How to dispose of used batteries

Abstract

The present invention relates to a battery processing method, the battery processing method of the present invention includes the steps of: preparing an output by reducing crushed material recovered from a waste battery at a high temperature; magnetically separating the output into a first magnetic material and a first non-magnetic material; crushing the first magnetic material to separate it into a second magnetic material and a second non-magnetic material; and flotation separating the first non-magnetic material.

Description

Technical Field

[0001] It relates to waste batteries, and more particularly to a method for treating waste batteries for the efficient recovery of materials such as valuable metals, lithium oxide, graphite, and copper.

Background Art

[0002] As the global demand for electric vehicles has become active, the problem of treating waste batteries generated from such electric vehicles has emerged as a social issue. In the case of lithium secondary batteries, which are the main raw material of the waste batteries, they contain organic solvents, explosive substances, and heavy metal substances such as Ni, Co, Mn, and Fe. In the case of Ni, Co, Mn, and Li, they have a high scarcity value as valuable metals, and the recovery and reuse processes after lithium secondary batteries are discarded have emerged as an important research field.

[0003] Specifically, a lithium secondary battery mainly consists of copper and aluminum used as current collectors, Li, Ni, Co, Mn-containing oxides constituting the positive electrode material, and graphite (Graphite) used as the negative electrode material. It also includes a separator for separating the positive electrode material and the negative electrode material and an electrolyte injected into the separator. The solvents used as the solvent (Solvent) and salt (Salt) constituting the electrolyte mainly use a mixture of carbonate organic substances such as ethylene carbonate (Ethylene Carbonate) and propylene carbonate (Propylene Carbonate), and for example, LiPF₆ is used.

[0004] Thus, a lithium secondary battery is composed of heavy metal substances such as Ni - Co - Mn - Fe, carbon (Carbon), and other electrolyte substances, among which Ni, Co, Mn, and Li are valuable as valuable metals.

[0005] Reuse for battery raw material recovery generally involves dismantling, discharging, crushing, heat treatment, recovery, and wet processing of batteries to recover valuable metals. In the case of discharge, saltwater discharge is performed, and substances such as Na, K, Mg, Ca, and Cl that enter at this time are included as impurities in the recovered raw material.

[0006] After heat treatment, the recovered material will produce different products depending on the heat treatment temperature. When heat-treated at temperatures below 600°C, it is called Black Powder, and is in the form of a powder mixture of Ni-Co-Mn-Li oxide and carbon, the negative electrode material. Al and Cu are removed beforehand, so they may be present in very small amounts.

[0007] When the aforementioned black powder is heat-treated at a high temperature of 1,000°C or higher, the metal oxides are reduced and alloyed by the carbon in the negative electrode material, resulting in a black alloy containing such alloy components, carbon, and other substances. Currently, research is needed to recover valuable metals, lithium oxide, and other substances from the black alloy by material, and to increase the recovery rate of valuable metals. [Overview of the project] [Problems that the invention aims to solve]

[0008] One embodiment of the present invention provides a battery processing method that efficiently recovers valuable metals, lithium oxide, and substances such as graphite from a black alloy obtained from black powder, separately for each material, thereby increasing the recovery rate of valuable metals and graphite. [Means for solving the problem]

[0009] A battery processing method according to one embodiment of the present invention may include the steps of: preparing an output by reducing crushed material recovered from a waste battery at a high temperature; magnetically separating the output into a first magnetic material and a first non-magnetic material; crushing the first magnetic material to separate it into a second magnetic material and a second non-magnetic material; and flotation separating the first non-magnetic material. In one embodiment, the step of preparing an output by reducing crushed material recovered from a waste battery at a high temperature may include the steps of: preparing a battery; crushing the battery into battery crushed material; and heat-treating the crushed battery crushed material in a temperature range of 600 to 1,500°C.

[0010] In one embodiment, the heat treatment step can be performed at an oxygen concentration of 0.1 to 2.0 vol%. In one embodiment, the first magnetic material includes a valuable metal alloy containing a valuable metal, and at least a portion of the valuable metal alloy may include a core-shell structure in which a lithium compound is disposed in at least a portion of the surface of the valuable metal alloy.

[0011] In one embodiment, the second non-magnetic material may include at least one of a lithium-containing compound and graphite. In one embodiment, the magnetic separation step can be performed in a magnetic force strength range of 1,000 to 5,000 Gauss.

[0012] In one embodiment, the process may further include a step of additionally separating the first magnetic material based on a particle size of 50 to 70 μm. In one embodiment, the step of crushing the magnetic product among the magnetically separated products to separate the second magnetic material and the second non-magnetic material can be carried out within a shear force range of 1 to 5 m / sec.

[0013] In one embodiment, the step of crushing the magnetic product among the magnetically separated products to separate the second magnetic material and the second non-magnetic material can be carried out for 20 to 80 minutes. In one embodiment, the step of crushing the magnetic product among the magnetically separated products to separate the magnetic material and the non-magnetic material can be carried out by crushing the magnetic product and then by one of particle size separation, flotation separation, and magnetic separation.

[0014] In one embodiment, the particle size separation can be performed based on a particle size of 70-80 μm. In one embodiment, the flotation separation step can separate suspended matter containing graphite from precipitates containing valuable metals.

[0015] In one embodiment, the precipitate can be magnetically separated to recover the substance containing the valuable metal, and the recovered substance can be ground together with the magnetic product. In one embodiment, the process may include a step of grinding the magnetic product from the magnetically separated product to separate the magnetic and non-magnetic materials, followed by a step of drying the final product.

[0016] In one embodiment, the step of drying the final product can be carried out in a temperature range of 80 to 200°C. In one embodiment, in the step of preparing a product obtained by reducing the crushed material recovered from the waste battery at a high temperature, at least a portion of the product may include a valuable metal recovery composition comprising a core portion containing a valuable metal recovery alloy and a shell portion disposed on the core portion and containing a lithium compound. [Effects of the Invention]

[0017] A battery processing method according to one embodiment of the present invention includes a step of magnetically separating and pulverizing the product that has undergone high-temperature reducing heat treatment, thereby enabling efficient recovery of valuable metals, lithium oxide, and substances such as graphite from the black alloy obtained from black powder, and increasing the recovery rate of valuable metals and graphite. [Brief explanation of the drawing]

[0018] [Figure 1a] A photograph of a valuable metal recovery alloy, a lithium compound, and a graphite-based material of a recovered product recovered from a waste battery according to an embodiment of the present invention.

[0019] [Figure 1b] A photograph of a valuable metal recovery alloy, a lithium compound, and a graphite-based material of a recovered product recovered from a waste battery according to an embodiment of the present invention.

[0020] [Figure 1c] A photograph of a valuable metal recovery alloy, a lithium compound, and a graphite-based material of a recovered product recovered from a waste battery according to an embodiment of the present invention.

[0021] [Figure 2] A flowchart of a battery processing method according to an embodiment of the present invention.

[0022] [Figure 3] XRD analysis results of a black alloy formed after heat treatment according to an embodiment of the present invention.

[0023] [Figure 4] SEM photograph of a composition for valuable metal recovery.

Mode for Carrying Out the Invention

[0024] Terms such as first, second, and third are used to describe various parts, components, regions, layers, and / or sections, but are not limited thereto. These terms are only used to distinguish one part, component, region, layer, or section from another part, component, region, layer, or section. Therefore, the first part, component, region, layer, or section described below can be referred to as the second part, component, region, layer, or section without departing from the scope of the present invention.

[0025] The technical terms used herein are for the sole purpose of referring to specific embodiments and are not intended to limit the invention. The singular form used herein also includes the plural form unless the phrase expressly indicates otherwise. The meaning of “including” as used in this specification is to embody certain characteristics, domains, integers, stages, operations, elements, and / or components, and does not exclude the presence or addition of other characteristics, domains, integers, stages, operations, elements, and / or components.

[0026] When one part is described as being "on top of" or "on" another part, it may be directly on top of or on the other part, or the other part may be present between them. In contrast, when one part is described as being "directly on top of" another part, there is no other part in between them.

[0027] Furthermore, unless otherwise specified, percentages in this specification refer to percentages by weight.

[0028] Unless otherwise defined, all terms used herein, including technical and scientific terms, have the same meaning as those generally understood by a person of ordinary skill in the art to which this invention pertains. Terms defined in commonly used dictionaries are interpreted in addition to having the meaning corresponding to the relevant technical literature and the present disclosure, and are not interpreted in their ideal or highly formal sense unless otherwise defined.

[0029] Embodiments of the present invention will be described in detail below. However, these are presented as examples only and do not limit the present invention, which is defined solely by the scope of the claims described below.

[0030] Figures 1a to 1c are photographs of valuable metal recovery alloys, lithium compounds, and graphite-based materials recovered from waste batteries according to one embodiment of the present invention.

[0031] Referring to Figures 1a to 1c, according to one embodiment of the present invention, the recovered material from a waste battery contains, based on 100% by weight of the recovered material, 20 to 35% by weight of a valuable metal recovery alloy, 25 to 50% by weight of a lithium compound, and the remainder being a graphite-based substance. The recovered material from a waste battery may also be the recovered material obtained by the battery processing method described later in Figure 2. Specifically, the recovered material may be a valuable metal recovery alloy containing valuable metals, a lithium compound containing lithium, and the remainder being a graphite-based substance.

[0032] In one embodiment, the recovered material may contain 20-35% by weight of a valuable metal recovery alloy, 25-50% by weight of a lithium compound, and the remainder being a graphite-based substance, based on 100% by weight of the recovered material. A valuable metal recovery alloy containing valuable metals, a lithium compound containing lithium, and a graphite-based substance containing carbon are recovered in powder form from the battery processing method described later.

[0033] In one embodiment, the valuable metal recovery alloy may be 20 to 35% by weight, based on 100% by weight of the recovered material. Specifically, the valuable metal recovery alloy may be 25 to 30% by weight. The valuable metal recovery alloy may be a substance containing valuable metals such as Ni, Co, and Mn.

[0034] If the weight percentage of the recovered alloy containing valuable metals satisfies the aforementioned range, it has the advantage of increasing the recovery rate of valuable metals such as Ni, Co, and Mn. If the recovery rate of valuable metals deviates from the upper limit of the aforementioned range, it can increase the recovery rate of valuable metals, but it presents uneconomical problems. If the recovery rate of valuable metals deviates from the lower limit of the aforementioned range, it presents the problem of a lower recovery rate of valuable metals.

[0035] In one embodiment, the valuable metal recovery alloy may contain, based on 100% by weight of the entire valuable metal recovery alloy, a total amount of Ni, Co, and Mn of 90% by weight or more, with the remainder being impurities. Specifically, the total amount of Ni, Co, and Mn may be 90-96% by weight, and more specifically, 92-95% by weight.

[0036] If the total amount of Ni, Co, and Mn in the valuable metal recovery alloy satisfies the aforementioned range, the recovery rate of valuable metals can be increased. If the total amount of Ni, Co, and Mn in the valuable metal recovery alloy deviates from the aforementioned range, there is a problem of economic unfeasibility or a low recovery rate of valuable metals.

[0037] In one embodiment, nickel (Ni) may be included in a range of 50 to 60% by weight, based on 100% by weight of the entire valuable metal recovery alloy. Specifically, nickel may be included in a range of 52 to 58% by weight.

[0038] If the nickel content exceeds the upper limit of the aforementioned range, there is a problem of reduced leaching rate due to the formation of nickel carbide (Ni3C). If the nickel content exceeds the lower limit of the aforementioned range, there is a problem of reduced Ni recovery rate during leaching and solvent extraction.

[0039] In one embodiment, cobalt (Co) may be included in a range of 18 to 28% by weight, based on 100% by weight of the entire valuable metal recovery alloy. Specifically, cobalt may be included in a range of 20 to 26% by weight.

[0040] If the cobalt content exceeds the upper limit of the aforementioned range, there is a problem of reduced leaching rate due to cobalt carbide formation. If the cobalt content exceeds the lower limit of the aforementioned range, there is a problem of reduced Co recovery rate during leaching and solvent extraction.

[0041] In one embodiment, manganese (Mn) may be included in a range of 10 to 20% by weight, based on 100% by weight of the entire valuable metal recovery alloy. Specifically, cobalt may be included in a range of 12 to 18% by weight.

[0042] If the manganese content exceeds the upper limit of the aforementioned range, there is a problem of reduced leaching rate due to manganese carbide formation. If the manganese content exceeds the lower limit of the aforementioned range, there is a problem of reduced Mn recovery rate during leaching and solvent extraction.

[0043] In one embodiment, the valuable metal recovery alloy may contain lithium (Li) in a range of 0.01 to 5% by weight, based on 100% by weight of the total alloy. Specifically, the lithium may be present in a range of 0.05 to 0.15% by weight.

[0044] The advantage of lithium satisfying the aforementioned range is that the Li recovery rate during the Li smelting process can be maximized. If the lithium deviates from the upper limit of the range, there is a problem of reduced Ni and Co recovery rates, and if it deviates from the lower limit of the range, there is a problem of reduced Li recovery rates during the Li smelting process and increased process costs.

[0045] In one embodiment, the valuable metal recovery alloy may contain copper (Cu) in an amount of 1.0 to 7% by weight. Specifically, the amount of copper may be in an amount of 3 to 5% by weight.

[0046] If the copper content exceeds the upper limit of the range, there is a problem of increased process costs due to the increased amount of CuSO4 precipitated during leaching and solvent extraction. If the copper content exceeds the lower limit of the range, there is a problem of increased unreacted material due to the difficulty in forming low-melting-point Ni-Co-Mn. In one embodiment, the copper can combine with nickel (Ni), one of the valuable metals, to form an alloy.

[0047] In one embodiment, the valuable metal recovery alloy may contain carbon (C) in the range of 0.1 to 10% by weight. By satisfying this range of carbon, the actual yield can be increased and the processing time in the wet process can be reduced. Specifically, the carbon may be contained in the range of 1 to 7% by weight.

[0048] If the value deviates from the upper limit of the aforementioned range, there is a problem that the negative electrode material remains in an unreacted state, resulting in insufficient alloying and residual valuable metal oxides within the positive electrode material. If the value deviates from the lower limit of the aforementioned range, there is a problem that lithium may be lost due to high temperatures.

[0049] In one embodiment, the valuable metal recovery alloy may contain aluminum (Al) in a range of 0.25 to 30% by weight. If the aluminum content deviates from the upper limit of the range, there is a problem of reduced Ni and Co recovery rates during the leaching and solvent extraction process. If the aluminum content deviates from the lower limit of the range, LiAlO2 formation becomes difficult, resulting in a problem of reduced Li recovery rates.

[0050] In one embodiment, the lithium compound may be present in an amount of 25 to 50% by weight, based on 100% by weight of the recovered material. Specifically, the lithium compound may be present in an amount of 30 to 40% by weight. In one embodiment, the lithium compound may be a compound containing lithium. For example, the lithium compound may contain lithium oxide, and the lithium oxide may contain lithium aluminum oxide.

[0051] By satisfying the aforementioned range, the recovery rate of lithium, one of the valuable metals, can be increased. If the lithium compound deviates from the lower limit of the aforementioned range, it means that a large amount of Li has been lost to the NCM alloy or graphite, which leads to a problem of reduced Li recovery rate. When Li is recovered in the subsequent wet smelting process, the Li content of the input raw materials will be lower, which will increase process costs.

[0052] In one embodiment, the lithium compound may contain 10 to 20% lithium (Li) based on 100% lithium compound by weight. Specifically, the lithium may be 12 to 18% by weight.

[0053] If the lithium content exceeds the upper limit of the aforementioned range, it means that lithium does not react with Al to form a lithium compound in the form of LiAlO2, but rather that the proportion of lithium hydroxide, lithium fluoride, lithium carbonate, etc. is high, which poses a problem that necessitates considering methods such as water leaching and acid leaching in the subsequent wet smelting process. If the lithium content exceeds the lower limit of the aforementioned range, it means that most of the lithium compound was recovered in the form of LiAlO2, which has low water solubility, and that the highly water-soluble lithium compound dissolved in water during the sorting process, which poses a problem that requires the recovery of lithium again from the water used in the sorting process.

[0054] In one embodiment, the lithium compound may contain 20-30% by weight of aluminum (Al) based on 100% by weight of the lithium compound. Specifically, it may be 23-28% by weight. By satisfying the above range of aluminum content, the lithium compound can be formed through physical or chemical bonding with lithium, thereby increasing the lithium yield.

[0055] If the aluminum content exceeds the upper limit of the range, excessive Al2(SO4)3 is produced in the leaching and solvent extraction processes, leading to increased costs in the Ni and Co solvent extraction and crystallization processes, as well as a decrease in the recovery rate of Ni and Co. If the aluminum content exceeds the lower limit of the range, insufficient aluminum content results in poor production of Li-Al-O oxide.

[0056] In one embodiment, the lithium compound may have a carbon (C) content of 1 to 7% by weight, based on 100% by weight of the lithium compound. Specifically, the carbon (C) content may be 3 to 5% by weight. Satisfying the above range for the carbon content offers advantages in optimizing the wet processing of the valuable metal recovery composition.

[0057] If the carbon content exceeds the upper limit of the range, there is a problem of reduced leaching rate due to the formation of nickel carbide (Ni3C). If the carbon content exceeds the lower limit of the range, there is a problem of reduced recovery rate of valuable metals such as Ni and Co in solvent extraction after the leaching process due to an increase in the content of other impurities such as Si.

[0058] In one embodiment, the graphite-based material may be included in an amount of 25-50% by weight, based on 100% by weight of the recovered material. Specifically, the graphite-based material may be included in an amount of 30-40% by weight. The content of the graphite-based material may be such that a large amount of graphite-based material is generated as the high-temperature reduction reaction is carried out in a low-oxygen content range that reduces carbon dioxide generation. By satisfying the above range for the graphite-based material, the reuse yield of graphite-based material that can be used as a negative electrode material can be increased.

[0059] If the graphite-based material exceeds the upper limit of the aforementioned range, the graphite content becomes excessively high, leading to a problem of reduced recovery rates of valuable metals. If the graphite-based material exceeds the lower limit of the aforementioned range, there is a problem of low graphite recovery rates.

[0060] In one embodiment, the graphite-based material has a carbon (C) content of 80-90% by weight, and may contain impurities. The carbon (C) content may also be 83-87% by weight. By satisfying the above range for the carbon content, high-purity graphite containing carbon can be obtained.

[0061] If the carbon content exceeds the upper limit of the aforementioned range, there is a problem of reduced recovery rates for valuable metals. If the carbon content exceeds the lower limit of the aforementioned range, there is a problem of low graphite recovery rates.

[0062] In one embodiment, the graphite-based material may contain 13 to 25% by weight of copper (Cu) relative to 100% by weight of the graphite-based material. Specifically, the copper content may be 15 to 20% by weight. If the copper content deviates from the upper limit of the aforementioned range, there is a problem in that the amount of acid used to remove Cu during the process of refining graphite into high-purity graphite increases.

[0063] Figure 2 is a flowchart of a battery processing method according to one embodiment of the present invention.

[0064] Referring to Figure 2, the battery processing method includes the steps of preparing an output by reducing crushed material recovered from a waste battery at a high temperature, magnetically separating the output, and crushing the magnetic output from the magnetically separated output to separate magnetic and non-magnetic materials. The present invention provides a battery processing method that can increase the recovery rate of valuable metals by efficiently performing magnetic separation from the output obtained by reducing crushed material recovered from a waste battery at a high temperature. Valuable metals in the present invention can mean expensive metallic components contained in the battery, and can mean nickel, cobalt, manganese, aluminum, copper, and lithium.

[0065] The step of preparing an output product obtained by reducing crushed material recovered from waste batteries at a high temperature includes the steps of preparing batteries, crushing the batteries into battery crushed material, and subjecting the crushed battery crushed material to high temperature heat treatment.

[0066] In the stage of preparing the battery, the battery may be a method for processing various types of batteries, including lithium-ion batteries, and the battery may be, for example, lithium secondary batteries separated from automobiles, secondary batteries separated from electronic devices such as mobile phones, cameras, and laptops, specifically lithium secondary batteries. More specifically, the battery has the advantage of being environmentally friendly by utilizing waste batteries.

[0067] In one embodiment, during the battery preparation stage, the battery may include lithium (Li) and aluminum (Al). The coexistence of lithium and aluminum in the battery results in a material in which lithium and aluminum are physically and / or chemically bonded in the product generated after battery processing.

[0068] The step of crushing the battery may mean a step of applying impact or pressure to the battery so that a part of the battery separates from the battery. In one embodiment, the step of crushing the battery may mean a step of pulverizing the battery, a step of cutting the battery, a step of compressing the battery, and a combination thereof. Specifically, the crushing step may include all steps of destroying the battery to obtain small fragments.

[0069] In one embodiment, the step of crushing the battery may include all steps of compressing the prepared battery or destroying the battery by applying an external force such as a shear force or a tensile force. The step of crushing the battery may be carried out, for example, using a crusher.

[0070] In one embodiment, the step of crushing the battery can be performed at least once. Specifically, the crushing step can be performed at least once, either continuously or discontinuously.

[0071] In one embodiment, the battery crushing step can be carried out under conditions of supplying an inert gas, carbon dioxide, nitrogen, water, or a combination thereof, or under a vacuum atmosphere of 100 torr or less. When carried out under the aforementioned conditions, oxygen supply can be suppressed to prevent the electrolyte from reacting with oxygen, thereby preventing explosion, and the vaporization of the electrolyte can be suppressed, thus preventing the generation of flammable gases such as ethylene, propylene, or hydrogen.

[0072] The step of high-temperature heat treatment of the crushed battery material involves placing the crushed battery material into a heating furnace capable of raising the temperature to above its melting point. The crushed battery material may also contain valuable metals such as Ni, Co, Mn, and Li. The high-temperature heat treatment may involve heat treatment conditions that carry out a high-temperature reduction reaction of the battery without going through a melting step.

[0073] In one embodiment, the step of heat-treating the battery fragments at high temperature can be carried out in a gas atmosphere of at least one of the following: an inert gas, carbon dioxide, carbon monoxide, hydrocarbon gas, and oxygen. In the case of the inert gas, for example, it may include at least one of argon and nitrogen. Carrying out the reduction reaction of the fragments in the gas atmosphere has the advantage of increasing the recovery rate of valuable metal elements contained in the battery fragments.

[0074] In one embodiment, the step of high-temperature heat treatment of the Ni, Co, Mn, and Li-containing battery fragments can be carried out in a gas atmosphere containing at least one of an inert gas, carbon dioxide, carbon monoxide, and hydrocarbon gas; and oxygen. In one embodiment, the oxygen concentration can be in the range of 0.1 to 2.0 vol%. Specifically, the oxygen concentration can be in the range of 0.4 to 1.2 vol%.

[0075] If the oxygen concentration exceeds the upper limit of the aforementioned range, the Li2O + C + O2(g) = Li2CO3 reaction is promoted as the oxygen concentration increases, but at the same time, there is a problem of a decrease in LiAlO2 and Li5AlO4. Specifically, if the oxygen concentration exceeds the upper limit of the aforementioned range, excessive carbon dioxide is formed during the reduction reaction process and either gasifies and disappears along with lithium, or excessive Li2CO3(s) is produced, making recovery by acid leaching difficult. If the oxygen concentration exceeds the lower limit of the aforementioned range, there is a problem of a decrease in the lithium recovery rate.

[0076] In one embodiment, the step of high-temperature heat treatment of the battery fragments can be carried out in the range of 600 to 1,500°C. Specifically, the high-temperature heat treatment step can be carried out in the range of 900 to 1,500°C, more specifically in the range of 1,100 to 1,500°C, and even more specifically in the range of 1,300 to 1,500°C. In the high-temperature heat treatment step of the battery fragments, as the temperature rises, Li5AlO2(s) + 2Li2CO3(s) = Li5AlO4 + 2CO2(g) reaction is produced, but the LiF(g) vaporization reaction is promoted, and when carried out in the aforementioned range, the lithium yield can be improved.

[0077] If the upper limit of the aforementioned range is exceeded, there is a problem of lithium loss due to lithium vaporization. Specifically, if the upper limit of the aforementioned range is exceeded, as the LiF(g) vaporization reaction is excessively accelerated, there is a problem of lithium recovery rate decreasing due to lithium loss.

[0078] If the value deviates from the lower limit of the aforementioned range, the sintering and reduction of the alloying elements do not proceed smoothly, and a stabilized lithium-containing compound is not formed. This leads to a problem in that it becomes difficult to recover the stabilized compound during subsequent lithium compound recovery. Specifically, if the value deviates from the lower limit of the aforementioned range, MnO among the Li-containing Ni, Co, and Mn oxides in the positive electrode material is not dissociated, and MnAl2O4 is produced by the reaction MnO(s) + 2Al(s) + 3 / 2O2 = MnAl2O4(s), which reduces the lithium concentration in the lithium compound and lowers the lithium recovery rate.

[0079] The step of magnetically separating the high-temperature heat-treated product allows for the magnetic separation of the product into a first magnetic material having magnetism and a first non-magnetic material having non-magnetism. Magnetic separation can utilize a magnetic material to separate particles through contact with the magnetic material, and various types of magnetic separation methods can be applied.

[0080] The first magnetic material is a composition comprising valuable metals Ni, Co, and Mn, and may specifically include a core portion and a shell portion disposed on the core portion. The core portion may include a valuable metal recovery alloy. The core portion of the valuable metal recovery composition may be recovered from the positive electrode material component inside a waste battery.

[0081] The shell portion is positioned on the core portion and may contain lithium compounds. Specifically, when recovering valuable metals from waste batteries, the valuable metals in the waste battery exist in oxide form and are reduced by graphite in the negative electrode material through a high-temperature heat treatment process. At this time, the copper current collector can melt and exist in a liquid state, playing a role in agglomerating the reduced valuable metals. The copper current collector and the aluminum current collector partially undergo a reduction reaction with the positive electrode material oxide, and the remainder reacts with lithium, leaving behind a compound in the form of an oxide containing lithium. A detailed explanation of this will be given later in Figures 3a, 3b and 4.

[0082] The second non-magnetic material may include at least one of a compound containing Li that is not bonded to a valuable metal in the magnetic separation stage and a graphite material containing carbon.

[0083] In one embodiment, the magnetic force separation stage can be performed in a magnetic force strength range of 1,000 to 5,000 Gauss. Specifically, the magnetic force separation stage can be performed in a magnetic force range of 2,000 to 3,000 Gauss.

[0084] Performing the magnetic separation step within the aforementioned magnetic strength range has the advantage of efficiently separating valuable metals. If the magnetic strength range deviates from the upper limit of the aforementioned range, even trace amounts of valuable metals are recovered, increasing the recovery rate. However, the grade of the recovered valuable metals decreases, and the amount of impurities such as graphite and copper increases. This leads to a problem where the process efficiency in the next step, the wet smelting process, decreases and processing costs increase. If the magnetic strength range deviates from the lower limit of the aforementioned range, the recovery rate of valuable metals decreases, and the loss of Ni, Co, and Mn increases.

[0085] The step of crushing the magnetic products among the magnetically separated products to separate the magnetic and non-magnetic materials may be a step of crushing the magnetically separated first magnetic material. The first magnetic material means, as described above, a core portion containing a valuable metal alloy and a compound containing lithium disposed on the core portion. The first magnetic material can be separated into a core portion and a shell portion through the crushing process. Specifically, the first magnetic material can be separated into a second magnetic material and a second non-magnetic material through the crushing process described above. The second magnetic material means, for example, an NCM alloy containing Ni, Co, and Mn, and the second non-magnetic material is a compound containing lithium, for example, lithium aluminate (LiAlO2).

[0086] In one embodiment, the first magnetic material can be separated into the valuable metal recovery alloy and a lithium-containing compound by mechanical or physical external force. In this way, not only can the valuable metal recovery alloy be recovered from the valuable metal recovery composition, but the lithium compound can also be separated at the same time, resulting in a high lithium recovery rate and a reduction in the amount of lithium lost.

[0087] In one embodiment, the grinding stage uses equipment that grinds using shear force in the form of a vertical attrition mill, and the RPM of the agitator of the vertical attrition mill can be set within a shear force range of 1 to 5 m / sec based on the tip speed. Specifically, the grinding stage can be performed within a shear force range of 2 to 3 m / sec tip speed. Because the grinding stage is performed within the aforementioned shear force range, the NCM alloy, which is the core of the first magnetic material, is not ground, and only the lithium-containing compound, which is the shell portion placed on the core portion, is ground into a fine powder.

[0088] At this time, the Tip Speed ​​can be calculated using the following formula. Tip Speed ​​= Pi × Impeller Diameter × RPM / 100

[0089] In one embodiment, if the shear force exceeds the upper limit of the range described above, the shell portion of the first magnetic material is separated, and then the internal magnetic material core is pulverized. Since the core is made of a flexible metal, the spherical particles are rolled up into plate-like particles and then pulverized again into smaller particles. At this time, there is a problem of reduced recovery rate in the process of separating the magnetic material of the core and the lithium compound of the shell using particle size. If the shear force exceeds the lower limit of the range described above, there is a problem that the lithium compound of the shell is not pulverized and is recovered together with the magnetic material of the core.

[0090] In one embodiment, the grinding step can be carried out for 20 to 80 minutes. Specifically, the grinding step can be carried out for 30 to 60 minutes. By carrying out the grinding step within the above range, the recovery rate of valuable metals such as Ni, Co, Mn, and Li can be increased.

[0091] If the grinding step deviates from the upper limit of the range described above, the magnetic material in the core and the magnetic material containing the lithium compound in the shell are excessively ground and rolled into a flexible plate shape. If the grinding continues to be excessively ground, the plate-shaped particles break again into fine powder particles, resulting in a problem where the effectiveness of the magnetic force is reduced during additional magnetic separation. If the grinding step deviates from the lower limit of the range described above, there is a problem where the shell portion containing the lithium compound is not easily separated from the magnetic material of the core-shell structure.

[0092] In one embodiment, the process may include an additional separation step after the grinding stage, using one of the following: particle size separation, flotation, and magnetic separation. Flotation is a method of separating particles by considering the difference in specific gravity of different substances, and may, for example, utilize a specific solvent to separate particles based on whether the specific gravity of the particles corresponding to the specific solvent is high or low.

[0093] When the first magnetic material undergoes the aforementioned pulverization step and the core and shell portions are separated, the valuable metal alloy is separated in a large particle size state due to the flexibility of the metal, while the lithium-containing compound is pulverized into a fine powder form with a small particle size. Specifically, the first magnetic material is separated into a lithium-containing compound with a particle size smaller than 70-80 μm and a valuable metal alloy with a particle size of 70-80 μm or larger.

[0094] In one embodiment, the core and shell portions separated after the grinding step are subjected to particle size separation based on a particle size of 70-80 μm. The lithium-containing compound, which is the shell portion, has a particle size smaller than the aforementioned particle size standard, and the valuable metal alloy, which is the core portion, has a particle size larger than the aforementioned particle size standard. Thus, the valuable metal alloy and the lithium-containing compound can be easily separated through particle size separation.

[0095] In other embodiments, the core and shell portions separated after the grinding step can be subjected to magnetic separation. Through this magnetic separation, a valuable metal alloy containing magnetic Co can be easily separated from a compound containing non-magnetic lithium.

[0096] In other embodiments, the core and shell portions separated after the grinding step can be subjected to flotation separation. Through flotation separation, the core portion containing precipitated valuable metals and the floating lithium-containing compounds can be easily separated.

[0097] In one embodiment, the process may include a step of flotation separation of the first non-magnetic material. This allows for the separation of the first non-magnetic material, which contains graphite and has non-magnetic properties, that was separated in the first magnetic separation step.

[0098] In one embodiment, the flotation separation step may be a step of separating suspended matter containing graphite from precipitates containing valuable metals. Specifically, the flotation separation step may be a step of suspending hydrophobic graphite in the first nonmagnetic material and precipitating and separating lithium-containing compounds and finely particulate valuable metal alloys.

[0099] In one embodiment, the precipitate can be separated by magnetic force to recover the substance containing the valuable metal, and the recovered substance can be pulverized together with the magnetic product. A detailed explanation of the pulverization step is as described above.

[0100] In one embodiment, the process may include a step of pulverizing the magnetic products among the magnetically separated products to separate the magnetic and non-magnetic materials, followed by a step of drying the final product. After the drying step, the valuable metal alloy, lithium-containing compound, and graphite are dried into powder form.

[0101] In one embodiment, the step of drying the final product can be carried out in the range of 80 to 200°C. Specifically, the step of drying the final product can be carried out in the range of 100 to 150°C.

[0102] If drying is performed outside the upper limit of the aforementioned temperature range, there is a problem that flammable materials such as graphite will burn. If drying is performed outside the lower limit of the aforementioned temperature range, the moisture in the final product, which is the powder particles, will not be completely dried, resulting in the discharge of a product with a high moisture content, which increases the amount of acid used in the leaching process of the subsequent wet smelting process.

[0103] Figures 3a and 3b show the XRD analysis results of a valuable metal recovery composition formed after heat treatment according to one embodiment of the present invention.

[0104] Referring to Figures 3a and 3b, it can be confirmed that the valuable metal recovery composition, which has been subjected to high-temperature reductive heat treatment, does not reduce to form alloys such as Ni, Co, and Mn, but instead combines with the Al component in the battery to form a lithium-containing compound, such as lithium oxide. It can be confirmed that the lithium oxide is formed as, for example, LiAlO2, Li5AlO4, and Li2CO3. In one embodiment, the valuable metal recovery composition may further contain LiF. The amount of LiF may be a result of the electrolyte residue depending on the degree of pretreatment.

[0105] In one embodiment, LiAlO2 may include at least one of the following XRD peaks: 20.5–21.5°, 29.0–29.5°, 31.5–32.0°, 32.2–33.0°, 60.5–61.5°, and 70.0–72.0°. Li5AlO4 may include at least one of the following XRD peaks: 19.5–20.2° and 21.6–22.2°.

[0106] The LiAl5O8 composition may contain at least one of the following XRD peaks: 15.0–17.4°, 24.2–26.1°, 31.4–33.1°, 36.2–40.3°, 46.1–47.3°, 61.1–63.4°, and 66.2–68.7°. The LiF composition may contain at least one of the following XRD peaks: 37.5–40.2°, 43.9–46.5°, and 64.5–66.5°.

[0107] Li3PO4 compositions may contain at least one XRD peak between 29.2–40.1° and 52–77.1°. Li2SiO3 compositions may contain at least one XRD peak between 17.7–20.1°, 26.1–29.5°, 32.2–36.2°, and 37.6–39.7°. Li4SiO4 compositions may contain at least one XRD peak between 16.2–18.3°, 21.4–25.2°, 34.2–39.7°, and 59.2–63.4°.

[0108] Li2Si2O5 compositions may contain at least one of the following XRD peaks: 16.2–18.3°, 21.4–25.2°, 34.2–39.7°, and 59.2–63.4°. Li2CO3 compositions may contain at least one of the following XRD peaks: 24.0–26.0°, 27.0–29.0°, 34.0–36.0°, and 37.0–39.0°.

[0109] Figure 4 is an SEM image of a valuable metal recovery composition according to one embodiment of the present invention.

[0110] Referring to Figure 4, the valuable metal recovery composition according to one embodiment of the present invention includes a core portion and a shell portion disposed on the core portion. The core portion may include a valuable metal recovery alloy. The valuable metals of the present invention can mean valuable metal components contained in batteries, and can mean nickel, cobalt, manganese, aluminum, copper, and lithium. The core portion of the valuable metal recovery composition may be recovered from the cathode material components in waste batteries.

[0111] The shell portion is positioned on the core portion and may contain lithium compounds. Specifically, when recovering valuable metals from waste batteries, the valuable metals in the waste battery exist in oxide form and are reduced by graphite in the negative electrode material through a high-temperature heat treatment process. At this time, the copper current collector can melt and exist in a liquid state, playing a role in agglomerating the reduced valuable metals. The copper current collector and the aluminum current collector partially undergo a reduction reaction with the positive electrode material oxide, and the remainder reacts with lithium, leaving behind a compound in the form of an oxide containing lithium.

[0112] In one embodiment, the lithium (Li) content in the lithium compound may be 4 to 35% by weight, specifically 4 to 25% by weight, based on 100% by weight of the total. By satisfying the above range for the Li content in the lithium compound, it is possible to satisfy the requirement of a composition containing a lithium-containing compound that has a high lithium content and excellent lithium recovery rate. If the Li content deviates from the upper limit of the above range, there is a problem that the Li2O content increases while a large amount of compound that is difficult to recover due to water solubility issues is generated, thus lowering the lithium recovery rate. If the Li content deviates from the lower limit of the above range, there is a problem that the lithium recovery rate is low and there is no utility value.

[0113] In one embodiment, the lithium compound may include at least one of LiAlO2, Li5AlO4, LiAl5O8, Li2CO3, LiF, Li3PO4, Li2SiO3, Li4SiO4, and Li2Si2O5. In one embodiment, the lithium compound may include lithium aluminum oxide.

[0114] The lithium compound may be, for example, a lithium oxide. In the lithium-aluminum oxide, the lithium contained in the composition is realized in oxide form by physical or chemical bonding.

[0115] In one embodiment, the lithium compound may include lithium aluminum oxide. Specifically, the content of lithium aluminum oxide may be 45.0 to 97.0% by weight based on 100% by weight of the valuable metal recovery composition. Specifically, the content may be 70 to 90% by weight.

[0116] If the content of lithium aluminum oxide exceeds the upper limit of the aforementioned range, there is a problem in that highly water-soluble lithium hydroxide, lithium carbonate, lithium fluoride, etc. dissolve in large quantities in water during the sorting process. If the content of lithium aluminum oxide exceeds the lower limit of the aforementioned range, it means that most of the lithium compounds were recovered in the less water-soluble LiAlO2 form, and the highly water-soluble lithium compounds dissolved in water during the sorting process, which presents a problem in that lithium must be recovered again from the water used in the sorting process.

[0117] In one embodiment, the lithium compound may contain lithium and silicon-containing oxides. Specifically, the content of the lithium and silicon-containing oxides may be 2 to 30% by weight based on 100% by weight of the valuable metal recovery composition. Specifically, it may be 10 to 25% by weight. By satisfying the aforementioned ranges for lithium and silicon-containing oxides, it is possible to ensure a stable product under high temperature and appropriate oxygen concentration atmospheres, thereby increasing the actual yield of lithium during acid leaching.

[0118] If the content of the lithium and silicon-containing oxides exceeds the upper limit of the aforementioned range, it means that the reactor was exposed to the maximum temperature for a long time during the high-temperature reduction reaction, which leads to a decrease in the productivity of the reactor and an increase in energy costs. If the content of the lithium and silicon-containing oxides exceeds the lower limit of the aforementioned range, it means that there was insufficient thermal energy for lithium to react with aluminum, silicon, etc., to produce lithium compounds such as lithium aluminate, or that the reactor temperature was excessively high, causing lithium to volatilize and be removed, which leads to a decrease in the recovery rate of lithium.

[0119] In one embodiment, the valuable metal recovery composition may contain 10% by weight or less silicon (Si) based on 100% by weight of the valuable metal recovery composition. Specifically, the silicon may be 1.0% by weight or less, and more specifically, 0.5% by weight or less.

[0120] If the silicon (Si) content exceeds the upper limit of the aforementioned range, there is a problem that the process time and cost will increase in the subsequent wet smelting process to remove the silicon to battery grade. If the silicon (Si) content exceeds the lower limit of the aforementioned range, the remaining weight % of the silicon in the input raw material will disperse into graphite and lithium compounds, causing a problem that the process time and cost will increase in the refining and smelting processes of the graphite and lithium compounds.

[0121] In one embodiment, Li2CO3 may be present in an amount of 30% or less based on 100% by weight of the entire composition. The amount of Li2CO3 may be 15.0% or less, and more specifically, 5% or less. Satisfying the above range for the content of Li2CO3 has the advantage of preventing the generation of large quantities of compounds that are difficult to recover due to water solubility issues.

[0122] In one embodiment, LiF may be present in an amount of 30% by weight or less based on 100% by weight of the entire composition. The amount of LiF may be 6.5 to 24.0% by weight, more specifically, 6.5 to 15% by weight or less based on 100% by weight of the entire composition. Satisfying the above range for the content of LiF has the advantage of preventing the generation of large quantities of compounds that are difficult to recover due to water solubility issues.

[0123] If the LiF exceeds the upper limit of the aforementioned range, there is a problem in that pH adjustment becomes difficult due to the mixing of sulfate ions and fluoride ions during sulfuric acid leaching, resulting in a decrease in the Li recovery rate. If the LiF exceeds the lower limit of the aforementioned range, the levels of Li2SiO3, Li4SiO4, and Li2Si2O5 increase, and there is a possibility that sulfuric acid leaching becomes difficult, leading to a delay in the leaching process time.

[0124] In one embodiment, the total content of Li2CO3 and LiF may be 50% or less based on 100% by weight of the entire composition. Specifically, the total content may be 0.5 to 50%, and more specifically, the content may be 0.5 to 30% or less.

[0125] If the total content exceeds the upper limit of the aforementioned range, a large amount of compounds that are difficult to recover due to water solubility issues are generated, making it difficult to recover Li. If the total content exceeds the lower limit of the aforementioned range, compounds such as Li2SiO3, Li4SiO4, and Li2Si2O5 increase, and sulfuric acid leaching becomes difficult, leading to delays in the leaching process time.

[0126] By ensuring that the total amount of Li2CO3 and LiF satisfies the aforementioned range, it is possible to prevent the large-scale generation of compounds that are difficult to recover due to water solubility issues, and to increase the efficiency of lithium recovery by generating a large amount of compounds that are stable due to appropriate adjustment of high temperature and oxygen concentration and have excellent sulfuric acid leaching rates.

[0127] In one embodiment, Li3PO4 may be present in an amount of 10% by weight or less based on 100% by weight of the entire composition. The Li3PO4 may be present in an amount of 5% by weight, specifically 3% by weight or less, and more specifically 0.1 to 0.7% by weight, based on 100% by weight of the entire composition. By satisfying the above range of Li3PO4 content, the acid leaching of PO4 is reduced. 3- This prevents a decrease in Li recovery rate due to leaching behavior caused by pH changes due to anions and the generation of LiOH during impurity removal. By satisfying the aforementioned range of Li3PO4 content, the Li3PO4 during acid leaching is reduced. 3- This prevents a decrease in Li recovery rate due to issues such as leaching behavior caused by pH changes due to anions and LiOH generation during impurity removal.

[0128] The following describes preferred embodiments and comparative examples of the present invention. However, the following embodiments are merely preferred embodiments of the present invention, and the present invention is not limited to these embodiments. [Examples]

[0129] <Experimental Example> - Controlling conditions of waste batteries The crushed battery material can be shredded through a shredding process so that the longest of its horizontal and vertical lengths is 100 mm or less. Specifically, the optimal size for the crushed battery material may be 10 to 40 mm in the longest of its horizontal and vertical lengths. This is to prevent the possibility of fire occurring when shredding batteries.

[0130] When the reaction distance between the positive electrode current collector and the negative electrode current collector is less than 10 mm, and the battery fragments are reduced by heat treatment, a composition can be obtained in which lithium reacts with aluminum and a lithium compound is bonded to the surface of the valuable metal recovery alloy. Specifically, when the distance is 10 mm or more, there is a problem in that the lithium in the aluminum, positive electrode material, electrolyte, and negative electrode material does not react with the aluminum and volatilizes, reducing the purity of the reaction between aluminum and lithium.

[0131] <Experimental Example 1> 1. Step of preparing the valuable metal recovery composition. Prepare a cell, module, or pack of a used electric vehicle battery containing a lithium-ion positive electrode material, a graphite negative electrode material, an aluminum current collector, a separator membrane, an electrolyte, and a copper current collector. After freezing the used battery at -30°C or below and then crushing it, or after discharging it under saltwater discharge or electrical discharge conditions, crush the used battery using a shredder equipped with a method under atmospheric or inert gas conditions so that the longest horizontal and vertical length is 100 mm or less.

[0132] After obtaining the valuable metal recovery composition using the method described above, the crushed battery fragments were heat-treated at 1,300°C under an oxygen partial pressure of 0.5% to perform a reduction process. After the reduction process, a valuable metal recovery composition was produced, consisting of a core portion containing valuable metals and a shell portion containing a lithium-containing compound on the core portion, as described above.

[0133] Table 1 below shows the components and content of the valuable metal recovery composition produced by the method described above.

[0134] The components and their contents in Table 1 below were measured using quantitative analytical methods such as ICP-OES and C / S analysis equipment.

[0135] [Table 1]

[0136] 2.1 Primary Magnetic Separation Stage A valuable metal recovery composition that had undergone a high-temperature reduction process was separated into magnetic and non-magnetic materials using a magnetic separator with a magnetic force of 3000 gauss.

[0137] Experimental Example 2_1 in Table 2 below shows the components and content of magnetic and non-magnetic materials separated by a 3000 Gauss magnetic separator.

[0138] [Table 2]

[0139] Looking at Table 2 above, in the case of magnetic materials separated by magnetic separation as in Experimental Example 2_1, it was confirmed that those containing valuable metals such as NCM metals had high content of Li, Ni, Co, and Mn. In the case of particles separated into non-magnetic materials by magnetic separation as in Experimental Example 2_2, it was confirmed that those separated with a large proportion of Li, Al, and graphite particles had high content of C.

[0140] 3_1. Flotation sorting stage As in Experimental Example 2_2, the non-magnetic materials separated by magnetic separation were subjected to flotation separation using the Denver Sub_A flotation equipment of Experimental Example 3_1, with a mineral solution concentration of 30%, an impeller rotation speed of 500 rpm, kerosene at 0.1 ml / 100 g, and MIBC at 0.1 ml / 100 g.

[0141] Through the flotation process described above, the lighter graphite powder floated to the top of the equipment, and the graphite was recovered by separating it.

[0142] Table 3 below shows the components and content of the product after undergoing the flotation separation process.

[0143] [Table 3]

[0144] Looking at Table 3 above, we can see that the carbon content of the material suspended in the Overflow (O / F) was 92.5%, which is a significant increase compared to the initial battery shredder's carbon content of 35.07% and the raw material separated into non-magnetic material through magnetic separation and fed into the flotation separator's carbon content of 75.30%. Furthermore, the carbon content of the precipitate remaining in the Underflow (U / F) was 5.75%, indicating that most of the hydrophobic carbon was recovered as suspended matter. Additionally, looking at the lithium content ratio between suspended matter and precipitate, we can see that most of the lithium did not float but remained in the precipitate, allowing for efficient separation of carbon and lithium through flotation. Also, given the high aluminum content of the precipitate, it is judged that most of the lithium remained in the precipitate in the form of LiAlO2. Additionally, most of the copper did not float but remained in the precipitate, with a content of 18.04%.

[0145] 4. Grinding stage and secondary magnetic separation stage 2. The magnetic material that has undergone the magnetic separation stage is then pulverized using an Attrition Mill, a vertical stirring mill, at 500 rpm, with an impeller tip speed of 2.8 m / sec, a pulverization time of 60 minutes, and a soil content of 30% by weight. As described above, it was confirmed that the valuable metal recovery composition, which consists of a core part containing a valuable metal and a shell part containing a lithium-containing compound placed on the core part, separates from the core part as it undergoes the pulverization process.

[0146] Table 5 below shows the components and content of the resulting material after separating the magnetic material, including the core and shell portions, according to particle size.

[0147] [Table 4]

[0148] As can be seen in Table 5 above, in order to separate the alloy core containing valuable metals from the lithium compound after the crushing process, a 3000 gauss magnetic separator was used to separate the magnetic and non-magnetic materials. The results confirmed that Experimental Example 4_1, which is the core containing valuable metals, contains excessive amounts of Ni, Co, and Mn. Experimental Example 4_2, which was separated into non-magnetic materials, is the result of crushing the shell containing lithium, and it was confirmed that it has a high lithium content. In the product recovered as magnetic products by magnetic separation, the shell, which is in oxide form, is crushed during the crushing process, and the flexible core is continuously crushed inside the crusher, and as it is rolled into a plate shape, the particle size becomes larger than the initial particle size and the thickness becomes thinner. Conversely, because the shell is in oxide form and is highly brittle, the crushing time increases and the crushing continues, causing the particle size to decrease.

[0149] 5.2 Separation Stage Experimental Example 4_1, after undergoing the grinding stage, can also be separated by particle size separation using the difference in grinding characteristics between the alloy core and the oxide compound shell. However, it is more preferable to perform secondary separation through a magnetic separation process using a magnetic force strength of 3000 Gauss, taking advantage of the magnetic properties of the alloy core. In this case, when separation is performed using magnetic separation, the recovery rate of valuable metals from the core can be increased compared to particle size separation. When particle size separation is applied, separation must be performed using a mesh with a mesh size of 75 μm or 45 μm. In this case, coarse particles are recovered as NCM alloy and fine particles are recovered as Li oxide.

[0150] 6. Drying stage The magnetic material containing Ni, Co, and Mn, the non-magnetic material containing Li, and the graphite, separated through the aforementioned steps, were dewatered to reduce their moisture content to 30% using a drum-type dewatering machine or a centrifugal dewatering machine. After that, they were dried to a moisture content of 5% or less using hot air at 100-200°C and then recovered.

[0151] Table 5 below shows the components and content of the final product recovered through the stages described above.

[0152] [Table 5]

[0153] As can be seen in Table 5 above, valuable metal alloys with Ni, Co, and Mn as the main components can be recovered from magnetic materials separated through magnetic separation, crushing, and magnetic separation stages, as in Experimental Example 4_1. Lithium compounds, with lithium as the main component, can be recovered from the total amount of non-magnetic materials separated through magnetic separation, crushing, and magnetic separation stages, as in Experimental Example 4_2, and the material precipitated through flotation, as in Experimental Example 3_2. Graphite can be recovered by separating the suspended material through flotation, as in Experimental Example 3_1. Thus, it was confirmed that by going through the battery processing method described above, valuable metal alloys containing valuable metals such as Ni, Co, and Mn can be recovered, and at the same time, lithium compounds with a high lithium content can be separated, thereby increasing the recovery rate of the valuable metals Li, Ni, Co, and Mn. Furthermore, it was confirmed that the recovery rate of graphite that can be used as a negative electrode material can be increased by separating graphite separately.

[0154] <Experimental Example 2>: Changes in the composition of magnetic and non-magnetic materials due to changes in magnetic field strength Table 6 below shows the changes in the composition of magnetic and non-magnetic materials due to changes in magnetic field strength during primary magnetic separation.

[0155] [Table 6]

[0156] Referring to Table 6 above, when examining the changes in the composition of magnetic and non-magnetic materials due to changes in magnetic force strength during primary magnetic separation, at weak magnetic force strengths of 500 and 1000 gauss (G), the grade of the NCM cathode material recovered as a magnetic product is high, but the recovery rate (Dist.) is low at 90% or less, resulting in low Li content and recovery rate. However, at 2000 gauss or higher, it can be confirmed that the majority of the NCM cathode material is recovered as magnetic material.

[0157] <Experimental Example 3>: Secondary magnetic separation after controlling grinding conditions Table 7 below shows the results of separating the magnetic and non-magnetic materials after primary magnetic separation, crushing the magnetic material, and then using a 3000 Gauss magnetic separator again.

[0158] In this study, a vertical agitation ball mill (Attrition Mill) was used as the grinder. The grinding conditions were RPM 500 (Tip Speed ​​2.65 m / sec), the grinding container size was 1 L, the solid content concentration was 30%, and the grinding time ranged from 0 to 90 minutes. Magnetic and non-magnetic materials were analyzed for each grinding time.

[0159] [Table 7]

[0160] Looking at Table 7 above, at point 10, which is the initial stage of pulverization, only a portion of the lithium compound in the shell coating the NCM alloy was pulverized and recovered as magnetic material. The recovery rate of the NCM alloy was only at levels of Ni 86%, Co 87%, and Mn 85%. However, when the pulverization time reached 30-60 minutes, it could be confirmed that the recovery rates of Ni, Co, and Mn exceeded 90%. Furthermore, when the pulverization time exceeded 60 minutes and then 90 minutes, most of the lithium compound was pulverized and recovered as non-magnetic material with a high recovery rate of 91%. However, after the shell portion of the core NCM alloy was completely removed, it was rolled into a plate-like shape due to its flexibility, and was continuously over-pulverized, causing the plate-like particles to break again into fine powder particles. This resulted in the particles becoming excessively fine, and the influence of magnetic force on individual particles was reduced. As a result, the finely pulverized NCM alloy was no longer recovered as magnetic material during magnetic separation, even if it was magnetic, and this resulted in a decrease again to below 85%, the recovery rate for Ni, Co, and Mn.

[0161] Although preferred embodiments have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concepts defined in the following claims also fall within the scope of the present invention.

Claims

1. The stage of preparing the product by treating the crushed material recovered from waste batteries with high-temperature reduction heat treatment; A step of magnetically separating the heat-treated product into a first magnetic material and a first non-magnetic material; The steps of crushing the first magnetic material to separate it into a second magnetic material and a second non-magnetic material; and A battery processing method comprising the step of flotation sorting the first non-magnetic material.

2. The step of preparing the product by subjecting the crushed material recovered from the aforementioned waste battery to a high-temperature reduction heat treatment is as follows: Preparing the battery; The step of crushing the battery as battery fragments; and The battery processing method according to claim 1, further comprising the step of heat-treating the crushed battery material in a temperature range of 600 to 1,500°C.

3. The battery processing method according to claim 2, wherein the heat treatment step is performed at an oxygen concentration of 0.1 to 2.0 vol%.

4. The first magnetic material includes a valuable metal alloy containing a valuable metal, The battery processing method according to claim 1, wherein at least a portion of the valuable metal alloy is a core-shell structure in which a lithium compound is disposed in at least a portion of the surface of the valuable metal alloy.

5. The battery processing method according to claim 1, wherein the second non-magnetic material comprises at least one of a lithium-containing compound and graphite.

6. The battery processing method according to claim 1, wherein the magnetic separation step is performed within a magnetic force strength range of 1,000 to 5,000 Gauss.

7. The battery processing method according to claim 1, further comprising the step of additionally separating the first magnetic material based on a particle size of 50 to 70 μm.

8. The battery processing method according to claim 1, wherein the step of crushing the magnetic product among the magnetically separated products to separate the second magnetic material and the second non-magnetic material is performed in a shear force range of 1 to 5 m / sec.

9. The battery processing method according to claim 1, wherein the step of crushing the magnetic product among the magnetically separated products to separate the second magnetic material and the second non-magnetic material is performed for 20 to 80 minutes.

10. The step of crushing the magnetic material among the magnetically separated products to separate the magnetic and non-magnetic materials is as follows: The battery processing method according to claim 1, wherein the magnetic product is crushed and then processed by one of particle size separation, flotation separation, and magnetic separation.

11. The battery processing method according to claim 10, wherein the particle size separation is performed based on a particle size of 70 to 80 μm.

12. The battery processing method according to claim 10, wherein the floating separation step separates floating matter containing graphite from precipitates containing valuable metals.

13. The precipitate is separated by magnetic force to recover the substance containing valuable metals. The battery processing method according to claim 11, wherein the recovered material is crushed together with the magnetic product.

14. After the step of crushing the magnetic material among the magnetically separated products to separate the magnetic and non-magnetic materials, The battery processing method according to claim 1, comprising the step of drying the final product.

15. The battery processing method according to claim 14, wherein the step of drying the final product is carried out in a temperature range of 80 to 200°C.

16. In the stage of preparing the product by subjecting the crushed material recovered from the aforementioned waste batteries to high-temperature reduction heat treatment, At least a portion of the aforementioned products is Core portion containing a valuable metal recovery alloy; and The battery processing method according to claim 1, comprising a valuable metal recovery composition comprising a shell portion containing a lithium compound disposed on the core portion.

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