WO2014168213A1 - Liquid-liquid extracting device and liquid-liquid extracting method - Google Patents

Abstract

[Problem] To provide a liquid-liquid extracting method and a liquid-liquid extracting device that has a simple structure that does not require a driving unit and can process a large volume of a solution for extraction. [Solution] A liquid-liquid extracting device that brings two liquids that are separated by an interface formed therebetween into contact and extracts a substance from one liquid into the other liquid, said liquid-liquid extracting device comprising an extracting unit (10) that has a plurality of extraction channels (10h) for passing two liquids (S, E), a liquid supplying unit (13) for supplying a liquid to the extracting unit (10), and a liquid discharging unit (14) for discharging the liquids (S, E) from the extracting unit (10). The extracting unit (10) is formed so that the cross-sectional area of the extraction channels (10h) changes in the direction of flow. Since the cross-sectional area of the extraction channels (10h) changes, the area of the interface between the two liquids flowing in the extraction channels (10h) can be changed, and a convective flow (CV) can be generated in each liquid. Thus, the extraction efficiency between the two liquid can be improved just by flowing the two liquids (S, E).

Description

Liquid-liquid extraction apparatus and liquid-liquid extraction method

The present invention relates to a liquid-liquid extraction apparatus and a liquid-liquid extraction method. More specifically, the present invention relates to a liquid-liquid extraction apparatus and a liquid-liquid extraction method that can extract valuable metal ions and the like contained in the extraction target solution simply by passing the extraction target solution and the extraction solution through the apparatus main body.

In recent years, gold, platinum, copper, lithium, etc. used in such products have become widespread with the spread of electronic materials such as small high-performance mobile phones and home appliances, light-emitting diodes and fuel cells, and functional materials such as photocatalysts. Demand for metals (hereinafter referred to as rare metals) such as tantalum, zirconium, nickel, cobalt (so-called rare metals and rare earths) is increasing. Since such rare metals are contained in trace amounts in minerals and the like, they are generally extracted by processing minerals and the like. For example, an aqueous solution containing a rare metal is prepared by pulverizing a mineral or the like and then acid-treating it. Then, a target rare metal is taken out (extracted) from this aqueous solution (hereinafter referred to as a solution to be extracted).

Conventionally, various techniques for selectively extracting rare metals from the solution to be extracted have been developed, but in general, a solution that does not mix with the solution to be extracted (including an extraction solvent or a solution in which the extraction solvent is dissolved). In the following, a liquid-liquid extraction method using an extraction solution) is used.

In the liquid-liquid extraction method, a rare metal is transferred from an extraction solution to an extraction solution by mixing two liquids (an extraction solution and an extraction solution) that are separated by forming an interface (that is, the rare metal is extracted from the extraction solution). This is a technique based on the principle of (extracting). In the liquid-liquid extraction method, if the area of the interface between the two liquids is increased, the rare metal can be efficiently extracted from the solution to be extracted. Therefore, in order to increase the area of the interface between the two solutions, the two solutions are stirred with a machine or the like. The technology of mixing and mixing has been developed.

At the laboratory level, there is a technique in which two solutions are placed in an extraction container and the extraction container is shaken manually or mechanically. For example, there is a liquid-liquid extraction method using a separatory funnel. This liquid-liquid extraction method using a separatory funnel is convenient when a small amount of solution to be extracted or the like such as a laboratory level is handled. However, with such a technique, the amount of the solution to be extracted that can be processed at one time is limited to about several liters, and continuous processing is also difficult. With such a technique, it is not possible to process a large amount of the solution to be extracted. Impossible.

Therefore, as a technique for efficiently processing a large amount of solution to be extracted, a technique having a stirring unit for stirring two liquids has been developed (for example, Patent Documents 1 and 2).

Patent Document 1 discloses a tank-type liquid-liquid extraction in which liquid-liquid extraction is performed using a mixer-settler-type extractor having two box-type large tanks and provided with a stirring unit equipped with an impeller in one tank. A method is disclosed.
In Patent Document 2, liquid-liquid extraction is carried out using a reciprocating plate type AC extraction device provided with a stirring portion having a perforated plate movable in the vertical direction in a main body having a hollow housing space inside. A column type liquid-liquid extraction method is disclosed. According to the techniques disclosed in these documents, since the liquid in which the extraction solution and the solution to be extracted are mixed is stirred in the stirring unit, both liquids can be mixed efficiently. There is an advantage that it can be processed.

On the other hand, a technique for performing liquid-liquid extraction by bringing two liquids into contact in a capillary having extremely fine through holes has been developed (for example, Patent Document 3).
Patent Document 3 discloses a microchip device having a capillary with an inner diameter of several tens to several hundreds of μm inside. By supplying two liquids to the capillary of this microchip device, an interface can be formed between the two liquids, so that the rare metal is extracted from the solution to be extracted into the extraction solution simply by passing the two liquids through the capillary. It is possible.

JP 2009-90164 A JP 2002-58903 A JP 2009-90164 A

However, in the technique disclosed in Patent Document 1 or Patent Document 2, when the mixed solution in which the solution to be extracted and the extraction solution are mixed is stirred, a large resistance is applied to the impeller and the porous plate of the stirring unit. For this reason, in order to sufficiently stir the two liquids against such a large resistance, there arises a problem that a driving unit such as a motor for operating the stirring unit must be enlarged. In addition, if the drive unit is made large, there is a problem that a large amount of power is consumed as the power.
Further, in the technique of Patent Document 1 or Patent Document 2, since it is necessary to adjust the operation of the drive unit in order to obtain stable extraction efficiency, the operation of the drive unit becomes complicated, and regular maintenance and the like are performed. The problem of becoming indispensable also arises.
Therefore, in order to perform liquid-liquid extraction more efficiently, a liquid-liquid extraction apparatus that does not have a drive unit is desired.

On the other hand, Patent Document 3 is a technique that does not have a drive unit, but requires that the inner diameter of the capillary be as fine as about 100 μm. For this reason, the amount of the solution to be extracted that can be passed through the capillary of Patent Document 3 is a very small amount of about 5 to 10 μL / min. Therefore, the capillary of Patent Document 3 has a problem that the amount of the solution to be extracted that can be substantially processed is only about several tens μL to several hundreds μL. In addition, if a liquid is allowed to flow into the capillary at a desired flow rate (for example, several tens to several hundreds ml / min), the pressure loss becomes very large, so a special liquid feed pump or the like is required. Further, if 100 ml of solution to be extracted is processed in one minute, at least 10,000 microchip devices are required.
Therefore, it is practically impossible to process a solution to be extracted generated industrially in a large amount in a short time using the technique of Patent Document 3.

At present, in the liquid-liquid extraction method, there is no liquid-liquid extraction apparatus having a structure capable of efficiently processing a large amount of extraction solution without using a drive unit for stirring the solution, etc. Development of a liquid-liquid extraction apparatus having a simple structure capable of processing a solution to be extracted generated industrially in large quantities without using a drive unit is desired.

In view of the above circumstances, an object of the present invention is to provide a liquid-liquid extraction apparatus and a liquid-liquid extraction method that can process a large amount of a solution to be extracted while having a simple structure that does not require a drive unit.

A liquid-liquid extraction apparatus according to a first aspect of the present invention is a liquid-liquid extraction apparatus that extracts two substances from one liquid by bringing two liquids that form an interface into contact with each other and delivering the two liquids. An extraction section having a plurality of extraction flow paths, a liquid supply section for supplying liquid to the extraction section, and a liquid discharge section for discharging liquid from the extraction section, The extraction unit is characterized in that a cross-sectional area of the extraction flow path is formed to change along the flow path direction.
The liquid-liquid extraction device of a second invention is characterized in that, in the first invention, the two liquids are composed of a main fluid and a sub-fluid having a smaller flow rate than the flow rate of the main fluid.
In the liquid-liquid extraction device according to a third aspect of the present invention, in the first or second aspect, the extraction unit includes a cylindrical main body and a flow path forming member accommodated in the main body, and the flow path formation The member is composed of a plurality of granules, and the plurality of granules are composed of a granular hydrophobic member having a hydrophobic function on the surface and / or a granular hydrophilic member having a hydrophilic function on the surface. It is configured.
The liquid-liquid extraction device according to a fourth aspect of the present invention is the liquid-liquid extraction device according to the third aspect, wherein the two liquids are a hydrophobic liquid as the main fluid and a hydrophilic liquid as the subfluid, and the plurality of granular materials are hydrophobic on the surface. It is comprised from the granular hydrophobic member which has a function.
The liquid-liquid extraction device according to a fifth aspect of the present invention is the liquid-liquid extraction device according to the third aspect, wherein the two liquids are such that the main fluid is a hydrophilic liquid, the subfluid is a hydrophobic liquid, and the plurality of granules are hydrophilic on the surface. It is comprised from the granular hydrophilic member which has a function, It is characterized by the above-mentioned.
The liquid-liquid extraction device according to a sixth aspect of the present invention is the first, second, third, fourth, or fifth aspect, wherein the extraction section is formed so that the porosity is 30% to 70%. It is characterized by.
The liquid-liquid extraction device according to a seventh aspect is characterized in that, in the third aspect, the plurality of granular materials contain the hydrophobic member in a volume ratio of 25% or more.
In the liquid-liquid extraction method of the eighth invention, two liquids to be separated by forming an interface are brought into contact in the extraction flow path to form a continuous liquid phase consisting of one liquid and a continuous liquid phase consisting of another liquid, A liquid-liquid extraction method for extracting a substance from one liquid to another liquid in a countercurrent or cocurrent manner, wherein the two liquids are passed through the extraction flow path whose cross-sectional area changes along the flow path direction. It is characterized by that.
The liquid-liquid extraction method of the ninth invention is characterized in that, in the eighth invention, the extraction flow path is formed in a mesh shape.

According to the first aspect, since the cross-sectional area of the extraction channel is changed, the area of the interface between the two liquids flowing in the extraction channel can be changed, and convection can be generated in each liquid. For this reason, it becomes easy to move a substance from one liquid to another liquid. That is, the extraction efficiency between the two liquids can be improved only by passing two liquids.
According to the second invention, if two liquids are passed through the extraction flow path, the liquid can be passed in a state in which the follower fluid is dispersed in the main fluid. For this reason, the extraction efficiency of the substance between two liquids can be improved more.
According to the third invention, since the granular material is composed of a hydrophilic member and / or a hydrophobic member, if the hydrophilic liquid and the hydrophobic liquid are passed through the extraction channel, the hydrophilic liquid becomes hydrophilic. Since the hydrophobic liquid flows along the surface of the member and flows along the surface of the hydrophobic member, the hydrophobic liquid can flow while maintaining the state in which the interface is formed between the two liquids in the extraction flow path. Therefore, the substance extraction efficiency between the two liquids can be further improved.
According to the fourth aspect of the present invention, a hydrophobic liquid layer can be formed on the surfaces of the plurality of granular bodies in the extraction flow path. For this reason, the hydrophobic main fluid can flow along the surfaces of the plurality of granular materials, and thus can flow while maintaining the state in which the interface is formed between the two liquids in the extraction flow path. Moreover, it is possible to flow in a state where the hydrophilic subfluid is dispersed in the hydrophobic main fluid. Therefore, the substance extraction efficiency between the two liquids can be further improved.
According to the fifth aspect, a hydrophilic liquid layer can be formed on the surfaces of the plurality of granular bodies in the extraction flow path. For this reason, since the hydrophilic main fluid can be flowed along the surfaces of the plurality of granular materials, it can be flowed while maintaining the state in which the interface is formed between the two liquids in the extraction flow path. Moreover, it is possible to flow in a state where the hydrophobic subfluid is dispersed in the hydrophilic main fluid. Therefore, the substance extraction efficiency between the two liquids can be further improved.
According to the sixth aspect of the invention, since the porosity of the extraction unit is adjusted to be within a predetermined range, pressure loss when two liquids are passed through the extraction flow path can be suppressed.
According to the seventh aspect, since the hydrophobic member contains a predetermined value or more, it is easy to maintain the state in which the interface is formed between the two liquids.
According to the eighth aspect, since the cross-sectional area of the extraction channel is changed, the area of the interface between the two liquids flowing in the extraction channel can be changed, and convection can be generated in one liquid. For this reason, it becomes easy to move a substance from one liquid to another liquid. That is, the extraction efficiency between the two liquids can be improved only by passing two liquids.
According to the ninth aspect, since the extraction channel is formed in a mesh shape, two liquids can be passed through the complicated channel. Then, the area change of the interface of the two liquids flowing in the extraction flow path can be further increased. In addition, since more complicated convection can be generated in both liquids, the extraction efficiency between the two liquids can be further improved.

It is a schematic explanatory drawing of the liquid-liquid extraction apparatus 1 of this embodiment. 2 is a schematic explanatory diagram of a solution to be extracted S and an extraction solution E flowing in a flow path 10h in the extraction unit 10. FIG. It is a schematic explanatory drawing of the liquid discharge part 14, Comprising: (A) is a schematic explanatory drawing of the two phases of the to-be-extracted solution S and the extraction solution E which were formed in the liquid separation space 14h of the liquid discharge part 14, ) Is a schematic explanatory diagram when a separation plate 10f is provided in the liquid separation space 14h of the liquid discharge section 14. It is a schematic explanatory drawing of the interface IF formed between both the to-be-extracted solution S and the extraction solution E which flow through the flow path 10h, and the convection CV in each liquid. (A) is a hydrophobic extraction solution Sp flowing in the flow path 10h in the extraction section 10 when the hydrophobic member 22 is used as the flow path forming member, and a hydrophilic substance having a lower flow rate than the extraction target solution Sp. It is a schematic explanatory drawing of the extraction solution Ew, (B) is the hydrophilic extraction solution Sw which flows through the inside of the flow path 10h in the extraction part 10 in case the hydrophilic member 21 is used as a flow path formation member, and this extraction target It is a schematic explanatory drawing of the hydrophobic extraction solution Ep with a smaller flow volume than the solution Sw. It is the figure which showed the experimental result.

Next, an embodiment of the present invention will be described with reference to the drawings.
The liquid-liquid extraction apparatus according to the present embodiment allows two liquids that form and separate an interface to contact each other, and can move (ie, extract) a substance from one liquid to another via the interface. This is a device that continuously applies a large amount of aqueous solution (hereinafter referred to as an extraction solution) containing a rare metal (hereinafter referred to as a rare metal) such as a rare metal or a rare earth (including a rare earth such as yttrium, lanthanum, or cerium). This equipment is suitable for equipment that needs to be processed.
In particular, the liquid-liquid extraction apparatus of the present embodiment can efficiently and continuously extract a large amount of the solution to be extracted simply by passing the solution to be extracted containing a rare metal through the apparatus. It has a feature in that.

(Explanation of extraction solution and extraction solution)
In the liquid-liquid extraction apparatus of the present embodiment, the two liquids that form an interface and are separated are not particularly limited as long as they are two liquids that can be used for liquid-liquid extraction. That is, the above-mentioned two liquids mean a liquid that forms an interface between the two liquids and separates into two phases if the liquids are stirred for a predetermined time after stirring. Specifically, a solution to be extracted having a hydrophilic property and a hydrocarbon-based organic solvent (hereinafter referred to as an extraction solution) having a hydrophobic property such as oil or kerosene are applicable.

For example, in the case of a rare metal recovery plant for extracting a rare metal from an aqueous solution containing a rare metal, the aqueous solution containing the rare metal is an extraction solution, and a liquid for extracting the rare metal from the extraction solution, for example, A kerosene-based kerosene or a hydrophobic organic solvent such as hexane, dodecane, chloroform, or toluene is used as the extraction solution.

Conversely, when a rare metal is extracted from a liquid obtained by extracting a rare metal from an aqueous solution containing a rare metal to another liquid (that is, back-extracted), the rare metal is extracted from the aqueous solution containing the rare metal. A liquid, for example, a hydrophobic organic solvent such as kerosene whose main component is kerosene is the solution to be extracted, and a liquid for extracting a rare metal from the solution to be extracted, for example, a hydrophilic aqueous solution such as water is extracted. Become a solution.

It should be noted that the extraction solution in the present specification may be any liquid as long as it has the above properties with respect to the solution to be extracted. For example, a liquid mixture having hydrophobic properties such as kerosene and hexane, an acidic chelate extractant such as a phosphonic acid-based extractant, an ion-associated extractant such as rhodamine B, and a neutral such as tributyl phosphate It is a concept that includes all solutions having the above properties, such as a solution containing an extractant that specifically binds to a rare metal or a rare metal ion thereof contained in the solution to be extracted such as an extractant.

In addition, the interface in the present specification means a surface formed when two liquids that are difficult to mix as described above come into contact with each other, and is formed between two liquids that flow substantially in parallel in the flow path direction. In addition to the interface (see FIG. 2), it is formed between two liquids in a state (see FIG. 5) in which one liquid formed when the two liquids are agitated is dispersed in the other liquid in a granular state. It is a concept that includes the surface to be processed.

The extraction solution and the extraction solution are not particularly limited as to which of the extraction solution and the extraction solution becomes the upper or lower phase when the two liquids are mixed and allowed to stand. In the following, when the two liquids are mixed and allowed to stand, the extraction solution exists in the lower phase and the extraction solution exists in the upper phase (that is, the specific gravity of the extraction solution is lighter than the specific gravity of the extraction solution). This is a case where the two are separated by forming an interface with each other.

In addition, in the liquid-liquid extraction apparatus of this embodiment, the direction in which each liquid flows when passing the two liquids is not particularly limited. For example, it is possible to employ either a case where the two liquids are brought into contact with each other in the same direction, ie, a so-called cocurrent flow, or a case where the two liquids are caused to face each other, ie, so-called countercurrent.
In the following description, the case where the two liquids are caused to flow in a so-called parallel flow will be described.

(Description of the liquid-liquid extraction apparatus 1 of this embodiment)
Next, the liquid-liquid extraction device of this embodiment will be described.

As shown in FIG. 1, a liquid-liquid extraction device 1 (hereinafter simply referred to as device 1) of the present embodiment includes an extraction unit 10, a liquid supply unit 13 that supplies liquid into the extraction unit 10, and an extraction unit 10. And a liquid discharge portion 14 for discharging liquid from the inside to the outside.

(Description of the extraction unit 10)
The extraction unit 10 is a member having a mesh-like gap inside. In other words, the extraction unit 10 is a member having a large number of continuous holes 10h inside. The hole 10h (gap) is formed so as to communicate between the surface on the liquid supply 13 side of the extraction unit 10 and the surface on the liquid discharge unit 14 side. For this reason, the liquid supplied into the extraction part 10 from the liquid supply 13 side can be made to flow to the liquid discharge part 14 side through this hole 10h. That is, the hole 10 h (gap) serves as a flow path for the liquid supplied into the extraction unit 10. Hereinafter, the hole 10h (gap) is referred to as a flow path 10h.

The flow path 10h is formed to have a portion (W1) in which the hole diameter W is narrowed and a portion (W2) in which the hole diameter W is widened (see FIG. 2). In other words, the flow path 10h is formed such that its cross-sectional area changes along the flow path direction. For example, when the liquid flows through the flow path 10h, the cross-sectional area is formed so as to repeat the enlargement / reduction.

Further, a plurality of the flow paths 10h are formed in the extraction unit 10. In other words, a mesh-like gap is formed inside the extraction unit 10. The ratio of the total volume of the mesh-like voids to the total volume of the extraction unit 10 is not particularly limited, but it is preferably formed so as to be about 30% to 70% with respect to the total volume of the extraction unit 10. In other words, the extraction unit 10 is desirably a member formed to have a porosity of about 30% to 70%.

The structure of the extraction unit 10 having the above structure is not particularly limited. For example, the extraction part 10 can be formed of a porous member having no opening on the side surface.
Moreover, as shown in FIG. 1, the thing which has the structure provided with the flow-path formation member 20 which has the several flow path 10h, and the main-body part 11 for hold | maintaining this flow-path formation member 20 is employ | adopted. Can do.

Hereinafter, the apparatus 1 of this embodiment having the extraction unit 10 having the above-described configuration will be described.

First, the main body 11 is a member that can hold the flow path forming member 20 therein. Specifically, the main body 11 is a cylindrical member having an accommodation space 11h for holding the flow path forming member 20 therein.
For example, as shown in FIG. 1, when the main body 11 has a structure having an upper plate 10a and a bottom plate 10b provided between both ends and a side wall connected between both ends, the upper plate 10a, the bottom plate 10b and the side walls are provided. The part surrounded by can have the accommodation space 11h.
The upper plate 10a and the bottom plate 10b have a structure that allows liquid to pass therethrough. For example, the top plate 10a and the bottom plate 10b may have a mesh structure having a plurality of communication holes that communicate the front and back.

In addition, the magnitude | size of the main-body part 11 is not specifically limited, It can determine suitably according to the quantity of the to-be-extracted solution to process, the property of the contained substance, etc.
For example, when the apparatus 1 of the present embodiment is used in a metal smelting factory or chemical plant, a plant that collects rare metals from the ocean, a valuable metal collection plant in an urban mine, the inner diameter is about 5 m. In addition, an axial length of about 10 m can be used.
On the other hand, when used at the laboratory level, for example, an inner diameter of about 50 mm and an axial length of about 100 mm can be used.

(Flow path forming member 20)
As shown in FIG. 1, the flow path forming member 20 is composed of a plurality of granular particles 21 and 22. Specifically, the flow path forming member 20 is composed of single or mixed granular bodies 21 and 22 having different particle diameters and / or surface properties.
For this reason, when the flow path forming member 20 is housed in the housing space 11h of the main body 11, a gap (that is, corresponding to the flow path 10h) is formed between the adjacent granular bodies 21 and 22 in the flow path forming member 20. (See FIG. 2).
In addition, the granular material as used in this specification is a concept including the thing of various shapes, such as a spherical thing and a cylindrical thing.

The granular materials 21 and 22 of the flow path forming member 20 are members having different particle diameters and / or surface properties as described above.
For example, the granular bodies 21 and 22 can use a granular hydrophilic member 21 having a hydrophilic function on the surface and a granular hydrophobic member 22 having a hydrophobic function on the surface, and details thereof will be described later. .

In addition, in this specification, when the flow path forming member 20 is accommodated in the accommodating space 11h of the main body 11, the granular bodies 21 and 22 of the flow path forming member 20 are free in the accommodating space 11h of the main body 11. This means a state in which the main body 11 is accommodated in a state where it cannot move, and a state in which the granular materials 21 and 22 are spread in the accommodation space 11h of the main body 11 (that is, the accommodation space 11h of the main body 11 is filled. Or a state where the particles 21 and 22 are accommodated in a state in which the movement of the granular materials 21 and 22 is substantially restricted even if the liquid is supplied into the accommodation space 11h of the main body 11 of the extraction unit 10. It is a concept that includes.

Further, the method for accommodating the flow path forming member 20 in the accommodating space 11h of the main body 11 of the extraction unit 10 is not particularly limited. For example, the main body 10 is vibrated with a shaker or the like in a state where the granular materials 21 and 22 of the flow path forming member 20 are accommodated in the accommodation space 11h of the main body 11. Then, the granular materials 21 and 22 can be accommodated in the accommodation space 11h so as to be in the most dense state.

(Regarding the liquid supply unit 13)
The liquid supply unit 13 is a member having a function capable of supplying two liquids (the solution to be extracted S and the extraction solution E) from the outside into the extraction unit 10. Specifically, the liquid supply unit 13 has a storage space 13h that can store two liquids S and E supplied from the outside, and the two liquids S and E stored in the storage space 13h. Can be supplied to the extraction unit 10 from within the accommodation space 13h.

As shown in FIG. 1, the liquid supply unit 13 is formed by an upper plate and a bottom plate provided between both ends (corresponding to the upper plate 10a of the main body 11 in FIG. 1), and a side wall connected between the both ends. ing. That is, the portion surrounded by the upper plate, the bottom plate, and the side wall becomes the accommodation space 13h. Further, tubular liquid inflow passages 13a and 13b for supplying liquid from the outside toward the internal storage space 13h are connected to the side wall of the liquid supply unit 13. Since the upper plate 10a has liquid permeability, liquid can be supplied from the liquid supply unit 13 to the extraction unit 10.

If the volume of the storage space 13h is increased, the time until the liquid is supplied from the liquid supply unit 13 to the extraction unit 10 is lengthened, or the amount of liquid supplied to the extraction unit 10 is adjusted by the liquid supply unit 13. can do.

(About the liquid discharge part 14)
The liquid discharge unit 14 is a member having a function of discharging the two liquids (the extraction target solution S and the extraction solution E) that have passed through the extraction unit 10 to the outside of the extraction unit 10.
Specifically, the liquid discharge unit 14 is a member having a storage space 14h that can hold the supplied liquid therein, and holds the liquid that has passed through the extraction unit 10 in the storage space 14h. It has a structure that can be discharged to the outside after the liquid held in the storage space 14h is in a predetermined state.

As shown in FIG. 1, the liquid discharge portion 14 is formed by an upper plate and a bottom plate (corresponding to the bottom plate 10 b of the main body 11 in FIG. 1) provided between both ends, and a side wall connected between the both ends. Yes. That is, the portion surrounded by the upper plate, the bottom plate, and the side wall becomes the accommodation space 14h. In addition, tubular liquid discharge passages 14 a and 14 b for discharging liquid from the internal storage space 14 h to the outside are connected to the side wall of the liquid discharge unit 14. Since the bottom plate 10b has liquid permeability, liquid can be supplied from the extraction unit 10 to the liquid discharge unit 14.

Since the configuration is as described above, liquid-liquid extraction can be performed as follows.

As described above, the two liquids (extracted solution S, extract solution E) are hydrophobic liquids when the extract solution S is hydrophilic (hereinafter simply referred to as the extract solution Sw). (Hereinafter simply referred to as the extraction solution Ep) is preferable, and when the solution S to be extracted is hydrophobic (hereinafter simply referred to as the solution to be extracted Sp), the extraction solution E is a hydrophilic liquid (hereinafter simply referred to as the extraction solution Ew). Is preferred. Hereinafter, of the two liquids, the extraction solution S is a water-soluble liquid (extraction solution Sw) containing an extraction substance such as a rare metal, and the extraction solution E is in contact with the extraction solution S. The case of kerosene (extraction solution Ep) mainly composed of kerosene that forms an interface between them is described.

Further, as described above, the flow path forming member 20 may be a single member or a mixture of the hydrophilic member 21 and / or the hydrophobic member 22, but in the following, a mixture of the granular member 21 and the granular member 22 is used. I will explain as a representative.
Further, the flow rate of the two liquids is not particularly limited. For example, the two liquids may be passed so as to have substantially the same amount, and a liquid having a large flow rate (hereinafter referred to as a main fluid) out of the two liquids. A liquid having a smaller liquid volume than the main fluid (hereinafter referred to as a secondary fluid) may be passed.

First, when two liquids (the solution to be extracted Sw and the extraction solution Ep) are supplied into the storage space 13h of the liquid supply unit 13 from the liquid inflow passages 13a and 13b of the liquid supply unit 13, the 2 supplied to the liquid supply unit 13 is supplied. The liquids Sw and Ep are mixed to some extent in the accommodation space 13h (see FIG. 1). Then, the two liquids Sw and Ep that are mixed to some extent are supplied to the extraction unit 10. That is, the two liquids supplied from the outside are allowed to flow from the upper side to the lower side of the main body 11 of the extraction unit 10 in a state where the two liquids are mixed to some extent in the liquid supply unit 13.

Next, the two liquids Sw and Ep supplied from the liquid supply unit 13 into the main body 11 of the extraction unit 10 are moved upward in the flow channel 10 h formed between the granular materials 21 and 22 constituting the flow channel forming member 20. It flows downward from. Specifically, as shown in FIG. 2 or FIG. 4, the solution to be extracted Sw and the extraction solution Ep form a continuous liquid phase, and flow so as to form an interface on the surface where they are in contact with each other.

At this time, as shown in FIG. 2 or FIG. 4, the flow path 20h is formed so that its hole diameter changes. For example, the channel 10h changes from a narrow channel 10h (hole diameter W1) to a wide channel 10h (hole diameter W2), and again from a wide channel 10h (hole diameter W2) to a narrow channel 10h (hole diameter W1). . In other words, the flow path 10h is formed such that its cross-sectional area changes along the flow path direction.
Then, if the two liquids Sw and Ep are passed through the flow path 10h, the interface IF formed by the contact of the two liquids Sw and Ep flowing in the flow path 10h can be passed while being enlarged or reduced. (See FIG. 4). That is, the inside of the extraction unit 10 can be passed from the upper side to the lower side while changing the area of the interface between the two liquids Sw and Ep.

Moreover, as shown in FIG. 4, since the cross-sectional area of the flow path 10h is formed so as to change along the flow path direction, in each liquid, the liquid layer near the interface IF and the liquid separated from the interface IF A flow that replaces the layers, that is, an internal circulation flow in the liquid can be generated. In other words, it is possible to cause the two liquids Sw and Ep to flow in the flow path 10h along the flow path direction while generating convection CV in the liquids Sw and Ep.

The two liquids Sw and Ep that have passed through the main body 11 of the extraction unit 10 are the liquid provided in the housing space 11h of the main body 11 formed in the bottom plate 10b of the main body 11 and below the main body 11. The liquid is supplied into the storage space 14h of the liquid discharge section 14 through a communication hole that communicates with the storage space 14h of the discharge section 14. The two liquids Sw and Ep supplied into the storage space 14h of the liquid discharge unit 14 are held in the storage space 14h until they reach a predetermined state, and then discharged to the outside through the liquid discharge passages 14a and 14b.

As described above, the two liquids (the solution to be extracted Sw and the extraction solution Ep) that form and separate the interface in the extraction unit 10 of the apparatus 1 of the present embodiment are supplied, and the supplied two liquids Sw and Ep are extracted from the extraction unit 10. It is easy to move a substance from one liquid to another by simply passing the liquid through the plurality of flow paths 10h formed therein. That is, liquid-liquid extraction between the two liquids Sw and Ep can be improved only by passing the liquids Sw and Ep through the extraction unit 10 of the apparatus 1 of the present embodiment.

Specifically, as shown in FIG. 4, when the two liquids Sw and Ep are caused to flow through the flow path 10h, (1) the area of the interface IF formed between the two liquids can be increased and reduced. Then, since the contact area between both can be improved, it becomes easy to move the extractable material which exists in the to-be-extracted solution Sw to the extraction solution Ep, ie, to extract.

In addition, (2) since convection CV can be generated in each of the liquids Sw and Ep, the extraction efficiency for extracting the substance to be extracted from the extraction solution Sw to the extraction solution Ep can be improved.

This phenomenon is presumed to be based on the concentration change of the substance to be extracted near the interface as follows.

The to-be-extracted substance existing in the to-be-extracted solution S located near the interface moves to the extracting solution E through the interface. Then, the concentration of the substance to be extracted in the solution to be extracted S located in the vicinity of the interface becomes low. On the other hand, in the extraction solution E located near the interface, the substance to be extracted moves from the solution S to be extracted via the interface, so that the concentration of the substance to be extracted in the extraction solution E located near the interface increases. Then, the movement of the substance to be extracted from the extraction solution S to the extraction solution E is suppressed. That is, the extraction efficiency decreases.

However, as shown in FIG. 4, since the convection CV is generated in each of the liquids Sw and Ep, the solution to be extracted Sw located in the vicinity of the interface is replaced with the solution to be extracted Sp located in a place away from the interface. For this reason, the to-be-extracted substance which exists in the to-be-extracted solution Sw located in the interface vicinity is always maintained in the state with a high density | concentration. Similarly, the extraction solution Ep located in the vicinity of the interface is replaced with the extraction solution Ep located in a location away from the interface. For this reason, the to-be-extracted substance which exists in the extraction solution Ep located in the interface vicinity is always maintained in a state with a low density | concentration.
Then, by generating convection CV in each of the liquids Sw and Ep, it becomes easy to move the substance to be extracted present in the extraction solution Sw by the extraction solution Ep via the interface IF. Therefore, the extraction efficiency for extracting the substance to be extracted from the extraction solution Sw to the extraction solution Ep can be improved.

As described above, the substance to be extracted contained in the extraction solution S can be obtained simply by supplying two liquids (the extraction target solution S and the extraction solution E) into the extraction unit 10 of the apparatus 1 of the present embodiment and letting them pass. Can be efficiently transferred to the extraction solution E. In addition, several tens to several hundreds ml of solution to be extracted S can be processed per minute.
Therefore, the apparatus 1 of the present embodiment can perform an efficient and quick extraction process.

In addition, since it is not necessary to provide a stirring unit for increasing the area of the interface between the two liquids S and E, power for operating the stirring unit is also unnecessary.
Moreover, despite the simple structure that only accommodates the flow path forming member 20 in the main body 11 of the extraction unit 10, an extraction function equivalent to that of a liquid-liquid extraction device provided with a conventional drive unit is provided. It can be demonstrated.

Note that the porosity of the flow path forming member 20 accommodated in the accommodating space 11h of the main body 11 is not particularly limited, but the extraction section can be adjusted by adjusting the porosity of the flow path forming member 20 to be within a predetermined range. The flow rates of the two liquids Sw and Ep through which the liquid 10 is passed can be adjusted. Specifically, based on the physical properties of the two liquids Sw and Ep, the chemical properties of the substance to be extracted, the concentration of the substance to be extracted present in the solution to be extracted Sw, etc. The porosity of the flow path forming member 20 accommodated in the accommodating space 11h is adjusted as appropriate. Then, the two liquids Sw and Ep can be flowed at an optimum flow rate while maintaining high extraction efficiency.

In particular, the flow path 10h is formed so that the volume ratio thereof is about 30% to 70% with respect to the volume of the flow path forming member 20 accommodated in the accommodating space 11h of the main body 11 of the extraction section 10. Preferably it is. In other words, the flow path forming member 20 is accommodated in the accommodating space 11h of the main body 11 such that the porosity of the flow path forming member 20 accommodated in the accommodating space 11h of the main body 11 is about 30% to 70%. It is preferable that With such a porosity, pressure loss when the two liquids Sw and Ep are allowed to flow can be suppressed. For example, the two liquids Sw and Ep can be flowed at a flow rate of several tens ml / min to several hundred ml / min.

In addition, the flow path 10h in this specification corresponds to the extraction flow path in the claims.

(Detailed explanation of each part)
Below, each part of the liquid-liquid extraction apparatus 1 of this embodiment is demonstrated in detail.
Before describing the liquid supply unit 13 and the liquid discharge unit 14, first, each unit of the extraction unit 10 will be described in detail.

(Detailed description of the extraction unit 10)
As shown in FIG. 1, the extraction unit 10 includes a flow path forming member 20 and a cylindrical main body 11 for holding the flow path forming member 20.

(About the main body 11)
As shown in FIG. 1, the main body 11 is a cylindrical member formed by an upper plate 10a and a bottom plate 10b provided between both ends, and a side wall connected between the both ends. The accommodation space 11h of the main body 11 surrounded by the upper plate 10a, the bottom plate 10b, and the side wall is separated into a liquid-liquid extraction unit 11a and a dispersion unit 11b by a separation plate 10c.

(About the liquid-liquid extraction part 11a)
As shown in FIG. 1, the liquid-liquid extraction part 11a is formed by an upper plate 10a and a separation plate 10c provided at both ends, and side walls connected between the both ends. And the liquid-liquid extraction part 11a has the hollow accommodation space (equivalent to the accommodation space 11h of the main-body part 11) enclosed by the upper board 10a, the separation plate 10c, and the side wall in the inside. The above-described flow path forming member 20 is accommodated in this accommodation space. That is, the liquid-liquid extraction unit 11a has a region for performing liquid-liquid extraction between the two liquids while allowing the two liquids S and E supplied into the main body 11 in the extraction unit 10 to pass therethrough. It is a member.

(About the flow path forming member 20)
As described above, the flow path forming member 20 is composed of a single or mixed granular bodies 21 and 22 having different particle diameters and / or surface properties.
For example, the granular body 21 is a granular hydrophilic member 21 having a hydrophilic function on the surface, and the granular body 22 is a granular hydrophobic member 22 having a hydrophobic function on the surface.

(Hydrophilic member 21 and hydrophobic member 22)
The hydrophilic member 21 and / or the hydrophobic member 22 constituting the flow path forming member 20 are accommodated in the liquid-liquid extraction part 11a of the main body part 11 so as to have a predetermined mixing ratio.

Before explaining the mixing ratio of both granular materials 21, 22, first, both granular materials 21, 22 will be described in detail.

(Hydrophilic member 21)
The material of the hydrophilic member 21 is not particularly limited as long as it is a granular member having a hydrophilic function on its surface. Specifically, when a water droplet is applied to the surface, a member having a property that the contact angle between the water droplet and the surface is 0 to about 26 degrees can be used as the hydrophilic member 21.

For example, glass beads may be employed as the hydrophilic member 21. Glass main component silica (Si0 _2), since having a hydroxyl group on its surface, if you stick water droplets on the glass surface can hydrogen bond gives rise between hydroxyl groups of molecules of water molecules and the surface of the water droplets. Then, the hydrogen bond between the two molecules makes the contact angle between the water droplet and the glass surface almost zero, so that a thin film of water can be formed on the glass bead surface so that the glass bead surface is covered with a thin film of water. .

The hydrophilic member 21 may impart hydrophilicity to the surface by a method such as coating. For example, if it coats with surfactant, hydrophilic resin, etc., even if the main body of the hydrophilic member 21 does not have sufficient hydrophilicity, it can be used as the hydrophilic member 21 used for the apparatus 1 of this embodiment.

(Hydrophobic member 22)
On the other hand, the material of the hydrophobic member 22 is not particularly limited as long as it is a granular member having a hydrophobic function on its surface. Specifically, when a water droplet is applied to the surface, a member having a property that the contact angle between the water droplet and the surface is about 45 to about 110 degrees can be used as the hydrophobic member 22.

For example, plastic or acrylic beads may be employed as the hydrophobic member 22. Acrylic is a kind of polymer resin, and has hydrophobic polymer side chains (for example, polymer hydrocarbons) on its surface. Hydrophobic kerosene and hydrocarbons such as hexane on the acrylic bead surface. If an oil containing an organic solvent is added, a predetermined binding force (for example, intermolecular force, etc.) is established between the hydrophobic polymer hydrocarbon in the oil and the polymer hydrocarbon on the surface of the acrylic beads. Can be generated. Then, the oil can be covered so as to coat the acrylic bead surface by a predetermined bonding force generated between the two. On the other hand, when a water droplet is applied to the surface of the acrylic bead, the water droplet repels on the surface of the acrylic bead, so that a substantially spherical shape is maintained.

It should be noted that the hydrophobic member 22 may impart hydrophobicity to its surface by a method such as coating. For example, if coating is performed with an alkylsilane coupling agent, a graft copolymer, or the like, the hydrophobic member 22 is used as the hydrophobic member 22 used in the apparatus 1 of the present embodiment even if the main body of the hydrophobic member 22 does not have sufficient hydrophobicity. be able to.

Then, the hydrophilic extraction solution Sw and the hydrophobic extraction solution Ep are mixed in the liquid-liquid extraction part 11a of the main body part 11 in a state where the plurality of hydrophilic members 21 and the plurality of hydrophobic members 22 are mixed and accommodated as described above. If the solution is passed through, the solution to be extracted Sw forms a thin film along the surface of the hydrophilic member 21, but has no affinity for the hydrophobic member 22. On the other hand, the extraction solution Ep forms a thin film along the surface of the hydrophobic member 22, but exhibits non-affinity for the hydrophilic member 21.

Then, as shown in FIG. 2, when the mixed solution of the two liquids Sw and Ep flows in the flow path 10h formed between the hydrophilic member 21 and the hydrophobic member 22 in the liquid-liquid extraction part 11a, 2 The liquids Sw and Ep flow so as to form a film on the surface of the hydrophilic member 21 or the surface of the hydrophobic member 22, respectively. Therefore, the two liquids Sw and Ep can flow in the flow path 10h formed between the hydrophilic member 21 and the hydrophobic member 22 with the interface IF formed.

Specifically, in the flow path 10h, there is a portion formed by the above-described hydrophilic member 21 and the hydrophobic member 22 approaching or adjacent to each other. In this portion, the flow path 10h becomes a hole (void) surrounded by a hydrophilic wall and a hydrophobic wall.
Then, as shown in FIG. 2, the two liquids Sw and Ep can flow in such a portion in the flow path 10 h in a state where an interface is formed between the two liquids Sw and Ep. This is because even if the two liquids Sw and Ep are mixed and flow into the flow path 10h, the hydrophilic solution to be extracted Sw flows around the hydrophilic member 21, and the hydrophobic extraction solution Ep flows around the hydrophobic member 22. Because it flows.

Therefore, if the two liquids Sw and Ep are allowed to flow in the liquid-liquid extraction part 11a of the main body part 11, the hydrophilic solution to be extracted Sw can be made to flow along the surface of the hydrophilic member 21 in the flow path 10h. On the other hand, the hydrophobic extraction solution Ep can flow along the surface of the hydrophobic member 22. That is, as shown in FIG. 2 or FIG. 4, the two liquids Sw and Ep flowing in the flow path 10h flow in the flow path direction in the flow path 10h while maintaining the behavior described above. In other words, in the flow channel 10h, the two liquids Sw and Ep can flow while forming an interface IF between them and forming a liquid phase in which the liquids Sw and Ep are continuous.

In addition, since the plurality of granular materials 21 and 22 constituting the flow path forming member 20 are accommodated in the liquid-liquid extraction part 11a of the main body part 11, the liquid-liquid extraction part 11a has a mesh shape. However, a plurality of complicated flow paths 10h can be formed. Then, if two liquids Sw and Ep are supplied into the liquid-liquid extraction part 11a from the upper end part of the liquid-liquid extraction part 11a of the main body part 11, it is possible to flow through the plurality of flow paths 10h that are in mesh. The interface IF between the two liquids Sw and Ep can be made larger.

Furthermore, since the flow path 10h is formed by the plurality of granular materials 21 and 22, the change in the cross-sectional area of the flow path 10h (W1 and W2 in FIG. 2 or FIG. 4) can be increased as described above, and each liquid Sw , The convection CV generated in Ep can be made larger.
Moreover, since the flow path forming member 20 is composed of the hydrophilic member 21 and / or the hydrophobic member 22 which are a plurality of granular bodies, the hydrophilic liquids Sw and Ew and the hydrophobic liquids Ep and Sp are passed through the flow path 10h. If the liquid is passed through, the hydrophilic liquids Sw and Ew flow along the surface of the hydrophilic member 21, and the hydrophobic liquids Ep and Sp flow along the surface of the hydrophobic member 22. It is possible to flow while maintaining the state in which the interface IF is formed between the two liquids S and E.
Therefore, the extraction efficiency of the substance to be extracted between the two liquids S and E can be further improved.

Further, the shape and size of the hydrophilic member 21 and the hydrophobic member 22 are not particularly limited. For example, in a state where the granular materials 21 and 22 are accommodated in the liquid-liquid extraction unit 11a, the volume occupied by the flow path 10h formed between adjacent or adjacent granular materials 21 and 22, that is, in the liquid-liquid extraction unit 11a It forms so that the ratio with respect to the volume of the accommodated flow-path formation member 20 may become a predetermined range. In other words, the hydrophilic member 21 and / or the hydrophobic member 22 are formed so that the porosity of the flow path forming member 20 of the extraction unit 10 is in a predetermined range. For example, if the void ratio is about 30% to 70%, the void ratio falls within the above range, so that it is easy to perform a quick extraction process as described above.

The porosity can be adjusted by appropriately adjusting the shape and size of the hydrophilic member 21 and the hydrophobic member 22. For example, if the granular materials 21 and 22 are prepared as follows, the porosity of the flow path forming member 20 accommodated in the liquid-liquid extraction part 11a can be set to about 30% to 70%.

As shown in FIG. 2, when the shape of the hydrophilic member 21 and the hydrophobic member 22 is substantially spherical, the flow path 10h has a pore diameter W smaller than the particle diameter D1 of the hydrophilic member 21 and the particle diameter D2 of the hydrophobic member 22. it can.
More specifically, when the shape of the hydrophilic member 21 and the hydrophobic member 22 is substantially spherical, it is preferably formed so that the particle size is about 3 mm or more, more preferably about 3 mm to 5 mm. With such a particle size, the hole diameter W of the flow path 10h can be formed to be about 0.5 to 0.8 mm (see FIG. 2). In this case, the two liquids (the solution to be extracted S and the extraction solution E) can be passed through the liquid-liquid extraction unit 11a of the main body 11 at an optimum flow rate while maintaining a desired extraction efficiency.

For example, when the substantially spherical hydrophilic member 21 and the hydrophobic member 22 having a particle diameter of about 3 mm are accommodated in the accommodating space in the liquid-liquid extraction part 11a having an inner diameter of about 50 mm and an axial length of about 100 mm, it is high. The extraction efficiency (that is, the material to be extracted can be recovered at a high level) can be achieved, and the flow rates of the two liquids S and E can each be about 120 ml / min.

In addition, when the hydrophilic member 21 and / or the hydrophobic member 22 are formed in a substantially spherical shape, the liquid-liquid extraction efficiency between the two liquids S and E can theoretically be improved if the particle diameter is formed to be smaller than about 5 mm. Further improvement can be achieved. This is because if the particle size is made smaller than about 5 mm, the flow path 10h formed between the granular materials 21 and 22 has a narrower pore diameter W (for example, the same as a capillary used in a microchip device). Become. For this reason, the ratio (namely, specific interface area) of the area of the interface IF of 2 liquids S and E and reaction volume can be enlarged more. Then, the liquid-liquid extraction efficiency can be further improved.

However, if the hole diameter W of the flow path 10h is made extremely small as described above, the pressure loss when the two liquids S and E are supplied into the liquid-liquid extraction part 11a of the main body part 11 becomes very large, and as a result, desired The liquid cannot flow at a flow rate of. That is, in the case of the particle size as described above, it is practically impossible to process a large amount of the solution S to be extracted.

On the other hand, if the particle size is larger than about 5 mm, the pressure loss when the two liquids S and E are supplied into the liquid-liquid extraction part 11a of the main body part 11 can be reduced. The flow velocity of the two liquids S and E can be increased, but the interface IF between the two liquids S and E is much smaller than the flow path 10h having a small pore diameter W. The liquid-liquid extraction efficiency between E and E becomes low.

Needless to say, the particle diameter D of the hydrophilic member 21 and / or the hydrophobic member 22 can be appropriately selected and used within the above range depending on the properties of the two liquids S and E.

Further, the hydrophilic member 21 and / or the hydrophobic member 22 may have a substantially cylindrical shape. In this case, fine holes (voids) having different sizes can be formed in an irregular and continuous state in the liquid-liquid extraction part 11a of the main body part 11 (hereinafter referred to as an irregular flow path) (flow path 10h). Equivalent).

For example, the irregular flow path is a communication hole having a hole diameter W having an irregular width, and a narrow portion having a hole diameter W1 (a width equivalent to that in the case where the granular materials 21 and 22 are substantially spherical), and this A portion having a hole diameter W2 that is slightly wider than a portion having a narrow hole diameter W is formed to be irregularly continuous (see FIG. 4). For this reason, when the two liquids S and E flow from the narrow part of the hole diameter W1 toward the wide part of the hole diameter W2 in the irregular flow path, a large convection CV is generated in each of the liquids S and E, and the two liquids S , The interface IF between E undulates. That is, when the particle size W of the irregular flow path (that is, the cross-sectional area of the irregular flow path) greatly changes along the flow path direction, the area of the interface IF under such a situation is enlarged or reduced.
Moreover, when the particle size W of the irregular flow path changes, a large convection CV can be generated in each of the liquids S and E as described above.
Therefore, when the irregular flow path is formed in the liquid-liquid extraction part 11a of the main body part 11, an effect equivalent to or higher than that described above can be obtained between the liquids S and E.

For example, when the shape of the hydrophilic member 21 and / or the hydrophobic member 22 is substantially cylindrical, the length in the axial direction is about 10 mm or more and the length in the radial direction is about 3 mm or more. The length in the radial direction is preferably about 3 to 5 mm.

Needless to say, as the hydrophilic member 21 and / or the hydrophobic member 22, a substantially spherical member or a substantially cylindrical member having a size as described above may be employed separately and mixed. .
In this case, if the hydrophilic member 21 and / or the hydrophobic member 22 having different shapes are accommodated in the liquid-liquid extraction portion 11a of the main body 11, the member having the substantially cylindrical shape of the hydrophilic member 21 and / or the hydrophobic member 22 is obtained. Since the irregular flow path can be formed in the liquid-liquid extraction part 11a of the main body part 11 as in the case where it is adopted, the same effect as described above can be obtained.

For example, a substantially spherical member having a particle diameter of about 3 mm is used as the hydrophilic member 21, and a substantially cylindrical member having an axial length of about 3 mm and a radial length of about 3 mm is used as the hydrophobic member 22. It is accommodated in the liquid-liquid extraction part 11a of the main body part 11 having a length of about 3 mm and an axial length of about 100 mm. And when the aqueous solution with low viscosity is used as the solution to be extracted Sw and the kerosene is used as the extraction solution Ep for the liquid-liquid extraction unit 11a containing the hydrophilic member 21 and the hydrophobic member 22, the desired extraction efficiency can be obtained. While maintaining, the liquid flow rate can be made to be about 120 ml / min or less.

(About mixing ratio)
The hydrophilic member 21 and the hydrophobic member 22 are preferably mixed so that the mixing volume ratio is 0: 100 to 75:25, and more preferably mixed so that the mixing volume ratio is 0: 100 to 60:40. To do. In other words, when the hydrophilic member 21 and the hydrophobic member 22 are mixed as a plurality of granular bodies constituting the flow path forming member 20, the both granular bodies 21, 22 are contained so that the hydrophobic member 22 is contained at least 25% or more in volume ratio. Are preferably mixed. If the hydrophobic member 22 is contained so as to exceed the above value, the interface IF between the two liquids S and E is formed almost uniformly in the flow path 10h at any position in the liquid-liquid extraction part 11a. Can do. In other words, since the flow path 10h formed in the liquid-liquid extraction part 11a can be efficiently used for liquid-liquid extraction of the two liquids S and E, the efficiency of liquid-liquid extraction can be further improved.

The method of mixing both members is not particularly limited. For example, if a container blender or a gravity blender is used, both members can be mixed almost uniformly.

(About the case where the flow path forming member 20 is composed of a single member)
In the above example, the case where the flow path forming member 20 is composed of a mixed granular body of the hydrophilic member 21 and the hydrophobic member 22 has been described. However, as described above, the flow path forming member 20 has the hydrophilic member 21 or the hydrophobic member 22 alone. The case where it was used in will be described.

When the hydrophilic member 21 or the hydrophobic member 22 is used alone, a member having any property may be used regardless of the property of the liquid to be passed, but the property of the liquid (main fluid) having a high flow rate out of the two liquids. It is preferable to use a member having the same property as (e.g., hydrophilic member 21 when the main fluid is hydrophilic, and hydrophobic member 22 when the main fluid is hydrophobic).

This is because when two liquids having different flow rates are passed, a layer having the same properties as the main fluid can be formed on the surface of the flow path forming member 20, so that the main fluid passes through the flow path forming member 20. (See FIG. 5).
On the other hand, a liquid (secondary fluid) having a smaller liquid volume than the main fluid has a property of forming an interface with the main fluid, so that a layer formed on the surface layer of the flow path forming member 20 (for example, flow path formation) In the case where the member 20 is the hydrophilic member 21, it exhibits non-affinity for the hydrophilic layer. That is, the subfluid flows in the flow path 10h away from the flow path forming member 20 (see FIG. 5). In addition, as described above, the flow path 10h is formed so that the cross-sectional area of the flow path changes along the flow path direction, so that when liquid is passed through the flow path 10h, as described above. A convection CV is formed at (see FIG. 4). By such convection CV, the flow of the subfluid flowing in the flow path 10h is cut and becomes a discontinuous flow.

Therefore, when the hydrophobic extraction solution Sp is used as the main fluid and the hydrophilic extraction solution Ew is used as the subfluid, the subfluid extraction solution Ew is used as the subfluid extraction solution Ew as shown in FIG. The extraction solution Sp can be made to flow in a granular state. On the other hand, when the hydrophilic extraction solution Sw is used as the main fluid and the hydrophobic extraction solution Ep is used as the subfluid, the subfluid extraction solution Ep is extracted from the main fluid as shown in FIG. The solution Sw can be flown in a granular state.
Then, since the contact area of both the liquids S and E can be increased compared with the case where both the liquids S and E form a substantially parallel interface along the flow path direction, the extraction efficiency can be further improved. it can.

When the hydrophobic extraction solution Ep is used as the main fluid and the hydrophilic solution to be extracted Sw is used as the subfluid, if the hydrophobic member 22 is used as in the case shown in FIG. The solution to be extracted Sw can be allowed to flow in a state of being dispersed in the main fluid extraction solution Ep. On the other hand, when the hydrophilic extraction solution Ew is used as the main fluid and the hydrophobic extraction solution Sp is used as the subfluid, if the hydrophilic member 21 is used as in the case shown in FIG. The solution to be extracted Sp can be made to flow in a state of being dispersed in a granular form in the extraction solution Ew of the main fluid.

Further, the flow rates of the main fluid and the subfluid are not particularly limited as long as the subfluid is adjusted so as to be smaller than the flow rate of the main fluid, and can be appropriately selected depending on how the two liquids are mixed. Specifically, the volume ratio is preferably adjusted so that the flow rate ratio between the main fluid and the secondary fluid is 100: 30 to 100: 90, and more preferably the volume ratio is 100: 50 to 100: 60. It is desirable to adjust so that it becomes. In the volume ratio, if the sub-fluid is smaller than 30%, the volume ratio of the main fluid to the sub-fluid increases, so that the extraction efficiency decreases. On the other hand, when the sub-fluid is larger than 60% in the volume ratio, it is difficult to disperse it in the flow path 10h. Therefore, the main fluid and the subfluid are preferably adjusted so that the volume ratio is 100: 30 to 100: 90, and more preferably the volume ratio is adjusted to be 100: 50 to 100: 60. It is desirable to let it pass through.
For example, when kerosene containing kerosene as the main component is used as the main fluid and water is used as the sub fluid, the flow rate can be adjusted so that the main fluid: the sub fluid is 2: 1 in the volume ratio.

(About dispersion unit 11b)
As shown in FIG. 1, the dispersion part 11b is formed by a separation plate 10c and a bottom plate 10b provided at both ends, and side walls connected between the both ends. The dispersion portion 11b has a hollow space 12h surrounded by the separation plate 10c, the bottom plate 10b, and the side wall. The hollow space 12h is filled with a plurality of granular bodies 30 larger than the granular bodies 21 and 22 accommodated in the accommodating space of the liquid-liquid extraction section 11a of the main body section 11. For this reason, a continuous hole (void) 30h (hereinafter referred to as a dispersion communication hole 30h) formed between adjacent or adjacent granular bodies 30 has a hole diameter larger than that of the flow path 10h formed in the liquid-liquid extraction unit 11a. Is also formed to be large. Specifically, in the dispersion communication hole 30h, in the two liquids S and E flowing through the dispersion holes 30h, both the liquids S and E are larger than the interface IF between the two liquids S and E. And is formed so as to have a size that is easy to form a state of being separated into two phases.

In this case, in the dispersion communication hole 30h formed so that the hole diameter becomes the above-described size, if the two liquids S and E that have been passed through the liquid-liquid extraction part 11a are allowed to flow inside, the two liquids S and E are allowed to flow. The flow flows from the channel 10h having a small hole diameter toward the dispersion communication hole 30h having a large hole diameter. That is, as in the case of flowing a liquid from a narrow flow path to a wide flow path, the flow speeds of the two liquids S and E flowing in the dispersion communication hole 30h are smaller than the flow speeds of the two liquids S and E flowing in the flow path 10h. it can. As a result, the flow rates of the two liquids S and E flowing in the dispersion communication holes 30h are reduced, so that the two liquids S and E can be separated to some extent in the dispersion communication holes 30h.

Then, since the two liquids S and E separated to some extent are supplied from the dispersion part 11b into the accommodating space 14h in the liquid discharging part 14, the two liquids S and E in the accommodating space 14h in the liquid discharging part 14 are supplied. Even if the residence time is shortened, each liquid can be discharged from the inside of the extraction unit 10 to the outside in a reliably separated state. That is, if the dispersion part 11b is provided between the liquid-liquid extraction part 11a and the liquid discharge part 14 of the main body part 11 of the extraction part 10, the processing time of the solution S to be extracted by the liquid-liquid extraction apparatus 1 of this embodiment is shortened. can do.

In particular, it is preferable to form the side wall forming the dispersion communication hole 30h with a side wall having affinity and hydrophobicity, because the two liquids S and E flowing through the dispersion communication hole 30h can be more maintained.

Specifically, as the granular material 30, a dispersed hydrophilic member 31 having the same shape and function as the hydrophilic member 21 described above and a dispersed hydrophobic member 32 having the same shape and function as the hydrophobic member 22 described above are mixed in a predetermined volume. It mixes so that it may become ratio (for example, it is the same as the mixing volume ratio of the hydrophilic member 21 and the hydrophobic member 22 mentioned above).

For example, when the dispersed hydrophilic member 31 and the dispersed hydrophobic member 32 are formed in a substantially spherical shape, the particle diameter is formed to be about 10 mm or more. Further, when the dispersed hydrophilic member 31 and the dispersed hydrophobic member 32 are formed in a substantially cylindrical shape, they are formed so that the axial length is about 10 mm or more and the radial length is about 10 mm or more.

(Detailed description of the liquid supply unit 13)
Next, the liquid supply unit 13 will be described in detail.

The liquid supply unit 13 may adopt a structure that does not have the accommodation space 13h inside. For example, if the liquid inflow passages 13 a and 13 b of the liquid supply unit 13 are directly connected to the upper part of the main body 11 of the extraction unit 10, the solution to be extracted S and the extraction solution E can be supplied into the extraction unit 10.

However, in the case where the solution to be extracted S and the extraction solution E are separately supplied from the liquid inflow passages 13a and 13b into the main body 11 of the extraction unit 10, the liquid supply unit 13 has a structure having an accommodation space 13h therein. Is preferred.
This is because when the two liquids S and E are subjected to liquid-liquid extraction in the flow path 10h in the extraction unit 10, it is preferable that the two liquids S and E exist in the flow path 10h in almost the same situation. is there. That is, if the two liquids S and E are mixed and supplied into the channel 10h, the liquid-liquid extraction can be performed efficiently in the channel 10h.

In addition, the liquid inflow passages 13a and 13b of the liquid supply unit 13 are formed at the leading ends thereof in the accommodation space 13h, and the liquid supply ports for supplying the liquid into the accommodation space 13h face each other at the leading ends. It is desirable to be provided as follows.
In this case, as shown in FIG. 1, if liquid is supplied from the pair of liquid supply ports to the accommodation space 13h, the two liquids S and E are formed in a region below the substantially central portion in the accommodation space 13h. A mixed state can be formed. And since the 2 liquids S and E can be supplied in the main-body part 11 of the extraction part 10 in the state which 2 liquids S and E mixed, as mentioned above, the liquid liquid in the flow path 10h in the extraction part 10 Extraction efficiency can be improved.

Moreover, if the two liquids S and E are mixed in the storage space 13h of the liquid supply unit 13 before the two liquids S and E are supplied into the main body 11 of the extraction unit 10, the interface between the two liquids can be obtained. Can be enlarged to some extent. That is, since liquids S and E can be preliminarily liquid-liquid extracted (preliminary extraction) in the storage space 13h of the liquid supply unit 13 before being supplied into the main body 11 of the extraction unit 10. More preferable.

Needless to say, the mixed liquid in a state where the two liquids S and E are mixed may be directly supplied from the liquid inflow passages 13a and 13b of the liquid supply unit 13 into the main body 11 of the extraction unit 10.

(Detailed description of the liquid discharge unit 14)
Next, the liquid discharge unit 14 will be described in detail.

When the two liquids S and E that have passed through the extraction unit 10 are discharged from the inside of the extraction unit 10 to the outside, it is preferable to discharge them separately to the outside of the extraction unit 10.
This is because if the extraction solution S and the extraction solution E can be discharged separately to the outside of the extraction unit 10, the work efficiency of the post-treatment process of the extraction solution E can be improved. That is, if the extraction solution S and the extraction solution E can be separately discharged from the inside of the extraction unit 10 to the outside, the target rare metal or the like from the extraction solution E containing the target substance such as the target rare metal or the like can be obtained. In the extraction solution post-treatment step (for example, back extraction step) for extracting the extraction target substance, the extraction solution E in a state that hardly contains the extraction target solution S that becomes an impurity can be prepared.
If the extraction solution E in such a state is subjected to the extraction solution post-treatment step, the processing efficiency of extracting the target substance to be extracted such as a target rare metal from the extraction solution E can be further improved.

In particular, as shown in FIG. 1, the liquid discharge section 14 is provided with a storage space 14h (hereinafter referred to as a liquid separation space 14h) that can temporarily hold the two liquids S and E that have passed through the extraction section 10. It is preferable to keep it.
In this case, the two liquids S and E can be held in the liquid separation space 14h of the liquid discharge part 14 to such an extent that the two liquids S and E are separated.

In addition, when the liquid discharge portion 14 has a liquid separation space 14h therein, the liquid discharge passage so that the extraction solution S and the extraction solution E separated into two phases in the liquid separation space 14h can be discharged separately. 14a and 14b are preferably provided.

For example, as shown in FIG. 1 or FIG. 3, a liquid discharge passage 14b is provided below the side wall of the liquid discharge portion 14 (lower side in the vertical direction in FIG. 1). On the other hand, a liquid discharge passage 14a is provided above the side wall of the liquid discharge portion 14 so as to be different from the liquid discharge passage 14b. A liquid discharge passage (not shown) that can adjust the amount of liquid discharged from the liquid discharge passage 14b by disconnecting the inside and outside of the liquid discharge portion 14 from the liquid discharge passage 14b provided below the side wall of the liquid discharge portion 14. Adjustment means are provided.

In this case, if the flow rates of the two liquids S and E discharged by the liquid discharge adjusting means in the liquid discharge passage 14a and the liquid discharge passage 14b are adjusted, the two liquids S and E are contained in the liquid separation space 14h of the liquid discharge portion 14. Since the residence time can be adjusted, both liquids S and E can be reliably separated.

Moreover, if the flow rates of the two liquids S and E discharged from the liquid discharge passage 14a and the liquid discharge passage 14b are adjusted, the interface between the two liquids S and E separated into two phases in the liquid separation space 14h of the liquid discharge portion 14 is obtained. , That is, the distance between the interface and the inner bottom surface of the liquid discharge portion 14 can be adjusted, so that the two liquids S and E discharged from the inside of the extraction portion 10 to the outside can be discharged in a reliably separated state. it can.

For example, when the interface becomes too high, the interface can be lowered by reducing the amount of liquid discharged from the liquid discharge passage 14a and increasing the amount of liquid discharged from the liquid discharge passage 14b. . Conversely, when the interface becomes too low, the interface can be raised by increasing the amount of liquid discharged from the liquid discharge passage 14a and decreasing the amount of liquid discharged from the liquid discharge passage 14b. Can do.
Of course, both the liquid discharge passage 14a and the liquid discharge passage 14b, or any one of the discharge liquid adjusting means may be closed to adjust the height of the interface.

(About other embodiment of the liquid discharge part 14)
Further, as shown in FIG. 3B, a separation plate 10f for partitioning the inside of the liquid discharge portion 14 may be provided in the vicinity of the discharge port of the liquid discharge passage 15a provided on the side surface above the liquid discharge portion 14. Good.
Specifically, a separation plate 10f is provided so as to separate the inside of the liquid discharge part 14 into a liquid separation space 14h and an extraction solution discharge space 14hp.

Note that the extraction solution discharge space 14 hp has a high specific gravity to be extracted S and an extraction solution E having a specific gravity that is lighter than that of the extraction solution S. In a state where E is held, it refers to a space in which the extraction solution E located above is accommodated.

The separation plate 10f has a communication path that connects the extraction solution discharge space 14hp and the liquid separation space 14h between the front end thereof and the upper surface of the liquid discharge portion 14 (the surface corresponding to the bottom surface of the bottom plate 10b). Is provided. For this reason, when the liquid located above the liquid separation space 14h through the communication passage, for example, when the extraction solution S is an aqueous solution and the extraction solution E is a hydrocarbon organic solvent mainly containing kerosene, the hydrocarbon system The organic solvent can flow into the extraction solution discharge space 14hp. Then, the two liquids (the extraction solution S of the aqueous solution and the extraction solution E of the hydrocarbon-based organic solvent) that have passed through the extraction unit 10 are retained in the liquid discharge unit 14 and separated into two phases. When discharging the liquid, it is possible to reliably prevent the two liquids from mixing with each other.

(About each plate 10a, 10c, 10b provided in the extraction unit 10)
As shown in FIG. 1, a mixing space 13 h of the liquid supply unit 13 is provided above the extraction unit 10 along the axial direction of the extraction unit 10, and a liquid separation space of the liquid discharge unit 14 is provided below the extraction unit 10. When 14h is provided, the upper plate 10a, the separation plate 10c, and the bottom plate 10b are all plate-like members, and a plurality of through holes are formed so as to penetrate the front and back surfaces.

It is preferable that the through-hole is formed to be slightly larger than the gap formed between the adjacent granular bodies 21, 22, and 30 and smaller than the granular bodies 21, 22, and 30. Then, the granular material 20 is held by the upper plate 10a and the separation plate 10c, and only the liquid supplied into the extraction unit 10 can be surely passed while holding the granular material 30 by the separation plate 10c and the bottom plate 10b. it can. However, the size of the through hole is not particularly limited as long as the granular materials 21, 22, and 30 do not pass through.

Further, by adjusting the size and / or number of the communication holes, the flow rate of the liquid in the extraction unit 10 can be adjusted. For this reason, for example, in the case of a low-viscosity liquid, if the size of the communication hole is small and the number is reduced, the residence time in the extraction unit 10 can be increased, so that the extraction efficiency is improved. Is possible.

In the above example, the case where the extraction unit 10 includes the dispersion unit 11b has been described. However, the liquid extraction unit 11a of the extraction unit 10 can sufficiently obtain a desired extraction efficiency, and the liquid discharge unit. If the two liquids S and E can be sufficiently separated into two phases by 14, it is not always necessary to provide the dispersion portion 11 b.

(Method of supplying liquid)
The method for supplying the liquid into the extraction unit 10 is not particularly limited as long as it is a method capable of supplying the liquid into the extraction unit 10 through the liquid inflow passages 13a and 13b of the liquid supply unit 13.
For example, if a flow rate adjusting means such as a pump capable of adjusting the flow rate is connected to the base ends of the liquid inflow passages 13a and 13b of the liquid supply unit 13, the amount of liquid supplied into the extraction unit 10 is set to a predetermined liquid amount Can be adjusted.

In the above example, the case where the two liquids S and E are separately supplied into the extraction unit 10 of the liquid-liquid extraction apparatus 1 of the present embodiment has been described. However, the two liquids are mixed in the extraction unit 10. Needless to say, it may be supplied.

Furthermore, in the above example, the case where the two liquids S and E are supplied into the extraction unit 10 from the upper end of the main body 10 of the liquid-liquid extraction device 1 of the present embodiment has been described. The liquids S and E may be supplied. In this case, even if air accumulation occurs in the extraction unit main body 10 (particularly, the flow path 10h in the liquid-liquid extraction unit 11a of the extraction unit 10), the two liquids S and E are supplied from the lower side to the upper side in the extraction unit 10. Since it flows, it is possible to remove the air accumulated in such an air reservoir almost certainly, so that stable liquid-liquid extraction can be performed.
When supplying the two liquids S and E in the extraction unit 10 from below to above, the liquid supply unit 13, the liquid-liquid extraction unit 11a, and the liquid-liquid extraction unit 11a from the bottom to the top along the axial direction of the extraction unit 10 Each part is arranged in the order of the liquid discharge part 14.

In the above example, when the two liquids S and E are supplied into the extraction unit 10 from the upper end or the lower end of the extraction unit 10 of the liquid-liquid extraction apparatus 1 of the present embodiment, that is, the two liquids flow in parallel ( In other words, the case where the flow is parallel flow) has been described. However, the two liquids may be supplied so as to be opposed to each other (that is, countercurrent). In this case, since the interface between the two liquids S and E can be made larger than when flowing in parallel flow, the liquid-liquid extraction efficiency can be further improved.

Specifically, the extraction solution S is supplied into the extraction unit 10 from the upper end of the extraction unit 10 of the liquid-liquid extraction apparatus 1 of the present embodiment, and the extraction solution E having a lighter specific gravity than the extraction solution S is extracted. Supply from the lower end of the part 10.

For example, an aqueous solution is supplied as the extraction target solution S from the upper end of the extraction unit 10, and a hydrocarbon-based organic solvent is supplied as the extraction solution E from the lower end of the extraction unit 10.
Then, the extraction solution S having a higher specific gravity can flow from the upper side to the lower side of the extraction unit 10, and conversely, the extraction solution E having a lower specific gravity than the extraction solution S is supplied from the lower side of the extraction unit 10. Since it can be made to flow upward, both liquids S and E can be made to flow in the counterflow direction in the extraction unit 10.

In this case, the extraction unit 10 is provided with the liquid discharge passage 14a of the liquid discharge unit 14 for discharging the extraction solution E to the outside at the upper end thereof, and discharges the solution S to be extracted to the outside at the lower end thereof. For this purpose, a liquid discharge passage 14b of the body discharge portion 14 is provided.

(About the arrangement of the extraction unit 10)
In the above example, as shown in FIG. 1, the case where the extraction unit 10 of the liquid-liquid extraction apparatus 1 of the present embodiment is erected in the substantially vertical direction has been described. As long as the liquids S and E are in a state where a desired liquid-liquid extraction can be performed in the extraction unit 10, the extraction unit 10 may be installed in any manner. For example, you may arrange | position the extraction part 10 so that the axial direction of the extraction part 10 may cross | intersect a horizontal axis.

(Another embodiment of the flow path forming member 20)
In the above example, the flow path forming member 20 has been described with respect to a case where the flow path forming member 20 is composed of a plurality of granular materials. However, as long as the plurality of flow paths 10h can be formed in a mesh shape, the flow path forming member 20 is formed. The member which comprises the member 20 is not specifically limited. For example, a fibrous member having an entangled structure can be exemplified.
When such a fibrous member is employed as the flow path forming member 20, a flow path that is meshed inside can be formed. For this reason, if the flow path forming member 20 using such a member is used in the apparatus 1 of the present embodiment, the two liquids S and E flowing in the flow path are the same as in the case of the flow path forming member 20 composed of granular materials. Since the change in the area of the interface can be increased and more complicated convection can be generated, the extraction efficiency between the two S and E can be further improved.

Below, the effectiveness of the liquid-liquid extraction apparatus and liquid-liquid extraction method of this embodiment was confirmed.
In the experiment, the following evaluation was performed with respect to the flow of the two liquids (the solution to be extracted and the extraction solution) supplied to the extraction unit of the liquid-liquid extraction apparatus of the present embodiment and the type of the flow path forming member.
(1) Case of flowing two liquids in parallel flow (2) An experiment in the case of flowing two liquids in countercurrent was conducted to confirm the effectiveness of the apparatus and method of the present invention.

The equipment, solutions, etc. used in the experiment are as follows.

As an extraction solution, an aqueous solution containing a rare earth metal (yttrium (Y), lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), dysprosium (Dy), etc.) as an extraction target substance is used. used.
As the extraction solution, kerosene mainly composed of kerosene was used.

Rare earth metal ions in the solution to be extracted before and after extraction were measured and quantified using ICP-MS (manufactured by Agilent, model number: 7700).
The extraction rate of the rare earth metal was calculated as (1- (rare earth metal ion concentration in the solution to be extracted after extraction) / (rare earth metal ion concentration in the solution to be extracted before extraction)) × 100 (%). .

Experiment (1)
The extraction unit used was a cylindrical packed tower having an inner diameter of 50 mm and a tower length of 100 to 400 mm packed with a flow path forming member. In addition, this packed tower is equivalent to the main-body part of the extraction part of a claim.
As the flow path forming member, a plastic cylindrical member having a diameter of 3 mm and an axial length of 5 mm was used.

Also, in Experiment (1), the extraction unit was arranged so that the axial direction was vertical, and both liquids were supplied from the upper end to the lower end of the extraction unit so that both liquids were in parallel flow. The flow rates at the time of supplying both liquids to the extraction unit were adjusted and supplied so that the solution to be extracted was 30 ml / min and the extraction solution was 60 ml / min.

Experiment (2)
The extraction unit used had an inner diameter of 50 mm and a tower length of 200 mm.
As the flow path forming member, a plastic cylindrical member having a diameter of 3 mm and an axial length of 5 mm and a glass sphere having a particle diameter of 5 mm were used. The plastic cylindrical member and the glass sphere were uniformly mixed at a volume ratio of 3: 1.

Further, in Experiment (2), the extraction unit was arranged so that the axial direction thereof was vertical, and the solution to be extracted was allowed to flow from the upper end to the lower end of the extraction unit. On the other hand, the extraction solution was allowed to flow from the lower end to the upper end of the extraction unit. That is, both liquids were flowed so as to face each other (so-called countercurrent) in the extraction unit.
The flow rates when supplying both liquids to the extraction unit were adjusted and supplied so that the solution to be extracted was 60 ml / min and the extraction solution was 120 ml / min.

(result)
In both results of Experiment (1) and Experiment (2), any rare earth metal ions present in the solution to be extracted could be extracted into the extraction solution at an extraction rate of 99.9% or more.

From the above results, by using the apparatus and method of the present invention, it is possible to liquid-liquid extract the rare earth metal present in the solution to be extracted with high extraction rate (in other words, high recovery rate) and quickly. Was confirmed.

In the following, the influence on the extraction efficiency of the apparatus and method of the present invention was confirmed.

The equipment, solutions, etc. used in the experiment are as follows.

As an extraction solution, a kerosene whose main component is a rare earth metal (lanthanoid-based rare earth metal such as ytterbium (Yb), terbium (Tb), cerium (Ce) and praseorodium (Pr)) as a main component is kerosene. The solution (kerosene solution) contained in was used.
Water was used as the extraction solution.

The rare earth metal ions in the extraction solution before and after extraction and the rare earth metal ions in the extraction solution after extraction were measured and quantified using ICP-MS (manufactured by Agilent, model number: 7700).

The extraction rate of the rare earth metal was evaluated by the distribution ratio.
The distribution ratio was calculated as (rare earth metal ion concentration (mg / g) contained in the extracted solution after extraction) / (rare earth metal ion concentration (mg / g) in the extracted solution after extraction)).
In this experiment, water was used as the extraction solution and kerosene solution was used as the solution to be extracted. Therefore, the smaller the distribution ratio, the better the extraction efficiency.

The extraction unit of the apparatus of the present embodiment used for the experiment is as follows.
The extraction part used what packed the flow-path formation member in the column-shaped packed tower made from a polyvinyl chloride column length of about 600 mm. Further, as the packed column in the extraction section, a thin column having an inner diameter of 2.53 cm (hereinafter simply referred to as “fine-packed column”) and a column having an inner diameter of 5.16 cm (hereinafter simply referred to as “thick-packed column”) were used. In addition, this packed tower is equivalent to the main-body part of the extraction part of a claim.
As the flow path forming member, a cylindrical member made of acrylic resin having a diameter of 2.6 mm and an axial length of 3.2 mm (hereinafter referred to as a small bead), and a polypropylene spherical shape A member having a diameter of 5.9 mm (hereinafter referred to as a large bead) was used.

Devices (devices A to C) having the following extraction units were created using the flow path forming member.
Apparatus A: An apparatus having an extraction section in which a fine-packed tower is filled with small beads. Apparatus B: An apparatus having an extraction section in which a fine-packed tower is filled with large beads. Apparatus C: An extraction in which a large-packed tower is filled with large beads. Device with parts

In addition, the volume (cm ³ ) of the gap between the flow path forming members in the extraction unit of each device is the same as that of the flow channel forming member of the packed tower in the state where the extraction unit of each device is filled with the flow channel forming member. The inner volume from the portion positioned at the upper end to the portion where the lower end of the flow path forming member is positioned) − (total volume of filled beads) was calculated.

In the experiment, both the liquids were supplied from the upper end to the lower end of the extraction unit so that the axial direction of the extraction unit was a vertical direction and both liquids were in parallel flow. The flow rates at the time of supplying both liquids to the extraction unit were adjusted and supplied so that the solution to be extracted (kerosene solution) was 60 ml / min and the extraction solution (water) was 30 ml / min.

The residence time of the extraction solution of each device (that is, the time required for the water to reach the lower end from the upper end of the extraction unit when supplying both liquids from the upper end to the lower end of the extraction unit),
The residence time of water in apparatus A is 1.5 min.
The residence time of water in apparatus B is 1.8 min.
The residence time of water in apparatus C is 5.6 min.
Met.

The residence time (min) was calculated as (volume of gap between flow path forming members (cm ³ )) / (flow rate (ml / min)).

It was confirmed that when the two liquids were passed from the upper end to the lower end of the extraction part of the apparatus so as to be in parallel flow as described above, the extraction solution passed while being in the form of droplets. The particle size of the droplet-shaped extraction solution (water) (hereinafter simply referred to as a droplet-shaped extraction solution) was measured using a digital camera (manufactured by Panasonic, model number: DMC-TZ10). The particle size of the suitable extraction solution is measured by arranging a scale in parallel with the axial direction of the packed tower, and the state in which the memory of the scale and the two liquids are passed with respect to the axial direction of the packed tower. The image was taken with a digital camera from a substantially orthogonal direction. The particle size of each drop-like extraction solution was estimated from the photograph taken.
Then, the particle diameter values of the obtained 50 droplet extraction solutions (water) were averaged to obtain the particle diameter of the droplet extraction solution (water) that passed through the extraction unit of each device.

The particle size of the drop-like extraction solution (water) that passed through the extraction part of each device is
The particle diameter of the drop-like extraction solution (water) that has passed through the extraction part of apparatus A is 1.4 mm,
The particle size of the drop-like extraction solution (water) that has passed through the extraction unit of apparatus B is 4.9 mm,
The particle size of the drop-like extraction solution (water) that has passed through the extraction unit of the device C is 5.0 mm,
Met.

The contact area between the extraction solution (water) of each device and the solution to be extracted (kerosene solution) is as follows from the particle size of water when passing through the extraction section of each device and the residence time of the extraction solution of each device: Calculated.

(Contact area between the extraction solution (water) of device A and the solution to be extracted (kerosene solution))
The particle diameter of the drop-like extraction solution (water) that passed through the extraction unit of apparatus A was 1.4 mm. Therefore, the volume of the drop-like extraction solution (water) of apparatus A was calculated to be 0.0014 cm ³ and the surface area was 0.059 cm ² .
The amount of the extraction solution (water) staying in the extraction section of the apparatus A was calculated as 45 ml from (residence time 1.5 min) × (flow rate of extraction solution (water) 30 ml / min).

Therefore, the contact area between the extraction solution (water) of the extraction unit of apparatus A and the solution to be extracted (kerosene solution) is:
First, the number of the drop-like extraction solution (water) existing in the amount of the extraction solution (water) staying in the extraction section of the apparatus A ((the extraction solution (water) staying in the extraction section of the apparatus A) Liquid volume 45 ml) / (volume of drop-like extraction solution (water) passed through the extraction part of apparatus A 0.0014 cm ³ )). Subsequently, the contact area was calculated by multiplying this value by the surface area of 0.059 cm ² of the drop-like extraction solution (water) that passed through the extraction part of the apparatus A (about 1900 cm ² (1896 cm ² )).

(Contact area between the extraction solution (water) of device B and the solution to be extracted (kerosene solution))
The particle size of the drop-like extraction solution (water) that passed through the extraction unit of the apparatus B was 4.9 mm. Therefore, the volume of the drop-like extraction solution (water) of the apparatus B was calculated as 0.060 cm ³ and the surface area was calculated as 0.74 cm ² .
The liquid volume of the extraction solution (water) staying in the extraction part of the apparatus B was calculated as 54 ml from (residence time 1.8 min) × (flow rate of extraction solution (water) 30 ml / min).

Therefore, the contact area between the extraction solution (water) and the solution to be extracted (kerosene solution) in the extraction unit of the apparatus B is
First, the number of drop-like extraction solutions (water) existing in the amount of the extraction solution (water) staying in the extraction section of the apparatus B is ((the extraction solution (water) staying in the extraction section of the apparatus B). Liquid volume 45 ml) / (volume of drop-like extraction solution (water) passed through the extraction part of apparatus B: 0.060 cm ³ )). Then, in such values (by multiplying the surface area 0.74 cm ² of dropwise extraction solution was passed through the extractor of the apparatus B (water), and calculates the contact area (about 700cm ² (666cm ^2)).

(Contact area between extraction solution (water) of device C and extraction target solution (kerosene solution))
The particle size of the drop-like extraction solution (water) that passed through the extraction part of the apparatus C was 5.0 mm. Therefore, the volume of the drop-like extraction solution (water) of the apparatus C was calculated to be 0.067 cm ³ and the surface area was 0.80 cm ² .
The amount of the extraction solution (water) staying in the extraction section of the apparatus C was calculated as (168 ml) from (residence time 5.6 min) × (flow rate of extraction solution (water) 30 ml / min).

Therefore, the contact area between the extraction solution (water) and the solution to be extracted (kerosene solution) in the extraction unit of the apparatus C is
First, the number of the drop-like extraction solution (water) existing in the amount of the extraction solution (water) staying in the extraction section of the apparatus C is calculated by (the liquid of the extraction solution (water) staying in the extraction section of the apparatus C. (Volume 168 ml) / (volume of the drop-like extraction solution (water) passed through the extraction part of apparatus C: 0.067 cm ³ ). Then, in such values (by multiplying the surface area 0.80 cm ² of dropwise extraction solution was passed through the extractor of the apparatus C (water), and calculates the contact area (approximately 2000cm ² (2005cm ^2)).

(result)
The results are shown in FIG.
FIG. 6 is a diagram showing the relationship between the distribution ratio of the rare earth metal and the contact area between the extraction solution (water) and the solution to be extracted (kerosene solution).
The vertical axis in FIG. 6 represents the distribution ratio of the rare earth metal (Distribution Ratio), and the horizontal axis represents the contact area (cm ² ) between the extraction solution (water) and the solution to be extracted (kerosene solution) when passing through the apparatus. Each is shown.
Note that rare earth metals such as ytterbium (Yb), terbium (Tb), cerium (Ce) and praseorhodium (Pr) were evaluated.
As shown in FIG. 6, as the contact area (cm ² ) of the extraction solution (water) and the solution to be extracted (kerosene solution) when passing through the apparatus increases, the distribution ratio of each rare earth metal decreases (that is, each It was confirmed that the recovery rate of rare earth metals increased). In particular, the recovery of cerium (Ce) and praseodymium rhodium (Pr) were confirmed to be increased rapidly by about 2000 cm ² and the contact area of about 1900 cm ^2.

In addition, the distribution ratio of each rare earth metal of ytterbium (Yb), terbium (Tb), cerium (Ce), and praseorhodium (Pr) when the contact area is about 700 cm ² , about 1000 cm ² , and about 2000 cm ² And recovery rates are Yb (distribution ratios 10, 3.17, 2.26; recovery rates 9.1%, 23.9%, 30.6%) and Tb (distribution ratios 2.56, 0.116, 0.0842; recovery rate 28.1%, 89.6%, 92.2%), Pr (partition ratio 0.627, 0.03, 0.0137; recovery rate 61.4%, 97.1%, 98.6%) and Ce (partition ratios 0.908, 0.0455, 0.0141; recovery rates 52.4%, 95.6%, 98.6%).

From the above results, by adjusting the contact area (cm ² ) between the extraction solution and the solution to be extracted using the apparatus and method of the present invention, the extraction status of the rare earth metal, which is a rare metal present in the solution to be extracted, can be determined. It was confirmed that it was possible to control.
For example, if water is used as an extraction solution and a kerosene solution is used as an extraction solution using this apparatus, and the contact area (cm ² ) of both liquids is about 700 cm ² or more, the extraction solution (kerosene solution) Thus, it was confirmed that cerium (Ce) and praseorhodium (Pr) can be selectively extracted into the extraction solution (water). That is, it can be confirmed that the rare earth metals cerium (Ce) and praseorhodium (Pr) can be selectively extracted from the extraction solution containing ytterbium (Yb) and terbium (Tb) having similar properties. It was.
On the other hand, under the conditions described above, if the contact area of both liquids (cm ²⁾ to about 1900 cm ² or more, confirmed that can be extracted with terbium (Tb) a selectively high recovery (approximately 89% higher) It was.
Therefore, it was confirmed that the target lanthanoid rare earth metal can be selectively extracted from the solution to be extracted containing a plurality of lanthanoid rare earth metals having similar properties by using this apparatus.

The extraction time when cerium (Ce) and praseorhodium (Pr) present in the solution to be extracted can be extracted at a high recovery rate (98.6% or more) is 5.6 min (in the above contact area). Equivalent to about 2000 m ² ). On the other hand, the extraction time when ytterbium (Yb) present in the solution to be extracted was extracted with a high recovery rate (about 89% or more) was 1.5 min (corresponding to about 1900 m ² in the contact area). It was. That is, by using this apparatus, it was confirmed that the efficiency of the extraction work of the target lanthanoid-based rare earth metal can be improved by controlling the contact area. In addition, extraction time was made into the residence time of the extraction solution (water) in the apparatus prepared so that the said contact area might become a predetermined value.

The liquid-liquid extraction apparatus and liquid-liquid extraction method of the present invention are suitable as an apparatus and method for liquid-liquid extraction using an extraction solution from a solution to be extracted containing rare earth metals or rare metals such as rare metals and rare earths. .

DESCRIPTION OF SYMBOLS 1 Liquid-liquid extraction apparatus 10 Extraction part 10h Flow path 11 Main body part 11a Liquid-liquid extraction part 12 Dispersion part 13 Liquid supply part 14 Liquid discharge part 20 Flow path formation member 21 Hydrophilic member 22 Hydrophobic member S Extracted solution E Extraction solution

Claims (9)

1. A liquid-liquid extraction device that contacts two liquids that form an interface and separates a substance from one liquid into another liquid,
   An extraction section having a plurality of extraction channels for passing the two liquids, a liquid supply section for supplying liquid to the extraction section, and a liquid discharge section for discharging liquid from the extraction section, With
   The extraction unit includes:
   A liquid-liquid extraction device characterized in that a cross-sectional area of the extraction flow path is formed to change along the flow path direction.
2. The two liquids are
   2. The liquid-liquid extraction device according to claim 1, comprising a main fluid and a sub-fluid having a lower flow rate than the flow rate of the main fluid.
3. The extraction unit includes:
   A tubular main body and a flow path forming member accommodated in the main body,
   The flow path forming member is:
   It is composed of a plurality of granular materials,
   The plurality of granules are
   The liquid-liquid extraction apparatus according to claim 1 or 2, comprising a granular hydrophobic member having a hydrophobic function on the surface and / or a granular hydrophilic member having a hydrophilic function on the surface. .
4. The two liquids are
   The main fluid is a hydrophobic liquid and the subfluid is a hydrophilic liquid;
   The plurality of granules are
   4. The liquid-liquid extraction apparatus according to claim 3, wherein the liquid-liquid extraction apparatus is composed of a granular hydrophobic member having a hydrophobic function on the surface.
5. The two liquids are
   The main fluid is a hydrophilic liquid and the subfluid is a hydrophobic liquid;
   The plurality of granules are
   4. The liquid-liquid extraction apparatus according to claim 3, wherein the liquid-liquid extraction apparatus is composed of a granular hydrophilic member having a hydrophilic function on the surface.
6. The extraction unit includes:
   6. The liquid-liquid extraction device according to claim 1, wherein the liquid-liquid extraction device is formed so as to have a porosity of 30% to 70%.
7. The plurality of granules are
   4. The liquid-liquid extraction apparatus according to claim 3, wherein the hydrophobic member contains 25% or more by volume ratio.
8. Two liquids that form an interface are brought into contact with each other in the extraction flow path to form a continuous liquid phase composed of one liquid and a continuous liquid phase composed of another liquid, and the substance is transferred from one liquid to another liquid. A liquid-liquid extraction method for countercurrent extraction or cocurrent extraction,
   A liquid-liquid extraction method characterized by causing the two liquids to flow through the extraction flow path whose cross-sectional area changes along the flow path direction.
9. The liquid-liquid extraction method according to claim 8, wherein the extraction channel is formed in a mesh shape.
   

Images