Methods for recovering lithium from waste lithium batteries

Abstract

This invention provides a low-temperature dry lithium recovery method that can efficiently recover lithium from waste lithium batteries. [Solution] The method includes the steps of heat-treating a mixture containing waste lithium battery cells and additives at a temperature in the range of 100°C to 1100°C, and collecting the lithium salt produced in the heat-treating step.

Description

Technical Field

[0001] This embodiment relates to a method for recovering lithium from waste lithium batteries. More specifically, it relates to a method of mixing an additive into a waste lithium battery and recovering a lithium salt under low-temperature melting conditions.

Background Art

[0002] Lithium batteries are widely used as secondary batteries because of their excellent charge-discharge performance and high energy density, and are particularly widely utilized in small electronic products such as mobile phones and notebook computers. Recently, with the increasing popularity of electric vehicles and the like

[0003] visible, the development of large-capacity lithium batteries has been actively carried out.

[0004] Conventional methods for extracting or recovering lithium from lithium batteries include separating the cathode material from the waste lithium battery, extracting with a strong acid, and then neutralizing with an alkali to precipitate and recover cobalt, nickel, etc. as hydroxides, and a wet process of dissolving the cathode material with sulfuric acid or nitric acid in the presence of hydrogen peroxide and then separating and recovering the metal by a neutralization precipitation method have generally been used. However, in the wet process, the methods using

[0005] hydrochloric acid, sulfuric acid, and nitric acid must use strong acids in the A dry process has been proposed in which an additive is mixed and melted to recover lithium. However, this Dry processes involving melting involve the input of additives such as CaCl2, MgCl2, and MnCl2. In the case of additives, along with the formation of lithium chloride, CaO, MgO, etc. are produced as slag, high This can reduce the viscosity and fluidity of slag at high temperatures. To resolve the liquidity problem, the addition of extra flux is unavoidable.

[0006] Therefore, it is necessary to develop technologies that are easy to operate while solving environmental pollution and equipment corrosion problems. It is essential. [Overview of the project] [Problems that the invention aims to solve]

[0007] In this embodiment, lithium can be efficiently recovered from waste lithium batteries using a low-temperature dry method. We aim to provide a lithium recovery method. [Means for solving the problem]

[0008] A method for recovering lithium from waste lithium batteries according to one embodiment involves waste lithium battery cells and a step of low-temperature melting a mixture containing additives; and the step of generating in the low-temperature melting step A step of collecting thium salts may be included.

[0009] A step of low-temperature melting of a mixture of waste lithium battery cells and additives; and the low-temperature melting stage This may include a step of collecting the lithium salts generated in the previous stage.

[0010] Furthermore, the step of low-temperature melting of the mixture containing the waste lithium battery cells and additives is 10 The process may be carried out at temperatures in the range of 0°C to 1500°C, specifically in the range of 100°C to 1100°C. It may be carried out at the temperature of the enclosure and may be carried out for a time in the range of 10 minutes to 5 hours.

[0011] Further, the additive may be FeCl3, and based on the lithium contained in the waste lithium battery cell, the additive FeCl3 can be introduced in a Cl equivalent range of 0.5 equivalent to 3 equivalents. It can be done.

[0012] Before the step of low-temperature melting the mixture containing the waste lithium battery cell and the additive, a step of pretreating the negative electrode material of the waste lithium battery cell can be performed.

[0013] The collected lithium salt may be in a liquid phase, a solid phase, a liquid phase or a mixture of a solid phase and a liquid phase, and the collected lithium salt can be washed with water to obtain a high-purity lithium salt.

[0014] Further, the collected lithium salt is in a gas phase, and after the gas-phase lithium salt is solidified in a cooling zone, it can be washed with water to obtain a high-purity lithium salt.

Advantages of the Invention

[0015] According to this embodiment, an additive is mixed with a waste lithium battery and melted at a low temperature, so that lithium in the waste lithium battery can be efficiently recovered.

[0016] By melting under low-temperature conditions using an additive, problems such as corrosion of equipment can be prevented, not only is the overall operation control easy, but also there is an advantage that the operation cost due to low-temperature operation can be reduced.

Brief Description of the Drawings

[0017] [Figure 1] It schematically shows a method for recovering lithium from a waste lithium battery according to an embodiment. ​​​​​​​ [Modes for carrying out the invention]

[0018] Terms such as 1st, 2nd, and 3rd refer to various parts, components, regions, layers and / or sectors. These terms are used to describe, but are not limited to, these terms. Distinguish a minute, region, layer, or section from other parts, components, regions, layers, or sections. It is used only for the purpose of: Therefore, the first part, component, region, layer or section described below The term is a second part, component, region, layer, or section, without departing from the scope of the present invention. It can be mentioned as such.

[0019] The technical terms used herein are merely for the purpose of referring to specific embodiments of the present invention. It is not intended to limit it. The singular form used here does not mean that the statement is clearly the opposite. Unless otherwise specified, this includes multiple forms. In this specification, "includes" refers to specific characteristics and domains. , embody integers, stages, actions, elements and / or components, and other characteristics, domains, integers, stages This does not exclude the presence or addition of actions, elements, and / or components.

[0020] When referring to one part being "on top of" or "on" another part, this directly refers to the other part Other parts may be present on, above, or between the minutes. In contrast, When referring to a part being "directly above" another part, it implies that no other part is in between them.

[0021] Although not specifically defined, all terms used herein, including technical and scientific terms, are used. The term has the same meaning as generally understood by a person with ordinary skill in the art to which this invention belongs. It has the meaning of: The term as defined in commonly used dictionaries is related to the technical literature and currently disclosed It is further interpreted to have a meaning that corresponds to the content, and unless otherwise defined, it is ideal or very It is not interpreted in an official sense.

[0022] The embodiments of the present invention will be described in detail below. However, these are presented as examples only. This does not limit the present invention, and the present invention is defined solely within the scope of the claims described below. It can be done.

[0023] Figure 1 schematically shows a method for recovering lithium from a waste lithium battery according to one embodiment. That is what it was.

[0024] Referring to Figure 1, lithium is recovered from a waste lithium battery according to one embodiment of the present invention. The method involves the steps of mixing waste lithium battery cells and additives and melting them at a low temperature (S1); and the low The step may include (S2) collecting the lithium salt obtained during the melting stage.

[0025] First, the waste lithium battery cells and additives are mixed and melted at a low temperature (S1). Cut.

[0026] Waste lithium battery cells are either crushed or fed into the reactor in an uncrushed state. It is possible.

[0027] A waste lithium battery cell may consist of a negative electrode material, a positive electrode material, and a cell structure. The negative electrode material is copper. It can contain carbon, etc., and the positive electrode material is lithium, cobalt, nickel, manganese, etc. It may contain aluminum and iron, and the cell structure may contain copper and aluminum. can.

[0028] In order to selectively recover lithium from waste lithium batteries, To minimize the formation of compounds such as LiAlO2, which is a compound of Al and Li, Li oxidation LiCl, LiF, and L are compounds that can maximize the vapor pressure of Li compared to other substances. It is advantageous to form compounds such as i3PO4, Li2S, Li2SO4, and LiNO3. That is the case.

[0029] In one embodiment, the additive is a Cl compound or F compound, a P compound, an S compound and an N compound. It may be one or more compounds selected from the combination, specifically MgCl2, FeCl2 And may be one or more selected from FeCl3, more specifically, FeC It may also be l3. In the case of FeCl3, it reacts with Li in the waste lithium battery at low temperatures. Cl can be produced, and when additives such as CaCl2 and MgCl2 react with chloride, high temperatures are required. This can solve problems that require temperature control.

[0030] On the other hand, the amount of additive used is calculated based on the amount of lithium contained in the waste lithium battery cell. It can be added in a range of 0.5 to 3 equivalents, specifically in a range of 1 to 2 equivalents.

[0031] If the amount of additive added is less than the aforementioned range, the lithium recovery rate may decrease. On the other hand, If the amount of additive added exceeds the aforementioned range, it may induce the formation of other metal chlorides. There is.

[0032] In the reactor, the additive FeCl3, along with the NiMnCo alloy in the waste lithium battery, is used as a metal capture agent. It can be utilized, and some is converted to FeO. Here, the excess carb in the waste lithium battery The presence of carbon (C) can make it difficult to collect metals. The added additive FeCl3 reacts. The remaining Fe can react with some NiCoMn and C to form an alloy in the form of Fe3C. For example, depending on the carbon content, the Cl in the implanted FeCl3 reacts with Li and Li Cl is formed, and the remaining Fe becomes Fe3C or FeO as a generated slag. It is capable of floating.

[0033] Additionally, oxides such as K2O, BaO, and Na2O can be added. By adding the oxide, the Al and Li compounds contained in waste lithium batteries are removed. This is advantageous in reducing the formation of compounds such as LiAlO2.

[0034] The waste lithium batteries and additives are mixed and dissolved at low temperatures.

[0035] The low-temperature melting temperature may be in the range of 100°C to 1500°C, specifically 100°C to 11 The temperature range may be 0°C, or more specifically, 100°C to 1000°C. Furthermore, the low-temperature melting time may be in the range of 10 minutes to 5 hours.

[0036] If the low-temperature melting temperature is lower than the aforementioned temperature range, the reaction generation driving force is low, and in the waste lithium battery There is a problem in that the efficiency of converting lithium to lithium salt decreases. Also, in the aforementioned temperature range If the temperature is too high, the atmosphere inside the reactor becomes unstable, leading to a problem of reduced quality of the lithium produced. This can occur, leading to increased operating costs due to rising temperatures.

[0037] On the other hand, before introducing waste lithium battery cells into the reactor, carbon contained in the negative electrode material is removed. A pretreatment process for the negative electrode material can be performed. The pretreatment method for the negative electrode material selects carbon. It can be selectively oxidized, or the negative electrode material can be used as is without prior removal. However, This is not limited to this.

[0038] When the carbon within the negative electrode material is treated through the aforementioned negative electrode material pretreatment, the dissolution of the reducing alloy Melting and collection are stabilized. This has the advantage of improving lithium recovery efficiency. be.

[0039] Next, the lithium salt generated during the low-temperature melting stage is collected in the collection unit (S2). It is possible.

[0040] During the low-temperature melting stage, the lithium in the waste lithium battery cell is converted into lithium salt, and the process temperature Depending on the cooling environment, it may be in one or more states among the gas phase, liquid phase, and solid phase.

[0041] Furthermore, the generated lithium salt can be collected in a separately provided collection unit. When the temperature is above 000°C, the generated lithium salt can evaporate and be in the gas phase. Once lithium is generated, it is solidified in a cooling zone in the downstream section and washed with water to remove lithium chloride. It will be recovered as a um aqueous solution.

[0042] When the reactor temperature is in the range of 600°C to 1000°C, the lithium salt produced is melted. When the reaction is in the liquid phase and the reactor temperature is below 600°C, the resulting lithium salt is in the solid phase. It is possible.

[0043] When the reactor temperature is in the range of 100°C to 1000°C, liquid phase, solid phase, liquid phase or solid phase and liquid It may be a mixture of phases.

[0044] When the lithium salt is in the liquid phase, solid phase, or a mixture of solid and liquid phases, the lower part of the reactor is located Lithium salts can be separated using a separate collection device. The lithium salt is converted to an aqueous lithium salt solution through water washing, and then high-purity lithium salt You can obtain this.

[0045] The lithium recovery rate is calculated by analyzing the lithium concentration in the lithium salt aqueous solution obtained above. It is possible.

[0046] On the other hand, if the lithium salt is in the liquid or solid phase, a high-temperature reactor is provided in the subsequent stage to chlorinate the salt. High-purity lithium chloride can be obtained by evaporating lithium at high temperatures. The temperature of the thermal reactor may be 1400°C or higher.

[0047] Examples and comparative examples of the present invention will be described in detail below. However, these are presented as illustrative examples only. Therefore, the present invention is not limited thereto, and the present invention is only within the scope of the claims described below. It is defined. [Examples]

[0048] (Example 1) Mix waste lithium battery cells with FeCl3 and heat at a temperature of 1100°C or less for 1 hour. The lithium salt was recovered by heating. The lithium salt remained as a product within the raw material without vaporizing. .

[0049] (Comparative Examples 1 and 2) Comparative Example 1 used CaCl2 instead of FeCl3 as the additive, while Comparative Example 2 used MgCl2. The lithium salt was recovered in the same manner as in Example 1, except that a different substance was used.

[0050] The lithium recovery rates obtained in Example 1, Comparative Example 1, and Comparative Example 2 are shown in Table 1 below. The recovery rate was shown as the amount of lithium recovered from water leaching relative to the total amount of lithium in the waste lithium battery cell. The lithium recovery rate from lithium salts was calculated.

[0051] [Table 1]

[0052] Referring to Table 1 above, the recovery rate of lithium recovered in Example 1 was 83.83%. Therefore, it is clear that this is superior to Comparative Example 1's 68.99% and Comparative Example 2's 69.09%. It became that.

[0053] The present invention is not limited to the above-described embodiments and can be manufactured in a variety of different forms. A person with ordinary skill in the art to which this invention belongs will understand the technical concept and essentials of this invention. It should be clear that this can be implemented in other specific forms without changing its characteristics. Therefore, the embodiments described above are illustrative and not limiting in all respects. It must be understood.

Claims

1. A step of heat-treating a mixture containing waste lithium battery cells and additives; and The step includes collecting the lithium salt generated in the heat treatment step; Methods for recovering lithium from waste lithium batteries.

2. The step of heat-treating the mixture containing the waste lithium battery cells and additives is performed at 100°C to 1 Lithium recovery from waste lithium batteries according to claim 1, carried out at temperatures in the range of 500°C. How to do it.

3. The step of heat-treating the mixture containing the waste lithium battery cells and additives is performed at 100°C to 1 Lithium recovery from waste lithium batteries according to claim 2, carried out at a temperature in the range of 100°C. How to do it.

4. The step of heat-treating the mixture containing the waste lithium battery cells and additives is 10 minutes to 5 hours. A method for recovering lithium from a waste lithium battery according to claim 1, which is performed over a period of time within the specified range. 。

5. The aforementioned additive is one of the following: a Cl compound or an F compound, a P compound, an S compound, or an N compound. Lithium from the waste lithium battery according to claim 1, which is one or more selected from Methods for recovery.

6. The Cl compound of the aforementioned additive is MgCl ２ FeCl ２ and FeCl ３ Choose from the following A method for recovering lithium from a waste lithium battery according to claim 5, wherein one or more of the above are performed.

7. Based on the lithium contained in the aforementioned waste lithium battery cell, the Cl equivalent is 0.5 to 3 Adding the additive in an equivalent amount range, the lithium is recovered from the waste lithium battery according to claim 5. A method of storage.

8. A step of heat-treating the mixture containing the waste lithium battery cells and additives; previously, The waste lithium battery cell according to claim 1, wherein the step of pre-treating the negative electrode material of the waste lithium battery cell is performed. Methods for recovering lithium from ponds.

9. The collected lithium salt is in the liquid phase, solid phase, liquid phase, or a mixture of solid and liquid phases. The collected lithium salt is washed with water to obtain a high-purity lithium salt, as described in claim 1. Methods for recovering lithium from waste lithium batteries.

10. The collected lithium salt is in the gas phase. The aforementioned gas-phase lithium salt is solidified in a cooling zone, and then washed with water to obtain a high-purity lithium salt. A method for recovering lithium from a waste lithium battery as described in claim 1.

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