Treatment method of waste battery

Abstract

The invention provides a treatment method for obtaining a solution containing nickel and / or cobalt from waste batteries. The treatment method sequentially comprises the following steps: (1) a pretreatment procedure: harmlessly treating and crushing the waste battery to obtain a crushed material; (2) an alkali leaching step in which an alkali is added to the crushed material to obtain an alkali leachate containing Li, Al, F, and P and an alkali leach residue containing Ni and / or Co; (3) a reduction leaching step in which the alkali leach residue is brought into contact with an acid and a reducing agent to obtain a reduction leachate in which Ni and / or Co are reduced and leached into an acid solution; (4) a vulcanization process: adding a vulcanizing agent into the reduction leachate to obtain a post-vulcanization liquid in which Cu is removed as sulfide; (5) an oxidation-neutralization step in which an oxidizing agent and a neutralizing agent are added to the post-vulcanization liquid to precipitate and remove Fe, P, and Al, thereby obtaining an oxidation-neutralized liquid; and (6) an ion exchange step in which the oxidized and neutralized solution is brought into contact with an ion exchange resin, and F is adsorbed to the ion exchange resin and separated, thereby obtaining a post-ion-exchange solution containing Ni and / or Co.

Description

Technical Field

[0001] The present invention relates to a method for treating waste batteries, and more particularly to a method for treating waste batteries for obtaining a solution containing nickel and / or cobalt from waste batteries containing nickel and / or cobalt. Background Art

[0002] Vehicles such as electric cars and hybrid cars, and electronic devices such as mobile phones, smartphones, and computers are equipped with lithium-ion batteries, which have the characteristics of being lightweight and having high output.

[0003] Lithium-ion batteries are made by placing negative electrode materials and positive electrode materials together with a separator made of a porous resin film such as polypropylene in an outer can made of metal such as aluminum or iron or plastic such as vinyl chloride, and placing lithium hexafluorophosphate (LiPF4) in a can. 6 The negative electrode material is a negative electrode collector composed of copper foil on which a negative electrode active material such as graphite is fixed, and the positive electrode material is a positive electrode collector composed of aluminum foil on which a positive electrode active material such as lithium nickelate and lithium cobaltate is fixed.

[0004] If lithium-ion batteries are assembled in vehicles, electronic devices, etc. as described above and used, they will soon become unusable due to the deterioration of the vehicle, electronic device, etc. or the life of the lithium-ion batteries, and become waste lithium-ion batteries. It should be noted that waste lithium-ion batteries also include batteries that are defective from the initial manufacturing process.

[0005] These waste lithium-ion batteries contain valuable components such as nickel, cobalt, and copper, and it is desired to recover the valuable components and reuse them to effectively utilize resources.

[0006] Generally, when attempting to efficiently recover valuable components from devices, parts, and materials made of metal, dry processing has been widely used in the past, in which the metal is placed in a furnace or the like and melted at high temperature to separate the metal containing the valuable substance from the other slag.

[0007] For example, Patent Document 1 describes a method for recovering valuable metals using dry treatment, wherein the dry treatment includes: a pre-oxidation step of roasting waste batteries to oxidize the waste batteries; and a dry step of melting the oxidized waste batteries to separate the valuable metals. If the method of Patent Document 1 is applied to waste lithium-ion batteries, a copper alloy containing nickel and cobalt can be obtained.

[0008] Although the dry treatment has the disadvantage of using a furnace heated to a high temperature and consuming a large amount of energy, it has the advantage of being able to separate various impurities at once. In addition, the slag obtained in the dry treatment is chemically stable, has little impact on the environment, and is easy to dispose of.

[0009] However, when waste lithium-ion batteries are treated by dry processing, a portion of valuable components, especially cobalt, is almost entirely distributed in the slag, which inevitably causes a loss of cobalt recovery.

[0010] In addition, the metal obtained by the dry treatment is an alloy in which valuable components coexist. In order to reuse it, it is necessary to separate the components from the alloy and purify it to remove impurities.

[0011] Among the methods of element separation commonly used in the dry process, there is a method of separating, for example, copper from lead or lead from zinc by slowly cooling from a high-temperature molten state. However, when copper and nickel are the main components, such as in waste lithium-ion batteries, copper and nickel have the property of melting uniformly over the entire composition range. Therefore, even if slowly cooled, copper and nickel are only mixed and solidified in a layered state and cannot be separated.

[0012] Furthermore, there is a purification method in which nickel is subjected to a disproportionation reaction using carbon monoxide (CO) gas to volatilize and separate it from copper and cobalt. However, since toxic CO gas is used, there is also a problem of difficulty in ensuring safety.

[0013] In addition, as an industrially performed method for separating copper and nickel, there is a method for roughly separating mixed matte (sulfide). In this method, a matte containing copper and nickel is generated in a smelting process, and the matte is slowly cooled in the same manner as in the above case, thereby separating sulfides containing a large amount of copper from sulfides containing a large amount of nickel.

[0014] However, even with this separation method, the separation of copper and nickel is limited to a rough separation, and in order to obtain high-purity nickel and copper, additional treatment such as electrolytic purification is required.

[0015] In addition, a method using a vapor pressure difference via chlorides has been studied. However, since this is a process for handling a large amount of toxic chlorine, it is necessary to take large-scale corrosion countermeasures and safety measures for the equipment, and it is difficult to say that this method is suitable for industry.

[0016] As described above, the separation and purification of each element by a dry method has the disadvantages of being limited to a crude separation level or being costly compared to a wet method.

[0017] Patent Document 2 describes a wet treatment using a method such as acid, neutralization, or solvent extraction. This wet treatment has the advantages of consuming little energy and being able to separate and recover mixed valuable components at a high purity.

[0018] However, when waste lithium-ion batteries are treated by wet treatment, hexafluorophosphate anions, an electrolyte component contained in waste lithium-ion batteries, are difficult to treat and cannot be completely decomposed even in high-temperature, high-concentration sulfuric acid, and are mixed into the acid solution that leaches valuable components.

[0019] Since the hexafluorophosphate anion is a water-soluble carbonate, it is difficult to recover phosphorus and fluorine from the aqueous solution after recovering the valuable substances. In order to suppress the discharge into public sea areas, etc., various measures need to be taken, and there are also great restrictions on the environment.

[0020] Furthermore, it is difficult to obtain a solution that can efficiently leach valuable components from waste lithium ion batteries for purification using only acid. The waste lithium ion battery body is a structure with strength as a battery, and it is difficult to leach valuable components using acid or the like, and it is difficult to completely leach valuable components.

[0021] In addition, if forced leaching is performed using an acid with strong oxidizing power, the following problems will arise: impurity components such as aluminum, iron, and manganese that are not industrially recovered will also be leached together with the valuable components, the cost of the neutralizer used to treat the impurities by neutralization will increase, and the amount of wastewater and sediment generated will increase.

[0022] Furthermore, there may be residual charges in the waste lithium-ion batteries. If they are directly disposed of, there is a possibility of causing heat generation, explosion, etc. Therefore, it takes time and effort to conduct harmless treatment such as discharging the residual charges.

[0023] As such, it cannot be said that only wet treatment is an advantageous method for treating spent lithium-ion batteries.

[0024] Therefore, for waste lithium-ion batteries that are difficult to treat using the above-mentioned dry treatment or wet treatment alone, a method of combining dry treatment and wet treatment has been used, that is, an attempt has been made to remove impurities as much as possible through dry treatment such as roasting the waste lithium-ion batteries to obtain a uniform melt of the waste lithium-ion batteries, and a method has been made to wet treat the melt as described above to separate it into valuable components and components other than valuable components.

[0025] However, waste lithium-ion batteries are dissolved into metals by dry treatment such as roasting waste lithium-ion batteries, and energy and chemical costs are required to dissolve the metals again.

[0026] In addition, a large amount of graphite, namely C, is used as a component in lithium-ion batteries. C is difficult to recycle, but on the other hand, it can also be used as a fuel. Therefore, in the above-mentioned treatment methods including dry treatment, it is usually treated by burning under high temperature conditions. However, in recent years, it is believed that the generation of carbon dioxide caused by combustion should be suppressed in terms of the environment, and it cannot be said that this is an excellent treatment method in terms of the environment.

[0027] Therefore, a method is also considered, which eliminates the danger of explosion by heating the battery under relatively low temperature conditions to the extent that only the organic components of the electrolyte contained in the battery are decomposed, thereby obtaining a harmless Ni / Co concentrated slag also called black mass, and then crushing and adjusting the black mass into a fine size to facilitate wet processing and provide it for wet processing.

[0028] Heating under low temperature conditions reduces the load and cost of the furnace in dry processing compared to the conventional method of melting under high temperature conditions. Furthermore, since the raw materials are adjusted to be uniform to a certain extent, the wet processing has the advantage of improving the handling efficiency compared to the whole wet processing.

[0029] However, when the black matter is used as a raw material, a large amount of carbon contained in the waste lithium ion battery remains, the amount of material increases, and further, thermally decomposed fluoride ions also remain in the raw material, so there is also a problem of increasing the load on wastewater in the wet treatment.

[0030] As described above, it is difficult to efficiently separate valuable substances such as Ni and Co and other impurity elements from alloys derived from waste lithium-ion batteries and the like while reducing the generation of carbon dioxide as much as possible.

[0031] It should be noted that the above-mentioned problem also exists when separating nickel and / or cobalt from an alloy containing copper, nickel and cobalt other than the waste batteries, such as waste nickel-metal hydride batteries other than waste lithium-ion batteries.

[0032] Prior art literature

[0033] Patent Literature

[0034] Patent Document 1: Japanese Patent Application Publication No. 2012-172169.

[0035] Patent document 2: Japanese Patent Application Laid-Open No. 63-259033. Summary of the invention

[0036] Problems to be solved by the invention

[0037] An object of the present invention is to provide a processing method capable of efficiently obtaining nickel and / or cobalt from waste batteries.

[0038] Means for solving problems

[0039] The first invention of the method for treating waste batteries is a method for obtaining a solution containing nickel and / or cobalt from waste batteries, characterized in that the method for treating waste batteries sequentially performs: (1) a pretreatment step, in which the waste batteries are rendered harmless and crushed to obtain crushed materials; (2) an alkaline leaching step, in which an alkali is added to the crushed materials to obtain an alkaline leaching solution containing Li, Al, F, and P and an alkaline leaching residue containing Ni and / or Co; and (3) a reduction leaching step, in which the alkaline leaching residue is contacted with an acid and a reducing agent to obtain a solution containing Ni and / or Co. (4) a sulfiding step, in which a sulfiding agent is added to the reducing leaching solution to obtain a sulfided solution in which Cu is removed as sulfide; (5) an oxidation neutralization step, in which an oxidizing agent and a neutralizing agent are added to the sulfided solution to precipitate and remove Fe, P, and Al to obtain an oxidized neutralized solution; and (6) an ion exchange step, in which the oxidized neutralized solution is contacted with an ion exchange resin to adsorb F on the ion exchange resin and separate it to obtain an ion exchanged solution containing Ni and / or Co.

[0040] The waste battery treatment method according to the second invention is characterized in that, in the first invention, the pre-treatment step includes a detoxification step of heating the waste battery to render the waste battery detoxified.

[0041] The method for treating waste batteries according to the third invention is characterized in that, in the first invention, the pre-treatment step includes a crushing step of crushing the waste batteries that have completed the detoxification step.

[0042] A waste battery treatment method according to a fourth invention is characterized in that, in the first invention, in the alkali leaching step, the alkali leaching is repeated three to five times.

[0043] The method for processing waste batteries of the fifth invention is characterized in that, in the first invention, the waste batteries are waste lithium-ion batteries.

[0044] Effects of the Invention

[0045] According to the first invention, by sequentially performing each step, impurities can be efficiently separated from waste batteries, and a solution containing nickel and / or cobalt can be selectively obtained. In addition, since the main treatment step of the present invention is a wet treatment, energy consumption is low, and the amount of carbon dioxide generated by the treated material is low, which is excellent in terms of the environment.

[0046] According to the second invention, since F and P contained in the waste batteries can be converted into harmless forms by heating, the risk of explosion in the subsequent process can be eliminated and the drainage load can be reduced.

[0047] According to the third invention, by crushing the waste batteries, wet processing in the main processing step can be easily performed.

[0048] According to the fourth invention, by repeating the alkaline leaching a plurality of times, impurities can be efficiently leached and separated, and a high-purity nickel and / or cobalt solution can be obtained.

[0049] According to the fifth invention, since the spent lithium-ion batteries contain nickel and / or cobalt, a high-purity nickel and / or cobalt solution can be obtained efficiently. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 It is a basic process diagram showing the method for treating waste batteries of the present invention.

[0051] Figure 2 It shows Figure 1 A process diagram showing details of the main processing step. DETAILED DESCRIPTION

[0052] Hereinafter, embodiments of the present invention will be described based on the drawings.

[0053] The present invention is not limited to the following embodiments, and can be implemented with appropriate modifications within the scope of the present invention. It should be noted that in this specification, the expression "X to Y" (X and Y are arbitrary numerical values) means "X or more and Y or less".

[0054] The treatment method of the present invention is a treatment method for obtaining a solution containing nickel and / or cobalt from waste batteries, characterized in that the treatment method sequentially performs: (1) a pretreatment step S1, in which the waste batteries are rendered harmless and crushed to obtain crushed products; (2) an alkaline leaching step S2, in which an alkali is added to the crushed products to obtain an alkaline leaching solution containing Li, Al, F, and P and an alkaline leaching residue containing Ni and / or Co; (3) a reduction leaching step S3, in which the alkaline leaching residue is contacted with an acid and a reducing agent to obtain a solution in which Ni and / or Co are reduced and leached. (4) a sulfiding step S4, in which a sulfiding agent is added to the reducing leaching solution to obtain a sulfided solution in which Cu is removed in the form of sulfide; (5) an oxidizing and neutralizing step S5, in which an oxidizing agent and a neutralizing agent are added to the sulfided solution to precipitate and remove Fe, P, and Al to obtain an oxidized and neutralized solution; and (6) an ion exchange step S6, in which the oxidized and neutralized solution is contacted with an ion exchange resin to adsorb F on the ion exchange resin and separate it to obtain an ion exchange solution containing Ni and / or Co.

[0055] The waste batteries to be processed in the present invention include not only waste lithium-ion batteries but also nickel-hydrogen batteries and the like.

[0056] Waste batteries contain nickel (Ni), cobalt (Co), copper (Cu), iron (Fe), manganese (Mn), lithium (Li), aluminum (Al), fluorine (F), phosphorus (P), carbon (C), etc. If the treatment method of the present invention is performed, Li, Al, F, P, and C can be efficiently separated from waste batteries containing these, and a solution containing nickel and / or cobalt can be obtained. In this specification, "nickel and / or cobalt" refers to three modes including "nickel and cobalt", "nickel only", and "cobalt only".

[0057] The waste batteries described in the present invention include not only batteries that have been discarded after use, but also defective batteries generated during the battery manufacturing stage and surplus batteries that do not need to be commercialized. Furthermore, batteries containing nickel and / or cobalt, such as batteries used in electric vehicles, electrodes of capacitors used in general electronic circuits including automobiles, and terminal materials of semiconductor elements, are also included. In this specification, these are collectively referred to as waste batteries.

[0058] Below, according to Figure 1 and Figure 2 , an implementation method for treating waste lithium-ion batteries that have been discarded after use as the object of treatment is described.

[0059] (Pre-treatment step S1)

[0060] like Figure 1 As shown, the pre-treatment step S1 is composed of a detoxification step S11, a crushing step S12, and a physical separation step S13.

[0061] (Detoxification process S11)

[0062] The detoxification step S11 is a step of heating the waste lithium-ion batteries at a temperature of about 500° C. to decompose F and P in the electrolyte contained in the waste lithium-ion batteries into harmless forms.

[0063] Waste lithium-ion batteries contain electrolytes composed of organic substances such as F and P, and sometimes have residual charges. Therefore, if they are directly crushed, leached, etc., there is a risk of explosion and an increase in drainage load, which is not preferred. Therefore, the detoxification step S11 is performed before supplying to the crushing step S12 as a subsequent step.

[0064] (Crushing process S12)

[0065] The crushing step S12 is a step of crushing the waste lithium-ion batteries to facilitate the treatments in the main treatment steps of the alkali leaching step S2 and below. A known crusher can be used in the crushing step.

[0066] (Physical separation step S13)

[0067] The physical separation step S13 is a step of screening the crushed product obtained in the crushing step S12.

[0068] The size of the crushed material can be any size that is easy to wet process in the main processing step and easy to handle. Specifically, the size of the crushed material can be several mm, and after crushing, the crushed material is screened using a sieve with a mesh size of the crushed material.

[0069] (Main Process)

[0070] The crushed material after the pre-processing step S1 is subjected to the following main processing step. Figure 1 The alkali leaching step S2, the reduction leaching step S3, the sulfidation step S4, the oxidation neutralization step S5 and the ion exchange step S6 are shown.

[0071] Below, according to Figure 2 The main processing steps are described in detail.

[0072] (Alkali Leaching Step S2)

[0073] The alkali leaching step S2 is a step of treating the crushed material after the pretreatment step S1 as a treatment object, adding an alkali agent for leaching, and obtaining an alkali leaching solution containing Li, Al, F, and P and an alkali leaching residue containing Ni, Co, C, Cu, F, Fe, P, and Al.

[0074] As the alkaline agent used in the alkali leaching step S2, there is sodium hydroxide, which is preferably added at a concentration of 1 to 8 mol / L. Although leaching can be performed at a liquid temperature ranging from room temperature to about 80°C, leaching at about 50 to 60°C is most effective industrially and is therefore preferred. Under the conditions of 50 to 60°C, the leaching rate does not change much from that at 80°C, and the energy cost is reduced. Furthermore, sodium hydroxide under high temperature conditions is not preferred in terms of handling safety, and there are also problems with the durability of the equipment, and there is almost no advantage in raising the temperature to 80°C for operation.

[0075] The alkali leaching step S2 is preferably repeated a plurality of times, for example, three to five times, because impurities can be efficiently leached and separated.

[0076] In addition, as an operation for repeating the alkaline leaching a plurality of times, a method of adding a new alkaline agent to the leached residue or a countercurrent multi-stage method of leaching by causing the leached residue and the alkaline agent to flow in opposite directions can be used.

[0077] Among the impurities contained in the waste lithium-ion battery, about 80% of Li, Al, P and F are removed in the alkali leaching step S2. However, when valuable substances such as Ni and Co are reused as battery raw materials, it is necessary to further remove the impurities.

[0078] Therefore, in the present invention, an oxidation neutralization step S5 and an ion exchange step S6 are provided as subsequent steps.

[0079] (Reduction leaching step S3)

[0080] The reduction leaching step S3 is a step of bringing the alkali leaching residue obtained in the alkali leaching step S2 into contact with a reducing agent to reduce Ni and Co to obtain a reduction leaching solution leached into an acid solution, and separating the reduction leaching solution from the alkali leaching residue.

[0081] In the reduction leaching step S3, the alkali leaching residue and the acid solution are mixed as slurry, and a reducing agent is further added to reduce Ni and Co contained in the alkali leaching residue from insoluble trivalent to easily leached divalent, and then leached into the acid solution to obtain a reduction leachate. In addition to Ni and Co, the reduction leachate also contains Cu, F, Fe, P, and Al. C is contained in the alkali leaching residue and is discharged out of the system at this stage.

[0082] In the acid solution used for reduction, solutions such as sulfuric acid, hydrochloric acid, and nitric acid can be used. When sulfuric acid is used, the concentration can be 1 mol / L, and it can be adjusted to add to a pH of about 0 to 3. Although the liquid temperature can be carried out at room temperature to about 80°C, about 50 to 60°C is the most practical in industry, so it is preferred. Under conditions of 50 to 60°C, the leaching rate does not change much from that at 80°C, and the energy cost is reduced. Furthermore, sodium hydroxide under high temperature conditions is not preferred in terms of handling safety, and there are also problems with the durability of the equipment. There is almost no advantage in raising the temperature to 80°C for operation.

[0083] As the reducing agent, sulfite compounds such as sodium sulfite and sodium bisulfite can be used. SO 2 Furthermore, a sulfiding agent such as sodium hydrosulfide can also be used.

[0084] As a method for adding a reducing agent, for example, it can be controlled by the following method: the potential of the Ag / AgCl electrode as a reference electrode (hereinafter the same) is in the range of 600 to 800 mV as a reference, and the reducing agent is added when the oxidation-reduction potential (hereinafter also referred to as ORP) increases compared to the reference. In addition, if the ORP is too low, the leached nickel and cobalt will precipitate and cannot be separated from the residue.

[0085] In the present invention, as described above, in the detoxification step S11, since the waste lithium-ion battery is not heated to be completely melted and alloyed, C remains in the alkali leaching residue. However, in the reduction leaching step S3, the target nickel and cobalt are leached, and C remains in the alkali leaching residue, so nickel and / or cobalt can be separated from C.

[0086] In addition, in the conventional dry method, carbon in the waste lithium ion battery is oxidized and removed, thereby generating carbon dioxide, but in the present invention, a wet treatment is performed, so carbon dioxide is not generated, which is also excellent in terms of the environment.

[0087] (Vulcanization step S4)

[0088] The sulfiding step S4 is a step of adding a sulfiding agent to the reducing leaching solution obtained in the reducing leaching step S3 to obtain a sulfided solution in which Cu is removed as sulfide. In the reducing leaching solution in the reducing leaching step S3, Cu is leached in addition to Ni and Co. Therefore, a sulfiding agent is added to the reducing leaching solution to lower (reduce) the redox potential to around -200 to 50 mV. In this way, the dissolved Cu can be fixed in the form of copper sulfide and separated from nickel and cobalt. Although the liquid temperature in the sulfiding is carried out below 80°C, the range of 50 to 60°C is the most practical in industry and is therefore preferred. The reason is the same as that of the alkali leaching step S2 and the reducing leaching step S3.

[0089] As the sulfidizing agent, for example, sodium hydrosulfide, hydrogen sulfide gas, etc. can be used.

[0090] In addition, Ni, Co, F, Fe, P, and Al remain in the post-sulfurization liquid. It should be noted that Li is not a target for recovery but is contained in the post-sulfurization liquid.

[0091] (Oxidation Neutralization Step S5)

[0092] The oxidation neutralization step S5 is a step of adding an oxidant and a neutralizer to the sulfided liquid obtained in the sulfidation step S4 to precipitate and remove Fe, P, and Al to obtain an oxidation neutralized liquid. The liquid temperature during the oxidation neutralization step S5 may be 40 to 80°C, more preferably 50 to 60°C.

[0093] As the neutralizing agent, an alkaline agent such as sodium hydroxide can be used. The pH may be adjusted to a pH that can remove Fe, Al, P, zinc, etc., and the pH may be about 4 to 6, preferably about 5 to 6.

[0094] The ORP during oxidation is preferably within a range in which the Fe ions contained are in a trivalent form, and specifically, may be maintained at approximately 350 to 400 mV.

[0095] In addition, Ni, Co, F, and Li remain in the oxidized neutralized solution.

[0096] (Ion Exchange Step S6)

[0097] The ion exchange step S6 is a step of bringing the oxidized neutralized liquid obtained in the oxidized neutralization step S5 into contact with an ion exchange resin to adsorb and separate F onto the ion exchange resin, thereby obtaining an ion exchanged liquid containing Ni and Co.

[0098] In the present invention, as described above, since the high temperature of the degree performed in the conventional dry treatment is not reached, even if the F in the electrolyte contained in the waste lithium ion battery is decomposed, it will not be removed. Therefore, even if F is leached in the aforementioned alkaline leaching step S2, a part of F will remain in the oxidizing neutralization solution.

[0099] Incomplete residual F in the black matter causes a problem of increased environmental load. Therefore, in the present invention, in order to remove F, the F is brought into contact with an ion exchange resin to adsorb and remove F ions, thereby obtaining a solution containing Ni and Co that are not adsorbed by the ion exchange resin.

[0100] Among the ion exchange resins capable of adsorbing F ions, there are materials containing, for example, hydroxide of cerium and hydroxide of zirconium. If these ion exchange resins are used, the concentration of F ions in the solution can be reduced to about 1 / 10. In addition, as an adsorbent (ion exchange resin) with hydroxide of cerium as the main matrix, there is an ion exchange resin with the trade name of READ-F (HG) manufactured by Nippon Kaisei Co., Ltd.

[0101] By sequentially executing the above-described steps S1 to S6, impurities can be efficiently separated from waste lithium-ion batteries, and a solution containing nickel and / or cobalt can be selectively obtained. In addition, since the main treatment step of the present invention is a wet treatment, energy consumption is low, and the amount of carbon dioxide generated by the treated material is low, which is excellent in terms of the environment.

[0102] Example

[0103] (Example 1) (Alkali leaching only once)

[0104] The waste lithium-ion batteries were heat-treated in an atmospheric (air) environment at 500° C. (detoxification step S11 ), crushed (crushing step S12 ), and then sorted with a sieve with a mesh size of 5 mm (physical separation step S13 ).

[0105] The grades of the crushed lithium ion battery materials (also referred to as black matter) after screening are shown in Table 1. The reason why the total mass % of the grades is less than 100% is that the materials exist in the form of oxides.

[0106] [Table 1]

[0107] Ni Co Cu Fe Mn Li Al F P C quality% 13 6 1 1 7 4 2 3 1 41

[0108] Then, the crushed product having the composition shown in Table 1 was subjected to the following main treatment process.

[0109] For the alkali leaching treatment, 0.2L to 2L of a sodium hydroxide solution with a concentration of 1 mol / L was added at room temperature to make the slurry concentration reach 100g / L, and the mixture was stirred to leach the crushed material (alkali leaching step S2). 90% of Al, 80% of F, and 99% of P were separated to the alkali leaching solution side (in addition, 20% of Li was also distributed to the alkali leaching solution), and solid-liquid separation was performed using filter paper and a filter (Nutsche) to obtain an alkali leaching residue.

[0110] A sulfuric acid solution adjusted to pH 1 was added to the obtained alkali leaching residue as a slurry, and the liquid temperature was maintained at 60°C. Then, sodium bisulfite (NaHSO) with a concentration of 1 mol / L was added as a reducing agent. 3 ) solution (reduction leaching step S3). The point at which the ORP rise stops following the addition is regarded as the end point.

[0111] Then, the filtrate was separated into solid and liquid using a filter bottle and filter paper, and the obtained filtrate (reduction leaching solution) was analyzed using an ICP analyzer to determine the concentration of each element component. The results are shown in Table 2.

[0112] Then, the temperature of the obtained reduction leaching solution was maintained at 60°C, and sodium hydrogen sulfide was added to perform sulfidation so that the ORP was less than 0 mV (sulfidation step S4). Then, solid-liquid separation was performed, and the obtained filtrate (sulfided liquid) was analyzed using an ICP analyzer to determine the concentration of each element component. The results are shown in Table 2.

[0113] Then, the liquid temperature of the obtained sulfidized liquid was maintained at 60°C, and the pH value was adjusted to 5 using a 25% sodium hydroxide solution and a 30% hydrogen peroxide solution, and the ORP was maintained at 300 mV or more. Then, solid-liquid separation was performed to obtain an oxidized neutralized liquid (oxidation neutralization step S5). The liquid (oxidized neutralized liquid) was analyzed using an ICP analyzer to determine the concentration of each element component. The results are shown in Table 2.

[0114] Then, the obtained oxidized neutralized liquid is passed through a column filled with an ion exchange resin with the trade name READ-F (HG) manufactured by Nippon Seawater Co., Ltd. at room temperature, so that the F ions are adsorbed on the resin and separated (ion exchange step S6), and an ion exchange liquid discharged from the column is obtained.

[0115] The ion exchange solution was analyzed using an ICP analyzer to determine the concentration of each element component.

[0116] [Table 2]

[0117]

[0118] -Evaluation of Example 1-

[0119] In Example 1, it was found that Cu, Fe, Mn, Li, Al, F, P, and C were efficiently separated from waste lithium-ion batteries and the like, and a solution containing nickel and / or cobalt was obtained.

[0120] The following Examples 2 to 5 are experimental examples conducted by changing the number of leaching treatments in the alkali leaching step S2.

[0121] (Example 2) (Alkaline leaching was repeated five times)

[0122] Similar to Example 1, waste lithium-ion batteries of a different type from those used in Example 1 are treated at 500° C. (detoxification step S11 ), crushed (crushing step S12 ) and screened (physical separation step S13 ).

[0123] The grades of the crushed waste lithium-ion batteries obtained after screening are shown in Table 3. It should be noted that the total does not reach 100% because it exists in the form of oxides.

[0124] [Table 3]

[0125] Ni Co Cu Fe Mn Li Al F P C quality% 17 9 6 1 10 4 5 2 1 30

[0126] As an alkali leaching treatment, the crushed material was leached using a sodium hydroxide solution maintained at 80° C. and having a concentration of 1 mol / L, and the leachate was removed, an equal amount of new sodium hydroxide solution of the same concentration was added, and leaching was performed again, and this treatment was repeated a total of five times (alkali leaching step S2).

[0127] As shown in Table 5, after five repetitions of leaching, 96% of Li, 88% of Al, 94% of F, and 93% of P in the waste lithium-ion battery crushed material were separated to the alkaline leaching solution side, and a residue mainly composed of Ni and Co was obtained.

[0128] The obtained alkali leaching residue was put into a sulfuric acid solution adjusted to pH 1, the liquid temperature was maintained at 60°C, and sodium bisulfite (NaHSO) with a concentration of 1 mol / L was added. 3 ) solution (reduction leaching step S3). The moment when the ORP rise stops with the addition is taken as the end point. Then, solid-liquid separation is performed, and the obtained filtrate (reduction leaching solution) is analyzed using an ICP analyzer to determine the concentration of each element component. The results are shown in Table 4.

[0129] Then, the liquid temperature of the obtained reduction leaching solution was set to 60°C, and sodium hydrogen sulfide was added to reduce the ORP to less than 0 mV, and copper was removed in the form of copper sulfide (sulfidation step S4). Then, solid-liquid separation was performed, and the obtained filtrate (sulfided liquid) was analyzed using an ICP analyzer to determine the concentration of each element component. The results are shown in Table 4.

[0130] Then, the obtained reducing solution was set to 60°C, and a 25% sodium hydroxide solution and a 30% hydrogen peroxide aqueous solution were used to adjust the pH to 5, and the ORP was maintained in a range of 300 mV or more. Then, solid-liquid separation was performed to obtain a filtrate (oxidation neutralization solution) (oxidation neutralization step S5). The oxidation neutralization solution was analyzed using an ICP analyzer to determine the concentration of each element component. The results are shown in Table 4.

[0131] Then, the obtained oxidized neutralized liquid was brought into contact with ion exchange resin READ-F (HG) manufactured by Nihon Kaisha Co., Ltd. packed in a column under normal temperature conditions (ion exchange step S6), and an ion exchanged liquid was obtained from the discharge side of the column. The results are shown in Table 4.

[0132] [Table 4]

[0133]

[0134] -Evaluation of Example 2-

[0135] In Example 2, it can also be seen that Cu, Fe, Mn, Li, Al, F, P, and C can be efficiently separated from waste lithium-ion batteries and the like, and a solution containing nickel and / or cobalt can be obtained.

[0136] (Example 3) (Alkaline leaching was repeated three times)

[0137] Using the same waste lithium-ion batteries as in Example 2, the alkaline leaching process in the alkaline leaching step S2 was repeated three times using a sodium hydroxide solution having a concentration of 1 mol / L at 80°C.

[0138] As shown in Table 5, 84% of Li, 69% of Al, 94% of F, and 12% of P were separated to the alkaline leaching solution side, and an alkaline leaching residue mainly composed of Ni and Co was obtained.

[0139] (Example 4) (Alkaline leaching was repeated twice)

[0140] Using the same waste lithium-ion battery as in Example 2, the alkaline leaching treatment in the alkaline leaching step S2 was repeated twice using a sodium hydroxide solution having a concentration of 1 mol / L at 80°C to leach the crushed product.

[0141] As shown in Table 5, 70% of Li, 47% of Al, 94% of F, and 7% of P were separated to the alkaline leaching solution side, and an alkaline leaching residue mainly composed of Ni and Co was obtained.

[0142] (Example 5) (Alkali leaching only once)

[0143] Using the same waste lithium-ion battery as in Example 2, an operation of leaching the crushed material using a sodium hydroxide solution having a concentration of 1 mol / L at 80° C. was performed once as an alkaline leaching treatment in the alkaline leaching step S2.

[0144] As shown in Table 5, 68% of Li, 44% of Al, 94% of F, and 5% of P were separated to the alkaline leachate side.

[0145] -Evaluation of Examples 2 to 5-

[0146] As shown in Table 5, in Examples 5 to 2, it can be seen that as the number of leaching times increases from one to five times, the ratios of lithium, aluminum, and phosphorus leached increase.

[0147] If there are many impurities remaining in the alkali leaching residue, a large amount of acid is required for dissolution in the subsequent reduction leaching step S3, and a large amount of alkali is also required in the oxidation neutralization step S5. Considering this situation, it can be seen that the amount of acid and alkali used can be reduced by increasing the number of alkali leaching in the alkali leaching step S2.

[0148] In addition, although Example 1 was leached once, its liquid distribution was higher than that of Example 5. This is probably because the types of waste lithium-ion batteries used as raw materials in Example 1 and Examples 2 to 5 were different, resulting in differences in dissolution in alkali. In addition, in Example 1, although Li is also a recycling target, it does not need to be completely removed like Al, F, and P, so the removal rate is still low in this example.

[0149] [Table 5] Distribution % to the alkaline leaching solution side in the alkaline leaching step S2

[0150] Leaching times Li Al F P Example 1 1 20 90 80 99 Example 2 5 96 88 94 93 Example 3 3 84 69 94 12 Example 4 2 70 47 94 7 Example 5 1 68 44 94 5

[0151] Industrial Applicability

[0152] In addition to being applicable to waste lithium-ion batteries that have been used up, the present invention can also be used to process batteries containing nickel, such as nickel-hydrogen batteries, their defective products, batteries for electric vehicles, electrodes of capacitors used in general electronic circuits including automobiles, terminal materials of semiconductor elements, and the like.

[0153] Description of Reference Numerals

[0154] S1: Pre-treatment process.

[0155] S11: Detoxification process.

[0156] S12: Crushing process.

[0157] S13: physical separation step.

[0158] S2: Alkali leaching process.

[0159] S3: reduction leaching process.

[0160] S4: Vulcanization process.

[0161] S5: Oxidation neutralization process.

[0162] S6: ion exchange process.

Claims

1. A method for treating waste batteries, which is a method for obtaining a solution containing nickel and / or cobalt from waste batteries, characterized in that: The method for treating waste batteries is performed in sequence: (1) a pre-treatment step, in which the waste batteries are rendered harmless and crushed to obtain crushed materials; (2) an alkali leaching step, in which alkali is added to the crushed material to obtain an alkali leaching solution containing Li, Al, F, and P and an alkali leaching residue containing Ni and / or Co; (3) a reduction leaching step, wherein the alkaline leaching residue is contacted with an acid and a reducing agent to obtain a reduction leaching solution in which Ni and / or Co are reduced and leached into an acid solution; (4) a sulfiding step, in which a sulfiding agent is added to the reducing leaching solution to obtain a sulfided solution in which Cu is removed in the form of sulfides; (5) an oxidation neutralization step, in which an oxidant and a neutralizer are added to the sulfided liquid to precipitate and remove Fe, P, and Al to obtain an oxidation neutralized liquid; and (6) An ion exchange step of bringing the oxidized neutralized liquid into contact with an ion exchange resin to adsorb F onto the ion exchange resin and separate the F, thereby obtaining an ion exchanged liquid containing Ni and / or Co.

2. The method for treating waste batteries according to claim 1, characterized in that: The pre-treatment step includes a detoxification step of heating the waste batteries to render them harmless.

3. The method for treating waste batteries according to claim 1, characterized in that: The pre-treatment process includes a crushing process, and the crushing process is to crush the waste batteries that have completed the harmless process.

4. The method for treating waste batteries according to claim 1, characterized in that: In the alkali leaching step, the alkali leaching is repeated three to five times.

5. The method for treating waste batteries according to claim 1, characterized in that: The waste batteries are waste lithium-ion batteries.

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