Recycling method of valuable metal, and recovered valuable metal alloy particles and sulfate solution therefrom

Abstract

A recycling method of a valuable metal according to the present invention comprises the steps of: preparing Ni-Co-Mn alloy particles having a compound containing lithium and aluminum located on the surface thereof; subjecting the alloy particles to primary acid-leaching to selectively remove the compound containing lithium and aluminum located on the surface of the alloy particles; and obtaining valuable metal recovery alloy particles, from which the compound containing lithium and aluminum has been removed.

Description

Method for recycling precious metals, precious metal recovery alloy particles and sulfate solution recovered using the same

[0001] The present invention relates to a method for recycling precious metals, precious metal recovery alloy particles recovered using the method, and a sulfate solution.

[0002] As demand for electric vehicles grows globally, the issue of disposing of waste batteries generated from electric vehicles is emerging as a social issue.

[0003] In the case of lithium secondary batteries, which are the main raw material for waste batteries, they contain organic solvents, explosive substances, valuable metals such as Ni, Co, and Mn, and heavy metals such as Fe.

[0004] Among these, Ni, Co, Mn, and Li have high scarcity value as valuable metals, so the recovery and recycling process after lithium secondary batteries are discarded is emerging as an important research field.

[0005] Specifically, a lithium secondary battery is mainly composed of copper and aluminum used as a current collector, oxides containing Li, Ni, Co, and Mn forming a cathode material, and graphite used as an anode material, and includes a separator that separates the cathode and anode materials and an electrolyte injected into the separator. The solvent used as the solvent and salt forming the electrolyte are mainly a mixture of carbonate organic substances such as ethylene carbonate and propylene carbonate, and LiPF6 is used as an example.

[0006] To utilize these waste batteries, active development is underway on a waste battery recycling process that crushes waste batteries to produce intermediate materials such as waste battery shreds or black powder, and then recovers valuable metals through post-processing.

[0007] The recovered valuable metals go through a process of acid leaching to recover valuable metals such as Li, Ni, Co, and Mn within the battery.

[0008] Using acids such as sulfuric acid, valuable metals in the battery are ionized and acid-leached, and then a process is performed to remove impurities. Ni, Co, Mn, etc. in the sulfuric acid from which impurities have been removed are extracted in the form of sulfides through solvent extraction and crystallization. After removing impurities, the solvent extraction to extract Ni, Co, and Mn is performed using a solvent that selectively recovers only each element, controlling the temperature and pH, absorbing the corresponding elements into the solvent, and then washing them again with sulfuric acid to produce a high-concentration Ni, Co, and Mn sulfuric acid solution.

[0009] At this time, the high cost of each solvent used increases manufacturing costs. Furthermore, there is the problem of having to wash again with sulfuric acid, and the amount of sodium hydroxide (NaOH) used to adjust the pH, which produces sodium sulfate (Na2SO4) through a precipitation reaction, is approximately 3 to 5 times higher than the amount of sulfate product produced, leading to problems such as increased landfill costs and environmental pollution.

[0010] Therefore, research on methods for supplying raw materials for manufacturing nickel-containing batteries is required for an eco-friendly and low-cost production process of Ni, Co, and Mn, which are key elements of secondary batteries.

[0011] The present invention aims to provide a method for recycling valuable metals that can be usefully used as raw materials for manufacturing nickel-containing batteries.

[0012] In addition, the present invention aims to provide valuable metal recovery alloy particles and sulfate solution that can be usefully used as raw materials for manufacturing nickel-containing batteries from waste batteries.

[0013] The present invention provides a method for recycling a valuable metal, comprising the steps of: preparing a Ni-Co-Mn alloy particle having a compound including lithium and aluminum located on the surface; selectively removing a compound including lithium and aluminum located on the surface of the alloy particle by first acid leaching the alloy particle; and obtaining a valuable metal recovery alloy particle from which the compound including lithium and aluminum has been removed.

[0014] In addition, the present invention provides a valuable metal recovery alloy particle derived from a Ni-Co-Mn alloy particle having a compound including lithium and aluminum located on the surface, and having a content of one or more impurities selected from the group consisting of Al, Fe, and Cu of 15 wt% or less.

[0015] The present invention also provides a sulfate solution comprising Ni, Co and Mn derived from the aforementioned valuable metal recovery alloy particles.

[0016] The method for recycling valuable metals according to the present invention has the advantage of easily obtaining valuable metal recovery alloy particles that can be useful as raw materials for manufacturing nickel-containing batteries. Furthermore, it has the advantage of easily producing a high-purity nickel-containing sulfate solution for precursors without a separate solvent extraction process.

[0017] In addition, the valuable metal recovery alloy and sulfate solution according to the present invention have the advantage of being useful as a raw material for manufacturing nickel-containing batteries.

[0018] FIG. 1 is a graph showing changes in battery voltage according to cooling temperature according to some embodiments of the present invention.

[0019] FIG. 2 is a graph showing the relationship between battery weight, external cooling temperature, and cooling time according to some embodiments of the present invention.

[0020] Figure 3 is an SEM image of a positive electrode active material precursor for a lithium secondary battery manufactured according to an example and a comparative example.

[0021] Hereinafter, embodiments of the present invention will be described in detail. However, these are presented as examples and are not intended to limit the present invention. The present invention is defined solely by the scope of the claims set forth below.

[0022] In the present invention, when it is said that a member is located “on” another member, this includes not only cases where a member is in direct contact with another member, but also cases where another member is interposed between the two members.

[0023] When a part of the present invention is said to "include" a certain component, this does not mean that other components are excluded, but rather that other components may be included, unless otherwise specifically stated.

[0024]

[0025] <Methods for Recycling Valuable Metals>

[0026] One aspect of the present invention relates to a method for recycling a valuable metal, comprising the steps of: preparing Ni-Co-Mn alloy particles having a compound including lithium and aluminum located on the surface; selectively removing the compound including lithium and aluminum located on the surface of the alloy particles by first acid leaching the alloy particles; and obtaining valuable metal recovery alloy particles from which the compound including lithium and aluminum has been removed.

[0027] The method for recycling precious metals according to the present invention has the advantage of easily obtaining precious metal recovery alloy particles that can be usefully utilized as a raw material for a positive electrode active material precursor for a lithium secondary battery by selectively removing compounds containing lithium and aluminum from Ni-Co-Mn alloy particles.

[0028] In the present invention, “valuable metal” may be a term referring to a non-valuable metal having a value such as Li, Ag, Zn, or Cu in addition to the above Ni, Co, and Mn.

[0029] Specifically, in the present invention, “valuable metal recovery alloy particles” refers to Ni-Co-Mn alloy particles from which compounds including lithium and aluminum have been removed.

[0030]

[0031] A method for recycling precious metals according to the present invention comprises the step of preparing Ni-Co-Mn alloy particles having a compound containing lithium and aluminum located on the surface thereof.

[0032] In one embodiment of the present invention, the step of preparing Ni-Co-Mn alloy particles having a compound including lithium and aluminum located on a surface may include the steps of: preparing a battery containing lithium; crushing the battery into battery shreds; subjecting the crushed battery shreds to high-temperature heat treatment; and separating Ni-Co-Mn alloy particles from the high-temperature heat-treated battery shreds.

[0033] The step of preparing the lithium-containing battery may be a step of processing various types of batteries containing lithium ions. The battery may be, for example, a lithium secondary battery separated from an automobile, a secondary battery separated from an electronic device such as a mobile phone, a camera, or a laptop, and specifically, a lithium secondary battery. More specifically, the battery may be a waste battery, and if the battery is a waste battery, it has the advantage of being environmentally friendly.

[0034] The step of preparing the lithium-containing battery may include a step of freezing the battery. The step of freezing the battery is a step for stabilizing the electrolyte within the battery. When the battery is frozen, the risk of fire occurring during the battery crushing step described below is reduced.

[0035] The step of freezing the above battery can satisfy the following equation 4.

[0036] [Formula 4]

[0037] Minimum cooling time (Hr) = A × (W 0.33 )

[0038] In the above equation 4,

[0039] A = 4 × e(-0.02×dT), W = battery weight (Kg), dT= │external cooling temperature - target temperature│, ││ represents an absolute value.

[0040]

[0041] The minimum cooling time in the above equation 4 refers to the weight of the battery, for example, the weight of a battery pack, a single battery, or a combination thereof. The minimum cooling time refers to the external cooling temperature, which is the cooling temperature applied to the battery, for example, the target temperature for cooling the electrolyte within the battery.

[0042] The step of freezing the battery has the advantage of being able to perform subsequent processes stably by cooling the electrolyte inside the battery by performing the step for a minimum cooling time or longer.

[0043] If the battery is frozen for a time shorter than the minimum cooling time in the step of freezing the battery, there is a problem that the electrolyte is not cooled, which may cause a risk of fire when crushed.

[0044] The step of freezing the battery may be performed at a temperature sufficient to freeze the electrolyte contained within the battery. Specifically, the step of freezing may be performed at a temperature range of, for example, -150 to -20°C. More specifically, the temperature range may be -150 to -50°C, and even more specifically, -80 to -60°C.

[0045] When the battery is frozen in the above temperature range, the voltage remaining slightly inside the battery, for example, about 2 to 3 V, is lowered to close 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.

[0046] In addition, since the electrolyte is in a frozen state or in a state where vaporization is suppressed, the mobility of lithium ions is very low, so that the current-carrying characteristics according to the movement of lithium ions 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.

[0047] If the above freezing process is performed outside the above temperature range, for example, when cooling to a temperature higher than -60°C, the voltage remaining inside the battery may not be reduced to 0V, which may cause a battery reaction due to a short circuit, and the electrolyte may not be completely frozen, which is not appropriate. In addition, if cooling to -150°C is performed, the electrolyte is sufficiently frozen, and the internal voltage of the battery is also reduced to 0V, so there is no need to lower the temperature below this.

[0048] In this way, the battery processing method has the advantage of preventing the risk of fire that may occur during the battery crushing process by including a freezing step before crushing a battery such as a lithium secondary battery.

[0049]

[0050] The step of crushing the battery into battery shredders may refer to a process of applying an impact or pressure to the battery so that a portion of the battery falls off from the battery.

[0051] The step of crushing the battery may refer to a process of crushing the battery, a process of cutting the battery, a process of compressing the battery, or a combination thereof.

[0052] Specifically, the shredding step may include any process that can destroy the battery to obtain small-sized shreds.

[0053] The step of crushing the battery may include any process of compressing the prepared battery or applying an external force, such as a shear force or tensile force, to destroy the battery. The step of crushing the battery may be performed, for example, using a crusher.

[0054] The step of crushing the battery may be performed at least once. Specifically, the step of crushing may be performed at least once, either continuously or discontinuously.

[0055] The step of crushing the battery can be performed under conditions of supplying an inert gas, carbon dioxide, nitrogen, water or a combination thereof, or under vacuum conditions of 100 torr or less.

[0056] For example, when the process of freezing a battery is performed by cooling in a temperature range of -60 to -20°C, when performed under the conditions described above, the supply of oxygen can be suppressed, preventing the electrolyte from reacting with oxygen, preventing an explosion caused by this, and suppressing the vaporization of the electrolyte, so that flammable gases such as ethylene, propylene, or hydrogen are not generated.

[0057] The step of shredding the battery may be performed so that the maximum size of the battery shreds is 100 mm or less. Specifically, the size of the battery shreds may be performed so that the size of the battery shreds is 50 mm or less.

[0058] When the maximum size of the above-mentioned battery shreds is 100 mm, the temperature of heat generated due to instability as the battery shreds are shredded rises to a temperature range of 120°C, which is the average vaporization temperature of the electrolyte, and thus a problem in stability such as a fire may occur.

[0059] The step of preparing the battery may include a step of performing a forced discharge of the battery. The forced discharge may be a step of electrically discharging the battery, and may be a step of lowering the voltage to below 3.2 V using reverse voltage, thereby lowering the voltage to near 0 V.

[0060] For example, if the battery is shredded after the step of freezing the battery and then the forced discharge is performed, problems such as electrolyte vaporization during discharge can be prevented.

[0061]

[0062] The step of high-temperature heat treatment of the shredded battery scrap may be to put the shredded battery scrap into a heating furnace capable of raising the temperature of the shredded battery scrap to a temperature higher than the melting point.

[0063] The above battery scrap may contain valuable metals such as Ni, Co, Mn and Li.

[0064] The above high temperature heat treatment may involve heat treatment conditions that perform a high temperature reduction reaction without the battery going through a melting step.

[0065]

[0066] The step of high-temperature heat treatment of the above-mentioned battery shreds may be performed in a range of 600 to 1500°C. Specifically, the step of high-temperature heat treatment may be performed in a range of 800 to 1400°C, and more specifically, in a range of 1000 to 1350°C.

[0067] Beyond the upper limit of the above range, there is a problem of lithium loss due to lithium vaporization. Beyond the lower limit of the above range, sintering and reduction of alloying elements do not proceed smoothly, and a stabilized lithium-containing compound is not formed, making it difficult to recover a stabilized compound when recovering a compound containing lithium and aluminum in the future.

[0068] In addition, as the temperature rises, Li5AlO4 is generated due to the reaction LiAlO2(s)+2Li2CO3(s) = Li5AlO4+ 2CO2(g), but the LiF(g) vaporization reaction is promoted, so it is preferable that the reaction temperature be performed within the above range.

[0069] In addition, in the range below 600℃, MnO among the Ni, Co, and Mn oxides containing Li in the cathode material is not dissociated, and MnAl2O4 is generated due to the reaction MnO(s)+2Al(s)+3 / 2O2= MnAl2O4(s), which reduces the Li concentration in the compound containing lithium and aluminum, which may cause a problem of a lower Li recovery rate.

[0070]

[0071] The step of high-temperature heat treatment of the above battery shreds can be performed in an atmosphere of at least one gas selected from the group consisting of an inert gas, carbon dioxide, carbon monoxide, hydrocarbon gas, and oxygen.

[0072] In the case of the above inert gas, it may include, for example, at least one of argon and nitrogen. When the reduction reaction of the shredded material is performed in the above gas atmosphere, there is an advantage in that the recovery rate of valuable metal elements contained in the battery shredded material can be increased.

[0073] The step of high-temperature heat treatment of the above-mentioned crushed battery waste can be performed in a gas atmosphere at a temperature range of 600 to 1,500°C and an oxygen concentration range of 0.1 to 2.0 vol%.

[0074] Specifically, the process can be performed in a gas atmosphere with an oxygen concentration in the range of 0.4 to 1.2 vol%.

[0075] If the oxygen concentration in the above gas exceeds the upper limit, there is a problem that the LiAlO2 and Li5AlO4 decrease as the Li2O + C + O2(g) = Li2CO3 reaction is promoted as the oxygen range is higher, so it is preferable that the oxygen range is performed at 2 vol% or less, which is the above-mentioned range. If the oxygen concentration exceeds the lower limit of the above-mentioned range, there is a problem that carbon dioxide is excessively formed during the reduction reaction process and is lost by being gasified together with lithium, or the Li2CO3(s) production increases excessively, making recovery by primary acid leaching difficult.

[0076] The step of high-temperature heat treatment of the above Ni, Co, Mn and Li-containing battery waste can be performed in a gas atmosphere including at least one of an inert gas, carbon dioxide, carbon monoxide, and hydrocarbon gas; and oxygen.

[0077]

[0078] It may include a step of separating a Ni-Co-Mn alloy from the high-temperature heat-treated battery shreds.

[0079] The separation of the above Ni-Co-Mn alloy particles, specifically the No-Co alloy particles having a compound containing lithium and aluminum located on the surface, can be achieved through, but is not limited to, a magnetic separation method.

[0080]

[0081] The method for recycling valuable metals according to the present invention includes a step of selectively removing a compound including lithium and aluminum located on the surface of the alloy particles by first acid leaching the alloy particles.

[0082] The compound containing lithium and aluminum may be at least one selected from the group consisting of LiAlO2, Li5AlO4, and LiAl5O8, Li2CO3, LiF, Li3PO4, Li2SiO3, Li4SiO4, and Li2Si2O5.

[0083] Specifically, the method for recycling valuable metals according to the present invention utilizes Ni-Co-Mn alloy particles derived from waste batteries, on the surface of which a compound including lithium and aluminum is located, so that a compound including lithium and aluminum can be located on the surface of the alloy particles.

[0084] Therefore, by selectively leaching the compound containing lithium and aluminum from the Ni-Co-Mn alloy particles, the compound containing lithium and aluminum, which may act as an impurity when producing a high-purity Ni-containing sulfate solution, can be removed.

[0085] Without wishing to be limited by theory, the selective leaching of lithium and aluminum-containing compounds from Ni-Co-Mn alloy particles obtained through high-temperature heat treatment and having lithium and aluminum-containing compounds located on the surface can be explained by the following reaction formula.

[0086] [Reaction Scheme 1] Ni(s)+H2SO 4(aq) = NiSO 4(aq) +H 2(g) , △G o m = -46.3 (kJ / mol)

[0087] [Reaction Scheme 2] Co(s)+H2SO 4(aq) = CoSO 4(aq) +H 2(g) , △G o m = -54.7 (kJ / mol)

[0088] [Reaction Scheme 3] Li2O(s)+H2SO 4(aq) = Li2SO 4(aq) +H2O (aq) , △G o m = -260.5 (kJ / mol)

[0089] As shown in the above reaction formulas 1 and 2, the Gibbs free energy of Ni and Co in sulfuric acid leaching is -46 to -53 kJ / mol, which is about 20% lower than the Gibbs free energy of lithium oxide in sulfuric acid leaching (-260.5 kJ / mol), so the leaching reaction is not accelerated.

[0090] Therefore, the compound containing lithium and aluminum located on the surface of the Ni-Co-Mn alloy particles can be selectively removed.

[0091]

[0092] The step of selectively removing the lithium and aluminum-containing compound located on the surface of the alloy particles by first acid leaching the alloy particles may be performed at a pH of 0.2 to 4.0, specifically 0.5 to 3.0, and more specifically 0.8 to 2.0.

[0093] When the pH satisfies the above range, the leaching of the compound containing lithium and aluminum is excellent and thus preferable.

[0094] The step of selectively removing the compound containing lithium and aluminum located on the surface of the alloy particles by first acid leaching the alloy particles can be performed using an acid.

[0095] Specifically, the step of selectively removing the compound containing lithium and aluminum located on the surface of the alloy particles by first acid leaching the alloy particles can be performed using sulfuric acid.

[0096] The equivalent ratio of the alloy particles to the sulfuric acid may be 1:0.5 to 1:4.0, specifically 1:1.0 to 1:3.8, and more specifically 1:1.5 to 1:3.5.

[0097] When the above sulfuric acid equivalent ratio satisfies the above range, it is preferable to increase the leaching rate of the compound containing lithium and aluminum while minimizing the content of sulfuric acid.

[0098] The step of selectively removing compounds containing lithium and aluminum located on the surface of the alloy particles by first acid leaching the alloy particles may be performed at a temperature of 10 to 200°C, specifically 30 to 150°C, and more specifically 50 to 85°C.

[0099] When the above-mentioned performance temperature satisfies the above-mentioned range, the phenomenon of the sulfuric acid boiling over is suppressed, while the leaching efficiency of the compound containing lithium and aluminum is excellent, which is preferable.

[0100] In another embodiment of the present invention, the step of selectively removing compounds including lithium and aluminum located on the surface of the alloy particles by first acid leaching the alloy particles may be performed for 240 minutes or less, preferably 60 to 180 minutes, and more preferably 90 to 120 minutes.

[0101] The step of selectively removing a compound containing lithium and aluminum located on the surface of the alloy particles by first acid leaching the alloy particles is preferably performed within the time range, that is, when acid leaching of the lithium compound is performed within the time range, the leaching rate of the compound containing lithium and aluminum can be increased while minimizing the leaching time.

[0102]

[0103] A method for recycling precious metals according to the present invention comprises a step of obtaining precious metal recovery alloy particles from which a compound including lithium and aluminum has been removed.

[0104] The above-mentioned metal recovery alloy particles can be obtained by magnetic separation or solid-liquid separation of an acid solution containing the compound containing the leached lithium and aluminum and an unleached Ni-Co-Mn alloy residue.

[0105]

[0106] In another embodiment of the present invention, the method may further include a step of secondary acid leaching of the obtained precious metal recovery alloy particles to obtain a sulfate solution containing Ni, Co, and Mn.

[0107] In another embodiment of the present invention, the method may further include a step of preparing a metal hydroxide precursor containing Ni, Co, and Mn using the obtained sulfate solution.

[0108]

[0109] In another embodiment of the present invention, in the step of obtaining a sulfate solution containing Ni, Co and Mn by secondary acid leaching of the obtained precious metal recovery alloy particles, the secondary acid leaching may be performed while adding oxygen.

[0110] When the above secondary acid leaching is performed by adding oxygen, it is advantageous in that it can accelerate the leaching rate of Ni, Co and Mn.

[0111] In another embodiment of the present invention, the oxygen is 0.1 to 20.0 Nm 3 / hr, specifically 1 to 15 Nm 3 / hr, more specifically 3 to 8 Nm 3 / hr can be supplied at a rate of .

[0112] When the supply rate of the oxygen satisfies the above range, the leaching rate is excellent and the leaching rate can be accelerated, which is preferable.

[0113] The oxygen partial pressure may be 0.1 to 1.0 atm, preferably 0.2 to 1.0 atm, and more preferably 0.4 to 1.0 atm.

[0114] When the secondary acid leaching is performed in an atmosphere where the oxygen partial pressure satisfies the above range, the phenomenon of accelerating the leaching speed is maximized, which is desirable.

[0115]

[0116] The step of obtaining a sulfate solution containing Ni, Co, and Mn by secondary acid leaching of the obtained precious metal recovery alloy particles may further include introducing air or hydrogen peroxide in addition to the oxygen, but is not limited thereto.

[0117]

[0118] In another embodiment of the present invention, the step of secondary acid leaching of the obtained precious metal recovery alloy particles to obtain a sulfate solution containing Ni, Co and Mn can be performed under pressurized conditions.

[0119] In short, the acid leaching of the obtained precious metal recovery alloy particles may be pressure leaching.

[0120] In another embodiment of the present invention, the pressurization condition may be 20 atm or less, preferably 2 to 16 atm, and more preferably 4 to 16 atm.

[0121] When the above pressurizing conditions satisfy the above range, it is preferable to increase the leaching rates of Ni, Co, and Mn.

[0122]

[0123] In another embodiment of the present invention, the step of secondary acid leaching of the obtained precious metal recovery alloy particles to obtain a sulfate solution containing Ni, Co and Mn can be performed at a temperature of 10 to 200°C.

[0124] In another embodiment of the present invention, the step of secondary acid leaching of the obtained precious metal recovery alloy particles to obtain a sulfate solution containing Ni, Co and Mn can be performed in a range of pH 0.2 to 4.0.

[0125] In another embodiment of the present invention, in the step of secondary acid leaching of the obtained precious metal recovery alloy particles to obtain a sulfate solution containing Ni, Co and Mn, the equivalent ratio of the acid may be 0.5 to 4.0.

[0126] In short, in the step of obtaining a sulfate solution containing Ni, Co, and Mn by subjecting the obtained precious metal recovery alloy particles to secondary acid leaching, the temperature, pH, equivalent ratio of sulfuric acid, etc. of the secondary acid leaching conditions can be applied to the contents of the acid leaching in the step of selectively removing the compound containing lithium and aluminum located on the surface of the alloy particles by subjecting the above-mentioned alloy particles to primary acid leaching.

[0127]

[0128] In another embodiment of the present invention, the method may further include a step of obtaining a sulfate solution containing Ni, Co, and Mn by secondary acid leaching of the obtained precious metal recovery alloy particles; and a step of removing copper from the sulfate solution by adding sodium hydrogen sulfide (NaHS) to the sulfate solution.

[0129] Although not wishing to be limited by theory, when the above sodium hydrogen sulfide is added, Cu among the impurities can be removed based on the reaction of the following reaction formula 5.

[0130] [Scheme 5] 2CuSO4(aq) + 2NaHS = 2CuS(s)+Na2SO4(aq)+H2SO4(aq)

[0131]

[0132] In another embodiment of the present invention, the sodium hydrogen sulfide may be added in an amount of 0.01 to 0.5 mol / L, preferably 0.05 to 0.5 mol / L, and more preferably 0.1 to 0.4 mol / L.

[0133] When the sodium hydrogen sulfide is included within the above range, it is preferable to increase the removal rate of the copper while minimizing the input amount of the sodium hydrogen sulfide.

[0134]

[0135] In another embodiment of the present invention, the method may further include a step of obtaining a sulfate solution containing Ni, Co, and Mn by secondary acid leaching of the obtained precious metal recovery alloy particles; and a step of removing iron and aluminum from the sulfate solution by adding sodium hydroxide to the sulfate solution.

[0136] Preferably, the method may further include a step of obtaining a sulfate solution containing Ni, Co, and Mn by secondary acid leaching of the obtained precious metal recovery alloy particles; a step of removing copper from the sulfate solution by adding sodium hydrogen sulfide (NaHS) to the sulfate solution; and a step of removing iron and aluminum remaining from the sulfate solution by adding sodium hydroxide to the sulfate solution.

[0137] Although not wishing to be limited by theory, when the sodium hydroxide is added, iron and aluminum among the impurities can be removed based on the reactions of the following reaction formulas 6 and 7.

[0138] [Reaction Scheme 6] Al2(SO4)3(aq) + 6NaOH = 2Al(OH)3(s)+3Na2SO4(aq)+H2SO4(aq)

[0139] [Scheme 7] Fe2(SO4)3(aq) + 6NaOH = 2Fe(OH)3(s)+3Na2SO4(aq)+H2SO4(aq)

[0140]

[0141] In another embodiment of the present invention, the sodium hydroxide may be added in an amount of 0.01 to 0.5 mol / L, preferably 0.05 to 0.5 mol / L, and more preferably 0.1 to 0.4 mol / L.

[0142] When the sodium hydroxide is included within the above range, it is preferable to increase the removal rate of iron and aluminum while minimizing the amount of sodium hydroxide added.

[0143]

[0144] The step of obtaining the above sulfate solution may further include a step of ion-exchanging the sulfate solution to remove impurities.

[0145] In short, the method may further include a step of removing copper by adding the sodium hydrogen sulfide, removing remaining iron and aluminum by adding the sodium hydroxide, and then ion-exchanging the sulfate solution to remove impurities such as calcium and magnesium remaining in small amounts in the sulfate solution.

[0146] The above ion exchange can be performed by passing the sulfate solution through an ion exchange resin, but is not limited thereto.

[0147]

[0148] The method for recycling valuable metals according to the present invention may include a step of preparing a metal hydroxide precursor containing Ni, Co and Mn using the obtained sulfate solution.

[0149] The step of manufacturing the metal hydroxide precursor containing the above Ni, Co and Mn may be manufactured by adding a complexing agent such as ammonia or ammonium sulfate to the above sulfate solution and performing a co-precipitation reaction, but is not limited thereto.

[0150]

[0151] <Recovery alloy particles and sulfate solution for valuable metals>

[0152] Another aspect of the present invention relates to a valuable metal recovery alloy particle, which is derived from a Ni-Co-Mn alloy particle having a compound including lithium and aluminum located on the surface, and has a content of one or more impurities selected from the group consisting of Al, Fe and Cu of 15 wt% or less.

[0153] Specifically, the content of one or more impurities selected from the group consisting of Al, Fe, and Cu in the above-described precious metal recovery alloy particles is 15 wt% or less with respect to the total 100 wt%.

[0154] The precious metal recovery alloy particles according to the present invention have the advantage of having a low content of one or more impurities selected from the group consisting of Al, Fe, and Cu, since they are derived from Ni-Co-Mn alloy particles having a compound including lithium and aluminum located on the surface.

[0155] Preferably, the content of one or more impurities selected from the group consisting of Al, Fe and Cu may be 10 wt% or less.

[0156] More preferably, the total content of the impurities may be 20 wt% or less, and most preferably, the total content of the impurities may be 15 wt% or less.

[0157]

[0158] In another embodiment of the present invention, the above-mentioned metal recovery alloy particles can satisfy the following equations 1 and 2.

[0159] [Formula 1]

[0160] 0.8 ≤ [Ni] / [Co] ≤ 20

[0161] [Formula 2]

[0162] 0.12 ≤ [Ni] / [Mn] ≤ 20

[0163] In the above equations 1 and 2,

[0164] [Ni], [Co] and [Mn] are the molar ratios of Ni, Co and Mn in the valuable metal recovery alloy, respectively.

[0165]

[0166] The above-mentioned valuable metal recovery alloy particles are derived from Ni-Co-Mn alloy particles having a compound including lithium and aluminum located on the surface, and since the Ni-Co-Mn alloy particles are derived from a spent battery, the above-mentioned valuable metal recovery alloy can satisfy the above-mentioned equations 1 and 2. Therefore, it can be usefully utilized as a raw material for a positive electrode active material precursor for a lithium secondary battery.

[0167] Specifically, the above formula 1 can satisfy 2.0 to 7.0, and more specifically 2.5 to 5.0.

[0168] When the above formula 1 is satisfied, it can be usefully applied to the production of a high-nickel positive electrode active material precursor, and is particularly preferable because it has the advantage of reducing the cost of raw materials when applied to the production of a high-nickel positive electrode active material precursor.

[0169]

[0170] Specifically, the above formula 2 can satisfy 0.5 to 7.0, and more specifically 1.0 to 5.0.

[0171] When the above formula 2 is satisfied, it can be usefully applied to the production of a high-nickel positive electrode active material precursor, and is particularly preferable because it has the advantage of providing high stability.

[0172]

[0173] In another embodiment of the present invention, the above-mentioned metal recovery alloy particles can satisfy the following equation 3.

[0174] [Formula 3]

[0175] 0.02 ≤ [C] / [Ni] ≤ 7

[0176] In the above equation 3,

[0177] [C] and [Ni] are the contents (in weight%) of C and Ni in the above-mentioned valuable metal recovery alloy particles, respectively.

[0178] Specifically, the above formula 3 may be 0.05 to 5, and more specifically 1 to 4.

[0179] The above-mentioned valuable metal recovery alloy particles may contain graphite because they are derived from a Ni-Co-Mn alloy derived from a spent battery.

[0180] Specifically, the above formula 3 is a relationship between the ratio of C and Ni contents in the valuable metal recovery alloy particles. When the above formula 3 is satisfied, graphite is dissolved in the alloy during the dry-wet refining process for recycling lithium secondary battery batteries, thereby suppressing the generation of CO2(g) during the process, making it easy to control impurities, and obtaining a sulfate solution containing high concentration nickel sulfate, which is preferable.

[0181]

[0182] In another embodiment of the present invention, the above-mentioned metal recovery alloy particles may contain Ni, Co, and Mn in an amount of 45 wt% or more, specifically 50 to 95 wt%, and more specifically 60 to 85 wt%, based on 100 wt% of the total.

[0183] When the above Ni, Co and Mn are included within the above range, it is preferable that the impurity content in the valuable metal recovery alloy is low, so that a high-purity sulfate solution can be obtained.

[0184]

[0185] In another embodiment of the present invention, the lithium may be included in an amount of 5 wt% or less, preferably 3 wt% or less, and more preferably 1 wt% or less, based on 100 wt% of the total weight of the above-described metal recovery alloy particles.

[0186] The above-mentioned metal recovery alloy particles have the advantage of being substantially free of compounds containing lithium and aluminum. Therefore, the cost and time required for lithium purification can be reduced, and their use yields a high-purity sulfate solution, making them advantageous.

[0187]

[0188] Another aspect of the present invention relates to a sulfate solution comprising Ni, Co and Mn derived from the aforementioned metal recovery alloy particles.

[0189] The acid concentration of the above sulfate solution, the equivalent ratio of the above metal recovery alloy particles and the above sulfuric acid, etc. can be applied to the above-mentioned contents.

[0190] The content of Ni in the sulfate solution may be 0.2 to 2.0 mol / L, specifically 0.4 to 2.0 mol / L, and more specifically 0.6 to 1.5 mol / L.

[0191] When the content of Ni in the above sulfate solution satisfies the above range, it is easy to increase the capacity of the battery, and it is preferable because it can be usefully applied to the production of a positive electrode active material precursor for a lithium secondary battery with excellent structural stability.

[0192]

[0193] The content of Co in the above sulfate solution may be 0.04 to 1.0 mol / L, specifically 0.06 to 0.8 mol / L, and more specifically 0.1 to 0.5 mol / L.

[0194] When the content of Co in the above sulfate solution satisfies the above range, it is preferable that it can be usefully applied to the production of a positive electrode active material precursor that can simultaneously achieve sufficient rate characteristics and high powder density of a positive electrode active material for a lithium secondary battery.

[0195]

[0196] The content of Mn in the above sulfate solution may be 0.04 to 2.0 mol / L, specifically 0.06 to 1.5 mol / L, and more specifically 0.08 to 1.0 mol / L.

[0197] When the content of Mn in the above sulfate solution satisfies the above range, it is preferable because it can be usefully applied to the production of a positive electrode active material precursor that has high stability and can improve the capacity and output characteristics of a battery.

[0198] Specifically, the sulfate solution according to the present invention may have a Ni content of 0.2 to 2.0 mol / L, a Co content of 0.04 to 1.0 mol / L, and a Mn content of 0.04 to 2.0 mol / L in the sulfate solution.

[0199] The above sulfate solution may be recovered from a spent battery.

[0200]

[0201] In another embodiment of the present invention, the sulfate solution may contain aluminum in an amount of 2.5 mol / L or less.

[0202] The sulfate solution according to the present invention has a very low aluminum content because it is manufactured using the aforementioned method for recycling precious metals, and thus has the advantage of high purity.

[0203] In another embodiment of the present invention, the sulfate solution may contain one or more impurities selected from the group consisting of Li, Cu, Ti, Zn, Pb, P, Ca, Mg, B, K, Na, Si and Fe.

[0204] The above impurities may be derived from the above valuable metal recovery alloy.

[0205]

[0206] In another embodiment of the present invention, the content of each element included in the impurities may be 2.5 mol / L or less, specifically 2.0 mol / L or less, and more specifically 1.5 mol / L or less.

[0207] When the content of each element included in the above impurities satisfies the above range, the purity of Ni, Mn and Co in the sulfate solution is preferably high.

[0208]

[0209] Hereinafter, preferred embodiments and comparative examples of the present invention are described. However, the following examples are only preferred embodiments of the present invention, and the present invention is not limited to the following examples.

[0210]

[0211] <Experimental Example>

[0212] Battery internal temperature according to minimum freezing time

[0213] FIG. 1 is a graph showing changes in battery voltage according to cooling temperature according to one embodiment of the present invention.

[0214] Referring to FIG. 1, it can be confirmed that a battery processing method according to one embodiment of the present invention can derive a minimum cooling time for cooling the battery during the battery freezing step. Specifically, it can be confirmed that the minimum cooling time is related to the battery weight, the external cooling temperature, and the target temperature.

[0215] FIG. 2 is a graph showing the relationship between battery weight, external cooling temperature, and cooling time according to one embodiment of the present invention.

[0216] Referring to Fig. 2, the external cooling temperature and minimum cooling time are shown when the target temperature is set to -70℃ and the battery weights are 2.5 kg (A), 10 kg (B), 20 kg (C), and 50 kg (D), respectively. When cooling the battery, it can be confirmed that the electrolyte of the battery begins to cool after a certain period of time and the voltage becomes 0. Through this, it can be confirmed that a minimum maintenance time is required to sufficiently cool the inside, specifically the electrolyte, when cooling the battery.

[0217] Specifically, in a heat transfer situation for cooling, where heat is lost to the outside, considering the specific heat of the battery itself, we can see that the battery's weight and cooling time are required. Even in a heat transfer situation for cooling, where heat is lost to the outside, considering the battery's own specific heat, we can see that the battery's weight and cooling time are required.

[0218] In this way, in the present invention, the minimum time required for cooling can be determined by using the external cooling temperature for cooling, the target temperature, and the battery weight to cool the battery.

[0219] Table 1 below lists the minimum cooling times based on battery weight and external cooling temperature.

[0220]

[0221] Battery weight [Kg] External cooling temperature [℃] Target temperature [℃] Minimum cooling time [h] A_12.5-120-70 1.9 A_22.5-100-70 2.9 A_32.5-80-70 4.4 B_110-120-70 3.1 B_210-100-70 4.6 B_310-80-70 7.0 C_120-120-70 3.9 C_220-100-70 5.8 C_320-80-70 8.8 D_150-120-70 5.3 D_250-100-70 7.9 D_350-80-70 11.9

[0222] Looking at Table 1 above, it can be seen that the smaller the battery weight, the shorter the minimum cooling time required for the battery to be cooled. Furthermore, when cooling is performed for the minimum cooling time derived from the relationship between battery weight, external cooling temperature, and target temperature, it can be confirmed that the battery, specifically the electrolyte of the battery, is cooled. Furthermore, when the battery is cooled for a time longer than the minimum cooling time listed in Table 1 above, no fire occurs during the subsequent process of crushing the battery.

[0223] In cooling the battery, the fire occurrence status of the shredded material when frozen for a time shorter than the minimum cooling time required was tested. In the experiment, when the battery weight was 25 kg, the external cooling temperature was -95°C, and the target freezing temperature was -70°C, the minimum cooling time, which is the value of Equation 4 below, was 7 hours, and the experiment was conducted for 5 hours, which is shorter than the minimum cooling time.

[0224]

[0225] [Formula 4]

[0226] Minimum cooling time = A × (W 0.33 )

[0227] In the above equation 4,

[0228] A = 4 × e(-0.02×dT), W = battery weight (Kg), dT= │external cooling temperature - target temperature│, ││ represents an absolute value.

[0229]

[0230] The fire occurrence status of shredded material when the battery was frozen for a period exceeding the minimum freezing time required for cooling was tested. In the above experiment, the fire occurrence status of shredded material when the battery was frozen for a period shorter than the minimum cooling time required for cooling was tested under the same conditions as the experiment, with the battery weight, external cooling temperature, and minimum freezing time of 7 hours or more.

[0231] Table 2 below compares the fire occurrence status of examples and comparative examples according to the same battery weight, external cooling temperature, and minimum freezing time. The fire occurrence status was determined as follows: if fire occurrence was observed after crushing the battery, "○"; otherwise, "×".

[0232]

[0233] Battery weight [Kg] External cooling temperature [℃] Target temperature [℃] Formula 1 Actual cooling time [h] Fire occurrence Comparative example 25- 95- 707.05 ○ Example 25- 95- 707.07 ×

[0234] Looking at Table 2 above, it can be seen that if the battery is cooled to a value lower than the value in Equation 4, which corresponds to the minimum cooling time, the electrolyte will not be cooled, resulting in a fire after the battery is shredded. Thus, it can be confirmed that if the battery is cooled using the value in Equation 4 as the minimum cooling time, the shredded material can be reliably utilized without a fire after the battery is shredded.

[0235]

[0236] Method for selective leaching of compounds containing lithium and aluminum

[0237] The selective leaching of lithium and aluminum-containing compounds (Li leaching) through sulfuric acid leaching of Ni-Co-Mn alloy particles, obtained through high-temperature heat treatment and having lithium and aluminum-containing compounds located on the surface, can be explained through the following reaction formula.

[0238] [Reaction Scheme 1] Ni(s)+H2SO 4(aq) = NiSO 4(aq) +H 2(g) , △G o m = -46.3 (kJ / mol)

[0239] [Reaction Scheme 2] Co(s)+H2SO 4(aq) = CoSO 4(aq) +H 2(g) , △G om = -54.7 (kJ / mol)

[0240] [Reaction Scheme 3] Li2O(s)+H2SO 4(aq) = Li2SO 4(aq) +H2O (aq) , △G o m = -260.5 (kJ / mol)

[0241] As shown in the reaction formulas 1 and 2 above, the Gibbs free energy of Ni and Co in sulfuric acid leaching is -46 to -53 kJ / mol, which is about 20% lower than the Gibbs free energy of lithium oxide in sulfuric acid leaching (-260.5 kJ / mol), confirming that the leaching reaction is not accelerated.

[0242] In one embodiment, Ni-Co-Mn alloy particles having a compound comprising lithium and aluminum located on the surface obtained through high-temperature heat treatment are prepared at a pH of 0.4 to 1.0 and a temperature of 50°C. And selective leaching of compounds containing lithium and aluminum was performed for 120 minutes by applying sulfuric acid equivalent ratio of 1.0 to 1.6 M.

[0243] Specifically, Table 3 shows the sulfuric acid equivalent ratio = 1.0M, temperature = 50 o The results of selective Li leaching rate (%) over time when C is used are shown in Table 4. Sulfuric acid equivalent ratio = 1.2 M, temperature = 50 o The results of selective Li leaching rate (%) over time when C is used are shown in Table 5. Sulfuric acid equivalent ratio = 1.6 M, temperature = 50 o The results of selective Li leaching rate (%) over time are shown when C is used.

[0244] As can be seen in Tables 3 to 5 below, it can be confirmed that the Li leaching rate is secured at 95% or more, while the leaching rates of Ni, Co, and Mn can be controlled to 20% or less.

[0245]

[0246] Time (minutes)LiNiCoMn000003078.10.90.92.76085.61.72.15.19092.42.93.67.812097.23.84.410.0

[0247] Time (minutes)LiNiCoMn000003083.11.41.82.96088.23.63.26.29094.14.95.59.612099.46.57.012.3

[0248] Time (minutes)LiNiCoMn000003084.33.84.14.56090.17.68.69.19095.112.512.613.512099.816.217.118.6

[0249] Method for leaching valuable metal recovery alloy particles

[0250] After selectively recovering Li, valuable metal recovery alloy particles were recovered through magnetic separation. The recovered valuable metal recovery alloy particles were leached in a sulfuric acid solution according to pH, temperature, oxygen intake amount, sulfuric acid equivalence ratio, and pressurization conditions, and the leaching rate was investigated as follows. The oxygen introduced in the present invention may include air, oxygen, or hydrogen peroxide.

[0251] Table 6 Temperature = 80 o C, sulfuric acid equivalent ratio = 2M, pressure condition = 1 atm, when obtaining a sulfate solution, the results of the leaching rate (%) of the alloy particles for the recovery of valuable metals according to the addition of oxygen are shown, and Table 7 shows the results at temperature = 80 o C, sulfuric acid equivalent ratio = 2M, P(O2) = 0.2 atm, when a sulfate solution is obtained, the results of the leaching rate (%) of the alloy particles for the recovery of precious metals according to the pressurized conditions are shown.

[0252] As can be seen in Table 6, the leaching rate is improved when oxygen is introduced, and the leaching rate is improved from approximately 30% to 99% within 48 hours of the same leaching time.

[0253] This can be explained through reaction formula 4. That is, when oxygen gas is introduced, by providing electrons to the aqueous solution, the nickel-containing alloy dissolves into the aqueous solution to balance the charge by the corresponding number of electrons.

[0254]

[0255] [Reaction Formula 4]

[0256] O2(g)+4H + +2(Ni 0.6 Co 0.2 Mn 0.2 )(s)=2H2O(l)+2[0.6Ni 2+ -0.2Co 2+ -0.2Mn 2+ ]

[0257] △G o m = -852.4 (kJ / mol)

[0258]

[0259] As shown in Tables 6 and 7, changes in pressurization conditions also confirm that the leaching rate improves and the leaching time shortens. This suggests that reaction equation 4 is accelerated and accelerated by increased pressure, thereby improving the dissolution of nickel-containing alloys.

[0260]

[0261] P(O2), atmNiCoMn0.13133360.23844420.45356540.87881771.0989799

[0262] Pressure condition (atm) Temperature ( o C)NiCoMn110041454321216670644145818379816189929016207979998

[0263] Method for preparing sulfate solution

[0264] High concentrations of impurities have the effect of reducing the shape of the precursor and ionic conductivity during precursor production, which causes problems in electrical performance evaluation after manufacturing the battery cell.

[0265] The present invention may include a process of removing Cu among impurities by adding sodium bisulfide (NaHS) to remove copper (Cu) and adding sodium hydroxide to remove remaining Fe and Al based on reactions 5 to 7 in a sulfate solution obtained by sulfuric acid leaching of valuable metal recovery alloy particles from which lithium compounds and aluminum-containing compounds have been removed through a selective leaching process of lithium. Thereafter, a high-purity Ni-containing sulfate solution may be prepared through an ion exchange method to remove Ca and Mg, etc. remaining in a small amount in the sulfate solution.

[0266] Table 8 below shows the components of a high-purity Ni-containing sulfate solution obtained by a method for recycling precious metals according to the present invention.

[0267]

[0268] [Reaction Scheme 5] 2CuSO4 (aq) + 2NaHS = 2CuS(s)+Na2SO 4(aq) +H2SO 4(aq)

[0269] [Reaction Scheme 6] Al2(SO4) 3(aq) + 6NaOH = 2Al(OH)3(s)+3Na2SO 4(aq) +H2SO 4(aq)

[0270] [Reaction Formula 7] Fe2(SO4) 3(aq) + 6NaOH = 2Fe(OH)3(s)+3Na2SO 4(aq) +H2SO 4(aq)

[0271]

[0272] Classification (mol%) NiCoMnFeAlCu Example (high purity Ni) 58.6221.4219.890.020.020.01

[0273] Evaluation of Precursor Manufacturing Using High-Purity Ni-Containing Sulfate Solution

[0274] According to one embodiment of the present invention, a precursor was prepared using a high-purity Ni-containing sulfate solution and its physical properties were evaluated.

[0275] A precursor was prepared using a high-purity Ni-containing sulfate solution obtained according to one embodiment of the present invention, a sulfate solution manufactured to a reagent grade with a purity of 99% or higher, and a Ni-containing sulfate solution that has not undergone an impurity removal process. Specifically, the sulfate solutions according to the examples and comparative examples were added to a reactor with equal amounts of NaOH and NH4OH and mixed. The pH was adjusted so that [Ni, Co, Mn]OH2 could undergo a coprecipitation reaction, and a precursor was obtained through solid-liquid separation. The components and results can be confirmed in Table 9 and Figure 3 below.

[0276] Table 9 shows the components of sulfate solutions according to examples and comparative examples, and Fig. 3 is an SEM image of a positive electrode active material precursor for a lithium secondary battery manufactured according to examples and comparative examples.

[0277] As can be seen in , the concentration of the high-purity Ni-containing sulfate solution shows a similar impurity level to the Ni-containing sulfate solution manufactured as a reagent grade, and in the case of the sulfate solution without removing the impurities, it can be confirmed that the concentrations of Fe, Cu, and Al are very high. As can be seen in Fig. 3, in the case of the precursor manufactured using the high-purity Ni-containing sulfate solution (Fig. 3 (b)), the spheroidization characteristic can be confirmed to be at the same level as the reagent grade (Fig. 3 (a)), but in the case of the precursor using the sulfate solution with a high content of Fe, Cu, and Al (Fig. 3 (c)), the shape of the precursor has a low degree of spheroidization, is non-uniform, and has a high particle agglomeration phenomenon, so it can be confirmed that spheroidization, which is one of the important properties of the precursor, cannot be secured.

[0278]

[0279] Classification (mol%) NiCoMnFeAlCu Example (high purity Ni) 58.6 2 2 1.4 2 19.8 9 0.0 2 0.0 2 0.0 1 Comparative Example 1 (impurities not removed) 33.0 9 11.9 2 11.1 8 0.3 2 3 1.6 7 11.8 2 Comparative Example 2 (reagent grade) 58.5 1 2 1.8 3 19.66 ---

[0280] 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. A step of preparing Ni-Co-Mn alloy particles having a compound containing lithium and aluminum located on the surface; A step of selectively removing the compound including lithium and aluminum located on the surface of the alloy particles by first acid leaching the alloy particles; and A step of obtaining valuable metal recovery alloy particles from which the compound including lithium and aluminum has been removed; A method for recycling precious metals including:

2. In paragraph 1, A method for recycling precious metals, further comprising the step of subjecting the obtained precious metal recovery alloy particles to secondary acid leaching to obtain a sulfate solution containing Ni, Co and Mn.

3. In paragraph 2, A method for recycling precious metals, further comprising a step of producing a metal hydroxide precursor containing Ni, Co and Mn using the obtained sulfate solution.

4. In paragraph 2, In the step of secondary acid leaching of the obtained precious metal recovery alloy particles to obtain a sulfate solution containing Ni, Co and Mn; A method for recycling valuable metals, wherein the above secondary acid leaching is performed by adding oxygen.

5. In paragraph 4, The above oxygen is 0.1 to 20.0 Nm 3 A method for recycling valuable metals, which is performed while being supplied at / hr.

6. In paragraph 2, A method for recycling a precious metal, wherein the step of secondary acid leaching the obtained precious metal recovery alloy particles to obtain a sulfate solution containing Ni, Co and Mn is performed at a temperature of 10 to 200°C.

7. In paragraph 2, A method for recycling precious metals, wherein the step of secondary acid leaching the obtained precious metal recovery alloy particles to obtain a sulfate solution containing Ni, Co and Mn is performed at a pH range of 0.2 to 4.

0.

8. In paragraph 2, A method for recycling a valuable metal, wherein the step of secondary acid leaching the obtained valuable metal recovery alloy particles to obtain a sulfate solution containing Ni, Co and Mn; wherein the equivalent ratio of the acid is 0.5 to 4.

0.

9. In paragraph 1, A method for recycling a precious metal, wherein the step of selectively removing a compound including lithium and aluminum located on the surface of the alloy particles by first acid leaching the alloy particles is performed for 240 minutes or less.

10. In paragraph 2, A method for recycling a precious metal, wherein the step of secondary acid leaching the obtained precious metal recovery alloy particles to obtain a sulfate solution containing Ni, Co and Mn is performed under pressurized conditions.

11. In paragraph 10, A method for recycling precious metals, wherein the above pressurization condition is 20 atm or less.

12. In paragraph 2, A step of obtaining a sulfate solution containing Ni, Co and Mn by secondary acid leaching of the obtained precious metal recovery alloy particles; thereafter, A step of removing copper from the sulfate solution by adding sodium bisulfide (NaHS) to the sulfate solution; A method for recycling precious metals, comprising:

13. In paragraph 12, A method for recycling precious metals, wherein the sodium bisulfide is added in an amount of 0.01 to 0.5 mol / L.

14. In paragraph 2, A step of obtaining a sulfate solution containing Ni, Co and Mn by secondary acid leaching of the obtained precious metal recovery alloy particles; thereafter, A step of removing iron and aluminum from the sulfate solution by adding sodium hydroxide to the sulfate solution; A method for recycling precious metals, comprising:

15. In paragraph 14, A method for recycling precious metals, wherein the sodium hydroxide is added in an amount of 0.01 to 0.5 mol / L.

16. In paragraph 1, A step of preparing Ni-Co-Mn alloy particles having a compound including lithium and aluminum located on the surface; Step for preparing a battery containing lithium; A step of crushing the above battery into battery waste; A step of performing high-temperature heat treatment on the shredded battery waste; and A step of separating Ni-Co-Mn alloy particles from the battery shreds subjected to the high temperature heat treatment; A method for recycling precious metals, comprising:

17. In paragraph 16, A method for recycling precious metals, wherein the high-temperature heat treatment step is performed in a gas atmosphere at a temperature range of 600 to 1,500°C and an oxygen concentration range of 0.1 to 2.0 vol%.

18. Derived from Ni-Co-Mn alloy particles having a compound containing lithium and aluminum located on the surface, The content of one or more impurities selected from the group consisting of Al, Fe and Cu is 15 wt% or less, Metal recovery alloy particles.

19. In paragraph 18, A metal recovery alloy particle satisfying Equations 1 and 2: [Formula 1] 0.8 ≤ [Ni] / [Co] ≤ 20 [Formula 2] 0.12 ≤ [Ni] / [Mn] ≤ 20 In the above formulas 1 and 2, [Ni], [Co] and [Mn] are the molar ratios of Ni, Co and Mn in the valuable metal recovery alloy, respectively.

20. In paragraph 18, A metal recovery alloy particle satisfying the following equation 3: [Formula 3] 0.02 ≤ [C] / [Ni] ≤ 7 In the above equation 3, [C] and [Ni] are the contents (in weight%) of C and Ni in the above-mentioned valuable metal recovery alloy particles, respectively.

21. In paragraph 18, A metal recovery alloy particle comprising 45 wt% or more of Ni, Co, and Mn relative to 100 wt% of the total metal recovery alloy particles.

22. In paragraph 18, A metal recovery alloy particle containing lithium in an amount of 5 wt% or less based on 100 wt% of the total metal recovery alloy particles.

23. A sulfate solution containing Ni, Co and Mn derived from the valuable metal recovery alloy particles according to Article 18.

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