within the battery, and since the electrolyte is not in a frozen state in the temperature range of -60 to -20°C, the electrolyte may vaporize and explode due to a spark generated when a short circuit occurs due to the remaining voltage.

[0124]

[0125] To further illustrate the present invention, examples of the present invention are described. The following examples are merely exemplary of the present invention, and the present invention is not limited to the examples described below.

[0126]

[0127] <Experimental Example>

[0128] <Example 1>

[0129] Steps to prepare the battery

[0130] 2750 g of NCM622 batteries were prepared, and the content ratio of the NCM622 batteries is as shown in Table 1 below.

[0131] Weight(g)Weight(%)Li[%]Ni[%]Co[%]Mn[%]Al[%]Cu[%]C[%]Cu / NiCu / MnCu / CNCM6222750.01006.0432.3510.739.986.0710.7324.5033.2107.544

[0132] Battery shredding stage

[0133] It is preferable to use a method of freezing the above-mentioned waste battery at -30℃ or lower and then crushing it, or to use a shredder device to crush the waste battery under atmospheric or inert gas conditions so that the longest length or width of the waste battery is 100 mm or less after discharging it under salt water discharge or electric discharge conditions. Specifically, an NCM622 battery having an SOC of 40% or less was frozen at -70℃ for 24 hours or more and then crushed under a nitrogen atmosphere using a shredder so that the longest length or width of the battery is 100 mm or less.

[0134]

[0135] High temperature heat treatment stage

[0136] After obtaining a composition for recovering valuable metals by the above-described method, the crushed battery scrap was heat-treated at 1,250°C under an oxygen partial pressure condition of 0.5% to perform a reduction process. At this time, as a heat treatment reduction condition, an inert gas was purged to maintain the oxygen concentration in the furnace at 0.5%, and the temperature was increased at 10°C / min from room temperature to 900°C and at 5°C / min from 900 to 1,250°C, and the process was performed under the condition that the inert gas injection was stopped when the oxygen partial pressure in the furnace was continuously maintained at 0.5% or lower. In addition, after maintaining the sample at 1,250°C for 3 hours or more, the sample was cooled at a cooling rate of 20°C / min or more. Through the above reduction process, a composition for recovering valuable metals was obtained.

[0137] FIG. 1 is an SEM photograph of a composition for recovering valuable metals according to one embodiment of the present invention.

[0138] FIG. 2a and FIG. 2b show XRD analysis results of a composition for recovering valuable metals according to one embodiment.

[0139] Referring to FIGS. 1, 2a, and 2b, it can be seen that the composition for recovering valuable metals is arranged such that a lithium compound, specifically lithium oxide, is bonded to a valuable metal recovery alloy. This structure may be developed by performing the reduction process described above.

[0140] FIG. 3 shows the results of XRD analysis on the change in state of Cu in a composition for recovering valuable metals according to one embodiment.

[0141] Referring to Fig. 3, the state change of the molten Cu in the composition for recovering valuable metals can be confirmed using XRD. It can be confirmed that the molten Cu reacts with Ni and chemically bonds in the reducing atmosphere of the present invention. This means that the molten Cu remains melted within the NCM alloy, and the content of Cu melted within the NCM alloy is controlled by the reduction temperature.

[0142] Figures 4a and 4b show the melting process of copper foil (Cu foil) in the heat treatment step of the battery shredder of the present invention.

[0143] Fig. 4a shows the state of copper foil (Cu foil) before melting, and Fig. 4b shows the state of copper foil after melting. Referring to Figs. 4a and 4b, it can be confirmed that copper melts at 1,050°C, and it can be confirmed that the brightly colored copper portion in Fig. 4a has completely disappeared in Fig. 4b.

[0144] Example 1 and Comparative Examples 1 to 3 are experimental results for reactants subjected to high-temperature reduction in an atmosphere with an oxygen concentration of 0.5% or less at a high-temperature heat treatment temperature range of 900 to 1500°C.

[0145] The high-temperature reduction reactants were separated using a 100 μm sieve because most of the reactants under 100 μm are mainly composed of carbon and metallic Cu, and the reactants larger than 100 μm were separated into magnetic products and non-magnetic products using a magnetic separator with a magnetic strength of 3000 G. The results of analyzing the components and ratios of the components are as follows. The components of the fine particles smaller than 100 μm were analyzed to have a C content of 79.2%, a Li content of 1% or less, a Ni content of 3% or less, and Co a and Mn of 2% or less.

[0146] <Comparative Example 1>

[0147] The same procedure as Example 1 was followed, except that the high-temperature heat treatment step was performed at 1,100°C.

[0148]

[0149] Comparative Example 2

[0150] The same procedure as Example 1 was followed, except that the high-temperature heat treatment step was performed at 1,500°C.

[0151]

[0152] <Comparative Example 3>

[0153] The same procedure as Example 1 was followed, except that the heat treatment was performed at 900°C in the high-temperature heat treatment step.

[0154]

[0155] <Evaluation Example 1> - Evaluation of components of valuable metal recovery composition

[0156] Table 2 below shows the components of a metal recovery composition manufactured by a high-temperature heat treatment process when subjected to magnetic separation.

[0157] The following components were measured using ICP-OES and C / S analyzer.

[0158] Particle size [㎛]Li [wt%]Ni [wt%]Co [wt%]Mn [wt%]Al [wt%]Cu [wt%]Cu / Ni [%]Cu / Mn [%]Cu / C [%]Example 1 (1250℃)Magnetic 5.7332.5014.079.959.124.083.4512.641.0118Non-magnetic 5.670.920.321.796.6935.4021.733847.81977.7163Comparative Example 1 (1100℃)Magnetic 5.6428.3011.019.5212.677.815.5727.682.0140Non-magnetic Magnetic 1.243.571.481.161.113.5279.2098.6303.44Comparative Example 2 (1500℃) Magnetic 0.3751.9016.503.101.290.103.680.23.22.7Non-magnetic 1.800.460.0712.404.170.010.122.20.18.3Comparative Example 3 (900℃) Magnetic 1.1729.4510.719.591.420.513.101.75.316.5Non-magnetic 6.0325.5311.348.0110.4510.656.5841.7133.0161.9

[0159] Looking at the example of Table 2 above, compared to the component ratio of the NCM622 battery of Table 1, the Cu / Ni, Cu / Mn, and Cu / C content ratios are consumed when the oxygen and carbon of the cathode material, NCM, react and convert into CO and CO2 gases during the high-temperature reduction process, and the Cu / C content ratio of the magnetic product rapidly increases from 44% to 118% due to the carbon and some of the burned carbon, and the non-magnetic product also increased to 16%. The Cu / Ni and Cu / Mn ratios of the magnetic product decreased by about half compared to Table 1 to 12.6% and 41.0%, respectively. This is because the NCM oxide, which is the cathode material, was reduced to metal and mostly separated into magnetic products. Accordingly, the Cu / Ni ratio and Cu / Mn ratio of the non-magnetic product increase to several thousand %. Comparative Example 1 is the result of magnetic separation of a material reacted at 1,100°C, which is slightly higher than 1,050°C at which Cu melts during the high-temperature reduction reaction, and it can be seen that the weight % of the valuable metal recovered as a magnetic product is somewhat lower than that of Example 1. This is because the reaction rate of the reduction reaction is highly temperature-dependent, becoming faster as the temperature increases, and thus the cathode material is not completely reduced compared to Example 1 and remains in the form of an oxide.

[0160] Comparative Example 2 reacted at a high temperature of 1,500℃, and most of the carbon was burned off and did not remain in the magnetic or non-magnetic products. In addition, because the reaction occurred at a temperature higher than the melting point of NCM and the volatilization temperature of Li, most of the NCM was melted after reduction and discharged in the form of molten iron, and the weight % of NCM in the magnetic product was the highest. However, most of the Li was volatilized and could not be recovered as a magnetic product, and only a trace amount could be recovered as a non-magnetic product in the form of slag.

[0161] Comparative Example 3 is a reaction performed at 900°C, which is lower than the melting point of Cu (1,050°C), and then magnetic and non-magnetic products are separated. In general, the reduction reaction by carbon is actively performed when the temperature is higher than the temperature at which the Boudwar reaction occurs thermodynamically. Since Comparative Example 3 is performed at a temperature similar to the Boudwar reaction temperature, although some of the cathode material is reduced and recovered as a magnetic product, it is only at a significantly lower level than that of Example 1. Therefore, the Cu / Ni ratio, Cu / Mn ratio, and Cu / C ratio are very low compared to those of the Example. Ultimately, the temperature of the high-temperature reduction reaction should be performed at an intermediate temperature, higher than 1100°C and lower than 1500°C.

[0162]

[0163] <Evaluation Example 2> - Component Evaluation of Valuable Metal Alloys Component Evaluation of Valuable Metal Recovery Composition

[0164] In the dry heat treatment step, the reaction product manufactured at a high temperature reduction reaction temperature of 1,300 ℃ was subjected to magnetic separation, and the components of the magnetic product and the ratio of each component were compared according to the strength of the magnetic force.

[0165]

[0166] <Example 2>

[0167] In the dry heat treatment step, a composition for recovering valuable metals was prepared in the same manner as in Example 1, except that the high-temperature reduction reaction temperature was set to 1,300°C. Afterwards, the prepared composition for recovering valuable metals was subjected to magnetic separation at a magnetic strength of 1,000 G to recover a magnetic body.

[0168]

[0169] <Example 3>

[0170] The same procedure as Example 2 was followed, except that the magnetic material was recovered by magnetic separation at a magnetic strength of 2,000 G.

[0171]

[0172] <Example 4>

[0173] The process was performed in the same manner as in Example 2, except that the magnetic material was recovered by magnetic separation at a magnetic strength of 3,000 G.

[0174]

[0175] Comparative Example 4

[0176] The process was performed in the same manner as in Example 2, except that the magnetic material was recovered by magnetic separation at a magnetic strength of 500 G.

[0177]

[0178] Comparative Example 5

[0179] The same procedure as Example 2 was followed, except that the magnetic material was recovered by magnetic separation at a magnetic strength of 5,000 G.

[0180]

[0181] Table 3 below shows the components of magnetic and non-magnetic alloys for the recovery of valuable metals when the composition for the recovery of valuable metals is subjected to magnetic separation according to the strength of the magnetic force. The magnetic separation method was performed using the method described below.

[0182] Magnetic separation method: Separation experiments were conducted according to magnetic strength using a magnetic separator, a drum-type wet magnetic separation device manufactured by Daebo Magnetic Co., Ltd.

[0183]

[0184] ClassificationLi[wt%]Ni[wt%]Co[wt%]Mn[wt%]Al[wt%]Cu[wt%]Cu / Ni[%]Cu / Mn[%]Cu / C[%]Example 2 (1000G)Magnetic material5.6435.5015.7010.508.414.233.1811.940.3133Non-magnetic material7.721.290.561.74 13.2027.9017.702162.81603.4158Example 3 (2000G)Magnetic body 5.8631.6014.009.289.514.212.9613.345.4142Non-magnetic body 6.431.190.501.8510.5034.8016.502924.41881.1211Example 4 (3000G)Magnetic body 5 .0932.9014.509.548.494.153.8412.643.5108Non-magnetic material6.870.820.351.9410.2034.5019.304207.31778.4179Comparative example 4 (500G)Magnetic material6.6332.2014.309.739.385.822.7518.159.8212Non-magnetic material8. 661.450.641.7814.3028.1020.401937.91578.7138Comparative Example 5 (5000G)Magnetic material5.9231.7014.079.469.473.925.6412.441.470.0Non-magnetic material5.670.380.272.078.0640.7413.21,072.11,968.1309

[0185] Looking at Table 3 above, when the magnetic strength of the example is in the range of 1000 to 3000 G, the Cu / Ni ratio of the magnetic product changes in a narrow range of 10 to 15%, the Cu / Mn ratio in a narrow range of 40 to 50%, and the Cu / C ratio in a narrow range of 100 to 150%, but in the comparative example of 500 G with a low magnetic strength, the Cu / Ni ratio of the magnetic product increases very sharply to 18.1%, the Cu / Mn ratio in a narrow range of 59.8%, and the Cu / C ratio in a narrow range of 212%. In addition, it can be seen that a significant amount of Li and NCM valuable metals remain in the non-magnetic product of 500 G and are not recovered as magnetic products. Comparative Example 5 is an experimental result for 5000 G with a very strong magnetic strength. Although the Cu / Ni ratio and the Cu / Mn ratio are similar to the ratio range of the example, it can be seen that the non-magnetic carbon is recovered as a magnetic product, so the Cu / C ratio increases to 70%, which is significantly reduced compared to the range of the example. This shows that when the magnetic strength is too strong for the range suggested by the present invention during magnetic separation, even non-magnetic materials are recovered as magnetic products, and the purpose of performing magnetic separation to separate valuable metals and carbon is reduced.

[0186] The present invention is not limited to the above-described embodiments, but can be manufactured in a variety of different forms. Those skilled in the art will appreciate that the present invention can be implemented in other specific forms without altering the technical spirit or essential characteristics of the present invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive.

Claims

1. Based on 100 wt% of the total composition of the alloy, The metal content is 45 wt% or more, and the remainder includes impurities. A valuable metal recovery alloy satisfying the following equation 1. <Formula 1> 5.0 ≤ [Cu] / [Ni] ≤ 15.0 % (In the above formula 1, [Cu] and [Ni] represent the contents of Cu and Ni in the valuable metal recovery alloy, respectively) 2. In paragraph 1, A valuable metal recovery alloy satisfying the following equation 2. <Formula 2> 30.0 ≤ [Cu] / [Mn] ≤ 55.0 % (In the above formula 2, [Cu] and [Mn] represent the contents of Cu and Mn in the valuable metal recovery alloy, respectively) 3. In paragraph 1, A valuable metal recovery alloy satisfying the following equation 3. <Formula 3> 50.0 ≤ [Cu] / [C] ≤ 200.0 % (In the above formula 3, [Cu] and [C] represent the contents of Cu and C in the valuable metal recovery alloy, respectively) 4. In paragraph 1, A valuable metal recovery alloy comprising a CuNi alloy.

5. In paragraph 1, A precious metal recovery alloy having an XRD peak value of at least one diffraction peak among 2θ = 44 °± 1 °, 2θ = 51.5 °± 1.5 °, and 2θ = 75.5 °± 1.5 °.

6. In paragraph 1, A valuable metal recovery alloy comprising copper (Cu) having a content of 0.02 to 5.00 wt% based on 100 wt% of the valuable metal recovery alloy.

7. In paragraph 1, A composition for recovering valuable metals, comprising carbon (C) having a content of 5.0 wt% or less based on 100 wt% of a valuable metal recovery alloy.

8. Step for preparing battery cells or battery shreds; A step of dry heat treating at a temperature range of 1,150 to 1,400° C without going through a melting step of the battery or the shredded material; and A method for recovering a valuable metal, comprising a step of recovering a valuable metal recovery alloy having magnetic properties by magnetic separation using a magnetic strength of 800 to 4,500 G from the resultant product of the above dry heat treatment.

9. In paragraph 8, A method for recovering valuable metals, wherein the above dry heat treatment step is performed in an atmosphere having an oxygen content of 5% or less.

10. In paragraph 8, The above dry heat treatment step includes a step of performing in multiple stages, A method for recovering valuable metals, wherein the steps performed in the above multiple stages include a preliminary heat treatment step and a high-temperature heat treatment step performed at a temperature higher than the preliminary heat treatment step.

11. In paragraph 8, The above preliminary heat treatment step is performed at a temperature of 900 ℃ or less, A method for recovering valuable metals, wherein the heating rate of the above preliminary heat treatment step is performed at 5 to 15°C / min.

12. In paragraph 8, The above high temperature heat treatment step is performed at 900 ℃ or higher, A method for recovering valuable metals, wherein the heating rate of the high-temperature heat treatment step is performed at 2.5 to 7.5 ℃ / min.

13. In paragraph 8, After the above high temperature heat treatment step, a cooling step is included, A method for recovering valuable metals, wherein the cooling step is performed at a cooling rate of 20°C / min or higher. A method for recovering valuable metals, wherein the high-temperature heat treatment step is performed at 900°C or higher.

14. In paragraph 8, A method for recovering a valuable metal, wherein the step of recovering the above valuable metal recovery alloy by magnetic separation is performed in a wet manner.

15. In paragraph 8, A method for recovering a valuable metal, wherein the step of recovering the above valuable metal recovery alloy by magnetic separation is performed in a range where the concentration of the solid content is 10 to 50%.

16. In paragraph 8, A method for recovering valuable metals, wherein the result obtained from the above dry heat treatment step separates a lithium compound bound to a portion of the surface of the above valuable metal recovery alloy by an external force.

17. In paragraph 8, A method for recovering valuable metals, wherein the step of preparing the battery or battery scrap in the unit of cells includes the step of preprocessing the battery or battery scrap in the unit of cells.

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