Coalescer filter for solvent extraction

Abstract

The present disclosure provides a coalescer filter that is used in a solvent extraction method for collecting metal contained in a secondary battery, said coalescer filter comprising first and second filter media, wherein the first filter medium has an average pore diameter of 0.8-8 μm, and the second filter medium has an average pore diameter of 9-100 μm.

Description

[Technical Field]

[0001] The present invention relates to a coalescer filter used in a solvent extraction method for recovering metals contained in secondary batteries. [Background technology]

[0002] Solvent extraction is a common technique in the hydrometallurgy of metals, in which an acidic aqueous solution containing metal ions is mixed with an extractant and / or diluent solvent specific to the metal, followed by rough separation using a mixer-settler (stationary separation) or the like to obtain a metal ion extract, which is then mixed with another acidic aqueous solution with a high acidity to strip-extract the metal ions, followed by rough separation using a mixer-settler or the like to obtain a metal ion strip-extract, and the metal is recovered from the roughly separated strip-extract by a method such as electrolysis or crystallization (see, for example, Patent Document 1 listed below).

[0003] However, in the recovery of specific metals (cobalt, nickel, etc.) from lithium-ion batteries, the separation efficiency is insufficient and the purity of the recovered metals is not satisfactory, so a method that can achieve stable and good separation efficiency is required. Furthermore, when recovering metals as raw materials for lithium-ion batteries rather than as metals themselves, the impurity concentration is regulated to stabilize battery performance, so it is important to improve the separation efficiency of the solvent extraction method.

[0004] The following Patent Document 2 discloses an oil-water separation device equipped with a coalescer filter that can efficiently recover organic solvents used in the solvent extraction process, but no coalescer filter with high separation efficiency (separation performance and productivity) that can efficiently recover specific metals from secondary batteries such as lithium-ion secondary batteries is known yet. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Japanese Patent Application Laid-Open No. 2016-194105 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-124539 Summary of the Invention [Problem to be solved by the invention]

[0006] In view of the above-mentioned conventional techniques, the problem to be solved by the present invention is to provide a coalescer filter having high separation efficiency (separation performance and productivity) that can be used in a solvent extraction method for recovering metals from secondary batteries. [Means for solving the problem]

[0007] In order to solve the above problems, the inventors of the present invention conducted extensive research and experiments and unexpectedly discovered that a coalescer filter containing two types of filter media with specific average pore sizes can achieve highly efficient oil-water separation in a solvent extraction method for recovering metals from secondary batteries, leading to the completion of the present invention.

[0008] That is, the present invention is as follows. [1] A coalescer filter used in a solvent extraction method for recovering metals contained in a secondary battery, The coalescer filter comprises a first filter medium and a second filter medium, The first filter medium has an average pore size of 0.8 μm or more and 8 μm or less, The average pore size of the second filter material is 9 μm or more and 100 μm or less. Coalescer filter. [2] The second filter medium is The average pore size is 9 μm or more and 50 μm or less, the average fiber diameter is 3 μm or more and 40 μm or less, and the basis weight is 30 g / m 2 More than 350g / m 2 Item 1. The coalescer filter according to item 1, comprising a nonwoven fabric having a porosity of 70% or more and less than 100%. [3] 3. The coalescer filter according to item 2, wherein the surface tension of the nonwoven fabric is 40 dyne / cm or more and 55 dyne / cm or less. [4] The second filter medium is 2. The coalescer filter of item 1, comprising a mesh. [5] 5. The coalescer filter according to item 4, wherein the surface tension of the mesh is 35 dyne / cm or more and 55 dyne / cm or less. [6] The first filter medium is Average fiber diameter is 1 μm or more and 3 μm or less, and the basis weight is 50 g / m 2 More than 250g / m 2 6. The coalescer filter according to any one of items 1 to 5, comprising a nonwoven fabric having a porosity of 60% or more and less than 100% and a surface tension of 60 dyne / cm or more and 80 dyne / cm or less. [7] The first filter medium is Average fiber diameter is 1 μm or more and 3 μm or less, and the weight is 150 g / m 2 More than 200g / m 2 7. The coalescer filter according to any one of items 1 to 6, comprising a nonwoven fabric having a porosity of 60% or more and less than 100% and a surface tension of 35 dyne / cm or more and 55 dyne / cm or less. [8] 8. The coalescer filter according to any one of items 1 to 7, wherein 90% by mass or more of the fiber components constituting the first filter medium and / or the second filter medium are one or more types selected from the group consisting of polyester, polypropylene, polyethylene, and glass. [9] a main body having an internal flow path into which a metal ion extract and / or stripped solution containing a mixed solution of an acidic aqueous solution and an extractant and / or a diluted organic solvent flows in a solvent extraction method for recovering metals from a secondary battery; A first filter material and a second filter material are arranged in the main body from the liquid upstream side so as to surround the internal flow path, The first filter medium has an average pore size of 0.8 μm or more and 8 μm or less, A coalescer cartridge in which the average pore size of the second filter material is 9 μm or more and 100 μm or less.

[10] A method for oil-water separation of a metal ion extract and / or stripped solution using a mixed solution of an acidic aqueous solution and an extractant and / or a diluted organic solvent in a solvent extraction method for recovering metals from a secondary battery, the method comprising the following steps: Roughly separating the extract and / or strip extract into an organic layer and an aqueous layer; and a step of treating the obtained roughly separated organic layer and / or aqueous layer with the coalescer filter described in any one of items 1 to 8; An oil-water separation method comprising:

[11] Item 11. The oil-water separation method according to item 10, wherein the coalescer filter is arranged so that the metal ion extract and / or stripped extract flows from a first filter material having a predetermined average pore size to a second filter material having an average pore size larger than that of the first filter material.

[12] The first filter medium is Average fiber diameter is 1 μm or more and 3 μm or less, and the basis weight is 50 g / m 2 More than 250g / m 2 The following includes nonwoven fabrics with a porosity of 60% or more but less than 100% and a surface tension of 60 dyne / cm or more but less than 80 dyne / cm: Item 12. The oil-water separation method according to Item 11, wherein the main component of the metal ion extract and / or stripping solution used in the solvent extraction method is a component derived from an acidic aqueous solution.

[13] The first filter medium is Average fiber diameter is 1 μm or more and 3 μm or less, and the weight is 150 g / m 2 More than 200g / m 2 , a nonwoven fabric having a porosity of 60% or more but less than 100% and a surface tension of 35 dyne / cm or more but 55 dyne / cm or less; Item 12. The oil-water separation method according to Item 11, wherein the main components of the metal ion extract and / or stripping solution used in the solvent extraction method are components derived from the extractant and / or components derived from the dilution solvent.

[14] 14. The oil-water separation method according to any one of items 10 to 13, wherein the secondary battery is a lithium ion secondary battery. [Effects of the Invention]

[0009] The coalescer filter according to the present invention has excellent separation efficiency (separation performance and productivity) when used in a solvent extraction method for recovering metals from secondary batteries. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described in detail. The coalescer filter of this embodiment is a coalescer filter used in a solvent extraction method for recovering metals contained in secondary batteries, and includes a plurality of filter media with different average pore sizes. The plurality of filter media with different average pore sizes includes a first filter media (also referred to in this specification as "filter media A") and a second filter media (also referred to in this specification as "filter media B").

[0011] The coalescer filter of this embodiment can be used to separate oil and water from a metal ion extract and / or strip extract using a mixed solution of an acidic aqueous solution and an extractant and / or a diluting solvent. Here, the inventors have focused on the coalescer filter, distinguishing between the function of capturing and coarsening fine droplets (free oil droplets dispersed finely in water, or free water droplets dispersed finely in oil) and the function of further promoting the coarsening of the captured fine droplets. That is, in the coalescer filter of this embodiment, filter material A mainly has the function of capturing and coarsening the fine droplets contained in the metal ion extract and / or strip extract, and filter material B mainly has the function of further promoting the coarsening of the fine droplets captured by filter material A. From the viewpoint of capturing and coarsening fine droplets, a relatively small average pore size is preferable, but from the viewpoint of further promoting the coarsening of fine droplets, a relatively large average pore size is preferable. The above-mentioned distinguished and focused functions have mutually opposite tendencies of preferred average pore size, and filter material A and filter material B are required to have different average pore size according to the above-mentioned distinguished and focused functions.According to this embodiment, by combining a plurality of filter materials that have different average pore size, that is, have different functions, can improve separation efficiency (separation performance and productivity).

[0012] The coalescer filter of this embodiment can be used to separate oil from water from a metal ion extract and / or strip extract obtained by a mixed solution of an acidic aqueous solution and an extractant and / or diluent solvent. In a solvent extraction method for recovering metals from secondary batteries using the coalescer filter of this embodiment, the secondary batteries are incinerated and crushed, and the resulting powder is treated with a mixed solution of an acidic aqueous solution and an extractant and / or diluent solvent to obtain a metal ion extract. The "acidic aqueous solution" is not particularly limited and may be selected appropriately depending on the metals contained in the secondary batteries. Examples of the acidic aqueous solution include aqueous solutions of sulfuric acid and hydrochloric acid. The "extractant and / or diluent solvent" is also not particularly limited and is selected appropriately depending on the metal contained in the secondary battery. For example, extractants include 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester extractants and acidic phosphate ester extractants, and diluent solvents include alkylbenzene diluents.

[0013] For example, one method of recycling lithium-ion secondary batteries involves incinerating, crushing, and sorting used batteries, followed by acid leaching, and then extracting and separating the various metals from the resulting leachate using solvent extraction. However, if the lithium-ion secondary batteries to be acid-leached contain not only the metals that make up the positive electrode, but also copper, iron, and aluminum, the copper, iron, and aluminum will also be leached out by the acid leaching, degrading the quality of the target recovered materials such as nickel and cobalt. Therefore, if copper, iron, and aluminum are present in the leachate obtained by acid leaching lithium-ion secondary batteries, they must be removed.

[0014] The metal mixture aqueous solution obtained by the acid leaching is not particularly limited, but can typically be a leaching solution obtained by acid leaching with sulfuric acid or the like waste materials including lithium-ion secondary batteries containing a positive electrode active material, nickel-cadmium batteries, nickel plating waste solution, etc. More specifically, the solution can be a leaching solution obtained by acid leaching with sulfuric acid or the like waste positive electrode active material from positive electrode active material manufacturers, positive electrode active material (sometimes mixed with a negative electrode active material and a solvent (PVDF or NMP)) from battery manufacturers that has been incinerated and dried, positive electrode material in which a positive electrode active material is bonded to a current collector such as aluminum foil via a binder, positive electrode material from which the positive electrode active material has been separated, or battery slag or crushed battery powder, which is obtained by incinerating, crushing, sieving, etc., to separate the positive electrode active material. In this specification, the term "metal ion extract" refers to an organic layer containing metal ions (cobalt, manganese, lithium, etc.) obtained by mixing an acidic aqueous solution containing metal ions leached from crushed waste lithium ion secondary batteries with a mixed solution of an extractant and / or diluent solvent, transferring the metal ions to an organic layer (mixed solution of extractant and / or diluent solvent) (generally referred to as extraction), and then separating the organic layer. In addition, in this specification, the term "metal ion stripping solution" refers to an acidic aqueous solution containing metal ions (cobalt, manganese, lithium, etc.) obtained by mixing the above-mentioned metal ion extraction solution with another acidic aqueous solution with high acidity, transferring the metal ions to the acidic aqueous solution (generally referred to as stripping), and then separating the metal ions.

[0015] The oil-water separation method of this embodiment includes a step of performing rough separation as a preliminary step to separation using a coalescer filter. The rough separation method is not particularly limited, but static separation is preferred. For static separation, separation methods such as mixer-settler type, rotary disk column type, and pulse column type can be used, but mixer-settler type is particularly preferred from the viewpoint of separation efficiency. Furthermore, rough separation does not have to be a single-stage process, and multiple stages may be used.

[0016] The oil-water separation method of this embodiment is characterized by including a step of treating the organic layer and / or aqueous layer obtained after crude separation with a coalescer filter. The coalescer filter coarsens and separates finely dispersed free water droplets in oil (organic solvent), or coarsens and separates finely dispersed free oil droplets in water.

[0017] The coalescer filter of this embodiment is disposed within a casing in an oil-water separation device. In one aspect, the casing is constructed by assembling upper and lower halves, and in the assembled state, is formed into a cylindrical shape extending vertically, with a closed space (internal space) formed therein. In another aspect, the casing is provided with a partition wall that divides the internal space into upper and lower sections (upper internal space and lower internal space), and this partition wall is formed with an opening that penetrates vertically, and one end of a vertical pipe extending toward the upper internal space is connected to this opening. Furthermore, in another aspect, a coalescer cartridge is disposed at the other end of the vertical pipe, and the coalescer filter of this embodiment is disposed within this coalescer cartridge. One coalescer cartridge or multiple coalescer cartridges may be disposed within the casing. In the oil-water separation method of this embodiment, the metal ion extract and / or stripping liquid flowing in from the solution inlet in the casing is guided to the coalescer cartridge through the opening and the vertical pipe, passes through the coalescer filter, and then flows out from the solution outlet in the casing. The coalescer filter is preferably configured as a cartridge to increase the processing flow rate. Such a cartridge comprises, for example, a main body having an internal flow path through which the metal ion extract and / or stripping solution flows, and filter media A and B arranged from the upstream side of the liquid within the main body so as to surround the internal flow path. One end of the main body is detachably connected to the vertical pipe in the casing, and the other end of the main body is capped. The solution from the vertical pipe is guided into the internal flow path extending vertically in the main body, and then passes through filter media A and B arranged so as to surround the internal flow path, during which oil-water separation occurs. The cartridge may comprise other components (filter media, reinforcing material, etc.) upstream of filter media A, between filter media A and B, and downstream of filter media B. In the cartridge, filter media A is preferably cylindrically pleated to increase its surface area. The number of overlapping filter media A is not limited, but in practice, it is approximately 2 to 8. In addition, the method of stacking is not limited in any way, but for example, if the nonwoven fabric that serves both as reinforcement and impurity removal, the filter material A, and the mesh that serves both as reinforcement and spacer are stacked and pleated in order from the side where the liquid enters the coalescer filter, this is preferable because it simultaneously achieves the effects of increasing the pressure resistance of the coalescer filter, increasing durability against impurities, and suppressing the reduction in the filter's effective area due to pleating.In addition, since the nonwoven fabric that serves both as reinforcement and impurity removal is also pleated, it can take up a large effective area within one cartridge and achieve high durability.In addition, the position of the filter material B in the coalescer filter shape is not particularly limited as long as it is located behind the filter material A.For example, it can be formed into a pleated layer together with the filter material A, or wrapped around the outside of the pleated layer one or more times.

[0018] From the viewpoint of separation ability and productivity, the average pore size of filter material A is 0.8 μm or more and 8 μm or less, preferably 1 μm or more and 5 μm or less, more preferably 2 μm or more and 3 μm or less.If the average pore size is smaller than 0.8 μm, it will be clogged early by foreign matter, and the life of filter material will be shortened quickly.In this case, the frequency of replacing the coalescer filter will increase, and productivity will be reduced.In addition, if the average pore size is larger than 8 μm, it will not be able to capture droplets (water droplets or oil droplets), and separation will be reduced.

[0019] When oil droplets of the extractant and / or dilution solvent present in the metal ion stripping solution are separated using a coalescer filter, the filter material A is preferably a nonwoven fabric having an average fiber diameter of 1 μm or more and 3 μm or less from the viewpoint of separation ability and productivity. In addition, in order to promote coarsening of the captured oil droplets, the filter material A is preferably a nonwoven fabric having a basis weight of 50 g / m 2 More than 250g / m 2 Preferably less than 150 g / m 2 More than 200g / m 2 More preferably, the nonwoven fabric has a porosity of 60% or more and less than 100%.For the same reason, the nonwoven fabric of filter material A is preferably one whose surface tension is 60 dyne / cm or more and 80 dyne / cm or less.In addition, when filter material A is a single-layer nonwoven fabric, the basis weight of filter material A refers to the basis weight of the single layer, and when filter material A is a laminate of multiple nonwoven fabrics, it refers to the basis weight of the laminate. In one aspect, the present embodiment is a filter medium A having an average fiber diameter of 1 μm or more and 3 μm or less and a basis weight of 50 g / m 2 More than 250g / m 2 The coalescer filter described below comprises a nonwoven fabric having a porosity of 60% or more but less than 100% and a surface tension of 60 dyne / cm or more and 80 dyne / cm or less, and the main component of the metal ion extract and / or strip extract used in the solvent extraction method is a component derived from an acidic aqueous solution. The coalescer filter of the above embodiment is suitable for use in solvent extraction methods in which the main component is a component derived from an acidic aqueous solution. Note that the "main component" refers to a component that accounts for 70% by mass or more, 80% by mass or more, or 90% by mass or more of the total amount of the metal ion extract and / or strip extract.

[0020] When separating water droplets of an acidic aqueous solution present in a metal ion extract using a coalescer filter, the filter material A is preferably a nonwoven fabric having an average fiber diameter of 1 μm or more and 3 μm or less from the viewpoint of separation ability and productivity. In addition, in order to promote coarsening of the captured water droplets, the filter material A is preferably a nonwoven fabric having a basis weight of 150 g / m. 2 More than 200g / m 2 It is preferable that the nonwoven fabric has a porosity of 60% or more and less than 100%. For the same reason, it is preferable that the filter medium A is a nonwoven fabric having a surface tension of 35 dyne / cm or more and 55 dyne / cm or less. In one aspect, the present embodiment is a filter medium A having an average fiber diameter of 1 μm or more and 3 μm or less and a basis weight of 150 g / m 2 More than 200g / m 2 The coalescer filter of the above embodiment comprises a nonwoven fabric having a porosity of 60% or more but less than 100% and a surface tension of 35 dyne / cm or more and 55 dyne / cm or less, and the main components of the metal ion extract and / or stripping solution used in the solvent extraction method are components derived from the extractant and / or components derived from the dilution solvent. The coalescer filter of the above embodiment is suitable for use in solvent extraction methods in which the main components are components derived from the extractant and / or components derived from the dilution solvent. The meaning of "main component" is the same as above.

[0021] In order to further promote the coarsening of droplets coarsened by filter medium A, filter medium B has an average pore size of 9 μm or more and 100 μm or less. Filter medium B may be a nonwoven fabric or a mesh, but mesh is preferable from the viewpoint of maintaining separation efficiency at high flow rates. Mesh has few film-like portions generated by calendaring, so liquid permeation is less likely to be hindered, and since the pore size distribution is uniform, the metal ion extract and / or stripping liquid easily flows at a constant flow rate throughout the filter medium. Therefore, when a mesh is used as filter medium B, droplets (water droplets or oil droplets) tend to remain within the filter medium and tend to coarsen even under high processing flow rates. Furthermore, a mesh with a uniform pore size distribution is less likely to open up because pressure is applied uniformly throughout the filter medium, making it easier to maintain separation efficiency even under high processing flow rates. In this specification, "mesh" refers to a structure woven with monofilaments (single fibers). If filter medium B is nonwoven fabric, the average pore size is 9 μm or more and 50 μm or less, the average fiber diameter is 3 μm or more and 40 μm or less, and the basis weight is 30 g / m 2 More than 350g / m 2 Preferably, the porosity is 70% or more and the surface tension is 35 dyne / cm or more and 55 dyne / cm or less. When the filter medium B is a mesh, the surface tension is preferably 35 dyne / cm or more and 55 dyne / cm or less.

[0022] The materials for filter media A and B include polyesters such as polyethylene terephthalate, polyethylene terephthalate adipate, polyethylene terephthalate isophthalate, polyethylene terephthalate sebacate, polyethylene terephthalate dodecanedioate, and polybutylene terephthalate, as well as polypropylene, polyethylene, and glass fiber. They can be selected based on the pH of the aqueous layer in the fluid and the chemical resistance of the organic layer. It is preferred that 90% or more by mass of the fiber components constituting the filter media of the coalescer filter be one or more selected from polyethylene terephthalate, polypropylene, polyethylene, and glass. The materials for filter media A and B may be the same or different. In addition, from the viewpoint of allowing filter medium A and filter medium B to optimally exhibit their respective functions, the thickness of filter medium A is preferably 0.2 mm or more and 2.00 mm or less, and the thickness of filter medium B is preferably 0.2 mm or more and 3.0 mm or less. Here, "thickness" refers to the total thickness of filter medium A or filter medium B when a plurality of filter medium A or filter medium B are stacked. Filter medium A can be thicker than filter medium B, and in this case, it is easy to realize a filter medium A that is stacked a plurality of sheets. On the other hand, filter medium B can be thicker than filter medium A, and in this case, it is easy to realize the overall configuration of the coalescer filter in which filter medium B is wrapped around the outside of filter medium A.

[0023] The manufacturing method of the nonwoven fabric is not limited in any way, and examples thereof include melt-blowing, spunbonding, spunlace, needle punching, and papermaking. However, for the filter material A, in order to have an average pore size of 0.8 μm or more and 8 μm or less, it is preferable to mainly use nonwoven fabric made by the melt-blowing method.

[0024] In addition, filter media A and filter media B may be surface-treated to be hydrophilic, lipophilic, or water-repellent. The hydrophilization method is not limited, but examples include introducing hydrophilic functional groups such as hydroxyl groups, carboxyl groups, amino groups, ketone groups, and sulfonic groups into fiber polymers through chemical reactions, or introducing compounds that become hydrophilic by alkali treatment, such as acrylic acid, into the side chains through graft polymerization. Other examples include hydrophilic treatment of the fiber surface using hydrophilic processing agents such as polyethylene glycol, polycarboxylic acid, polyisocyanate, vinyl groups, glycidyl ether groups, polyamines, polyalkylene oxides containing N-methoxymethylol, polymer electrolytes, and hydrophilic cellulose-based materials. Water-repellent processing can be performed using conventional methods, such as fluorine-based resins such as acrylic acid perfluoroalcohol, silicone-based resins such as dimethyl silicone, paraffin-based resins, and wax-based resins, which can be applied during yarn production or to fiber structures by padding, immersion, spraying, exhaustion, etc.

[0025] The filter media A and B may be used alone or in combination to enhance strength or provide functionality, and a reinforcing material may also be used. Examples of reinforcing materials include metal mesh, woven fabric, knitted fabric, and nonwoven fabric. The materials constituting these woven fabrics, knitted fabrics, and nonwoven fabrics are not particularly limited, and examples thereof include fibers of polyester copolymers such as polyethylene terephthalate, polyethylene terephthalate adipate, polyethylene terephthalate isophthalate, polyethylene terephthalate sebacate, polyethylene terephthalate dodecanedioate, and polybutylene terephthalate; polyhexamethylene adipamide (polyamide 66); polyhexamethylene sebacamide; polyhexamethylene decamide; polyhexamethylene hexamide; and polycapramide (polyamide 6). ), polyamide fibers such as polyoctamide, polynonamide, polydecamide, polydodecamide, and polytetraamide, polyamide-imide fibers, aromatic polyamide fibers, polyester ether fibers such as polyparaoxybenzoate, halogen-containing polymer fibers such as polyvinyl chloride, polyvinylidene chloride, polyvinylidene fluoride, and polytetrafluoroethylene, polyolefin fibers such as polypropylene and polyethylene, various acrylic fibers, polyvinyl alcohol fibers, regenerated cellulose, acetate, and natural fibers such as cotton, linen, silk, and wool.

[0026] It is also possible to further promote oil-water separation by using multiple coalescer filters or circulating the treatment liquid through coalescer filters. Also, in order to capture impurities in the treatment liquid, a prefilter can be placed to capture impurities before treating the liquid with the coalescer filter. [Example]

[0027] The present invention will be specifically described below with reference to examples and comparative examples. First, the methods used to measure the physical properties will be explained below. (1) Average pore diameter Measurements were performed using a PMI Perm Porometer (model: CFP-1200AEX) and Galvic (PMI) as the immersion liquid after the sample had been thoroughly degassed. Measurements were performed three times for the same sample, and the average of the obtained mean flow pore diameters was taken as the mean pore size for that sample.

[0028] (2) Average fiber diameter The surface of the nonwoven fabric was magnified using a microscope or electron microscope photograph, and the fiber diameter (thickness) was measured at 50 points, and the average value was calculated.

[0029] (2) Metsuke The weight of a 100mm x 100mm sample was measured and calculated in g / m 2 was calculated by converting it into

[0030] (3) Porosity According to the measurement method specified in JIS-L-1913-2010, a probe of φ16 was used to measure 20 g / cm 2 The thickness under load is measured at five points and the average value is calculated from the basis weight and thickness using the following formula: [1-[{(basis weight / 1000) ÷ specific gravity} ÷ thickness]] x 100 The specific gravity of polyethylene terephthalate was calculated as follows: 1.38

[0031] (4)Surface tension A non-porous film made of the same material as the fibers forming each filter medium was prepared as a measurement sample. When various processing agents were coated or chemically bonded to the fiber surface, first, a non-porous film made of the same material as the fiber was prepared. A nonporous film was prepared and treated under the same conditions as when the same finishing agent was coated or chemically bonded to the fiber surface to prepare a measurement sample. The contact angles of the samples were measured with liquids having various surface tensions, and the surface tension at a contact angle θ = 0 was calculated by extrapolation, and this was used as the surface tension of each sample.

[0032] (5) Separation performance A cobalt-containing sulfuric acid aqueous solution, which simulates a secondary battery extract, and an organic layer consisting of 2-ethylhexylphosphonic acid mono-2-ethylhexyl ester extractant and a naphthenic diluent were mixed in a beaker, and the mixture was left to stand for 10 minutes for rough separation. After that, only the aqueous layer and only the organic layer were collected, and these were used as simulated test solutions. When the recovered aqueous solution layer is used as a simulated test solution, 1 L of the simulated test solution is passed through a coalescer filter (flat membrane type, 12.5 cm) using a small pump. 2 ) to the reference flow rate (1 ml / min / cm 2 The TOC (total organic carbon) of the resulting aqueous solution layer was measured using a TOC meter, and the TOC concentration remaining in the aqueous solution layer was calculated. The TOC concentration of the simulated test liquid before the liquid was passed through and the saturated oil concentration of the organic layer relative to the water were calculated using the following formula:

number

number

[0033] (6) Coarsening droplet diameter In the standard flow rate test in (5) above, photographs of droplets in the simulated test liquid after passing through the filter were taken, and the droplet diameters were measured at 10 points, and the average value was calculated.

[0034] (7) Productivity In the test (5) above, productivity was evaluated as follows. E(〇): Even when the flow rate was increased to three times the standard flow rate, the oil-water separation rate did not decrease by more than 1%. A (△): Even when the flow rate was increased to 1.5 times the standard flow rate, the oil-water separation rate did not decrease by more than 1%. P(×): When the flow rate was increased to 1.5 times the standard flow rate, the oil-water separation rate decreased by more than 1%.

[0035] [Preparation of coalescer filter] As filter material A, a plurality of sheets are stacked together, folded into pleats, and formed into a cylindrical shape.Filter material B is wound around the outside of this filter material A once, to prepare a coalescer filter.Hereinafter, in each embodiment and each comparative example, those that do not have filter material A and / or filter material B are omitted, and similarly prepare a coalescer filter.Coalescer filter can be used to prepare a coalescer cartridge by ordinary method.

[0036] [Example 1] Filter medium A was made by stacking four sheets of filter medium that had been hydrophilized with a polyester-based SR processing agent, with an average pore size of 1 μm, an average fiber diameter of 1.1 μm, and a basis weight of 160 g / m. 2 (Basis weight 40g / m 2 By stacking four sheets of filter media, the weight is 160g / m 2 The filter medium B was a polyester nonwoven fabric with a porosity of 67% and a surface tension of 70 dyne / cm, and had an average pore size of 38 μm, an average fiber diameter of 30 μm, and a basis weight of 315 g / m. 2 A simulated test liquid consisting of an aqueous solution layer was treated using a filter made of polyester nonwoven fabric with a porosity of 86% and a surface tension of 44 dyne / cm. The results are shown in Table 1 below.

[0037] [Example 2] Filter medium A was made by stacking four sheets of filter medium that had been hydrophilized with a polyester-based SR processing agent, with an average pore size of 1 μm, an average fiber diameter of 1.1 μm, and a basis weight of 160 g / m. 2A polyester nonwoven fabric with a porosity of 67% and a surface tension of 70 dyne / cm was used as filter medium B, with an average pore size of 40 μm, an average fiber diameter of 20 μm, and a basis weight of 50 g / m. 2 A simulated test liquid consisting of an aqueous solution layer was treated using a filter made of polyester nonwoven fabric with a porosity of 81% and a surface tension of 44 dyne / cm. The results are shown in Table 1 below.

[0038] [Example 3] Filter medium A was made by stacking four sheets of filter medium that had been hydrophilized with a polyester-based SR processing agent, with an average pore size of 1 μm, an average fiber diameter of 1.1 μm, and a basis weight of 160 g / m. 2 A polyester nonwoven fabric with a porosity of 67% and a surface tension of 70 dyne / cm was used as filter medium B, with an average pore size of 9 μm, an average fiber diameter of 4 μm, and a basis weight of 260 g / m. 2 A simulated test liquid consisting of an aqueous solution layer was treated using a filter made of polyester nonwoven fabric with a porosity of 72% and a surface tension of 44 dyne / cm. The results are shown in Table 1 below.

[0039] [Example 4] Filter medium A was made by stacking two sheets of filter medium that had been hydrophilized with a polyester-based SR processing agent, with an average pore size of 5 μm, an average fiber diameter of 2.3 μm, and a basis weight of 180 g / m. 2 A polyester nonwoven fabric with a porosity of 78% and a surface tension of 70 dyne / cm was used as filter medium B, with an average pore size of 38 μm, an average fiber diameter of 30 μm, and a basis weight of 315 g / m. 2 A simulated test liquid consisting of an aqueous solution layer was treated using a filter made of polyester nonwoven fabric with a porosity of 86% and a surface tension of 44 dyne / cm. The results are shown in Table 1 below.

[0040] [Example 5] Filter medium A was made by stacking four sheets of filter medium that had been hydrophilized with a polyester-based SR processing agent, with an average pore size of 1 μm, an average fiber diameter of 1.1 μm, and a basis weight of 160 g / m. 2 A polyester nonwoven fabric with a porosity of 67% and a surface tension of 70 dyne / cm was used as filter medium B, with an average pore size of 90 μm, an average fiber diameter of 50 μm, and a basis weight of 100 g / m. 2A simulated test liquid consisting of an aqueous solution layer was processed using a filter with a mesh having a porosity of 25% and a surface tension of 44 dyne / cm. The results are shown in Table 1 below.

[0041] [Example 6] Filter medium A is made by stacking two sheets of filter medium together, with an average pore size of 2 μm, an average fiber diameter of 1.7 μm, and a basis weight of 160 g / m. 2 A polyester nonwoven fabric with a porosity of 62% and a surface tension of 44 dyne / cm was used as filter medium B, with an average pore size of 38 μm, an average fiber diameter of 30 μm, and a basis weight of 315 g / m. 2 A simulated test liquid consisting of an organic layer was treated using a filter made of polyester nonwoven fabric with a porosity of 86% and a surface tension of 44 dyne / cm. The results are shown in Table 2 below.

[0042] [Example 7] Filter medium A is made by stacking two sheets of filter medium together, with an average pore size of 2 μm, an average fiber diameter of 1.7 μm, and a basis weight of 160 g / m. 2 A polyester nonwoven fabric with a porosity of 62% and a surface tension of 44 dyne / cm was used as filter medium B, with an average pore size of 40 μm, an average fiber diameter of 20 μm, and a basis weight of 50 g / m. 2 A simulated test liquid consisting of an organic layer was treated using a filter made of polyester nonwoven fabric with a porosity of 81% and a surface tension of 44 dyne / cm. The results are shown in Table 2 below.

[0043] [Example 8] Filter medium A is made by stacking two sheets of filter medium together, with an average pore size of 2 μm, an average fiber diameter of 1.7 μm, and a basis weight of 160 g / m. 2 A polyester nonwoven fabric with a porosity of 62% and a surface tension of 44 dyne / cm was used as filter medium B, with an average pore size of 9 μm, an average fiber diameter of 4 μm, and a basis weight of 260 g / m. 2 A simulated test liquid consisting of an organic layer was treated using a filter made of polyester nonwoven fabric with a porosity of 72% and a surface tension of 44 dyne / cm. The results are shown in Table 2 below.

[0044] [Example 9] Filter medium A is made by stacking two sheets of filter medium together, with an average pore size of 5 μm, an average fiber diameter of 2.3 μm, and a basis weight of 180 g / m. 2 A polyester nonwoven fabric with a porosity of 79% and a surface tension of 44 dyne / cm was used as filter medium B, with an average pore size of 38 μm, an average fiber diameter of 30 μm, and a basis weight of 315 g / m. 2 A simulated test liquid consisting of an organic layer was treated using a filter made of polyester nonwoven fabric with a porosity of 86% and a surface tension of 44 dyne / cm. The results are shown in Table 2 below.

[0045] [Example 10] Filter medium A is made by stacking two sheets of filter medium together, with an average pore size of 2 μm, an average fiber diameter of 1.7 μm, and a basis weight of 160 g / m. 2 A polyester nonwoven fabric with a porosity of 62% and a surface tension of 44 dyne / cm was used as filter medium B, with an average pore size of 90 μm, an average fiber diameter of 50 μm, and a basis weight of 100 g / m. 2 A simulated test liquid consisting of an organic layer was treated using a filter with a mesh having a porosity of 25% and a surface tension of 44 dyne / cm. The results are shown in Table 2 below.

[0046] [Comparative Example 1] The simulated test solution consisting of an aqueous solution layer was treated without using a coalescer filter by leaving it to stand for 30 minutes. The results are shown in Table 1 below.

[0047] Comparative Example 2 Filter medium A was made by stacking four sheets of filter medium that had been hydrophilized with a polyester-based SR processing agent, with an average pore size of 1 μm, an average fiber diameter of 1.1 μm, and a basis weight of 160 g / m. 2 A simulated test liquid consisting of an aqueous solution layer was treated using a filter that was made of polyester nonwoven fabric with a porosity of 67% and a surface tension of 70 dyne / cm and did not contain filter material B. The results are shown in Table 1 below.

[0048] Comparative Example 3 Without filter media A, filter media B has an average pore size of 38 μm, an average fiber diameter of 30 μm, and a basis weight of 315 g / m 2A simulated test liquid consisting of an aqueous solution layer was treated using a filter made of polyester nonwoven fabric with a porosity of 86% and a surface tension of 44 dyne / cm. The results are shown in Table 1 below.

[0049] Comparative Example 4 Filter medium A is made by stacking three sheets of filter medium, with an average pore size of 0.5 μm, an average fiber diameter of 0.8 μm, and a basis weight of 180 g / m. 2 A polyester nonwoven fabric with a porosity of 60% and a surface tension of 44 dyne / cm was used as filter medium B, with an average pore size of 38 μm, an average fiber diameter of 30 μm, and a basis weight of 315 g / m. 2 A simulated test liquid consisting of an aqueous solution layer was treated using a filter made of polyester nonwoven fabric with a porosity of 86% and a surface tension of 44 dyne / cm. The results are shown in Table 1 below.

[0050] Comparative Example 5 Filter medium A has an average pore size of 40 μm, an average fiber diameter of 20 μm, and a basis weight of 50 g / m 2 A polyester nonwoven fabric with a porosity of 81% and a surface tension of 44 dyne / cm was used as filter medium B, with an average pore size of 38 μm, an average fiber diameter of 30 μm, and a basis weight of 315 g / m. 2 A simulated test liquid consisting of an aqueous solution layer was treated using a filter made of polyester nonwoven fabric with a porosity of 86% and a surface tension of 44 dyne / cm. The results are shown in Table 1 below.

[0051] Comparative Example 6 Filter medium A is made by stacking four sheets of filter medium, with an average pore size of 1 μm, an average fiber diameter of 1.1 μm, and a basis weight of 160 g / m 2 A polyester nonwoven fabric with a porosity of 67% and a surface tension of 44 dyne / cm was used as filter medium B, with an average pore size of 7 μm, an average fiber diameter of 2.3 μm, and a basis weight of 90 g / m. 2 A simulated test liquid consisting of an aqueous solution layer was treated using a filter made of polyester nonwoven fabric with a porosity of 78% and a surface tension of 44 dyne / cm. The results are shown in Table 1 below.

[0052] Comparative Example 7 A simulated test solution consisting of the organic layer was treated without using a coalescer filter by leaving it to stand for 30 minutes. The results are shown in Table 2 below.

[0053] [Comparative Example 8] Filter medium A is made by stacking two sheets of filter medium together, with an average pore size of 2 μm, an average fiber diameter of 1.7 μm, and a basis weight of 160 g / m. 2 A simulated test liquid consisting of an organic layer was treated using a filter made of polyester nonwoven fabric with a porosity of 62% and a surface tension of 44 dyne / cm, and without filter medium B. The results are shown in Table 2 below.

[0054] Comparative Example 9 Without filter media A, filter media B has an average pore size of 38 μm, an average fiber diameter of 30 μm, and a basis weight of 315 g / m 2 A simulated test liquid consisting of an organic layer was treated using a filter made of polyester nonwoven fabric with a porosity of 86% and a surface tension of 44 dyne / cm. The results are shown in Table 2 below.

[0055] [Comparative Example 10] Filter medium A is made by stacking three sheets of filter medium, with an average pore size of 0.5 μm, an average fiber diameter of 0.8 μm, and a basis weight of 180 g / m. 2 A polyester nonwoven fabric with a porosity of 82% and a surface tension of 44 dyne / cm was used as filter medium B, with an average pore size of 38 μm, an average fiber diameter of 30 μm, and a basis weight of 315 g / m. 2 A simulated test liquid consisting of an organic layer was treated using a filter made of polyester nonwoven fabric with a porosity of 60% and a surface tension of 44 dyne / cm. The results are shown in Table 2 below.

[0056] [Comparative Example 11] Filter medium A has an average pore size of 40 μm, an average fiber diameter of 20 μm, and a basis weight of 50 g / m 2 A polyester nonwoven fabric with a porosity of 81% and a surface tension of 44 dyne / cm was used as filter medium B, with an average pore size of 38 μm, an average fiber diameter of 30 μm, and a basis weight of 315 g / m. 2 A simulated test liquid consisting of an organic layer was treated using a filter made of polyester nonwoven fabric with a porosity of 86% and a surface tension of 44 dyne / cm. The results are shown in Table 2 below.

[0057] [Comparative Example 12] Filter medium A is made by stacking two sheets of filter medium together, with an average pore size of 2 μm, an average fiber diameter of 1.7 μm, and a basis weight of 160 g / m. 2 A polyester nonwoven fabric with a porosity of 62% and a surface tension of 44 dyne / cm was used as filter medium B, with an average pore size of 7 μm, an average fiber diameter of 2.3 μm, and a basis weight of 90 g / m. 2 A simulated test liquid consisting of an organic layer was treated using a filter made of polyester nonwoven fabric with a porosity of 78% and a surface tension of 44 dyne / cm. The results are shown in Table 2 below.

[0058] [Table 1]

[0059] [Table 2] [Industrial Applicability]

[0060] INDUSTRIAL APPLICABILITY The present invention is industrially useful because it enables highly efficient separation of specific useful metals from secondary batteries such as lithium ion secondary batteries, nickel-metal hydride secondary batteries, and nickel-cadmium secondary batteries.

Claims

1. A coalescer filter used for oil-water separation of a metal ion extract and / or stripped solution using a mixed solution of an acidic aqueous solution and an extractant and / or a diluted organic solvent in a solvent extraction method for recovering metals contained in a secondary battery, The coalescer filter comprises a first filter medium and a second filter medium, The first filter material has an average pore size of 0.8 μm or more and 8 μm or less, The average pore size of the second filter material is 9 μm or more and 100 μm or less. Coalescer filter.

2. The second filter medium is The average pore size is 9 μm or more and 50 μm or less, the average fiber diameter is 3 μm or more and 40 μm or less, and the basis weight is 30 g / m ２ 350g / m or more ２ 2. The coalescer filter according to claim 1, comprising a nonwoven fabric having a porosity of 70% or more but less than 100% and a surface tension of 40 dyne / cm or more and 55 dyne / cm or less.

3. 3. The coalescer filter according to claim 2, wherein the surface tension of the nonwoven fabric is 40 dyne / cm or more and 55 dyne / cm or less.

4. The second filter medium is 10. The coalescer filter of claim 1, comprising a mesh.

5. 5. The coalescer filter according to claim 4, wherein the surface tension of the mesh is 35 dyne / cm or more and 55 dyne / cm or less.

6. The first filter medium is Average fiber diameter is 1 μm or more and 3 μm or less, and the basis weight is 50 g / m ２ More than 250g / m ２ The coalescer filter according to any one of claims 1 to 5, comprising a nonwoven fabric having a porosity of 60% or more but less than 100% and a surface tension of 60 dyne / cm or more and 80 dyne / cm or less.

7. The first filter medium is Average fiber diameter is 1 μm or more and 3 μm or less, and the basis weight is 150 g / m ２ More than 200g / m ２ The coalescer filter according to any one of claims 1 to 5, comprising a nonwoven fabric having a porosity of 60% or more but less than 100% and a surface tension of 35 dyne / cm or more and 55 dyne / cm or less.

8. 90% by mass or more of the fiber components constituting the first filter material and / or the second filter material is one or more selected from the group consisting of polyester, polypropylene, polyethylene and glass. Coalescer filter according to any one of claims 1 to 5.

9. a main body having an internal flow path into which a metal ion extract and / or stripped solution containing a mixed solution of an acidic aqueous solution and an extractant and / or a diluted organic solvent flows in a solvent extraction method for recovering metals from a secondary battery; A first filter material and a second filter material are arranged in the main body from the liquid upstream side so as to surround the internal flow path, The first filter material has an average pore size of 0.8 μm or more and 8 μm or less, A coalescer cartridge, wherein the average pore size of the second filter material is 9 μm or more and 100 μm or less.

10. A method for oil-water separation of a metal ion extract and / or stripped solution using a mixed solution of an acidic aqueous solution and an extractant and / or a diluted organic solvent in a solvent extraction method for recovering metals from a secondary battery, the method comprising the following steps: Roughly separating the extract and / or strip extract into an organic layer and an aqueous layer; and a step of treating the obtained roughly separated organic layer and / or aqueous layer with the coalescer filter according to any one of claims 1 to 5; An oil-water separation method comprising:

11. The oil-water separation method described in claim 10, wherein the coalescer filter is arranged so that the metal ion extract and / or stripping liquid flows from a first filter material having a predetermined average pore size to a second filter material having an average pore size larger than that of the first filter material.

12. The first filter medium is Average fiber diameter is 1 μm or more and 3 μm or less, and the basis weight is 50 g / m ２ More than 250g / m ２ The following includes a nonwoven fabric having a porosity of 60% or more but less than 100% and a surface tension of 60 dyne / cm or more and 80 dyne / cm or less, The oil-water separation method according to claim 11, wherein the main component of the metal ion extract and / or stripping solution used in the solvent extraction method is a component derived from an acidic aqueous solution.

13. The first filter medium is Average fiber diameter is 1 μm or more and 3 μm or less, and the basis weight is 150 g / m ２ More than 200g / m ２ , a nonwoven fabric having a porosity of 60% or more and less than 100% and a surface tension of 35 dyne / cm or more and 55 dyne / cm or less, The oil-water separation method according to claim 11, wherein the main components of the metal ion extract and / or stripping solution used in the solvent extraction method are components derived from the extractant and / or components derived from the dilution solvent.

14. The oil-water separation method according to claim 10, wherein the secondary battery is a lithium ion secondary battery.

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