KR20130035214A - Method for separating aluminium and manganese - Google Patents

Abstract

PURPOSE: A method for separating aluminium and manganese is provided to suppress the loss of at least one kind of nickel, lithium, and cobalt from solution including aluminum and manganese; and at least one kind of cobalt, nickel, and lithium during the collection of aluminium and manganese. CONSTITUTION: A method for separating aluminium and manganese comprises: a step of simultaneously separating aluminium and manganese by extracting at least one kind of nickel, lithium, and cobalt and sulfuric acid solution as a solvent; and a step of using an extraction agent of acid-phosphatase ester as an extraction solvent. [Reference numerals] (AA) Sulfuric acid solution(Containing Co, Ni, Li, Al, and Mn); (BB) Liquid after extraction(Containing Co, Ni, and Li); (CC) Extracting a solvent; (DD) Equilibrium pH 2.6-3.0; (EE) Solvent(Containing Co, Ni, Li, Al, and Mn); (FF) Washing liquid(Containing Co, Ni, and Li); (GG) Washing; (HH) Manganese sulfate solution, Average pH 1.8-2.0; (II) Solvent(Containing Al and Mn);

Description

METHOD FOR SEPARATING ALUMINIUM AND MANGANESE}

The present invention relates to a method for separating aluminum and manganese, and, for example, to a method for separating aluminum and manganese from an leachate obtained by acid leaching of a raw material after incineration, pulverization and sorting of a lithium ion battery.

The use of lithium ion batteries is rapidly expanding for hybrid vehicles, and the production of large batteries is expected to increase rapidly due to the higher capacity of the unit. In addition, in order to expand the demand for lithium ion batteries, it is required to establish a valuable metal recovery method from lithium ion batteries.

A lithium ion battery mainly consists of a positive electrode, a negative electrode, a separator, and a housing | casing, and a positive electrode consists of a positive electrode active material containing manganese, cobalt, nickel, lithium, and electrically conductive agents, such as carbon black, on a collector of aluminum foil to binders, such as a fluorine system, etc. It has a kneaded and coated structure. The positive electrode material is composed of a binder layer containing an aluminum foil having a thickness of about 15 micrometers and a positive electrode active material, and has an external appearance in which a black positive electrode active material is coated on the aluminum foil.

As a recycling method of a lithium ion battery, the method of extracting and separating each metal by solvent extraction from the obtained leachate after performing acid leaching using the raw material after incineration, crushing, and sorting a used lithium ion battery is proposed. . However, if iron or aluminum is contained as an impurity in the raw material, iron or aluminum is leached out by acid leaching and adverse effects are caused by extraction and extraction in solvent extraction. Therefore, when iron and aluminum are contained in the leaching liquid which acid-leached the raw material, iron and aluminum are removed.

As a method for removing iron or aluminum in an acidic solution, a neutralization method is generally proposed. As such a neutralization method, for example, Patent Document 1 discloses a method of neutralizing to pH 4.0 to 4.5 with alkaline earth metal hydroxides. In addition, Patent Document 2 discloses a method of blowing a mixed gas of sulfurous acid gas and air or oxygen, and adding calcium carbonate to adjust the pH to 4.0 to 4.5.

Japanese Patent Application Laid-Open No. 2002-154825 Japanese Patent Application Publication No. 2010-180439

The metal to be recovered in lithium ion battery recycling is manganese, cobalt, nickel, lithium, and iron and aluminum need to be separated as impurities. If the method of separating aluminum and iron by neutralization as in patent document 1 is applied to a lithium ion battery recycling wet process, cobalt, nickel, and lithium will easily co-precipitate when neutralizing, and it will become a recovery loss. On the other hand, if neutralization conditions are relaxed in order to suppress recovery loss of cobalt or the like, removal of aluminum becomes insufficient. In addition, although the method of patent document 2 can state that co-precipitation of nickel can be suppressed, it is not specified about the behavior of cobalt and lithium, and it also purchases gas, such as sulfurous acid gas and oxygen, and blows it into solution. A need arises. Thereby, installation of a blowing device, electric power for operating the device, and an exhaust gas treatment facility when using sulfurous acid gas, and fire prevention measures when using oxygen are necessary. Moreover, the method of patent document 2 collects valuable metals, such as manganese, after iron and aluminum are isolate | separated and removed at once. When aluminum is recovered simultaneously with iron in this manner, aluminum is precipitated at once in the raw material, and gel-shaped aluminum hydroxide, which is generated in large quantities, deteriorates the filterability, so that separation takes a very long time. As a result, treatment efficiency is high in the recovery of aluminum and manganese. It becomes bad.

Accordingly, the present invention provides a method for efficiently recovering aluminum and manganese while suppressing at least one loss of cobalt, nickel and lithium from at least one of cobalt, nickel and lithium, and a solution containing aluminum and manganese. It is a task to do it.

MEANS TO SOLVE THE PROBLEM As a result of earnestly examining in order to solve the said subject, it does not separate aluminum and manganese separately about the solution containing at least 1 sort (s) of cobalt, nickel, and lithium, and aluminum and manganese, but also simultaneously By separating by solvent extraction, it was found that aluminum and manganese can be efficiently recovered while suppressing at least one loss of cobalt, nickel and lithium. Furthermore, we found solvent extraction conditions that are optimal for the simultaneous separation of aluminum and manganese.

The present invention completed on the basis of the above knowledge, in one aspect, by solvent extraction of sulfuric acid acid solution containing at least one of cobalt, nickel and lithium, and aluminum and manganese, aluminum and manganese are simultaneously extracted with a solvent to separate It is a separation method of aluminum and manganese.

The separation method of aluminum and manganese which concerns on this invention WHEREIN: In one Embodiment, in the said solvent extraction, the acidic phosphate ester type extractant is used as an extraction solvent.

In another embodiment of the method for separating aluminum and manganese, the acidic phosphoric acid ester-based extractant is bis (2-ethylhexyl) phosphate.

In another embodiment, the separation method of aluminum and manganese according to the present invention is solvent extraction at equilibrium pH2.6 to 3.0 in the solvent extraction.

In another embodiment of the method for separating aluminum and manganese, the sulfuric acid acid solution containing at least one of the cobalt, nickel, and lithium, and aluminum and manganese is used as a sulfuric acid solution. A leaching liquid obtained by leaching.

According to the present invention, there can be provided a method for efficiently recovering aluminum and manganese while suppressing at least one loss of cobalt, nickel and lithium from at least one of cobalt, nickel and lithium, and a solution containing aluminum and manganese. Can be.

1 is a flowchart of a method for separating aluminum and manganese according to an embodiment of the present invention.
2 is a graph showing the relationship between the equilibrium pH at the time of solvent extraction and the extraction rate of each element.
3 is a flowchart of a method for separating aluminum and manganese from a leaching solution obtained by leaching waste materials of a lithium ion battery with sulfuric acid.
Fig. 4 is a graph showing the reduction rate of the neutralization reaction solution before the neutralization reaction of iron, aluminum, manganese, cobalt and nickel when the aqueous solution of sodium hydroxide is used as a neutralizing agent and the pH value is changed to neutralization treatment.

The separation method of aluminum and manganese which concerns on embodiment of this invention can be used suitably for the method of collect | recovering a valuable metal from the used lithium ion battery main body, and it is included in a lithium ion battery if it describes in detail. It can use for the method of separating aluminum which is an impurity, and manganese which is a valuable metal from the solution which arises when processing the positive electrode material used. Hereinafter, the case of separating aluminum and manganese in the leachate in lithium ion battery recycling will be described as an example. However, the present invention is not limited to the following examples, and in addition, it can be used for various purposes for separating aluminum and manganese. Of course.

(First Embodiment: Separation Method of Aluminum and Manganese)

1 is a flow chart of a method for separating aluminum and manganese from an acidic solution containing cobalt, nickel and lithium, and aluminum and manganese. The sulfuric acid acid solution containing cobalt, nickel and lithium, and aluminum and manganese is not specifically limited, For example, the solution after removing iron from the leaching liquid in lithium ion battery recycling, etc. can be used.

Next, aluminum and manganese are extracted simultaneously by solvent extraction from the sulfuric acid acid solution. At this time, cobalt, nickel, and lithium are mostly recovered in the extraction after-liquid rather than being extracted in a solvent, but some may be extracted. Partially extracted cobalt, nickel and lithium are not lost because they can be recovered in the washing process after solvent extraction described later. By simultaneously extracting aluminum and manganese in solvent extraction, aluminum and manganese can be efficiently recovered while suppressing the loss of cobalt, nickel and lithium.

The extractant used here is preferably an acidic phosphate ester extractant. Among the acidic phosphate ester extractants, bis (2-ethylhexyl) phosphate has a close pH value for extracting aluminum and a pH value for extracting manganese, and thus is particularly useful as an extractant for simultaneous extraction of aluminum and manganese. desirable.

Solvent extraction is performed by mixing the solvent extracted by diluting the said extractant with the hydrocarbon-type solvent, and a sulfuric acid acidic solution. When using bis (2-ethylhexyl) phosphate as an extractant, it is preferable that the mixing ratio of this extractant and a hydrocarbon type solvent is 1: 3. As the hydrocarbon solvent, an aromatic solvent, a paraffin solvent, a naphthenic solvent, or the like can be used, and among these, a naphthenic solvent is more preferable.

Fig. 2 shows the relationship between the equilibrium pH at the time of solvent extraction and the extraction rate of each element. 2 shows that the equilibrium pH at the time of extracting manganese and aluminum is preferably adjusted to the range of 2.6 to 3.0 by adding a neutralizing agent. As the neutralizing agent, sodium hydroxide, sodium carbonate and the like can be used. When equilibrium pH is higher than 3.0, the hydroxide of aluminum contained in a leach liquid may generate | occur | produce and the piping of an apparatus may be clogged. If the pH is lower than 2.6, the extraction rate of manganese and aluminum is lowered, and extraction separation of manganese and aluminum from the leach solution may not be sufficient.

Thus, by simultaneously solvent-extracting aluminum and manganese from a sulfuric acid acid solution, the separation process efficiency of aluminum and manganese becomes favorable.

Next, the solvent (extraction liquid) containing aluminum and manganese obtained by solvent extraction is wash | cleaned using the manganese sulfate solution whose equilibrium pH was adjusted to 1.8-2.0. By this washing, metals such as cobalt, nickel and lithium contained in the extract are recovered. The wash liquid containing the recovered metal can be returned as the extraction liquid of solvent extraction, thereby reducing the loss of metals such as cobalt, nickel and lithium. If the equilibrium pH of the manganese sulfate solution at the time of washing | cleaning is less than 1.8, there exists a possibility that a back extraction may arise and the problem that a part of manganese in a solvent is extracted to a washing | cleaning liquid may arise. In addition, when the equilibrium pH of the manganese sulfate solution at the time of washing | cleaning is more than 2.0, since it is close to the pH from which cobalt is extracted, washing | cleaning may become inadequate.

(Second Embodiment: Separation Method of Aluminum and Manganese from Leachate Obtained by Leaching Waste Materials of Lithium Ion Battery with Sulfuric Acid)

3 is a flowchart of a method for separating aluminum and manganese from a leaching solution obtained by leaching waste materials of a lithium ion battery with sulfuric acid. As a separation method of aluminum and manganese from the leaching liquid obtained by leaching the waste material of a lithium ion battery with sulfuric acid, an acid leaching liquid is prepared first. As this acid leaching liquid, the sulfuric acid acid solution containing aluminum, manganese, iron, cobalt, nickel, lithium, etc. which were obtained by lithium ion battery recycling can be used. Such acid leaching liquids typically have 10 to 300 g / L sulfuric acid, 0.001 to 10 g / L iron, 0.001 to 20 g / L aluminum, 0.001 to 30 g / L manganese, 0.001 to 40 g / L cobalt, And 0.001 to 30 g / L nickel and 0.001 to 30 g / L lithium.

Next, iron is separated and removed as a hydroxide from this acid leaching liquid by neutralization treatment. The neutralizing agent may be any hydroxide aqueous solution or alkali aqueous solution of an alkali metal or alkaline earth metal, and for example, an aqueous solution of sodium hydroxide or sodium carbonate may be used. In FIG. 4, the reduction rate with respect to the neutralization reaction of iron, aluminum, manganese, cobalt, and nickel in the neutralization reaction liquid when a sodium hydroxide aqueous solution is used as a neutralizing agent, and a pH value is changed and a neutralization process is shown is shown. It can be seen from FIG. 4 that the pH in the neutralization treatment is preferably adjusted in the range of 3.5 to 4.5. If the pH is higher than 4.5, the reduction rate of other metals such as manganese, cobalt and nickel increases. If the pH is less than 3.5, there is a possibility that iron removal will be insufficient.

The redox potential (silver / silver chloride electrode reference) at the time of neutralization treatment is preferably 500 kV or more. If it is 500 Pa or less, oxidation of iron in the liquid will be insufficient, and iron removal in the neutralization treatment will be insufficient. As a method of setting the redox potential to 500 kPa or more, there are a method of adding hydrogen peroxide and a method of blowing air.

As described above, by defining the pH value and the redox potential at the time of neutralization, while aluminum is well separated and removed from the acid leaching liquid as a hydroxide, only a part of aluminum can be precipitated as a hydroxide, and most of it can be left in the neutralizing after-liquor. For this reason, the time used for removing the hydroxide of aluminum which is a filterability defect in the said neutralization process becomes short, and precipitation of other metals, such as cobalt and nickel, by the co-precipitation effect at the time of neutralization is also suppressed, As a result, In the subsequent step, other metals can be recovered efficiently.

Next, aluminum and manganese are simultaneously extracted by solvent extraction of the neutralized after-liquid obtained by filtering and filtering from an acid leaching liquid. When copper is contained in the neutralizing after-liquid, this copper will be extracted and removed alone in advance, but since the processing efficiency becomes good, it is preferable to extract it at once with aluminum, manganese, etc. by the solvent extraction mentioned above. By simultaneously extracting aluminum and manganese by solvent extraction, aluminum and manganese can be efficiently recovered while suppressing the loss of cobalt, nickel and lithium.

As the extractant used herein, an acidic phosphate ester extractant is preferable, and bis (2-ethylhexyl) phosphate is particularly preferable.

Solvent extraction is performed by mixing the solvent which was diluted and adjusted with the hydrocarbon-type solvent, and a neutralization after-treatment. When using bis (2-ethylhexyl) phosphate as an extractant, it is preferable that the mixing ratio of this extractant and a hydrocarbon type solvent is 1: 3. As the hydrocarbon solvent, an aromatic solvent, a paraffin solvent, a naphthenic solvent, or the like can be used, and among these, a naphthenic solvent is more preferable.

Moreover, it is preferable to adjust the equilibrium pH at the time of extraction of manganese and aluminum to add the neutralizing agent, and to adjust to the range of 2.6-3.0.

Next, the solvent (extraction liquid) containing aluminum and manganese obtained by solvent extraction is wash | cleaned using the manganese sulfate solution whose equilibrium pH was adjusted to 1.8-2.0. This cleaning recovers metals such as cobalt, nickel and lithium contained in the extract in addition to aluminum and manganese by extraction. The wash liquid containing the recovered metal can be returned as the extraction liquid of solvent extraction, thereby reducing the loss of metals such as cobalt, nickel and lithium.

Next, aluminum and manganese are extracted to a back extraction liquid by back extracting the extract after a washing | cleaning process with a sulfuric acid acidic solution. The sulfuric acid concentration of the sulfuric acid acid solution is preferably 25 to 200 g / L. If the sulfuric acid concentration is less than 25 g / L, there is a possibility that the back extraction of aluminum may be insufficient, and if it is more than 200 g / L, there is a problem of cost.

Next, the back extraction liquid obtained by back extraction is neutralized, and aluminum and manganese are isolate | separated from the reaction liquid. The neutralizing agent may be any hydroxide aqueous solution or alkali aqueous solution of an alkali metal or alkaline earth metal, and for example, an aqueous solution of sodium hydroxide or sodium carbonate may be used. It is preferable to adjust pH in neutralization process to the range of 4.0-4.5. If the pH is higher than 4.5, the reduction rate of manganese may increase. If the pH is less than 4.0, there is a possibility that the removal of aluminum becomes insufficient. By this neutralization, aluminum is separated and recovered as a hydroxide. Manganese is contained in the neutralization after-liquid, and can be collect | recovered by a well-known means as needed.

<Examples>

Examples of the present invention are described below, but the examples are not intended to limit the invention for the purpose of illustration.

(First embodiment)

Sulfuric acid solution containing various metals shown in Table 1 (H ₂ SO ₄ concentration 10g / L) and bis (2-ethylhexyl) phosphate (LANXESS brand name: D2EHPA) to a naphthenic solvent (shell chemicals brand name: shellsolD70) The mixture dilute and adjusted to 25 vol% was mixed and stirred so as to have an organic phase / water phase = 4 (volume ratio), and extraction of manganese and aluminum was carried out while adjusting with sodium hydroxide to obtain an equilibrium pH of 2.8. The extraction rate of each element is shown in Table 2. In addition, the concentration of each element in the extraction liquid is shown in Table 3.

It can be seen from Table 2 and Table 3 that most of the manganese and aluminum in the liquid could be extracted. Although Co is also extracted about 20%, Co extracted is not lost because it can be recovered by washing with solvent extraction.

Next, after extraction, the solvent was back extracted with a sulfuric acid solution (H ₂ SO ₄ concentration 100 g / L), and a back extract having a composition shown in Table 4 was obtained. The back extract was adjusted to pH 4.0 with sodium hydroxide. It adjusted and the neutralization process was performed. The reduction rate of each element concentration in the neutralization treatment liquid compared with before the neutralization treatment is shown in Table 5. In addition, the concentration of each element in the neutralization treatment liquid is shown in Table 6.

Tables 5 and 6 show that manganese and aluminum can be separated by neutralization treatment.

(Comparative Example 1)

The sulfuric acid solution (H ₂ SO ₄ concentration 10g / L) containing the various metals of Table 7 was adjusted to pH5.0 with sodium hydroxide, and the neutralization process was performed. The reduction rate of each element concentration in the neutralization treatment liquid compared with before the neutralization treatment is shown in Table 8. In addition, Table 9 shows the concentration of each element in the neutralization treatment liquid.

From the first example and the first comparative example, it is understood that aluminum and manganese are simultaneously extracted by solvent extraction, rather than separating aluminum alone by neutralization treatment, so that the loss of other metals is smaller.

Claims (5)

A method for separating aluminum and manganese, wherein at least one of cobalt, nickel and lithium, and a sulfuric acid acidic solution containing aluminum and manganese are extracted by solvent extraction, thereby simultaneously separating aluminum and manganese with a solvent. The method of claim 1,
The said solvent extraction WHEREIN: The separation method of aluminum and manganese using the acidic phosphoric acid ester extractant as an extraction solvent. The method of claim 2,
A separation method of aluminum and manganese, wherein the acidic phosphate ester extractant is bis (2-ethylhexyl) phosphate. 4. The method according to any one of claims 1 to 3,
In the solvent extraction, the solvent extraction to the equilibrium pH 2.6 to 3.0, the separation method of aluminum and manganese. 4. The method according to any one of claims 1 to 3,
The sulfuric acid acidic solution containing at least 1 sort (s) of said cobalt, nickel, and lithium, and aluminum and manganese is a leachate obtained by leaching waste material of a lithium ion battery with sulfuric acid, The separation method of aluminum and manganese.

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