Method for recovering metals from used battery using bioleaf process using

Abstract

The present invention relates to a method for recovering metals from waste batteries using a bioleaching process in which a magnetic field is applied. According to the method of the invention, by applying a magnetic field to the bioleaching process, the metal recovery rate can be increased, and valuable metals can be leached. Furthermore, the present invention is environmentally friendly and has a simple and practical process compared to a dry melting process or an acid leaching process mainly used for metal recovery. Accordingly, the metal recovery method of the present invention can recover metals from wastes in the waste resource field, such as waste batteries and waste catalysts, and convert the recovered metals into resources.

Description

Technical Field

[0001] The present invention relates to a method for recovering metals from waste batteries using a bioleaching process with applied magnetic field, and more particularly, to a method for recovering metals from waste batteries, which significantly improves metal recovery efficiency through an environmentally friendly process in which a system for applying a magnetic field is combined with a bioleaching process. Background Art

[0002] As the demand for portable electronic products increases year by year, the use of secondary batteries is also steadily increasing, and this increase in demand inevitably generates a large amount of waste batteries.

[0003] Waste batteries contain harmful metals such as lead, cadmium and mercury, and use potassium hydroxide, ammonium chloride, lithium salts, sulfuric acid, organic solutions, etc. as electrolyte solutions, making the impact of aqueous batteries on the environment non-negligible. In addition, since waste batteries contain valuable metals such as silver, cobalt, nickel, zinc, manganese and lithium, there is a need to reuse waste batteries to protect the environment and effectively use limited resources.

[0004] As companies pay more attention to environmental issues, the secondary utilization industry of waste batteries is attracting attention, and the market size is expanding as the supply price of secondary battery raw materials rises and competition to attract supply chains intensifies.

[0005] The secondary utilization technology of waste batteries is divided into recycling and reuse methods. The recycling method is used to extract expensive metals from waste batteries mainly from IT equipment, and is divided into pre-processing and post-processing processes. Elimination of the risk of explosion of waste batteries, magnetic and specific gravity sorting, crushing, etc. are classified as pre-processing processes, while dry methods, wet methods, direct recovery, etc. for actual recovery and extraction of metals are classified as post-processing processes.

[0006] The reuse method is a method of applying medium and large-sized scrap batteries mainly from electric vehicles to large-sized batteries such as ESS, and since the capacity and safety of scrap batteries are inspected and then their modules are disassembled and analyzed to reuse products of a specific grade or higher, there is a restriction that it is difficult to reuse batteries that do not meet that grade.

[0007] To increase the recovery rate of spent battery materials through recycling or reuse processes, mobility companies such as Tesla and Volkswagen, secondary battery companies such as Northvolt and CATL, and chemical companies such as LG Chem and BASF are developing technologies, and Tesla is leading the market by introducing technology that can recycle about 92% of the raw materials of battery cells.

[0008] However, except for some companies leading the market, most companies involved in recycling waste batteries cannot guarantee a higher recycling rate than about 60%. In addition, the dry method mainly used has technical limitations in separating metals other than cobalt in a molten state, and the wet method using acid has the problem of environmental pollution caused by waste acid, so it is necessary to develop a technology for the secondary use of waste batteries to replace the above process or improve the above process.

[0009] As an example of research to solve the above limitations and problems, Korean Patent Publication No. 10-0796369 discloses a method for recovering valuable metals and recycling plastics from waste batteries, and describes a method for concentrating and recovering cobalt and copper, which are valuable metals with high added value, from waste lithium-ion batteries by using a dry melting method, but there is a problem that the melting of waste lithium-ion batteries requires a large amount of energy and wastes costs due to a complicated process involving melting, cooling and separation steps.

[0010] In addition, Korean Patent Publication No. 10-2022-0038416 discloses a method for recycling waste batteries by a wet process, and describes that a recycling efficiency of more than 50% can be achieved by using concentrated sulfuric acid, but the disadvantage is that the use of strong acid may cause environmental pollution.

[0011] Under such circumstances, the inventors of the present invention have studied a metal recovery method capable of obtaining a high recovery rate of valuable metals in waste batteries only through a simple and environmentally friendly process, and as a result, have completed the present invention. Summary of the invention

[0012] The object of the present invention is to provide a method for recovering metals from spent batteries in an eco-friendly and efficient manner by applying a magnetic field to the bioleaching process.

[0013] In order to achieve the above-mentioned object, the present invention provides a method for recovering metals from waste batteries, the method comprising the following steps: culturing acidophilic microorganisms in a culture medium to which a magnetic field is applied; adding crushed waste battery material to the culture medium to leach metals; and recovering the leached metals.

[0014] In the present invention, the leaching of the metal may be performed in a state where a magnetic field is applied.

[0015] In the present invention, the acidophilic microorganism may be one or more of Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans and Acidithiobacillus caldus.

[0016] In the present invention, the leached metal may include one or more of cobalt (Co), nickel (Ni), lithium (Li), and aluminum (Al).

[0017] In the present invention, the culturing step may be performed for 3 to 7 days.

[0018] In the present invention, the initial pH of the culture medium may be 1.5 to 3.5.

[0019] In the present invention, the magnetic field may be a direct current (DC) magnetic field or an alternating current (AC) magnetic field.

[0020] In the present invention, the magnetic field may be a DC magnetic field, and the magnetic field may have a magnetic flux density of 5G to 90G.

[0021] In the present invention, the magnetic field may be an alternating current magnetic field, and the magnetic field may have a magnetic flux density of 1G to 10G.

[0022] Beneficial effects

[0023] The present invention applies a system of applying a magnetic field to the bioleaching process of spent batteries, thereby providing a simpler, safer and more environmentally friendly metal recovery method than typical dry melting and acid leaching processes.

[0024] According to the present invention, the growth of microorganisms is improved by applying a magnetic field, thereby improving the recovery efficiency of metals, which can lead to the leaching of a large amount of metals from waste batteries and can minimize the loss of recyclable resources, which is economical. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1a A disk-type magnetic field applying device according to an embodiment of the present invention is schematically shown.

[0026] Figure 1b An image showing cultivation of microorganisms using the disk-type magnetic field application device according to an embodiment of the present invention.

[0027] Figure 2a A cylindrical magnetic field applying device according to an embodiment of the present invention is schematically shown.

[0028] Figure 2b An image showing cultivation of microorganisms using a cylindrical magnetic field applying device according to an embodiment of the present invention.

[0029] Figure 3 The results of measuring pH according to whether a magnetic field is applied in the embodiment of the present invention are shown.

[0030] Figure 4 An image showing a flask in which microorganisms are cultured depending on whether a magnetic field is applied in an embodiment of the present invention.

[0031] Figure 5a to Figure 5d Results of measuring leaching concentrations of cobalt (a), lithium (b), nickel (c), and aluminum (d) by using Acidithiobacillus ferrooxidans according to magnetic field types in an embodiment of the present invention are shown. DETAILED DESCRIPTION

[0032] Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which the invention belongs. Generally, the terms used herein are well known and commonly used in the art.

[0033] The present invention relates to a method for effectively recovering metals contained in waste batteries, and more particularly, to an environmentally friendly metal recovery method for improving metal recovery rate through a simple and safe process of applying a magnetic field during a bioleaching process.

[0034] Generally, waste batteries include expensive metals such as cobalt, lithium, and nickel, and these metals are very important target metals in the waste battery secondary use industry.

[0035] In order to recover metals from waste batteries, a dry method or a wet method is generally used, but the dry method produces a large amount of sulfur gas and thus causes many problems in equipment operation, and the wet method using acid uses strong acid and strong alkali solvents in the metal leaching process and thus has the disadvantage of causing very serious environmental pollution.

[0036] In order to solve the above problems, a bioleaching process has been proposed, which is a more environmentally friendly leaching method and is a wet process for recovering valuable metals using microorganisms capable of leaching metals.

[0037] Specifically, the bioleaching process is a technology that uses the following characteristics: by combining anions on the surface of microorganisms with metal cations dissolved in water, the microorganisms obtain the energy required for metabolism, and the metal ions are reduced to metals and precipitated, and when such microorganisms are used, the metal ions dissolved in water can be precipitated into solid particles and obtained.

[0038] The above-mentioned bioleaching process can solve the environmental problems caused by the dry melting method, and does not require strong acid and strong alkali solvents, and is therefore environmentally friendly because wastewater can be reduced, and has the advantages of low investment and operating costs, easy process control, and no need for advanced technical knowledge compared to other dry and wet methods. However, the bioleaching process has the limitation that the metal recovery rate is lower than other commonly used methods.

[0039] In the present invention, by applying a magnetic field to a typical bioleaching process, the recovery rate of metals is maximized, and even a small amount of valuable metals contained in waste batteries can be recovered with high efficiency, and thus, are not detected or detected only in a small amount.

[0040] In this regard, the method of recovering metals from waste batteries of the present invention may be performed by the steps of: culturing acidophilic microorganisms in a culture medium to which a magnetic field is applied; adding pulverized waste battery materials to the culture medium to leach metals; and recovering the leached metals.

[0041] In the present invention, as microorganisms applied to the bioleaching process, microorganisms capable of leaching metals from various industrial wastes can be used, and acidophilic microorganisms capable of dissolving metal oxides contained in waste batteries in a solution to form metal salts and then leaching metals through a direct or indirect oxidation reaction with the formed metal salts can be used.

[0042] Specifically, the above-mentioned microorganism can be selected from the acidophilic Acidithiobacillus genus, preferably using one or more of Acidithiobacillus ferrooxidans, Acidithiobacillus thiooxidans and Acidithiobacillus caldus, among which Acidithiobacillus ferrooxidans is most preferred.

[0043] The microorganism can first be cultured in a culture medium and prepared for the metal recovery process. In this case, a culture medium commonly used for culturing microorganisms known in the art can be used, for example a culture medium such as 9K culture medium, culture medium 271, DSMZ 882 or DSM 71 can be used.

[0044] Since the microorganisms used for metal leaching require inorganic compounds to grow as chemolithoautotrophs, it is preferred to include nitrogen, phosphorus, magnesium, etc. in the culture medium. For example, for optimal growth of the microorganisms, it is preferred to use a culture medium supplying ammonium salts, phosphates, magnesium salts, etc.

[0045] Setting the initial pH of the culture medium is important for the growth of acidophilic microorganisms and the metal extraction activity after growth. The initial pH of the culture medium may be 1.5-3.5, preferably 1.8-3.0. According to the growth of the microorganisms, the pH of the culture medium increases to a certain peak value and then decreases, and metal leaching from waste batteries can be performed at the pH peak value.

[0046] A stirrer or mixer for air injection is provided in the culture medium to promote oxygen supply for microbial growth. Stirring may be performed at a rate of 100-200 rpm, preferably 120-180 rpm. If the rate exceeds the above rate range, an appropriate amount of oxygen for growing microorganisms may not be supplied, so that the growth of the microorganisms is degraded, which may result in a reduction in metal recovery rate.

[0047] The microorganism may be cultured at a temperature of 20° C. to 40° C., preferably 25° C. to 35° C. Temperature is the factor that has the greatest influence on the metabolism and growth of the microorganism, and when cultured at a temperature outside the appropriate range, the cell concentration may be significantly reduced, which may result in a reduction in metal recovery rate.

[0048] In the present invention, the cultivation of microorganisms can be carried out under the condition of applying a magnetic field. Since the application of a magnetic field promotes the cultivation of microorganisms, the time from initial pH control to an appropriate pH range can be shortened, the leaching efficiency is maximized within this pH range, and the metal leaching activity of the microorganism is increased, thereby solving the disadvantage of the bioleaching process with low metal recovery rate. In an embodiment of the present invention, it has been confirmed that valuable metals such as Co, Ni and Li that are difficult to leach or leach at low yields in typical bioleaching processes can be recovered at high concentrations.

[0049] If the microorganism is cultured under the condition of applying a magnetic field, the growth of the microorganism is promoted, so that even if the microorganism is cultured for a relatively short time, a microorganism with excellent metal extraction activity can be cultured. Therefore, it is preferred to culture the microorganism for 3-7 days. In an embodiment of the present invention, it has been confirmed that if the microorganism is cultured in a culture medium to which a magnetic field is applied, the pH of the culture medium reaches a peak at about 2.5 after only 5 days.

[0050] In the present invention, direct current (DC) or alternating current (AC) can be used to apply the magnetic field, but in terms of maximizing the leaching efficiency of Co, Ni and Al that are difficult to recover in a typical bioleaching process, AC is preferred. In an embodiment of the present invention, it has been confirmed that when an alternating magnetic field is applied to the culture medium, the leaching concentrations of Co, Ni and Al are significantly increased, while the yield of Li is maintained without a significant decrease, compared to when a static magnetic field is applied.

[0051] When a magnetic field is applied, the flux density can be from 1G to 90G.

[0052] In the present invention, if the type of magnetic field is direct current (DC), the magnetic flux density may be 5 G to 90 G, preferably 10 G to 80 G, and more preferably 30 G to 50 G. In this regard, in an embodiment of the present invention, when a static magnetic field is applied, microorganism culture and metal leaching are performed by changing the magnetic flux density conditions to 5 G, 40 G, and 90 G, and as a result, it has been confirmed that the leaching efficiency of cobalt, lithium, and nickel is most excellent under the condition of 40 G.

[0053] In the present invention, if the type of magnetic field is alternating current (AC), the magnetic flux density may be 1 G to 10 G, preferably 2 G to 8 G, and more preferably 3 G to 7 G. In this regard, in an embodiment of the present invention, when an alternating magnetic field is applied, microorganism culture and metal leaching are performed by changing the magnetic flux density conditions to 1 G, 5 G, and 10 G, and as a result, it has been confirmed that the leaching efficiency of cobalt, lithium, and nickel is most excellent under the condition of 5 G.

[0054] Application of the magnetic field can be performed by any method as long as the magnetic field can be applied to the culture medium, and can be applied using, for example, a disk-type or cylindrical-type magnetic field applying device.

[0055] Figure 1a , Figure 1b and Figure 2a , Figure 2b Images of exemplary disk-type and cylindrical-type magnetic field application devices and images of the magnetic field application devices used for microbial cultivation are shown. Figure 1a As shown, the disk-type magnetic field applying device is configured to install a permanent magnet on a circular rotating disk and arrange a microbial culture medium thereon to culture microorganisms, and as Figure 1b As shown, a microbial culture medium can be placed on a tray and used.

[0056] In addition, the cylindrical magnetic field applying device is as follows Figure 2a The solenoid device shown in FIG. Figure 1b Shown is the cultivation of microorganisms within a solenoid.

[0057] When the acidophilic microorganisms are cultured through the above steps, the waste battery pulverized material may be added to the culture medium to leach metals.

[0058] The term "waste battery pulverized material" used herein refers to a pulverized material obtained by treating various wastes (i.e., various types of debris, jelly rolls, slurries, waste batteries, etc.) generated in the manufacturing process of lithium secondary batteries or generated from waste batteries by a typical pulverization method. In order to more specifically describe an example of a pretreatment method for making solid waste such as collected debris into a pulverized material form, the solid waste is cut into appropriate sizes, preliminarily classified, and fired to separate electrode active materials and collectors, and other organic substances and separators are volatilized. Subsequently, the fired solid is secondary classified and sorted by specific gravity sorting, magnetic sorting, etc. to obtain waste battery pulverized material. The waste battery pulverized material thus obtained basically contains valuable metals such as Co, Ni and Li, and contains metals such as Al, Fe and Cu and carbon, but can have various compositions depending on the type of waste battery.

[0059] After adding the above-mentioned waste battery pulverized material to the culture medium for culturing acidophilic microorganisms, a step of leaching metals may be performed for a predetermined time.

[0060] The leaching step may be performed at 20° C. to 35° C., preferably 26° C. to 31° C. As in the culturing step, it is desirable to maintain an optimal temperature during the leaching step in order not to interfere with the metabolism of the microorganisms.

[0061] Furthermore, the culture medium may be stirred at a rate of 100-200 rpm for efficient leaching, preferably at a rate of 120-180 rpm.

[0062] In this case, the longer the leaching time, that is, the longer the reaction time between the microorganisms and the waste battery crushed material, the better the leaching concentration, because the increase in leaching concentration slows down after an initial certain period of time, and it is preferred to carry out the process until a significant increase in concentration is difficult to be expected. The time for leaching metals with optimal efficiency relative to the reaction time can be 3 days to 30 days, preferably 5 days to 21 days.

[0063] In an embodiment of the present invention, metal leaching can also be performed under the condition of applying a magnetic field. The magnetic field can be applied to have the same application conditions as in the microorganism culturing step, specifically, an alternating current can be applied, wherein the magnetic flux density can be 1G to 90G.

[0064] In the present invention, by adding the waste battery pulverized material in the microorganism culturing step, the culturing step and the metal leaching step can be simplified to simultaneously perform microorganism culturing and metal leaching. In this case, the growth rate of the microorganism may be reduced due to the toxicity of the waste battery powder, but the advantage is that the process can be simplified.

[0065] When metals are leached from the waste battery pulverized material according to the above method, a step of recovering the leached metals may be performed.

[0066] The leached metal may be recovered using methods known in the art, such as precipitation, solvent extraction and electrowinning, and in embodiments of the invention, the leached metal is recovered by thermal precipitation, wherein heat is applied to the leached metal to dry the leached metal.

[0067] The method for recovering metals from waste batteries according to the present invention has the advantages of being environmentally friendly, having a high metal recovery rate and being simple in process compared to the typical methods such as dry melting and acid leaching that are mainly used. In addition, the present invention is characterized in that a system for applying a magnetic field is added during the bioleaching process, thereby being able to recover specific valuable metals that are not easily recovered through the bioleaching process alone, and is therefore suitable for application to waste lithium-ion batteries containing a relatively large amount of expensive metals.

[0068] Example

[0069] Hereinafter, the present invention will be described in more detail with reference to examples. However, these examples show some experimental methods and compositions to exemplarily describe the present invention, and the scope of the present invention is not limited to these examples.

[0070] Experimental Example 1: Analysis of metal leaching concentration according to microbial use

[0071] Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans were provided by the Korea Collection of Type Cultures (KCTC) and used as microorganisms for leaching metals from waste batteries. Acidithiobacillus ferrooxidans was cultured in a conical flask at 25° C. for 5 days using 9K medium and adjusting the initial pH to 1.8, and Acidithiobacillus thiooxidans was cultured in a conical flask at 25° C. for 7 days using medium 271 and adjusting the initial pH to 3.0.

[0072] Waste battery powder was added to the cultured flask at a concentration of 3 g / 100 mL, and metal leaching was performed for 21 days.

[0073] The positive electrode material (lithium nickel cobalt aluminum oxide (NCA), LiNiCoAlO2) powder physically separated from the coin cell was diluted and used as a waste battery powder, which had the composition shown in Table 1 below.

[0074] [Table 1]

[0075]

[0076] Inductively coupled plasma-optical emission spectroscopy (ICP-OES) was performed on the culture medium where metal leaching was completed to analyze the metal leaching concentration, which is shown in Table 2. For comparison, waste battery powder was added to the culture medium without culturing microorganisms to compare the metal leaching concentration.

[0077] [Table 2]

[0078]

[0079] Referring to Table 2, it can be seen that when metals are leached using microorganisms, the metal leaching concentration increases compared to when metals are leached in a culture medium without culturing microorganisms, and it can be confirmed that the leaching tendency of metals varies depending on the types of microorganisms and culture medium.

[0080] Specifically, it was confirmed that when Acidithiobacillus ferrooxidans was used to leach metals, the leaching amount of cobalt was similar, while the leaching concentration of lithium was about 4 times higher, that of nickel was about 2 times higher, and that of aluminum was about 20 times higher.

[0081] Furthermore, it could be confirmed that when the metals were leached using Acidithiobacillus oxidans, cobalt was additionally leached, while lithium was leached at a concentration about 14 times higher, nickel about 1.2 times higher, and aluminum about 300 times higher.

[0082] Experimental Example 2: Analysis of microbial growth rate based on whether a magnetic field is applied

[0083] Acidithiobacillus ferrooxidans was cultured in the same manner as in Experimental Example 1, except that Figure 1b The disk-shaped magnetic field application device shown in FIG. cultivates microorganisms and compares pH changes with Figure 3 The pH changes of the culture medium in which the microorganisms were cultured without applying a magnetic field are compared as shown in FIG.

[0084] refer to Figure 3 , it was confirmed that, in the case of the culture medium without application of a magnetic field, the pH was initially 1.8, peaked at 2.36 after 7 days, and then began to decrease, while in the case of the culture medium with application of a magnetic field, the pH reached 2.39 within 5 days and then began to decrease, thereby shortening the time required to complete the growth of microorganisms to 2 days.

[0085] The images of the culture medium on the 4th day of culture without applying a magnetic field and the images of the culture medium on the 3rd day of culture with applying a magnetic field are compared and shown in Figure 4 middle.

[0086] exist Figure 4 In the figure, it was confirmed that the culture medium to which microorganisms were cultured by applying a magnetic field (right) appeared darker than the culture medium to which the magnetic field was not applied (left), which can be visually identified with the naked eye, so it can be seen that the growth of microorganisms is further promoted in the culture medium to which the magnetic field is applied.

[0087] Experimental Example 3: Analysis of metal leaching concentration according to magnetic field application method

[0088] The microorganisms were cultured in the same manner as in Experimental Example 1, except that Figure 2b The cylindrical magnetic field applying device (DC: 5G, AC: 3G) shown was used to culture microorganisms, and diluted waste battery powder was added to the flask where the culture was completed to perform metal leaching for 5 days.

[0089] For comparison, the metal leaching concentrations were analyzed by leaching metals from microorganisms cultured without applying a magnetic field and are shown in Table 3, where the leaching concentrations of cobalt, lithium, nickel, and aluminum using Acidithiobacillus ferrooxidans are shown in Table 3, respectively. Figure 5a to Figure 5d middle.

[0090] [Table 3]

[0091]

[0092] refer to Figure 5a to Figure 5d and Table 3, when a static magnetic field is applied and an alternating magnetic field is applied, the leaching concentrations of Co, Li, Ni and Al are measured to be much higher than when no magnetic field is applied.

[0093] Specifically, when a static magnetic field was applied to Acidithiobacillus ferrooxidans, the measured leaching concentration of Co was about 10 times higher than that when no magnetic field was applied, the measured leaching concentration of Li was about 1.15 times higher, the measured leaching concentration of Ni was about 2 times higher, and the measured leaching concentration of Al was about 1.2 times higher. When an alternating magnetic field was applied thereto, the measured leaching concentration of Co was about 200 times higher than that when no magnetic field was applied, the measured leaching concentration of Li was about 1.05 times higher, the measured leaching concentration of Ni was about 4 times higher, and the measured leaching concentration of Al was about 3 times higher.

[0094] Furthermore, when comparing the cases where a direct current and an alternating magnetic field were applied, it was confirmed that when the alternating magnetic field was applied, the concentrations of Co, Ni, and Al were significantly increased while the yield of Li was maintained without a significant decrease.

[0095] On the other hand, when an alternating magnetic field was applied to Acidithiobacillus ferrooxidans, it was confirmed that other metals were not detected, but the lithium concentration increased by about 2 times, and it was confirmed that Acidithiobacillus ferrooxidans was not significantly affected by the magnetic field compared to Acidithiobacillus ferrooxidans.

[0096] Experimental Example 4: Analysis of metal leaching efficiency based on DC magnetic field flux density conditions

[0097] Using the method of Experimental Example 3, Acidithiobacillus ferrooxidans (A. ferrooxidans) was cultured under the condition of applying a DC magnetic field, and waste battery powder was added thereto for metal leaching. The same experiment was carried out by changing the magnetic flux density to 5G, 40G or 90G, and the leaching efficiency of cobalt, lithium and nickel for the magnetic flux density conditions, oxidation-reduction potential (ORP) and iron ion concentration is shown in Table 4 below.

[0098] [Table 4]

[0099]

[0100] From the experimental results, it can be confirmed that when a DC magnetic field is applied under the conditions of a magnetic flux density of 5G, 40G or 90G, the leaching efficiency is improved compared with the control group. In particular, when the magnetic flux density is 40G, the leaching efficiency of cobalt, lithium and nickel relative to the iron ion concentration is 53%, 85% and 54%, respectively, which indicates that the leaching efficiency is very excellent.

[0101] Experimental Example 5: Analysis of metal leaching efficiency based on AC magnetic field flux density conditions

[0102] Using the method of Experimental Example 3, Acidithiobacillus ferrooxidans (A. ferrooxidans) was cultured under the condition of applying an AC magnetic field, and waste battery powder was added thereto for metal leaching. The same experiment was carried out by changing the magnetic flux density to 1G, 5G or 10G, and the leaching efficiency of cobalt, lithium and nickel for the magnetic flux density conditions, oxidation-reduction potential (ORP) and iron ion concentration is shown in Table 5 below.

[0103] [Table 5]

[0104]

[0105] From the experimental results, it can be confirmed that when an AC magnetic field is applied under the conditions of a magnetic flux density of 1G, 5G or 10G, the leaching efficiency is improved compared with the control group. In particular, when the magnetic flux density is 5G, the leaching efficiency of cobalt, lithium and nickel relative to the iron ion concentration is 57%, 60% and 63%, respectively, which indicates that the leaching efficiency is very excellent.

[0106] Although some embodiments of the present invention have been described above, the present invention is not limited to the above-mentioned embodiments and can be implemented by modifying and changing them within the scope without departing from the spirit of the present invention, and it should be understood that such modified and changed forms also fall within the technical spirit of the present invention.

Claims

1. A method for recovering metals from waste batteries, the method comprising the following steps: Cultivating acidophilic microorganisms in a culture medium to which a magnetic field is applied; adding the waste battery crushed material to the culture medium to leach the metals; as well as The leached metals are recovered.

2. The method according to claim 1, wherein: The leaching of the metal is performed in a state where a magnetic field is applied.

3. The method according to claim 1, wherein: The acidophilic microorganism is one or more of Acidithiobacillus ferrooxidans, Acidithiobacillus oxidans and Acidithiobacillus thermophilus.

4. The method according to claim 1, wherein: The metal includes one or more of cobalt (Co), nickel (Ni), lithium (Li), and aluminum (Al).

5. The method according to claim 1, wherein: The culturing step is performed for 3 to 7 days.

6. The method according to claim 1, wherein: The initial pH of the culture medium is 1.5 to 3.

5.

7. The method according to claim 1, wherein: The magnetic field is a direct current (DC) magnetic field or an alternating current (AC) magnetic field.

8. The method according to claim 1, wherein: The magnetic field is a DC magnetic field, and the magnetic field has a magnetic flux density of 5G to 90G.

9. The method according to claim 1, wherein: The magnetic field is an alternating current magnetic field, and the magnetic field has a magnetic flux density of 1G to 10G.

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