JP2000119765A - Recovering method of lithium and recovering device therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simply and efficiently perform recovery by irradiating an aq. solution containing lithium with ultrasonic wave to selectively recover lithium. SOLUTION: The aq. solution containing lithium and an adsorbent are introduced into a vessel 1 and the aq. solution is irradiated with ultrasonic wave generated by an ultrasonic generator 4. If necessary, the aq. solution is stirred by a stirring impeller 6. The aq. solution containing the lithium adsorbent is moved to a vessel 2 and a scavenger is introduced and the aq. solution is irradiated with ultrasonic wave generated by an ultrasonic generator 5. If necessary, the aq. solution is stirred by the stirring impeller 6. The adsorbent is floated on the surface of the solution by adding the scavenger. The floated adsorbent is moved together with the aq. solution to a filter 3 to separate the aq. solution incorporated in the adsorbent. The separated aq. solution is discharged from a discharge port 13. Lithium adsorbed on the adsorbent is eluted by a chlorine based weak acid introduced from a weak acid supply port 12 and recovered fruit the discharge port 13 as a lithium concentrated solution.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for selectively separating and recovering lithium from an aqueous solution containing lithium, such as industrial wastewater, particularly water treated with a constituent material of a lithium battery. The present invention relates to a lithium recovery method and a lithium recovery device capable of recovering lithium.

[0002]

2. Description of the Related Art Metal lithium and lithium compounds are:
It is used in many fields as a battery, a refrigerant absorbent, a pharmaceutical, and the like. In particular, a demand for a lithium battery as a primary battery for watches and cameras and a small secondary battery for portable devices is increasing.

[0003] A used lithium battery has a risk of ignition when it is disassembled at home, and it is desirable to recover the lithium battery from the viewpoint of the environment and the reuse of resources.

[0004] After recovery, the constituent materials are separated and recovered, as shown in Japanese Patent Publication No. 272467/1998. Among them, lithium is stabilized by dissolving it in a large amount of water so as not to cause exothermic ignition.

[0005] In addition, lithium is contained in aqueous solutions such as brine, geothermal water, and seawater. Although the lithium concentration at this time is low, it can be used as metallic lithium by separating and collecting and concentrating.

As a method for recovering lithium in an aqueous solution, Japanese Patent Application Laid-Open No.
An electrochemical method as disclosed in Japanese Patent No. 535748, and a method in which lithium is adsorbed on an adsorbent and separated as disclosed in Japanese Patent Publication No. 2531790 published in 1996 are disclosed.

[0007]

In the case of recovering lithium from an aqueous solution as described above, it is necessary to treat a large amount of the aqueous solution in a short time because the lithium ion content in the aqueous solution is small.

However, in the electrochemical method, it is difficult to treat a large amount of an aqueous solution even if the efficiency is high. Further, in the method of adsorbing lithium on the adsorbent, a large amount of aqueous solution can be treated, but it is necessary to increase the adsorption efficiency.

SUMMARY OF THE INVENTION The present invention has been made to solve such a problem, and a method for easily and efficiently recovering lithium from a large amount of lithium-containing aqueous solution such as brackish water, geothermal water, and water treated with battery constituent materials is disclosed. An object of the present invention is to provide a recovery device.

[0010]

In order to solve the above problems, a method for recovering lithium according to the present invention is characterized in that an aqueous solution containing lithium is irradiated with ultrasonic waves to selectively recover the lithium. And

[0011] When irradiating the aqueous solution containing lithium with ultrasonic waves, the aqueous solution is stirred.

Further, an adsorbent for selectively adsorbing lithium is added to an aqueous solution containing lithium, and the lithium is adsorbed on the adsorbent.

Further, the method is characterized in that an adsorbent for selectively adsorbing lithium is added to an aqueous solution containing lithium, and then the adsorbent adsorbing lithium is separated from the aqueous solution.

Further, when the adsorbent having adsorbed lithium is separated from the aqueous solution, a collecting agent is added to the aqueous solution.

Further, the lithium recovery apparatus of the present invention is an apparatus for selectively recovering lithium from an aqueous solution containing lithium, wherein an ultrasonic generator is provided in a container for introducing the aqueous solution containing lithium. It is characterized by having.

At this time, it is useful to have a mechanism for stirring the aqueous solution containing lithium.

It is also useful to have an adsorbent introducer. It is also useful to have an adsorbent introducing device and a separating section for the adsorbent.

It is also useful to have a collector introducing device and a filter for the adsorbent.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a lithium recovery apparatus used in the present invention.

The tanks 1 and 2 for storing the treatment aqueous solution and the filter 3 are installed.
And a stirring blade 6. Further, the tank 1 is provided with a supply port 7 for the aqueous solution containing lithium, a supply port 8 for the adsorbent, and an open / close valve 9 from the tank 1 to the tank 2. The tank 2 is provided with a collecting agent supply port 10 and an openable / closable valve 11 from the tank 2 to the tank 3. The filter 3 is provided with a weak acid supply port 12 and a drain port 13.

First, an aqueous solution containing lithium is introduced into the tank 1 from the supply port 7. Subsequently, the adsorbent is introduced into the aqueous solution containing lithium from the supply port 8. As the adsorbent at this time, amorphous aluminum hydroxide, metallic aluminum, a manganese compound, or the like can be used. Next,
Ultrasonic waves generated by the ultrasonic generator 4 are applied to the above-described aqueous solution. Further, if necessary, the aqueous solution is stirred by rotating the stirring blade 6.

In the conventional method, only the aqueous solution was stirred. However, as will be described later in the examples, the ultrasonic irradiation improves the adsorption efficiency. Also,
The stirring efficiency is further improved by stirring at the same time. Such a phenomenon is caused by ultrasonic irradiation.
The adsorption reaction progresses actively, almost adsorbs lithium ions coming to the surface of the adsorbent, and the lithium ions can penetrate into the concave portions of the irregularities on the surface of the adsorbent, making effective use of the surface area of the adsorbent I think we can do it.

Subsequently, the aqueous solution containing the lithium adsorbent is moved from the tank 1 to the tank 2 by the open / close valve 9.
Then, the collecting agent is introduced from the supply port 10 and the aqueous solution is irradiated with ultrasonic waves by the ultrasonic generator 5 in the same manner as described above. In addition, stirring is performed by the rotating blades 6 as needed. Even with this operation, the collection efficiency becomes very high as before. As the collecting agent at this time, a fatty acid-based collecting agent, a sulfonic acid-based collecting agent, or the like can be used. Then, by adding the collecting agent, the adsorbent floats on the solution surface.

The suspended adsorbent is moved to the filter 3 by the open / close valve 11 together with the aqueous solution in the tank 2. Then, the aqueous solution mixed in the adsorbent is separated. The separated aqueous solution is drained from the drain 13. Further, the lithium adsorbed by the adsorbent is eluted by the chlorine-based weak acid introduced from the supply port 12 and can be recovered as a lithium concentrate from the drain port 13.

The recovered lithium concentrate is purified, dehydrated by heating to obtain anhydrous lithium chloride, and subjected to molten salt electrolysis to be reused as metallic lithium.

The above operation can be continuously performed on a large amount of aqueous solution.

[0027]

Embodiments of the present invention will be described below with reference to FIG.

(Example 1) As a lithium-containing aqueous solution,
Three types of lithium chloride aqueous solutions having lithium concentrations of 10, 1, and 0.1 mM / L were prepared. The pH was adjusted to 9 by adding a buffer solution. Prepare 3L of each solution,
One liter was used for each of the following three conditions. 1) In-solution stirring only 2) In-solution ultrasonic irradiation only 3) In-solution stirring + ultrasonic irradiation Experiments were performed using the apparatus shown in Fig. 1. After each experiment, the inside of the container was always thoroughly washed, and residual There was no influence of things.

The oscillating ultrasonic wave had a frequency of 50 kHz. 1 L of each aqueous solution was supplied to the tank 1, 18 g of an adsorbent (manganese adsorbent) was added, and the treatment under the above three conditions was performed for 10 minutes. Thereafter, the aqueous solution was transferred to the tank 2, 30 mg of a fatty acid collecting agent was added, and the above three conditions were performed each time for 5 minutes.

Table 1 shows the residual lithium concentration in each aqueous solution at that time.

[0031]

[Table 1]

As is evident from Table 1, it is understood that the ultrasonic irradiation treatment has a higher lithium recovery efficiency than the stirring only treatment during the adsorption and the collection. Furthermore, it can be seen that the effect is enhanced when the stirring and the ultrasonic treatment are combined. Further, it can be seen that even when the initial lithium concentration of the aqueous solution is low, when the ultrasonic irradiation treatment is performed, the recovery ability does not decrease.

Thereafter, the adsorbent was filtered by the filter 3, and lithium was separated from the adsorbent by using dilute hydrochloric acid, and could be recovered as a lithium concentrated solution.

Therefore, when recovering lithium from a lithium-containing aqueous solution, by irradiating ultrasonic waves, lithium can be efficiently recovered from a large amount of aqueous solution, and the efficiency is to maintain the recovery ability even in an aqueous solution having a low lithium concentration. I understand.

In this embodiment, lithium chloride is used as the lithium-containing aqueous solution. However, it is apparent that the present invention can be applied to brine, seawater, geothermal water, industrial wastewater, a lithium battery treatment solution, and the like. is there.

It is also possible to adjust the moving amount of the aqueous solution by adjusting the opening ratio of the open / close valve, and to continuously process a large amount of the aqueous solution.

Further, the method of irradiating an ultrasonic wave may be applied to a lithium recovery method using an electrochemical electrode.

In this embodiment, the ultrasonic irradiation is performed from the side of the container, but may be performed from below.

[0039]

According to the present invention, since the above-described method and apparatus for recovering lithium are used, lithium can be efficiently recovered from a lithium aqueous solution in a short time, and a large amount of an aqueous solution can be continuously produced at a low lithium concentration. This makes it possible to obtain an effect that a highly concentrated lithium solution can be easily recovered.

[Brief description of the drawings]

FIG. 1 is a schematic view of a lithium recovery apparatus according to one embodiment of the present invention.

[Explanation of symbols]

 1, 2 tank 3 filter 4, 5 ultrasonic generator 6 stirring blade 7 lithium-containing aqueous solution supply port 8 adsorbent supply port 9, 11 openable valve 10 collector supply port 12 weak acid supply port 13 drain port

Claims (10)

[Claims] 1. A method for recovering lithium, comprising: irradiating an aqueous solution containing lithium with ultrasonic waves to selectively recover the lithium. 2. The method for recovering lithium according to claim 1, wherein, when irradiating the aqueous solution containing lithium with ultrasonic waves, the aqueous solution is stirred. 3. The method for recovering lithium according to claim 1, wherein an adsorbent for selectively adsorbing lithium is added to an aqueous solution containing lithium, and the lithium is adsorbed on the adsorbent. 4. The method according to claim 1, wherein an adsorbent for selectively adsorbing lithium is added to an aqueous solution containing lithium, and then the adsorbent adsorbing lithium is separated from the aqueous solution. The method for recovering lithium according to the above. 5. The method for recovering lithium according to claim 3, wherein a collecting agent is added to the aqueous solution when the adsorbent having adsorbed lithium is separated from the aqueous solution. 6. An apparatus for selectively recovering lithium from an aqueous solution containing lithium, wherein an ultrasonic generator is provided in a container for introducing the aqueous solution containing lithium. Collection device. 7. The lithium recovery apparatus according to claim 6, further comprising a mechanism for stirring an aqueous solution containing lithium. 8. The lithium recovery apparatus according to claim 6, further comprising an adsorbent introduction device. 9. The lithium recovery apparatus according to claim 6, further comprising an adsorbent introducing device and a separating section for the adsorbent. 10. The apparatus according to claim 6, further comprising a collector introducing device and a filter for the adsorbent.
An apparatus for recovering lithium according to the above.