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 valuable metals, valuable metal recovery alloy particles and sulfate solution recovered using the same

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

[0002] As global demand for electric vehicles (EVs) grows, the issue of disposing of waste batteries is emerging as a social problem.

[0003] In the case of lithium-ion 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 are highly valuable metals due to their scarcity, so recovery and recycling processes after the disposal of lithium-ion batteries are emerging as an important field of research.

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

[0006] To utilize these waste batteries, active development is underway for waste battery recycling processes that involve crushing the batteries to generate intermediate materials such as shredded waste batteries or black powder, followed by post-processing to recover valuable metals.

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

[0008] Acid leaching is performed on valuable metals within the battery in an ionized state using an acid such as sulfuric acid, followed by a process to remove impurities. Ni, Co, Mn, and other elements within the sulfuric acid, from which impurities have been removed, are extracted in the form of sulfides through solvent extraction and crystallization. For the solvent extraction to extract Ni, Co, and Mn after impurity removal, a solvent that selectively recovers each element is used. By controlling the temperature and pH, the corresponding elements are absorbed into the solvent and then washed again with sulfuric acid to produce a high-concentration sulfuric acid solution of Ni, Co, and Mn.

[0009] At this time, the high cost of each solvent used poses a problem of increasing manufacturing costs. In addition, there is the problem of having to wash it again with sulfuric acid, and the amount of sodium hydroxide (NaOH) generated by the precipitation reaction caused by sodium hydroxide (NaOH) used to adjust the pH is about 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 supply methods for raw materials used in the manufacture of nickel-containing batteries is required to enable eco-friendly and low-cost production processes for 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 a 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 valuable metals, comprising the steps of: preparing Ni-Co-Mn alloy particles having a compound containing lithium and aluminum located on the surface; first acid leaching the alloy particles to selectively remove the compound containing lithium and aluminum located on the surface of the alloy particles; and obtaining a valuable metal recovery alloy particle from which the compound containing lithium and aluminum has been removed.

[0014] In addition, the present invention provides valuable metal recovery alloy particles derived from Ni-Co-Mn alloy particles having a compound containing lithium and aluminum located on the surface, and having a content of 1 or more impurities selected from the group consisting of Al, Fe, and Cu of 15 weight% or less.

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

[0016] The recycling method for valuable metals according to the present invention has the advantage of easily obtaining valuable metal recovery alloy particles that can be usefully used as raw materials for manufacturing nickel-containing batteries. In addition, it has the advantage of easily producing a high-purity nickel-containing sulfate solution for use as a precursor 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 raw materials for manufacturing nickel-containing batteries.

[0018] Figure 1 is a graph showing the change in battery voltage according to the 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 showing the positive electrode active material precursors for lithium secondary batteries prepared according to the examples and comparative examples.

[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, and the present invention is defined only by the scope of the claims set forth below.

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

[0023] In the present invention, when a part is described as "comprising" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0024]

[0025] Recycling Methods for Valuable Metals

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

[0027] The recycling method for valuable metals according to the present invention has the advantage of easily obtaining valuable 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, the term “valuable metal” may refer to valuable non-ferrous metals such as Li, Ag, Zn, and Cu, in addition to 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 containing lithium and aluminum have been removed.

[0030]

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

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

[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 a vehicle, or a secondary battery separated from electronic devices such as mobile phones, cameras, and laptops; specifically, it may be a lithium secondary battery. More specifically, the battery may be a waste battery, and if the battery is a waste battery, there is an environmentally friendly advantage.

[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, and freezing the battery has the advantage of reducing the risk of fire during the battery crushing step described later.

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

[0036] [Equation 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 the absolute value.

[0040]

[0041] The minimum cooling time in Equation 4 above 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 is an external cooling temperature applied to the battery, for example, a target temperature for cooling the electrolyte within the battery.

[0042] The step of freezing the battery has the advantage of allowing the electrolyte inside the battery to be cooled and subsequent processes to be performed stably by performing the step for a minimum cooling time or longer.

[0043] In the step of freezing the battery, if the battery is frozen for a time shorter than the minimum cooling time, the electrolyte is not cooled, which may cause a fire hazard during crushing.

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

[0045] When the above battery is frozen in the above temperature range, the voltage remaining in the battery, for example, about 2 to 3 V, is reduced to near 0 V. Since a short circuit occurs where the positive and negative electrodes come into direct contact, no battery reaction occurs, so the battery temperature does not increase, and thus no gas generation or combustion of the electrolyte occurs.

[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 the current conduction characteristics due to the movement of lithium ions can be significantly reduced, and since vaporization of the electrolyte does not occur, flammable gases of ethylene, propylene, and hydrogen can not be generated.

[0047] If the above freezing process falls outside the above temperature range, for example, if it is cooled to a temperature higher than -60°C, the voltage remaining inside the battery does not drop to 0V, so a battery reaction caused by a short circuit may occur, and the electrolyte is not completely frozen, making it unsuitable. Also, if it is cooled to -150°C, the electrolyte is sufficiently frozen and the internal voltage of the battery drops to 0V, so there is no need to lower it to a lower temperature.

[0048] As such, 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 the battery, such as a lithium secondary battery.

[0049]

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

[0051] The step of crushing the battery may mean a process of crushing the battery, a process of cutting the battery, a process of compressing the battery, and any combination thereof.

[0052] Specifically, the crushing step may include any process that destroys the battery to obtain small-sized crushed material.

[0053] The step of crushing the battery may include all processes of compressing the prepared battery or destroying the battery by applying external forces such as shear force or tensile force. The step of crushing the battery may be carried out, for example, using a crusher.

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

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

[0056] For example, when the process of freezing the battery is carried out by cooling it in a temperature range of -60 to -20°C, or when carried out under the aforementioned conditions, the oxygen supply can be suppressed to prevent the electrolyte from reacting with oxygen, thereby preventing an explosion caused by this, and the vaporization of the electrolyte can be suppressed so as not to generate flammable gases such as ethylene, propylene, or hydrogen.

[0057] The step of crushing the battery can be performed so that the maximum size of the battery crushed material is 100 mm or less. Specifically, the size of the battery crushed material can be performed so that it is 50 mm or less.

[0058] When the maximum size of the battery fragments is 100 mm, the heat generated due to instability as the battery fragments are fragmented rises to a temperature range of 120°C, which is the average vaporization temperature of the electrolyte, and may cause safety problems such as fire.

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

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

[0061]

[0062] The step of high-temperature heat treatment of the crushed battery material may involve introducing the battery material into a furnace capable of raising the temperature to a high temperature and raising the battery material to a temperature above its melting point.

[0063] The above battery crushed material 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 going through a melting step of the battery.

[0065]

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

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

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

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

[0070]

[0071] The step of high-temperature heat treatment of the battery crushed material can be performed in a gas atmosphere of at least one of inert gas, carbon dioxide, carbon monoxide, hydrocarbon gas, and oxygen.

[0072] The above inert gas may include, for example, at least one of argon and nitrogen. When the reduction reaction of the crushed 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 crushed material can be increased.

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

[0074] Specifically, the above can be performed in a gas atmosphere in which the oxygen concentration is in the range of 0.4 to 1.2 vol%.

[0075] If the oxygen concentration in the gas exceeds the upper limit, as the oxygen range increases, the reaction Li2O + C + O2(g) = Li2CO3 is promoted, and there is a problem that LiAlO2 and Li5AlO4 decrease. Therefore, it is desirable to perform the oxygen range at 2 vol% or less, which is the aforementioned range. If the oxygen concentration exceeds the lower limit of the aforementioned range, carbon dioxide is excessively formed during the reduction reaction process and is lost by gasification along with lithium, or the generation of Li2CO3(s) becomes excessive, 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 crushed material can be performed in a gas atmosphere comprising 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 the Ni-Co-Mn alloy from the battery crushed material that has been heat-treated at a high temperature.

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

[0080]

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

[0082] The above-mentioned compounds containing lithium and aluminum may be one or more selected from the group consisting of LiAlO2, Li5AlO4, and LiAl5O8, Li2CO3, LiF, Li3PO4, Li2SiO3, Li4SiO4, and Li2Si2O5.

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

[0084] Accordingly, compounds containing lithium and aluminum can be selectively leached from the above Ni-Co-Mn alloy particles to remove compounds containing lithium and aluminum that may act as impurities when preparing a high-purity Ni-containing sulfate solution.

[0085] Although not intended to be limited by theory, the selective leaching of lithium and aluminum-containing compounds from Ni-Co-Mn alloy particles, in which lithium and aluminum-containing compounds are located on the surface and obtained through high-temperature heat treatment, can be explained by the following reaction scheme.

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

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

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

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

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

[0091]

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

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

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

[0095] Specifically, the step of first acid leaching the alloy particles to selectively remove the compound containing lithium and aluminum located on the surface of 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 desirable to increase the leaching rate of the compound containing lithium and aluminum while minimizing the sulfuric acid content.

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

[0099] It is desirable that the above operating temperature satisfies the above range, as this suppresses the phenomenon of the sulfuric acid boiling over while maintaining excellent leaching efficiency of the compound containing lithium and aluminum.

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

[0101] It is desirable that the step of first acid leaching the alloy particles to selectively remove a compound containing lithium and aluminum located on the surface of the alloy particles is performed within the time range, that is, the acid leaching of the lithium compound is performed within the time range, so that the leaching rate of the compound containing lithium and aluminum can be increased while minimizing the leaching time.

[0102]

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

[0104] The acquisition of the above valuable metal recovery alloy particles can be carried out by magnetic separation or solid-liquid separation of an acid aqueous solution containing a 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 step of obtaining a sulfate solution containing Ni, Co and Mn by secondary acid leaching of the obtained valuable metal recovery alloy particles may be further included.

[0107] In another embodiment of the present invention, the method may further include the 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, the step of obtaining a sulfate solution containing Ni, Co and Mn by secondary acid leaching of the obtained valuable metal recovery alloy particles; wherein the secondary acid leaching may be performed by adding oxygen.

[0110] When the above secondary acid leaching is performed with the addition of oxygen, it is desirable as it has the advantage of accelerating 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 It can be supplied at a rate of / hr.

[0112] If the above oxygen supply rate satisfies the above range, it is desirable because the leaching rate is excellent and the leaching rate can be accelerated.

[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 under an atmosphere in which the oxygen partial pressure satisfies the above range, the phenomenon that can accelerate the leaching rate 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 valuable metal recovery alloy particles may additionally blow in 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 obtaining a sulfate solution containing Ni, Co and Mn by secondary acid leaching of the obtained valuable metal recovery alloy particles may be performed under pressurized conditions.

[0119] In short, the acid leaching of the above-mentioned valuable metal recovery alloy particles may be pressurized leaching.

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

[0121] It is desirable that the above pressurization conditions satisfy the above range, as this can increase the leaching rate of Ni, Co, and Mn.

[0122]

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

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

[0125] 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 valuable metal recovery alloy particles; 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 secondarily acid leaching the obtained valuable metal recovery alloy particles; the temperature, pH, and equivalent ratio of sulfuric acid of the second acid leaching conditions may be applied to the acid leaching in the step of first acid leaching the alloy particles to selectively remove compounds containing lithium and aluminum located on the surface of the alloy particles.

[0127]

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

[0129] Although it is not desired 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 Reaction Scheme 5 below.

[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 introduced 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 desirable to increase the removal rate of 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 the step of obtaining a sulfate solution containing Ni, Co, and Mn by secondary acid leaching of the obtained valuable metal recovery alloy particles; and then adding sodium hydroxide to the sulfate solution to remove iron and aluminum from the sulfate solution.

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

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

[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 introduced 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 desirable to increase the removal rate of iron and aluminum while minimizing the amount of sodium hydroxide added.

[0143]

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

[0145] In short, the method may further include a step of removing copper by introducing the sodium hydrogen sulfide and removing residual iron and aluminum by introducing 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 above sulfate solution through an ion exchange resin, but is not limited thereto.

[0147]

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

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

[0150]

[0151] <Valuable Metal Recovery Alloy Particles and Sulfate Solution>

[0152] Another aspect of the present invention relates to valuable metal recovery alloy particles derived from Ni-Co-Mn alloy particles having a compound containing lithium and aluminum located on the surface, and having a content of 1 or more impurities selected from the group consisting of Al, Fe, and Cu of 15 weight% or less.

[0153] Specifically, the above valuable metal recovery alloy particles have a content of 15% by weight or less of one or more impurities selected from the group consisting of Al, Fe, and Cu, based on 100% by weight of the total.

[0154] The valuable 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, because they are derived from Ni-Co-Mn alloy particles in which compounds including lithium and aluminum are 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 weight% or less.

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

[0157]

[0158] In another embodiment of the present invention, the valuable metal recovery alloy particles may satisfy the following formulas 1 and 2.

[0159] [Equation 1]

[0160] 0.8 ≤ [Ni] / [Co] ≤ 20

[0161] [Equation 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, respectively, within the alloy of recovered valuable metals.

[0165]

[0166] The above valuable metal recovery alloy particles are derived from Ni-Co-Mn alloy particles having compounds containing lithium and aluminum located on the surface, and since the Ni-Co-Mn alloy particles are derived from waste batteries, the above valuable metal recovery alloy can satisfy Equations 1 and 2. Therefore, it can be usefully utilized as a raw material for a cathode active material precursor for a lithium secondary battery.

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

[0168] When satisfying the above Equation 1, it can be usefully applied to the manufacture of high-nickel cathode active material precursors, and is particularly desirable as it has the advantage of reducing the cost of raw materials when applied to the manufacture of high-nickel cathode active material precursors.

[0169]

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

[0171] When satisfying the above Equation 2, it can be usefully applied to the manufacture of high-nickel cathode active material precursors, and is particularly desirable as it has the advantage of providing high stability.

[0172]

[0173] In another embodiment of the present invention, the valuable metal recovery alloy particles may satisfy the following Equation 3.

[0174] [Equation 3]

[0175] 0.02 ≤ [C] / [Ni] ≤ 7

[0176] In the above Equation 3,

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

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

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

[0180] Specifically, the above Equation 3 is a relationship for the ratio of C and Ni content within the alloy particles of recovered valuable metals. When Equation 3 is satisfied, graphite is dissolved in the alloy during the dry-wet smelting process for recycling lithium secondary batteries, thereby suppressing the generation of CO2 (g) during the process, facilitating impurity control, and making it desirable to obtain a high-concentration nickel sulfate-containing sulfate solution.

[0181]

[0182] In another embodiment of the present invention, Ni, Co, and Mn may be included in an amount of 45% or more by weight, specifically 50 to 95% by weight, and more specifically 60 to 85% by weight, based on 100% by weight of the total valuable metal recovery alloy particles.

[0183] When the above Ni, Co, and Mn are included within the above range, it is desirable to obtain a high-purity sulfate solution because the impurity content in the valuable metal recovery alloy is low.

[0184]

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

[0186] The above-mentioned valuable metal recovery alloy particles have the advantage of substantially not containing compounds including lithium and aluminum. Therefore, it is desirable to reduce the process cost and time for refining lithium and to obtain a high-purity sulfate solution when using them.

[0187]

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

[0189] The acid concentration of the above sulfate solution, the equivalent ratio of the above valuable metal recovery alloy particles to the above sulfuric acid, etc., may be applied according to the aforementioned contents.

[0190] The content of Ni in the above 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 Ni content in the above sulfate solution satisfies the above range, it is easy to achieve high capacity of the battery, and it is desirable to apply it effectively to the manufacture of a cathode 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 desirable to apply it usefully to the manufacture of a cathode active material precursor that can simultaneously achieve sufficient rate characteristics and high powder density of the cathode 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 desirable that this can be usefully applied to the manufacture of a positive electrode active material precursor that has high stability and can improve the capacity and output characteristics of the 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 waste batteries.

[0200]

[0201] In another embodiment of the present invention, the sulfate solution may contain aluminum at a concentration of 2.5 mol / L or less.

[0202] Since the sulfate solution according to the present invention is manufactured by the aforementioned recycling method of valuable metals, it has a very low aluminum content 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 originate 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] If the content of each element included in the above impurities satisfies the above range, it is desirable that the purity of Ni, Mn, and Co in the sulfate solution is high.

[0208]

[0209] Preferred embodiments and comparative examples of the present invention are described below. However, the following examples are merely 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 based on minimum freezing time

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

[0214] Referring to FIG. 1, it can be seen that a battery processing method according to one embodiment of the present invention can derive a minimum cooling time for cooling the battery in the step of freezing the battery. Specifically, it can be seen 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 illustrated when the target temperature is set to -70°C 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 observed that the battery electrolyte begins to cool after a predetermined period of time, and the voltage becomes zero. Through this, it can be confirmed that when cooling the battery, a minimum maintenance time is required to sufficiently cool the interior, specifically the electrolyte.

[0217] Specifically, in a heat transfer scenario for cooling where heat is removed to the outside, considering the specific heat of the battery itself, it can be confirmed that the battery weight and cooling time are required. Even in a heat transfer scenario for cooling where heat is removed to the outside, considering the specific heat of the battery itself, it can be confirmed that the battery weight and cooling time are required.

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

[0219] Table 1 below lists the minimum cooling time according to battery weight and external cooling temperature.

[0220]

[0221] Battery Weight [Kg] External Cooling Temperature [°C] Target Temperature [°C] Minimum Cooling Time [h] A_12.5-120-701.9 A_22.5-100-702.9 A_32.5-80-704.4 B_110-120-703.1 B_210-100-704.6 B_310-80-707.0 C_120-120-703.9 C_220-100-705.8 C_320-80-708.8 D_150-120-705.3 D_250-100-707.9 D_350-80-7011.9

[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, it can be confirmed that when cooled for the minimum cooling time derived from the relationship between battery weight, external cooling temperature, and target temperature, the battery, specifically the electrolyte of the battery, is cooled. Additionally, when the battery is cooled for a time longer than the minimum cooling time listed in Table 1, no fire occurs during the subsequent battery crushing process.

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

[0224]

[0225] [Equation 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 the absolute value.

[0229]

[0230] The fire occurrence status of the crushed material was tested when the battery was frozen for a duration longer than the minimum freezing time required for cooling. In the above experiment, the battery weight, external cooling temperature, and minimum freezing time were set to 7 hours or more, identical to the experiment that tested the fire occurrence status of the crushed material when the battery was frozen for a duration shorter than the minimum cooling time required for cooling.

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

[0232]

[0233] Battery Weight [Kg] External Cooling Temperature [°C] Target Temperature [°C] Formula 1 Actual Cooling Time [h] Fire Occurrence Comparison 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 smaller than the value of Equation 4 corresponding to the minimum cooling time, the electrolyte is not cooled, and a fire occurs after the battery is crushed. As such, it can be confirmed that if the battery is cooled using the value of Equation 4 as the minimum cooling time, the crushed material can be utilized stably without a fire occurring after the battery is crushed.

[0235]

[0236] Selective leaching method for compounds containing lithium and aluminum

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

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

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

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

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

[0242] In one embodiment, Ni-Co-Mn alloy particles having a compound containing lithium and aluminum obtained through high-temperature heat treatment located on the surface are subjected to pH = 0.4 ~ 1.0, temperature = 50℃ Selective leaching of compounds containing lithium and aluminum was carried out for 120 minutes using a sulfuric acid equivalent ratio of 1.0 to 1.6 M.

[0243] Specifically, Table 3 shows sulfuric acid equivalent ratio = 1.0M, temperature = 50 o This shows the results of the selective Li leaching rate (%) over time at C, and Table 4 is for sulfuric acid equivalent ratio = 1.2M, temperature = 50 o This shows the results of the selective Li leaching rate (%) over time at C, and Table 5 is for sulfuric acid equivalent ratio = 1.6M, temperature = 50 o This shows the results of the selective Li leaching rate (%) over time at C.

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

[0245]

[0246] Hour(minute)LiNiCoMn000003078.10.90.92.76085.61.72.15.19092.42.93.67.812097.23.84.410.0

[0247] Hour(minute)LiNiCoMn000003083.11.41.82.96088.23.63.26.29094.14.95.59.612099.46.57.012.3

[0248] Hour(minute)LiNiCoMn000003084.33.84.14.56090.17.68.69.19095.112.512.613.512099.816.217.118.6

[0249] Leaching method for alloy particles recovered from valuable metals

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

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

[0252] As can be seen in Table 6, it can be confirmed that the leaching rate improves with oxygen blowing, and the leaching rate improves from about 30% to 99% within the same leaching time of 48 hours.

[0253] This can be explained through reaction equation 4. That is, when oxygen gas is blown in, it provides electrons to the aqueous solution, and the nickel-containing alloy dissolves into the aqueous solution to achieve charge balance equal to the number of electrons.

[0254]

[0255] [Reaction Equation 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 can be seen in Tables 6 and 7, it can also be observed that when the pressurization conditions are changed, the leaching rate improves and the leaching time is shortened. This is believed to be because the dissolution of the nickel-containing alloy is improved as reaction equation 4 is promoted and accelerated due to the increase in pressure.

[0260]

[0261] P(O2), atmNiCoMn0.13133360.23844420.45356540.87881771.0989799

[0262] Pressurization conditions (atm) temperature ( o C)NiCoMn110041454321216670644145818379816189929016207979998

[0263] Method for preparing sulfate solution

[0264] High concentrations of impurities lead to non-uniform precursor shapes and reduced ion conductivity during precursor formation, resulting in a problem where the electrical performance of the battery cell is inferior after manufacturing.

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

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

[0267]

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

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

[0270] [Reaction Equation 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 Preparation 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 reagent-grade sulfate solution prepared with a purity of 99% or higher, and a Ni-containing sulfate solution that has not undergone an impurity removal process. Specifically, equal amounts of NaOH and NH4OH were added to the sulfate solutions according to the examples and comparative examples and mixed in a reactor. While adjusting the pH, [Ni,Co,Mn]OH2 was allowed to undergo a co-precipitation reaction, and the precursor was obtained through solid-liquid separation. The composition and results can be confirmed through Table 9 and Figure 3 below.

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

[0277] As can be seen, the concentration of the high-purity Ni-containing sulfate solution shows an impurity level similar to that of the reagent-grade Ni-containing sulfate solution, and in the case of the sulfate solution with unremoved 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 prepared using the high-purity Ni-containing sulfate solution (Fig. 3 (b)), the sphericity characteristic can be confirmed to be at the same level as that of the reagent-grade (Fig. 3 (a)), but in the case of the precursor prepared using the sulfate solution containing high amounts of Fe, Cu, and Al (Fig. 3 (c)), it can be confirmed that the precursor shape has a lower degree of sphericity, is non-uniform, and has a high particle aggregation phenomenon, so sphericity, which is one of the important physical properties of the precursor, cannot be secured.

[0278]

[0279] Classification (mol%) NiCoMnFeAlCu Example (High Purity Ni) 58.6 221.4 219.8 90.0 20.0 20.0 1 Comparative Example 1 (Impurities Not Removed) 33.0 91 1.9 211.1 80.3 231.6 11.8 2 Comparative Example 2 (Reagent Grade) 58.5 121.8 319.6 6---

[0280] The present invention is not limited to the above embodiments and can be manufactured in various different forms, and those skilled in the art will understand that the invention can be implemented in other specific forms without changing the technical concept or essential features of the 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 first acid leaching the alloy particles to selectively remove the compound containing lithium and aluminum located on the surface of the alloy particles; and A step of obtaining valuable metal recovery alloy particles from which the compound containing lithium and aluminum is removed; A method for recycling valuable metals including 2. In Paragraph 1, A method for recycling valuable metals, further comprising the step of obtaining a sulfate solution containing Ni, Co, and Mn by secondary acid leaching of the obtained valuable metal recovery alloy particles.

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

4. In Paragraph 2, In the step of obtaining a sulfate solution containing Ni, Co, and Mn by secondary acid leaching of the obtained valuable metal recovery alloy particles; A method for recycling valuable metals in which 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 that is performed while being supplied at a rate of / hr.

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

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

0.

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

0.

9. In Paragraph 1, A method for recycling valuable metals, wherein the step of first acid leaching the alloy particles to selectively remove a compound containing lithium and aluminum located on the surface of the alloy particles is performed for 240 minutes or less.

10. In Paragraph 2, A method for recycling valuable metals, wherein the step of obtaining a sulfate solution containing Ni, Co, and Mn by secondary acid leaching of the obtained valuable metal recovery alloy particles is performed under pressurized conditions.

11. In Paragraph 10, A method for recycling valuable metals in which the above-mentioned pressurization conditions are 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 valuable metal recovery alloy particles; thereafter, A step of removing copper from the sulfate solution by adding sodium hydrogen sulfide (NaHS) to the sulfate solution; A method for recycling valuable metals that further includes 13. In Paragraph 12, A method for recycling valuable metals in which the above sodium hydrogen sulfide is introduced 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 valuable 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 valuable metals that further includes 15. In Paragraph 14, A method for recycling valuable metals in which the sodium hydroxide is introduced in an amount of 0.01 to 0.5 mol / L.

16. In Paragraph 1, The step of preparing Ni-Co-Mn alloy particles having a compound containing lithium and aluminum located on the surface; Step of preparing a lithium-containing battery; A step of crushing the above battery into battery shredders; A step of high-temperature heat treatment of the crushed battery material; and A step of separating Ni-Co-Mn alloy particles from the battery crushed material that has been heat-treated at high temperature; A method for recycling valuable metals that includes 17. In Paragraph 16, A method for recycling valuable metals, wherein the high-temperature heat treatment step is performed in a gas atmosphere with 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, and The content of one or more impurities selected from the group consisting of Al, Fe, and Cu is 15 weight% or less, Precious metal recovery alloy particles.

19. In Paragraph 18, Valuable metal recovery alloy particles satisfying Equations 1 and 2: [Equation 1] 0.8 ≤ [Ni] / [Co] ≤ 20 [Equation 2] 0.12 ≤ [Ni] / [Mn] ≤ 20 In the above equations 1 and 2, [Ni], [Co], and [Mn] are the molar ratios of Ni, Co, and Mn, respectively, within the alloy of recovered valuable metals.

20. In Paragraph 18, Valuable metal recovery alloy particles satisfying the following Equation 3: [Equation 3] 0.02 ≤ [C] / [Ni] ≤ 7 In the above Equation 3, [C] and [Ni] are the content (weight%) of C and Ni, respectively, within the above-mentioned valuable metal recovery alloy particles.

21. In Paragraph 18, A valuable metal recovery alloy particle comprising 45 weight% or more of Ni, Co, and Mn based on 100 weight% of the total valuable metal recovery alloy particle.

22. In Paragraph 18, A valuable metal recovery alloy particle containing 5% by weight or less of lithium with respect to 100% by weight of the total valuable metal recovery alloy particle.

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

Images