Patent Application
20250055053
The present exemplary embodiments relate to recycling of waste battery components, and more particularly, to a method of producing concentrated metals from waste batteries, and more particularly, to a valuable metal recovery alloy, a valuable metal recovery composition, and a method of recovering a valuable metal.
A problem of disposing of secondary batteries, such as waste batteries from electric vehicles, is emerging around the world. Secondary batteries, especially lithium-ion batteries, have fire problems due to organic solvents, explosive substances, and heavy metals such as Ni, Co, Mn, and Fe. Accordingly, the recovery and recycling process for lithium-ion batteries after the lithium-ion batteries are disposed of has become a very important issue.
Secondary batteries are primarily made of copper (Cu) and aluminum (Al) used as a current collector, lithium (Li), nickel (Ni), cobalt (Co), and manganese (Mn)-containing oxide constituting the cathode, and graphite used as an anode, and are composed of a separator that separates the cathode and the anode, and an electrolyte injected into the separator. The electrolyte may be composed of a solvent and a salt, and the solvent may adopt a mixture of carbonate organic substances such as ethylene carbonate and propylene carbonate, and the salt may adopt, for example, Lithium hexafluorophosphate (LiPF6).
For recycling of the batteries of the secondary battery, such as battery cells, battery modules, and battery packs, a black powder in which the cathode and the anode are mixed is extracted from waste batteries, which are used batteries through a shredding process, a pulverizing process, a specific gravity sorting process, and a magnetic sorting process. The black powder contains, for example, oxides of nickel, cobalt, manganese, lithium, aluminum, and oxygen as the cathode and some impurities such as graphite and mixtures thereof, aluminum and copper as the anode.
A method of recovering the valuable metal from the black powder is largely divided into a wet process and a dry process. In the wet process, through leaching-solvent extraction-lithium production, NiSO4, CoSO4, MnSO4, and Li2CO3 are produced. The biggest problem when processing the black powder through the wet process is that the graphite, which is the cathode contained in the black powder, is not dissolved in a strong acid atmosphere, so the leaching process takes a long time, and the real yield decreases as the black powder is separated along with the graphite.
In addition, the dry process which is a process of removing aluminum from slag through a high temperature dry process of the black powder, may produce Ni—Co—Mn—C alloy. In the dry process, while CO or CO2 gas is generated by reducing the Ni—Mn—Li—Al—O oxide in the black powder by utilizing graphite and oxygen blowing is utilized at a high temperature, for example, 1400° C. to 1600° C., Ni—Co—Mn alloy and lithium and aluminum in slag may be removed. The separated Ni—Co—Mn alloy may undergo the same wet process. Through the leaching-solvent extraction process in the wet process, NiSO4, CoSO4, and MnSO4, are produced, and the carbon is dissolved in the alloy, so the time required for the leaching process is reduced to approximately 70% compared to when the black powder is applied.
However, in the above process, not only the valuable metals lithium and aluminum are consumed as slag, but the lithium becomes impossible to recover. In addition, excessive carbon dioxide may be generated due to the blowing of oxygen to remove graphite in the black powder introduced into the high-temperature dry process, which may cause environmental problems.
Therefore, in order to solve the environmental problem, development of a high-temperature melting reduction process that can minimize carbon dioxide generation, minimize the exhaustion of lithium, a valuable metal, and perform production with a carbon content of 10% or less in the Ni—Co—Mn alloy, and proportions of alloyed components are required.
A technical object to be solved by the present invention is to provide a valuable metal recovery alloy which minimizes generation of carbon dioxide in a black powder, provides a high concentration degree of a valuable metal, prevents environmental pollution, and provides a high recovery rate of the valuable metal.
Another technical object to be achieved by the present invention is to provide a valuable metal recovery composition having the advantage.
Yet another technical object to be achieved by the present invention is to provide a method of recovering a valuable metal for providing the valuable metal recovery alloy having the advantage.
According to an exemplary embodiment of the present invention, based on 100 wt % of the total composition of an alloy, the valuable metal recovery alloy may include a valuable metal of 45 wt % and a remainder which is impurities, and the valuable metal recovery alloy may satisfy Equation 1 below.
In an exemplary embodiment, the value metal may be 70 wt % or more. In an exemplary embodiment, the valuable metal recovery alloy may include lithium (Li) of 0.01 to 5 wt %. In an exemplary embodiment, an XRD peak value has at least one diffraction peak among 2θ=44°±1°, 2θ=51.5°±1.5°, and 2θ=75.5°±1.5°.
In an exemplary embodiment, the valuable metal recovery alloy may satisfy Equation 2 below.
In an exemplary embodiment, the valuable metal recovery alloy may include copper (Cu) of 0.02 wt % or more. In an exemplary embodiment, the copper (Cu) may be bound to nickel (NiO among the valuable metals to form an alloy.
In an exemplary embodiment, the valuable metal recovery alloy may include carbon (C) of 0.1 to 10 wt %. In an exemplary embodiment, the valuable metal recovery alloy may include aluminum (Al) of 0.25 to 30 wt %. In an exemplary embodiment, the valuable metal may include at least one of lithium (Li), cobalt (Co), nickel (Ni), aluminum (Al), and manganese (Mn).
According to another exemplary embodiment of the present invention, a valuable metal recovery composition may include: a valuable metal recovery alloy; and a lithium compound, and a lithium content of the composition may be 0.1 to 10 wt %, and a content of a valuable metal in the composition including the lithium content may be 45 wt % or more. In an exemplary embodiment, the valuable recovery alloy may satisfy Equation 1 below.
In an exemplary embodiment, the lithium compound may be bound to a part of the surface of the valuable metal recovery alloy. In an exemplary embodiment, the lithium compound bound to a part of the surface of the valuable metal recovery alloy may be separated by external force.
In an exemplary embodiment, the valuable metal recovery composition may include a carbon-based material. In an exemplary embodiment, the valuable metal recovery composition may include aluminum (Al) of 10 to 30 wt %. In an exemplary embodiment, the valuable metal may include at least one of lithium (Li), cobalt (Co), nickel (Ni), aluminum (Al), and manganese (Mn).
According to yet another exemplary embodiment of the present invention, a valuable metal recovery method may include: preparing a cell-based battery or battery shredding material; dry heat-treating the shredding material, and separating the heat-treated shredding material by at least one of particle size separation and magnetic separation, and the dry heat-treating of the shredding material may involve a heat treatment condition for performing a high-temperature reduction reaction at 900 to 1800° C. without going through a melting step, the heat-treatment condition may satisfy an operating reference temperature of Equation 3 below, and a lithium content is 0.1 to 10 wt % based on 100 wt % of a total composition of a valuable metal recovery composition including a valuable metal recovery alloy and a lithium compound, and a content of a valuable metal in the composition including the lithium content may be 70 wt % or more, and may be recovered from a remainder which is impurities.
In an exemplary embodiment, the battery shredding material may include aluminum (Al) and copper (Cu). In an exemplary embodiment, the battery shredding material may include aluminum (Al) of 0.5 to 30 wt %. In an exemplary embodiment, the battery shredding material may include copper (Cu) of 2.25 wt % or more.
In an exemplary embodiment, in the separating of the heat-treated shredding material by at least one of particle size separation and magnetic separation, the magnetic separation may be first performed, and then the particle size separation may be performed. In an exemplary embodiment, based on a total composition of 100 wt % of the valuable metal recovery alloy, the valuable metal recovery alloy may include lithium (Li) of 0.1 to 10 wt %, valuable metal of 45 wt % or more, and a remainder which is impurities.
In an exemplary embodiment, the valuable metal recovery method may further include, before the preparing of the battery shredding material, freezing a battery. In an exemplary embodiment, the freezing of the battery may be performed by cooling the battery at −150° C. to −60° C.
In an exemplary embodiment, the freezing of the battery may be performed by cooling the battery at −60° C. to −20° C. under a vacuum atmosphere condition of 100 torr or less. In an exemplary embodiment, the dry heat-treatment may be performed under at least one atmosphere of reducing gas and inert gas. In an exemplary embodiment, in the dry heat-treatment, an average oxygen partial pressure may be 0.01 to 1 atm.
In an exemplary embodiment, the content of the valuable metal of the valuable metal recovery alloy may be concentrated by 150 to 500 wt % compared to the content of the valuable metal of the shredding material. In an exemplary embodiment, in the dry heat-treatment, a lithium compound may be generated.
In an exemplary embodiment, the lithium compound may be bound to a part of the surface of the valuable metal recovery alloy. In another exemplary embodiment, the lithium compound bound to a part of the surface of the valuable metal recovery alloy may be separated by external force.
In an exemplary embodiment, components of the battery shredding material may include nickel (Ni) of 5 to 40 wt %, cobalt (Co) of 1 to 15 wt %, manganese (Mn) of 1 to 15 wt %, lithium (Li) of 0.5 to 5 wt %, and a remaining amount of impurities, and components of the valuable metal alloy may include nickel (Ni) of 10 to 60 wt %, cobalt (Co) of 5 to 20 wt %, manganese (Mn) of 1 to 20 wt %, lithium (Li) of 3 to 15 wt %, and a remaining amount of impurities.
According to an exemplary embodiment of the present invention, a valuable metal recovery alloy is provided that can minimize generation of carbon dioxide, and maximize recovery of a valuable metal by reducing a carbon content from a battery shredding material.
According to another embodiment of the present invention, a valuable metal recovery composition is provided, which has the advantage.
According to yet another embodiment of the present invention, provided is a method of recovering a valuable metal for providing the valuable metal recovery alloy having the advantage.
Terms including first, second, and third are used for describing various arts, components, regions, layers, and/or sections, but are not limited thereto. The terms are only used to distinguish any part, component, region, layer, or section from the other part, component, region, layer, or section. Accordingly, the first part, component, region, layer, or section described below may be mentioned as the second part, component, region, layer, or section within the range without departing from the range of the present invention.
Special terms used herein is for the purpose of describing specific exemplary embodiments only and are not intended to be limiting of the present invention. The singular forms used herein include plural forms as well if the phrases do not clearly have the opposite meaning. “Including” used in the specification means that a specific feature, region, integer, step, operation, element and/or component is embodied and other specific features, regions, integers, steps, operations, elements, and/or components are not excluded.
When any part of or referred to as being “on”, “over” the other part, which might be directly on or over the other parts or may be a different part involves therebetween. On the contrary, when any part is mentioned as being “directly on” the other parts, the other part is not interposed therebetween.
Unless defined otherwise, all terms including technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the art to which the present invention belongs. Commonly used predefined terms are further interpreted as having a meaning consistent with the relevant technical literature and the present disclosure and are not to be construed as ideal or very formal meanings unless defined otherwise.
Hereinafter, an exemplary embodiment of the present invention will be described in detail. However, this is presented as an example, and the present invention is not limited thereto, and the present invention is just defined by the scope of claims to be described below.
Referring to
In an exemplary embodiment, the valuable metal recovery alloy may satisfy Equation 1 below.
Equation 1 above is a content ratio of carbon to nickel, and a value of Equation 1 above may be 0.02 to 7, and specifically, may be 0.02 to 6, and more specifically, may be 0.02 to 3. The content ratio of the carbon to the nickel satisfies a range of Equation 1 above, so there is an advantage in that it is excellent in terms of reduction of a generation amount of carbon dioxide and efficiency of a wet reaction.
When the value of Equation 1 above is larger than 7%, there is a problem that a reaction speed is very low, and when the value of Equation 1 above is larger than 6%, the carbon is saturated in the nickel, so evaluation is difficult, and when the value of Equation 1 above is larger than 3%, there is a problem in that the amount of residual alloy remaining after reaction is excessively large. When the value of Equation 1 above is smaller than 0.02%, a ratio of oxygen increases depending on an oxygen partial pressure, causing the loss of lithium, which will be described later, and reducing efficiency in a wet reaction. In an exemplary embodiment, lithium (Li) among the valuable metals may be included in the range of 0.01 to 5 wt %
There is an advantage in that the Li recovery rate may be maximized during a Li smelting process because the lithium satisfies the above range. When the lithium deviates from an upper limit value of the range, there is a problem in that recovery rates of Ni and Co decrease, and when the lithium deviates from a lower limit value of the range, the Li recovery rate decreases during the Li smelting process, and a process cost increases.
In an exemplary embodiment, the valuable metal recovery alloy may contain copper (Cu) of 0.02 wt % or more. Specifically, the valuable metal recovery alloy may be included in the range of 0.1 to 15 wet %. When the content of the copper deviates from the upper limit value of the above range, there is a problem of the process cost due to an increase in precipitation amount of CuSO4, and when the content of the copper deviates from the lower limit value of the above range, it is difficult to produce low melting point Ni—Co—Mn, which increases the amount of unreacted material.
In an exemplary embodiment, the copper may form an alloy by combining with nickel (Ni) among the valuable metals. In an exemplary embodiment, the nickel may be included in the range of 5 to 40 wt %. When the nickel deviates from the upper limit value of the above range, there is a problem of a decrease in leaching speed due to the generation of nickel carbide (Ni3C), and when the nickel deviates from the lower limit value of the above range, there is a problem of reduced Ni recovery rate in leaching and solvent extraction.
In an exemplary embodiment, the valuable metal recovery alloy may include carbon (C) in the range of 0.1 to 10 wt %. When the carbon satisfies the above range, a real yield may be increased and the processing time in the wet process may be decreased. Specifically, the carbon may be included in the range of 1 to 7 wt %.
When the carbon deviates from the upper limit value of the above range, there is a case where the anode remains in an unreacted state, and alloying does not occur properly, and there is a problem in that the carbon remains in the form of the value metal oxide in the cathode. When the carbon deviates from the lower limit value of the above range, there is a problem in that lithium may be lost due to a high temperature.
In an exemplary embodiment, the valuable metal recovery alloy may include aluminum (Al) in the range of 0.25 to 30 wt %. When the content of the aluminum deviates from the upper limit value of the above range, there is a problem in a decrease of the Ni and Co recovery rates in the leaching and solvent extraction process, and when the content of the aluminum deviates from the lower limit value of the above range, it is difficult to produce LiAlO2, which decreases the Li recovery rate.
Referring to
It can be seen that the valuable metal recovery alloy includes at least one of the peak intensity values of the azimuth angles to include carbon and nickel, and specifically, it can be seen that a content ratio of oxygen to the nickel may be included in the scope of the present invention.
In an exemplary embodiment, the valuable metal recovery alloy may satisfy Equation 2 below.
Equation 2 above which is derived from a relational equation for copper and nickel satisfies Equation 1 above to provide a high valuable metal recovery alloy while minimizing carbon dioxide generation.
Referring to
In an exemplary embodiment, the lithium content in the composition may be included in the range of 0.1 to 10 wt %. Specifically, the lithium content in the composition may be included in the range of 8 to 10 wt %.
The content of the lithium in the composition may include a content of lithium included in the lithium compound in addition to the valuable metal recovery alloy. When the lithium content deviates from an upper limit value of the above range, there is a problem in that lithium is lost in a process of oxygen burns carbon rather than an oxygen-free reaction, making recovery of lithium, one of the expensive metals in the battery, impossible. When the lithium content deviates from a lower limit value of the above range, there is a problem such as a decrease in recovery rate of the valuable metal.
The lithium compound may be, for example, lithium-aluminum oxide.
The lithium-aluminum oxide may be a lithium-aluminum compound, for example, lithium-aluminate (LiAl2O3). The lithium-aluminum oxide may be combined into an oxide through physical or chemical bonding between lithium contained in the composition, and the aluminum.
For example, when recovering the valuable metal from the waste battery, the valuable metal in the waste battery exists in the form of oxide, and reduction occurs by graphite in the anode at a process temperature and an oxygen atmosphere of the present invention described later. At this time, copper as a current collector is melted and exists in a liquid state and may serve to agglomerate the reduced valuable metal. Aluminum in the current collector and other current collectors participates in a partial reduction reaction with cathode oxide, and the remainder reacts with lithium and may remain as lithium-aluminum oxide.
Referring to
In an exemplary embodiment, the lithium compound partially bound to the surface of the valuable metal recovery alloy may be separated by using the wet process. In another embodiment, the lithium compound may be separated from the valuable metal recovery alloy by mechanical or physical external force. As such, the valuable metal recovery alloy may be recovered from the valuable metal recovery composition, and at the same time, the lithium compound may be separated, so the amount of lost lithium may be reduced because the recovery rate of lithium is high.
In an exemplary embodiment, the valuable metal recovery composition may include a carbon-based material. For example, the carbon-based material may be a carbon (C) element. The carbon content may range from 1% to 7%. When the carbon content satisfies the above range, there is an advantage in optimizing wet processing of the valuable metal recovery composition.
When the carbon content deviates from an upper limit value of the above range, there is a problem of a decrease in leaching speed due to the generation of nickel carbide (Ni3C), and when the carbon content deviates from a lower limit value of the above range, contents of other impurities such as Si increase, resulting in the recovery rate of valuable metals such as Ni and Co in solvent extraction after the leaching progress.
In an exemplary embodiment, the valuable metal recovery composition may include aluminum (Al) in the range of 10 to 30 wt %. When the content of the aluminum satisfies the above range, a lithium compound may be formed through physical or chemical bonding with lithium, and as the lithium compound is separated in the future, there is an advantage in increasing the yield of lithium.
When the content of the aluminum deviates from an upper limit value of the above range, there is a problem of Ni and Co solvent extraction and crystallization process costs and decreased Ni and Co recovery rates due to excessive production in the leaching and solvent extraction process. When the aluminum content deviates from a lower limit value of the above range, there is a problem of poor production of Li—Al—O oxide due to insufficient aluminum content.
Referring to
The preparing of the battery shredding material (S100) is a step of shredding and preparing a material which becomes a base material of the battery shredding material or preparing a shredded material itself. The base material of the battery shredding material may include a battery which reaches the end of the life, positive electrode materials such as scraps, jelly rolls, and slurries constituting the waste battery, defective products generated during a production process, residues inside the production process, waste materials in a manufacturing process of a waste battery, e.g., a lithium ion battery, such as generated debris. The material which is shredded itself may be, for example, a shredded product itself such as the black powder.
In an exemplary embodiment, the preparing of a cell-based battery or battery shredding material (S100) may further include shredding the material which becomes the base material of the battery shredding material when the material which becomes the base material of the battery shredding material is shredded and prepared. A ground material of the base material of the battery shredding material may be obtained by using a shredder. The shredding as a non-limiting example may include crushing the waste battery by applying physical or mechanical force and pulverizing the waste battery into fine powder. In the shredding step, some impurities having a large size among impurities such as aluminum (Al), copper (Cu), iron (Fe), and plastic may be separated in a configuration included in the waste battery. A state in which the large impurities are separated is referred to as the black powder, and the battery shredding material such as the black powder may be produced through the shredding step.
In an exemplary embodiment, the battery shredding material may include aluminum (Al), manganese (Mn), lithium (Li), copper (Cu), cobalt (Co), nickel (Ni), carbon (C), and remaining impurities. In an exemplary embodiment, the black powder may contain 5 to 40 wt % of nickel (Ni), 1 to 20 wt % of cobalt (Co), 1 to 15 wt % of manganese (Mn), 0.5 to 5 wt % of lithium (Li), 10 to 70 wt % of carbon (C), 0.0001 to 20 wt % of aluminum (Al), and 0.0001 to 20 wt % of copper (Cu), and the total amount of impurities such as iron (Fe) and phosphorus (P) may be less than 10 wt %. The components of the black powder may vary depending on the ratio of nickel, cobalt, and manganese, and the nickel, cobalt, and manganese may be adjusted by a cathode oxide in the lithium secondary battery when the lithium secondary battery is shredded.
In an exemplary embodiment, the shredding of the material which becomes the base material of the battery may be a shredding method using at least one of shear, compression, and tensile for. Specifically, in the shredding step, the material may be shredded by, for example, at least one of a hammer mill, a ball mill, and an agitated ball mill. By the hammer mill, at least one step of disassembly, punching, and milling may be performed, and this is a non-limiting example, and it is apparent that the material may be shredded using various types of crushing or shredding devices, for example, an industrial shredder.
In an exemplary embodiment, a particle size of the battery shredding material may be within 50 mm, and specifically within 30 mm. When the particle size is larger than the above range, more energy needs to be supplied in a heat treatment step to be described below, so there is an uneconomical problem.
In an exemplary embodiment, the method may further include, before the shredding of the material that becomes the base material of the battery shredding material, a pretreatment step to prevent explosion or detoxify the base material of the battery shredding material. The method includes the pretreatment step to remove a material with a risk of explosion, such as the electrolyte in the base material, and for example, discharge the base material such as the waste battery, thereby increasing stability and increasing recovery and productivity of the valuable metal upon performing the shredding step.
In the dry heat-treating of the shredding material (S200), the shredding material is input into a heating furnace capable of raising a temperature of the shredding material to a high temperature to raise the temperature of the shredding material to at melting point or more. The dry heat-treating of the shredding material (S200) may involve a heat treatment condition for performing a high-temperature reduction reaction without going through the melting step.
In an exemplary embodiment, the heat treatment condition may involve a heat treatment condition in the range of 900 to 1800° C. Specifically, the above range may be performed in the range of 1200 to 1800° C., more specifically in the range of 1300 to 1700° C. When the heat treatment condition deviates from an upper limit value of the above range, there is a problem of loss due to lithium vaporization, and when the heat treatment condition deviates from a lower limit value of the above range, there is a problem that sintering, and reduction of the alloy elements cannot be conducted. In the above temperature range, the reduction reaction may be performed with minimal carbon dioxide generation by burning the carbon in the shredding material to a minimum. A detailed description thereof will be described below in
In an exemplary embodiment, the dry heat-treating of the shredding material may be performed in a gas atmosphere of at least one of inert gas, carbon dioxide, carbon monoxide, and hydrocarbon gas. For example, the inert gas may include at least one of argon and nitrogen. By performing the reduction reaction of the shredding material in the gas atmosphere, the valuable metal recovery alloy containing the valuable metal contained in the shredding material as a component may be effectively recovered.
In an exemplary embodiment, a part of the gas atmosphere may contain impurities including a residual amount of oxygen. When the content of the oxygen among the impurities is high, carbon dioxide may be formed in combination with component of the shredding material during the reduction reaction, and as a result, the carbon dioxide is gasified together with lithium, making recovery difficult.
In an exemplary embodiment, the average oxygen partial pressure may be in the range of 0.01 to 1 atm in the dry heat treatment step (S200). Specifically, when the partial pressure of the oxygen is higher than the above value, there is a problem in that lithium is lost at a local high temperature state and a large amount of carbon dioxide is generated. When the partial pressure of the oxygen is lower than a lower limit value of the above range, there is a problem of lower Li recovery rate due to poor production of LiAlO2.
Specifically, in the dry heat treatment step (S200), the valuable metal recovery composition as a valuable metal recovery composition obtained by alloying components such as nickel, cobalt, manganese, and lithium-containing oxides in the shredding material may include valuable metals and remaining impurities. The valuable metal composition may include, for example, aluminum (Al), manganese (Mn), lithium (Li), copper (Cu), cobalt (Co), nickel (Ni), carbon (C), and remaining impurities, and a detailed description thereof is the same in a range which does not contradict to the valuable metal recovery composition described above in
The valuable metal recovery composition may include a lithium compound, and the lithium compound may be produced through the reduction reaction. For example, the lithium compound may be lithium-aluminate (2LiAlO2), and a reaction formula for this is as follows.
Li2O+Al2O3=2LiAlO2 [Reaction Formula 1]
Referring to
Equation 3 shows relationships between upper limit and lower limit values of temperatures of contents of copper and aluminum. Specifically, there is an effect of promoting alloy generation because a melting point is low compared to nickel, cobalt, and manganese (Ni—Co—Mn) when adding copper based on Equation 3 above. In addition, the addition of aluminum has an effect of reducing a stabilization temperature when generating a lithium compound, for example, lithium-alumina (LiAlO2).
(1550±250)×exp((−0.0005×[Cu])+(−0.01×[Al])) in which (1550)×exp((−0.0005×[Cu])+(−0.01×[Al])) of Equation 3 above means an operating reference temperature. At the operating reference temperature, by considering securing a real yield of copper alloy and a real yield of lithium, the maximum and minimum temperature management range may have a temperature management range as (1550±250)×exp((−0.0005×[Cu])+(−0.01×[Al])).
In Equation 3 above, (1550+250)×exp((−0.0005×[Cu])+(−0.01×[Al])) as an upper limit temperature is an upper limit temperature for preventing vaporization of lithium, and in Equation 3 above, (1550−250)×exp((−0.0005×[Cu])+(−0.01×[Al])) is a lower limit temperature for securing a real yield through molten alloy of copper.
In an exemplary embodiment, the value of (1550±250)×exp((−0.0005×[Cu])+(−0.01×[Al])) of Equation 3 above may have a range of 1050 to 1800° C. When the value of Equation 3 above deviates from an upper limit value, there is a problem of reduced Li recovery rate due to evaporation of Li due to exposure to high temperature, and there is a problem of deviating from the commercial use temperature range of a refractory material. When the value of Equation 3 above deviates from a lower limit value, there is a problem of inferior generation of valuable metal due to a decrease in the reaction between Ni—Co—Mn oxide and carbon in the anode, and there is a problem that copper cannot be melted.
In an exemplary embodiment, the content of the aluminum in the valuable metal recovery composition may be 0.25 to 30 wt %. The addition of the aluminum has an effect of reducing a stabilization temperature when generating a lithium compound, for example, lithium-alumina (LiAlO2).
When the aluminum content deviates from an upper limit value of the above range, there is a problem of reduced Li recovery rate due to generation of Li—Al—O oxide (LiAl11O17) having a high content of Al2O3. When the aluminum content deviates from a lower limit value of the above range, there is a problem of poor production of Li—Al—O oxide due to insufficient Al2O3 content.
Referring back to
In the separating of the heat-treated shredding material by at least one of particle size separation and magnetic separation (S300), the heat-treated shredding material, e.g., the valuable metal recovery alloy may be separated by at least one of the particle size separation and the magnetic separation, for example. The particle size separation method as separating the particle size according to a size or a diameter of a particle may include, for example, various methods of separating the particle size by using a sieve, for example. The magnetic separation method may separate particles through a contact with a magnetic body by using the magnetic body and may adopt various types of magnetic separation methods.
In an exemplary embodiment, the separating of the heat-treated shredding material by at least one of particle size separation and magnetic separation (S300) may be a step of separating by at least one of the particle size separation, the magnetic separation, and specific gravity separation. The specific gravity difference separation method as a method of separating the particles by considering a difference in specific gravity for each material may adopt, for example, various types of specific gravity difference separation methods, which may separate the particles based on the size of the specific gravity of the particle corresponding to a specific solvent by using the specific solvent.
In an exemplary embodiment, the separating of the heat-treated shredding material by at least one of the particle size separation and the magnetic separation (S300) includes both the step of performing the particle size separation, the magnetic separation, and the particle size separation, and the step of performing the magnetic separation to separate the valuable metal recovery alloy. In the performing of only the particle size separation, the valuable metal recovery alloy may be recovered only by separating the particle size of the valuable metal recovery composition having a particle size of the valuable metal recovery composition of 100 μm to 300 mm.
In the case of the magnetic separation, when the valuable metal recovery composition contains a material having a particle size of 100 μm or less, the valuable metal may be recovered from the valuable metal recovery composition only through the magnetic separation. In the case of the material of 100 μm or less, since the particle size is similar to that of carbon, the recovery rate of valuable metals lost only through the particle size separation may be increased through the magnetic separation.
In an exemplary embodiment, when the particle size separation and the magnetic separation are performed together, the particle size separation may be performed after the magnetic separation is performed first. By first performing the magnetic separation, it is possible to prevent the loss of the valuable metal recovery alloy from the valuable metal recovery composition of 100 μm or less.
In an exemplary embodiment, the separating of the heat-treated shredding material by at least one of particle size separation and magnetic separation (S300) may be a step of separating the shredding material from the lithium compound containing lithium. The step of separating the shredding material from the lithium compound containing lithium may be performed before or after the separating of the heat-treated shredding material by at least one of particle size separation and magnetic separation (S300).
The lithium compound may be, for example, a lithium-containing oxide, and may be separated by physical external force. For a detailed description thereof, reference may be made to the valuable metal recovery alloy of
In an exemplary embodiment, a step of freezing the battery may be further included before the step of preparing the battery shredding material (S100). It is described as above that when the base material of the battery shredding material is the battery itself, the step of shredding the battery shredding material should be performed.
When using the battery as the base material for the battery shredding material, the step of freezing the battery may be included before shredding the battery shredding material. When the battery is directly shredded, explosion or fire may occur due to the electrolyte contained in the battery. Specifically, as a specific pressure is applied to the battery, the separator is physically shredded and a high current is formed due to a short circuit, so a spark is generated, and the spark may ignite the electrolyte, resulting in the fire.
In the step of freezing the battery, the battery is frozen to suppress the ignition of the liquid electrolyte contained in the battery, and then the shredding process is performed, so that the problem due to the electrolyte ignition does not occur.
In an exemplary embodiment, the step of freezing the battery may be performed by cooling to a temperature ranging from −150° C. to −60° C. When the temperature of the frozen battery deviates from an upper limit value of the above range, the voltage remaining inside the battery does not drop to 0 V, which may cause a battery reaction due to a short circuit, and the electrolyte is not completely frozen, which is not appropriate.
When the temperature of the frozen battery deviates from a lower limit value of the above range, the electrolyte is sufficiently frozen and the battery's internal voltage also decreases to 0 V, and as a result, even if a short circuit occurs where positive and negative electrodes are in direct contact, the battery reaction does not occur, so the battery temperature decreases, so gas generation and combustion of the electrolyte do not occur. In addition, because the electrolyte is in a frozen state, the mobility of lithium ions is very low, so the current conduction characteristics due to lithium ion movement may be significantly reduced, and since vaporization of the electrolyte solution does not occur, flammable gases such as ethylene, propylene, and hydrogen may not be generated.
In the step of freezing the battery, when the temperature of the frozen battery deviates from the upper limit value of the above range, the voltage remaining inside the battery does not drop to 0 V, which may cause the battery reaction due to the short circuit, and the electrolyte is not completely frozen, which is not appropriate. When the temperature of the frozen battery deviates from the lower limit value of the above range, there is an uneconomical problem because a lot of energy must be administered for freezing.
In an exemplary embodiment, the step of freezing the battery may be performed by cooling to a temperature ranging from −60° C. to −20° C. under vacuum atmosphere conditions of 100 torr or less. The step of freezing the battery may be performed in the above temperature range, which is a temperature that may suppress the vaporization of the electrolyte solution. The vacuum atmosphere may be, for example, an inert gas, carbon dioxide, nitrogen, water, or a combination thereof.
Since the freezing step is performed by adjusting the pressure to the vacuum atmosphere of 100 torr or less, it is possible to prevent the electrolyte from reacting with oxygen by suppressing the supply of oxygen, thereby preventing explosion, and suppressing the vaporization of the electrolyte solution. Therefore, flammable gases such as ethylene, propylene, and hydrogen may not be generated.
In the step of freezing the battery, when the freezing step is performed in an air atmosphere or at a pressure exceeding 100 torr, voltage may remain in the battery, and the electrolyte is not in the frozen state in the temperature range of −60 to −20° C., and as a result, there is a problem that the electrolyte may vaporize and explode due to sparks generated when the short circuit occurs due to the residual voltage.
In this way, according to an exemplary embodiment of the present invention, there may be provided an environmentally friendly method of manufacturing the waste battery recovery alloy in which the content of the valuable metals, such as nickel, cobalt, lithium, and manganese, is concentrated by 150 to 500% compared to the constituent content of the heat-treated battery shredding material, so the valuable metal recovery rate is excellent, and carbon of less than 10% is contained, so generation of carbon dioxide may be suppressed upon a post-process.
Referring to
Referring to
Specifically, when the battery is cooled in the temperature range of −150 to −60° C., the voltage remaining slightly inside the battery, for example, 2 V to 3 V, drops to almost 0 V and converges. Therefore, it can be confirmed that even if the short circuit occurs where positive and negative electrodes are in direct contact, a battery reaction does not occur, so the battery temperature does not increase, so gas generation and combustion of the electrolyte do not occur.
To explain the present invention in more detail, examples of the present invention are described. The following example is only an example of the present invention, and the present invention is not limited to the following example.
In the experimental example of the present invention, a carbon content was measured by a combustion method using a CS analysis device (made by LECO) to analyze the carbon content. In addition, for oxygen content analysis, an oxygen content was measured using an infrared detection method using a NO analysis device (made by LECO). In addition, component analysis of inorganic substances other than carbon and oxygen was performed through ICP wet analysis.
In the experimental example of the present invention, in order to measure a particle size, a particle size analysis for each material was estimated through particle size analysis using a particle size analysis device and component analysis of the separated material through screening.
Referring to
Table 1 below shows a process oxygen fraction, an NCM shredding material amount, a recovered valuable metal alloy amount, a lithium aluminum compound amount, an unreacted material, and a process loss at process temperatures of 900, 1000, 1100, 1200, 1300, 1500, 1600, and 1700° C. based on a process oxygen fraction of 0.01 atm and copper of 25 g. In the above temperature range, the battery shredding material was put into a heat treatment furnace in an argon (Ar) gas atmosphere.
Looking at Table 1 above, it can be seen that under the same NCM shredding material amount and the same process oxygen fraction conditions, the recovered alloy amount of the valuable metal has a high value above 900° C., specifically above 1200° C. In addition, looking at the lithium aluminum compound amount, it can be confirmed that the lithium aluminum compound is included in the temperature range of 900 to 1700° C. Specifically, it can be confirmed that the lithium aluminum compound amount is large at a temperature above 1100° C., and more specifically at a temperature above 1500° C. Accordingly, it can be confirmed that there is an advantage in that the loss of lithium is reduced in the above temperature range.
Table 2 below shows the content ratio of C/Ni and the ratio of Li in the alloy according to the oxygen partial pressure in the process.
Looking at Table 2 above, the content ratio of C/Ni and the ratio of Li in the alloy according to the oxygen partial pressure in the process can be seen. It can be seen that the temperature inside a process reaction furnace increases as the amount of oxygen increases, and this can be judged to be due to the oxidation heat of carbon and oxygen.
Looking back at Table 2, it can be seen that the higher the oxygen input, the lower the C/Ni content ratio, but the loss of lithium (Li) also increases. It can be seen that when the average oxygen partial pressure in the process reactor is similar to that of the atmosphere, most of the lithium is lost, and graphite used as an anode reacts with carbon dioxide and disappears.
Table 3 below shows the amount of alloy products according to the content of copper (Cu) in the shredding material of the waste battery. After particle size separation was performed on the alloy product, the recovered valuable metal alloy amount was confirmed according to the copper content in the shredding material.
Looking at Table 3 above, when a lot of copper (Cu) is included, the characteristic of collecting reduced nickel (Ni), manganese (Mn), cobalt (Co), and aluminum (Al) while liquefying at 1500° C. As the copper content decreases, the collecting characteristics deteriorate and the size of the reduced alloy is very small, making particle size separation difficult.
It can be seen that as the content of copper (Cu) decreases at a low temperature, the recovery rate obtained through the particle size separation or magnetic separation is very low. Accordingly, it can be seen that the appropriate amount of copper input is 0.02% or more.
Referring to
Referring back to
After conducting contact-type magnetic separation using a 5000 G magnet on a sample for which the high-temperature reaction was completed, particle size separation was performed using a 250-μm sieve for the non-magnetic part, and the resulting component distribution is as shown in Table 4.
From Table 4 above, it can be seen that Ni, Co, and Mn were mainly concentrated in the magnetic portion, and Cu also formed a solid solution with the concentrated metal components. In addition, the non-magnetic separated material consists of coarse lithium aluminate and micronized graphite and can be effectively separated through the particle size separation.
Approximately 98% of the total Ni and Co present in the battery were magnetic alloys and were effectively separated. Li was found to be distributed over 70% within the alloy and lithium aluminate.
The reason is that the Li-NCM alloy in which the cathode active material is reduced exhibits magnetism, and LiAlO2 oxide is fused on the surface of the magnetic alloy melted, and then coagulated in the form of droplet. In addition, it can be seen that some LiAlO2, as a material formed when the aluminum current collector bonded to the cathode in a plate shape is oxidized in the process of reacting with lithium, also exists independently in some cases without being fused to the surface of the alloy. LiAlO2 maintaining the shape of the current collector may be separated from powdered graphite through the particle size separation.
In addition, in a different order from the above-mentioned method, when particle size separation was performed first before the magnetic separation and materials separated by 250 μm or more were further magnetically separated, the recovery rate of Ni and Co was confirmed to be approximately 78%, and the recovery rate of Li was confirmed to be approximately 60%. In this case, it can be seen that since the cathode active material in powder form, which is simply reduced and does not form the droplet, is divided into powder along with the anode active material through the particle size separation, loss of Ni, Co, and Li contained in the cathode active material occurred.
The present invention is not limited to the exemplary embodiments but may be manufactured in various different forms and it can be understood by those skilled in the art that the present invention can be executed in other detailed forms without changing the technical spirit or requisite features of the present invention. Therefore, it should be appreciated that the aforementioned embodiments are illustrative in all aspects and are not restricted.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2021-0183833 | Dec 2021 | KR | national |
| Filing Document | Filing Date | Country | Kind |
|---|---|---|---|
| PCT/KR2022/019731 | 12/6/2022 | WO |
