Waste battery treatment method

Abstract

The waste battery treatment method according to the present invention includes a discharging step of discharging a waste battery, a disassembling step of disassembling the discharged waste battery into cell units, a crushing step of crushing the disassembled waste battery, a roasting step of roasting the waste battery crushed into cell units, a pulverizing step of pulverizing the roasted waste battery, and a wet process of extracting and recovering metals from the pulverized waste battery.

Description

Technical Field

[0001] The present invention relates to a method for treating waste batteries, and more particularly, to a method for recovering metallic compounds from end-of-life batteries in the form of packs.

Background Art

[0002] Recently, with the spread of the Battery Electric Vehicle (BEV) market, the demand for secondary batteries has been increasing. Secondary batteries cannot be used permanently and have a specific expiration date. End-of-life secondary batteries can be discarded, reused, or recycled, and recently, research has been continuously conducted to recover rare metals, which are useful resources in the batteries, through recycling of secondary batteries.

[0003] Conventionally, since the development of treatment technologies for waste batteries mainly in the form of small batteries has been promoted, the development of elemental technologies has been carried out rather than integrated process technologies. However, since most of the recently increasing battery demand is for medium and large-sized batteries in packs used as power sources for electric vehicles, waste battery treatment technologies for medium and large-sized batteries are required. In addition, rather than the development of existing elemental technologies, the development of integrated recycling technologies from the complete form of the battery to the final target metallic compounds is required.

Summary of the Invention

Problems to be Solved by the Invention

[0004] An object of the present invention is to provide a method for treating waste batteries that can efficiently recover metals in the form of compounds from end-of-life batteries in the form of packs through a discharging process, a disassembling process, a crushing process, a roasting process, a pulverizing process, and a wet process.

Means for Solving the Problems

[0005] The waste battery treatment method according to an embodiment of the present invention includes a discharging step of discharging a waste battery; a disassembling step of disassembling the discharged waste battery into cell units; a crushing step of crushing the waste battery disassembled into cell units; a roasting step of roasting the crushed waste battery; a pulverizing step of pulverizing the roasted waste battery; and a wet process of extracting and recovering metals from the pulverized waste battery.

[0006] The waste battery may be a battery in pack units that has reached the end of its life.

[0007] In the waste battery treatment method according to the present invention, the waste battery can be discharged through the discharging step so that the voltage of the waste battery becomes 30 V or less.

[0008] In the waste battery treatment method according to the present invention, the battery in cell units can be crushed to a size of 20 cm or less through the crushing step.

[0009] In the waste battery treatment method according to the present invention, the step of separating black mass from the pulverized waste battery may be omitted.

[0010] In the waste battery treatment method of the present invention, the discharging step, the disassembling step, the crushing step, the roasting step, and the pulverizing step can be continuously performed by automated equipment.

[0011] In the waste battery treatment method of the present invention, the discharging step, the disassembling step, and the crushing step can be performed by automated equipment using robots.

[0012] In the waste battery treatment method of the present invention, metal compounds can be recovered through the wet process.

[0013] The metal compound may include at least one or more selected from the group consisting of lithium hydroxide, lithium carbonate, and lithium phosphate.

[0014] The metal compound may include a sulfate of one kind selected from the group consisting of nickel, cobalt, and manganese.

[0015] The metal compound may include a nickel-cobalt-manganese-based compound in a solution state.

Advantages of the Invention

[0016] According to the present invention, after disassembling a discharged waste battery into cell units and then performing a wet process, the time required to recover metals in the form of compounds from the battery can be shortened, by-products generated during the operation of the process can be reduced, and the metal recovery rate can be increased.

[0017] In particular, in the present invention, after crushing / grinding a battery in cell units, metals are recovered directly through a wet process without a separate process of separating black mass, so that the loss rate of metal components present in the battery in pack form can be minimized.

[0018] Further, in the present invention, by automatically performing the processes of discharging, disassembling, crushing, roasting, and grinding except for the wet process on a battery in pack form, the time required to recover metals in the form of compounds from the battery can be significantly reduced.

Brief Description of the Drawings

[0019]

Figure 1

Figure 2

Modes for Carrying Out the Invention

[0020] The waste battery treatment method according to the present invention includes a discharging step of discharging a waste battery, a disassembling step of disassembling the discharged waste battery into cell units, a crushing step of crushing the waste battery disassembled into cell units, a roasting step of roasting the crushed waste battery, a grinding step of grinding the roasted waste battery, and a wet process of extracting and recovering metals from the ground waste battery.

[0021] The present invention will be described below with reference to the drawings. FIG. 1 is an overall process diagram of the waste battery treatment method according to the present invention. As shown in FIG. 1, the waste battery treatment method according to an embodiment of the present invention may include a discharging step (S100), a disassembling step (S200), a crushing step (S300), a roasting step (S400), a pulverizing step (S500), and a wet process step (S600).

[0022] Discharging process (S100) The discharging step (S100) is a step of discharging the electric power stored in the waste battery in order to prevent an explosion of the waste battery that may occur during subsequent steps. For example, in the discharging step (S100), the waste battery may be connected to a discharger and discharged so that the voltage of the waste battery becomes 30 V or less, preferably 0.2 V or less. By discharging the waste battery to the voltage within the above numerical range through the discharging step (S100), an explosion of the waste battery in the subsequent disassembling step (S200) can be prevented, and stability can be ensured.

[0023] The waste battery treatment method according to the present invention can be performed on medium and large-sized batteries used in electric vehicles. In this case, the waste battery to be discharged through the discharging step (S100) may be a battery in the form of a pack whose life has ended.

[0024] The discharging step (S100) can be performed through mechanical discharging using a discharger, or saline discharging using saline water, etc. Preferably, the discharging step (S100) can be performed through mechanical discharging. When mechanical discharging is used, stability against fire and explosion can be ensured, the discharging state can be confirmed, and the discharging time required and the expenditure of incidental costs can be reduced.

[0025] Disassembly process (S200) The disassembling step (S200) is a step of further disassembling the waste battery in the form of a pack into smaller units. The disassembling step (S200) according to the present invention disassembles the waste battery in the pack form into cells. For example, in the disassembling step (S200), the waste battery in the pack form can be disassembled into modules first and then into cells.

[0026] If used directly for recycling waste batteries in pack units, there is convenience, but since the BMS (Battery Management System) and various control devices also flow in, there is a problem of increased inflow of impurities. Therefore, in order to recycle the batteries, they must be disassembled at least to the module unit. The present invention is characterized by disassembling waste batteries in pack form not only to the module unit but also to the cell unit. According to the present invention, compared with the case of disassembling waste batteries in pack form to the module unit, the present invention can significantly reduce the inflow of impurities (for example, Al and Fe) in the recovered metal substances by disassembling waste batteries in pack form to the cell unit. In addition, since the inflow of aluminum in the recovered metal substances is significantly small, there is an advantage that a separate process for removing aluminum in the recovery of metal substances can be minimized.

[0027] On the other hand, when disassembling waste batteries in pack form to the module unit, a dry process (roasting process) is performed at a high temperature of at least 1200 °C, so that manganese (Mn) is discharged as slag in the form of manganese oxide (MnO) and manganese recovery is impossible, and lithium volatilizes in a gaseous state, and the lithium recovery rate may decrease. On the other hand, when disassembling waste batteries in pack form to the cell unit as in the present invention, the temperature in the dry process can be relatively lowered. Therefore, different from the case of disassembling waste batteries in pack form to the module unit, manganese recovery is possible, and the lithium (Li) recovery rate can be significantly increased compared with the case of disassembling to the module unit.

[0028] According to one embodiment, as shown in FIG. 1, the disassembly process (S200) can be performed after the discharge process (S100). However, the present invention is not limited to this. According to other embodiments, different from that shown in FIG. 1, the disassembly process (S200) can be performed first and then the discharge process (S100) can be performed.

[0029] Crushing process (S300) The crushing process (S300) is a process of crushing the waste battery disassembled in cell units. The crushing process (S300) can crush the battery in cell units to a size of 20 cm or less, specifically 15 cm or less, and more specifically 10 cm or less. By crushing the battery to the size within the above numerical range through the crushing process (S300), the battery crushed in the roasting process (S400) can be reduced and roasted more uniformly.

[0030] The crushing process (S300) can be performed while spraying water under a nitrogen (N2) atmosphere for the prevention of sparks and explosions. After the crushing is performed, the sprayed water and the electrolyte flowing out from the waste battery can be removed. For example, the water and the electrolyte can be removed by a centrifugal separation method through a rotary barrel.

[0031] The crushing process (S300) may include a drying process (not shown) for drying the crushed battery.

[0032] According to the present invention, the above-described discharging process (S100), disassembling process (S200), and crushing process (S300) can be performed by automated equipment using a robot, thereby significantly reducing the time required to recover metals from the waste battery.

[0033] Roasting process (S400) The roasting process (S400) is a process of dry-treating the crushed battery. Specifically, the roasting process (S400) can be a process of reducing and roasting the crushed battery in an atmosphere of an inert gas (IAR: Inert Atmospheric Roaster). For example, in the roasting process (S400), the battery crushed to a size of 5 cm to 10 cm can be reductively roasted at a temperature of 800°C to 900°C for 1 hour to 3 hours in a nitrogen (N2) atmosphere. By roasting the crushed battery in an inert gas atmosphere, lithium (Li) can be converted into a form of Li2CO3 that can dissolve in water. In the process of reductively roasting the crushed battery for the preliminary separation of lithium, some higher oxides (Me2O3, Me = Ni, Co, Mn) are reduced to lower oxides (MeO, Me = Ni, Co, Mn), and the amount of auxiliary raw materials (H2O2, hydrogen peroxide) input during sulfuric acid leaching can be reduced.

[0034] Grinding process (S500) The grinding process (S500) is a process of grinding the battery dry-treated through the roasting process (S400). For example, in the grinding process (S500), the battery reductively roasted through a ball mill can be classified to 80% or more below 200 mesh.

[0035] The grinding process (S500) can be performed while spraying water under a nitrogen (N2) atmosphere to prevent sparks and explosions. After grinding, the sprayed water and the electrolyte flowing out from the waste battery can be removed. For example, the water and the electrolyte can be removed by a centrifugal separation method through a rotary barrel.

[0036] In the waste battery treatment method according to the present invention, a separate process of separating black mass after crushing / grinding the battery in cell units is omitted. Since the present invention immediately recovers metals through a wet process without a separate process of separating black mass, the loss rate of metal components existing in the battery in pack form can be minimized.

[0037] The discharge process (S100), disassembly process (S200), crushing process (S300), roasting process (S400), and grinding process (S500) according to the present invention can be continuously performed by automated equipment. Therefore, it is possible to realize an integrated recycling process technology from the waste battery in the pack form to the final target metal compound, and the time required to recover the metal from the waste battery can be significantly reduced.

[0038] Wet process (S600) The wet process (S600) is a process for recovering metal substances using the crushed battery. The metal recovered through the wet process (S600) can be in the form of a compound. For example, the wet process (S600) can recover metal substances in the form of a compound from the crushed battery after the grinding process (S500).

[0039] The metal compound recovered through the wet process (S600) may contain at least one or more selected from the group consisting of lithium hydroxide, lithium carbonate, and lithium phosphate. It is possible to produce high-purity lithium carbonate (Li2CO3) and high-purity lithium hydroxide (LiOH·H2O) with excellent lithium recovery rates through the wet process (S600) of the present invention. Lithium hydroxide can be produced through the pre-separation process (S610), weak acid leaching process (S612), post-separation process (S614), lithium phosphate production process (S616), lithium sulfate solution production process (S618), lithium carbonate production process (S620), lithium hydroxide solution production process (S622), and ion exchange resin process (S624) as described below.

[0040] In addition, the metal compound recovered through the wet process (S600) may contain copper(II) sulfide (CuS).

[0041] In one embodiment of the present invention, the metal compound recovered through the wet process (S600) may contain one sulfate selected from the group consisting of nickel, cobalt, and manganese. In another embodiment of the present invention, the metal compound recovered through the wet process (S600) may contain a nickel-cobalt-manganese-based compound in a solution state, for example, an NCM (Ni, Co, Mn) solution.

[0042] Nickel sulfate can be produced through the pre-separation step (S610), weak acid leaching step (S612), post-separation step (S614), two-stage leaching step (S626), first solvent extraction step (S628), and first impurity removal step (S630) as described below.

[0043] Cobalt sulfate can be produced through the pre-separation step (S610), weak acid leaching step (S612), post-separation step (S614), two-stage leaching step (S626), first solvent extraction step (S628), second solvent extraction step (S632), and second impurity removal step (S634) as described below.

[0044] Manganese sulfate can be produced through the pre-separation step (S610), weak acid leaching step (S612), post-separation step (S614), two-stage leaching step (S626), first solvent extraction step (S628), second solvent extraction step (S632), and third impurity removal step (S636) as described below.

[0045] Hereinafter, each stage of the wet process (S600) will be described in more detail with reference to FIG. 2. FIG. 2 is a process diagram of the wet process (S600) among the waste battery treatment methods according to the present invention.

[0046] Pre-separation process (S610) The pre-separation step (S610) is a step of adding water to the battery pulverized after roasting to leach and separate lithium (Li). For example, in the pre-separation step (S610), the pulverized battery after the pulverization step (S500) is dissolved in water, and a lithium (Li) solution is leached at 10°C to 30°C for 1 hour to 3 hours to produce a lithium carbonate (Li2CO3) solution, and the cake can be separated. Through the pre-separation step (S610), the operating cost and the cost of auxiliary raw materials in the subsequent lithium phosphate production step (S616) can be reduced, the mixing of impurities during the production of high-purity lithium hydroxide can be minimized, and the processing cost during the production of lithium hydroxide can be reduced.

[0047] After the pre-separation step (S610), a first evaporation and concentration step (not shown) can be performed. The first evaporation and concentration step is a step of evaporating and concentrating the lithium (Li) solution (filtrate) generated in the pre-separation step (S610) to produce lithium carbonate (Li2CO3) crystals. By producing lithium carbonate crystals through the pre-separation step (S610) and the first evaporation and concentration step, the usage amounts of phosphoric acid (H3PO4) and sodium hydroxide (NaOH) in the subsequent lithium phosphate production step (S616) can be reduced by 50% or more, and the loss of lithium (Li) distributed as filtrate in the lithium phosphate production step (S616) can be greatly reduced.

[0048] Weak acid leaching process (S612) The weak acid leaching step (S612) is a step of leaching the cake separated in the pre-separation step (S610) using sulfuric acid (H2SO4). Specifically, the weak acid leaching step (S612) is a step of reductively leaching the generated cake with sulfuric acid and hydrogen peroxide (H2O2) at 80°C to 85°C for 1 hour to 4 hours after lithium is pre-separated in the pre-separation step (S610). When nickel (Ni), cobalt (Co), and manganese (Mn) are dissolved from the cake from which lithium (Li) has been pre-separated through the pre-separation step (S610), the usage amount of auxiliary raw materials can be minimized, and stable process control in the continuous process is possible.

[0049] Post-separation process (S614) The post-separation step (S614) is a step of neutralizing the leachate produced in the weak acid leaching step (S612) to separate it into a lithium (Li) solution and a nickel-cobalt-manganese-based cake (hereinafter referred to as NCM cake). Specifically, in the post-separation step (S614), the leachate in the weak acid leaching step (S612) is neutralized with sodium hydroxide (NaOH) (pH 10 to pH 12) and reacted at 70°C to 85°C for 4 to 8 hours, so that nickel (Ni), cobalt (Co), and manganese (Mn) can be precipitated and recovered, and lithium (Li) can be distributed as a filtrate and separated. The precipitation rate of nickel (Ni), cobalt (Co), and manganese (Mn) in the post-separation step (S614) can be 99.9% or more.

[0050] Furthermore, in the post-separation step (S614), the filtered NCM cake can be repulped two or more times to remove residual sodium salts (Na salts). For example, the sodium (Na) grade in the NCM cake can be removed from 3.43% to 0.4%. In this specification, the repulping step means a step of repulping a solid-state cake with water to wash the filtrate components (such as residual sodium salts) present in the cake.

[0051] Lithium phosphate manufacturing process (S616) The lithium phosphate production step (S616) is a step of adding phosphoric acid (H3PO4) and sodium hydroxide (NaOH) to the lithium (Li) solution separated in the post-separation step (S614) to produce a lithium phosphate (Li3PO4) cake. Specifically, phosphoric acid (H3PO4) is added to the lithium (Li) solution separated in the post-separation step (S614) and reacted at 70°C to 85°C for 1 to 4 hours, so that lithium (Li) can be precipitated and recovered in the form of lithium phosphate (Li3PO4). Also, sodium hydroxide (NaOH) can be added to neutralize to pH 10.0 to pH 12.0.

[0052] Lithium sulfate solution manufacturing process (S618)

[0053] The lithium sulfate solution production step (S618) is a step of producing a lithium sulfate (Li2SO4) solution by dissolving lithium carbonate (Li2CO3) crystals recovered by evaporating and concentrating the solution (lithium carbonate (Li2CO3) solution) produced in the previous separation step (S610) and lithium phosphate (Li3PO4) cake produced in the lithium phosphate production step (S616) in sulfuric acid respectively. For example, the temperature in the lithium sulfate solution production step (S618) is 60°C to 80°C, the reaction time is 0.5 hour to 3 hours, and the pH is 2.0 or less.

[0054] After the lithium sulfate solution production step (S618), a second evaporation and concentration step (not shown) can be performed. The second evaporation and concentration step is a step of evaporating and concentrating the lithium sulfate solution produced in the lithium sulfate solution production step (S618) to separate lithium sulfate (Li2SO4) crystals and phosphoric acid (H3PO4) filtrate. The phosphoric acid (H3PO4) filtrate can be recycled in the lithium phosphate production step (S616) and used as a lithium precipitation auxiliary material. The evaporation condensate generated in the second evaporation and concentration step can be recycled as the process liquid in the lithium (Li) previous separation step (S610). Through this, the amount of waste liquid generated outside the system and the amount of fresh water flowing into the system can be reduced.

[0055] The first phosphorus removal step (not shown) is a step of removing phosphorus (P) using aluminum sulfate (Al2(SO4)3) and caustic soda (NaOH) after putting the lithium sulfate (Li2SO4) crystals produced in the second evaporation and concentration step into pure water and dissolving them. For example, by adding aluminum sulfate (Al2(SO4)3) to the solution produced in the lithium sulfate solution production step (S618) to adjust the pH to 5.0 to 6.0 and reacting at 50°C to 70°C for 4 hours to 8 hours, most of the phosphorus (P) can be removed by precipitation, and iron (Fe) and other impurities can also be removed by coprecipitation.

[0056] Lithium carbonate manufacturing process (S620) The lithium carbonate production process (S620) is a process of adding sodium carbonate (Na2CO3) to lithium sulfate (Li2SO4) produced in the lithium sulfate solution production process (S618) to precipitate lithium carbonate (Li2CO3). For example, in the lithium carbonate production process (S620), sodium carbonate (Na2CO3) is added to the filtrate generated in the first phosphorus removal process, and the reaction is carried out at 80°C to 85°C for 1 hour to 6 hours to precipitate lithium carbonate.

[0057] Preferably, a repulping process can be carried out to remove residual sodium (Na) salts in the cake in the lithium carbonate production process (S620). In this case, repulping can be carried out at 80°C to minimize the loss of lithium (Li). The filtrate in the lithium carbonate production process (S620) can be recycled in the lithium phosphate production process (S616).

[0058] Lithium hydroxide solution manufacturing process (S622) The lithium hydroxide solution production process (S622) is a process of adding the lithium carbonate cake generated from the lithium carbonate to pure water to dissolve it, and then adding calcium oxide (CaO) to produce a lithium hydroxide (LiOH) solution. For example, calcium oxide (CaO) and water are added to the lithium carbonate cake produced in the lithium carbonate production process (S620), and the reaction is carried out at 80°C to 100°C for 3 hours or less, and then the reaction is carried out at 80°C to 100°C for 2 hours or less to produce a lithium hydroxide (LiOH) solution. Preferably, a repulping process for recovering lithium inherent in the calcium carbonate (CaCO3) residue generated in the lithium hydroxide solution production process (S622) can be carried out.

[0059] Ion exchange resin process (S624) The ion exchange resin process (S624) is a process for removing calcium (Ca) and magnesium (Mg), which are impurities in the produced lithium hydroxide (LiOH) solution.

[0060] The third evaporation and concentration step (not shown) is a step of evaporating and concentrating the lithium hydroxide (LiOH) solution produced in the lithium hydroxide solution production step (S622) and / or the ion exchange resin treatment liquid from which impurities have been removed through the ion exchange resin step (S624) to produce lithium hydroxide (LiOH) crystals. Specifically, in the third evaporation and concentration step, the lithium hydroxide (LiOH) solution and / or the ion exchange resin treatment liquid can be evaporated and concentrated to produce a LiOH·H2O product.

[0061] Two-stage leaching process (S626) The two-stage leaching step (S626) is a step of leaching the weak acid leaching step cake produced in the weak acid leaching step (S612) and the NCM cake generated in the post-separation step (S614) using sulfuric acid and hydrogen peroxide (H2O2). For example, in the two-stage leaching step (S626), the weak acid leaching step cake and the NCM cake from which lithium has been separated can be dissolved in sulfuric acid (H2SO4) at 60°C to 80°C for 2 to 4 hours (pH 1.5 to 2.5). A small amount of reducing agent may be added to improve the dissolution rate of the NCM cake. At this time, hydrogen peroxide (H2O2) can be used as the reducing agent.

[0062] Preferably, an impurity removal step can be performed to remove impurities from the filtrate produced in the two-stage leaching step (S626). In this case, the impurity removal step may include a first copper removal step and a first aluminum & phosphorus removal step. The first copper removal step (not shown) is a step of adding NaSH to remove copper (Cu), which is an impurity, from the filtrate produced in the two-stage leaching step (S626). The first aluminum & phosphorus removal step (not shown) is a step of injecting caustic soda (NaOH) and oxygen gas (O2) to remove additional impurities, aluminum (Al) and phosphorus (P), from the filtrate produced in the first copper removal step.

[0063] First solvent extraction process (S628) The first solvent extraction step (S628) is a step of extracting cobalt using an extractant from the filtrate produced in the two-stage leaching step (S626) and / or the filtrate produced in the aforementioned impurity removal step.

[0064] Preferably, the nickel hydroxide production process and the nickel weak acid leaching process can be performed on the filtrate produced in the first solvent extraction step (S628). For example, the nickel hydroxide production process (not shown) is a process of producing nickel hydroxide (Ni(OH)2) using caustic soda (NaOH) on the filtrate produced in the first solvent extraction step (S628). The nickel weak acid leaching process (not shown) is a process of adding water, sulfuric acid (H2SO4), and hydrogen peroxide (H2O2) to the cake produced in the nickel hydroxide production process and dissolving them.

[0065] First impurity removal process (S630) The first impurity removal step (S630) is a step for removing impurities from the filtrate produced in the first solvent extraction step (S628) and / or the filtrates produced in the nickel hydroxide production process and the nickel weak acid leaching process. Specifically, the first impurity removal step (S630) may include a second copper removal step and a first aluminum removal step. For example, the second copper removal step is a step of adding sodium hydrosulfide (NaSH) to remove copper (Cu), which is an impurity, from the filtrate produced in the nickel weak acid leaching process. The first aluminum removal step is a step of adding caustic soda (NaOH) and injecting oxygen gas (O2) to remove aluminum (Al), which is an additional impurity, from the filtrate produced in the second copper removal step.

[0066] The fourth evaporation and concentration step (not shown) is a step of evaporating and concentrating the solution produced in the first impurity removal step (S630) to produce nickel sulfate (NiSO4) crystals.

[0067] Second solvent extraction process (S632) The second solvent extraction step (S632) is a step of extracting manganese using an extractant from the stripping liquid produced in the first solvent extraction step (S628).

[0068] Preferably, a first cobalt extraction step (not shown) can be performed on the filtrate produced in the second solvent extraction step (S632). The first cobalt extraction step is a step of extracting cobalt from the filtrate generated in the second solvent extraction step (S632) using an extractant.

[0069] Second impurity removal process (S634) The second impurity removal step (S634) is a step for removing impurities from the filtrate produced in the second solvent extraction step (S632) and / or the filtrate produced in the first cobalt extraction step. Specifically, the second impurity removal step (S634) may include a third copper removal step (not shown) and a second aluminum removal step (not shown). For example, the third copper removal step is a step of adding sodium hydrosulfide (NaSH) to remove copper (Cu), which is an impurity, from the stripping solution generated in the first cobalt extraction step. The second aluminum removal step is a step of adding caustic soda (NaOH) and injecting oxygen gas (O2) to remove aluminum (Al), which is an additional impurity, from the filtrate produced in the third copper removal step.

[0070] The fifth evaporation and concentration step (not shown) is a step of evaporating and concentrating the filtrate produced in the second impurity removal step (S634) to produce cobalt sulfate (CoSO4) crystals.

[0071] Third impurity removal process (S636) The third impurity removal step (S636) is a step for removing impurities from the stripping solution generated in the second solvent extraction step (S632). Specifically, the third impurity removal step (S636) may include a fourth copper removal step (not shown) and a third aluminum removal step (not shown). The fourth copper removal step is a step of adding sodium hydrosulfide (NaSH) to remove copper (Cu) from the stripping solution generated in the second solvent extraction step (S632). The third aluminum removal step is a step of injecting caustic soda (NaOH) and oxygen gas (O2) to remove aluminum (Al), which is an additional impurity, from the filtrate produced in the fourth copper removal step.

[0072] The sixth evaporation and concentration step (not shown) is a step of evaporating and concentrating the filtrate generated in the third impurity removal step (S636) to produce manganese sulfate (MnSO4) crystals.

[0073] Hereinafter, the present invention will be described in detail through examples and comparative examples. In the examples, valuable metals were recovered from waste batteries through the above-described steps. On the other hand, in the comparative examples, valuable metals were recovered in the same manner as in the examples, except that the waste batteries in pack units were disassembled to module units in the disassembly step (S200).

[0074] The inflow amounts of impurities in the substances recovered in the examples and comparative examples are shown in Table 1 below. At this time, the method for calculating the inflow amount of impurities is as follows. Specifically, the amount of NCM622 waste batteries processed per day was 285.7 tons (ton) based on packs, 205.5 tons based on modules excluding other parts after disassembling the packs, and 168.2 tons based on cells excluding other parts after disassembling the modules. At this time, the inflow amount of impurities was calculated by deriving the ratios of aluminum (Al) and iron (Fe) in the substances recovered from the waste batteries in module form.

[0075]

Table 1

[0076] According to Table 1, it can be confirmed that in the case of the examples where the waste batteries are disassembled from pack units to cell units, the inflow amounts of aluminum (Al) and iron (Fe) are significantly reduced compared to the comparative examples. Specifically, the inflow amount of aluminum (Al) in the examples decreased by 82.4% compared to the comparative examples, and the inflow amount of iron (Fe) decreased by 100%.

[0077] On the one hand, the recovery rates of each valuable metal in the substances recovered in the examples and comparative examples are shown in Table 2 below. The recovery rate of an individual valuable metal means a value calculated by excluding losses in the process of recovering the target metal (for example, Li) in a commercial form (for example, LiOH). At this time, the weight of the raw material (and slag) containing the target metal was measured using a scale, the concentration of the metal in the leached compound form was measured through ICP-AES spectroscopic analysis, and the recovery rate of each metal was calculated from this.

[0078]

Table 2

[0079] According to Table 2, it can be confirmed that the lithium (Li) recovery rate in the examples increased significantly compared to the comparative examples. Also, in the examples, it can be confirmed that, unlike the comparative examples, manganese (Mn) can be recovered.

[0080] In this specification, although the present invention has been described in connection with some examples, it should be understood that various modifications and changes can be made without departing from the idea and scope of the present invention that can be understood by those of ordinary skill in the technical field to which the present invention belongs. Also, such modifications and changes should be considered to fall within the scope of the appended claims of this specification.

Claims

1. A discharging step of discharging a spent battery; A disassembling step of disassembling the discharged spent battery into cells; A crushing step of crushing the spent battery disassembled into cells; A roasting step of roasting the crushed spent battery; A pulverizing step of pulverizing the roasted spent battery; and A wet process of extracting and recovering metals from the pulverized spent battery, A method for treating a spent battery.

2. The method for treating a spent battery according to Claim 1, wherein the spent battery is a battery in pack units whose life has ended.

3. The method for treating a spent battery according to Claim 1, wherein the spent battery is discharged through the discharging step so that the voltage of the spent battery becomes 30 V or less.

4. The method for treating a spent battery according to Claim 1, wherein the battery in cell units is crushed to a size of 20 cm or less through the crushing step.

5. The method for treating a spent battery according to Claim 1, wherein the step of separating black mass from the pulverized spent battery is omitted.

6. The method for treating a spent battery according to Claim 1, wherein the discharging step, the disassembling step, the crushing step, the roasting step, and the pulverizing step are continuously performed by automated equipment.

7. The method for treating a spent battery according to Claim 1, wherein the discharging step, the disassembling step, and the crushing step are performed by automated equipment using a robot.

8. The method for treating a spent battery according to Claim 1, wherein metal compounds are recovered through the wet process.

9. The method for treating a spent battery according to Claim 8, wherein the metal compound contains at least one or more selected from the group consisting of lithium hydroxide, lithium carbonate, and lithium phosphate.

10. The method for treating a spent battery according to Claim 8, wherein the metal compound contains one sulfate selected from the group consisting of nickel, cobalt, and manganese.

11. The method for treating a spent battery according to Claim 8, wherein the metal compound contains a nickel-cobalt-manganese-based compound in a solution state.

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