JP6316228B2 - Metal recovery apparatus and metal recovery method - Google Patents

Description

  Embodiments described herein relate generally to a metal recovery apparatus and a metal recovery method.

  In recent years, effective use of water resources is required due to industrial development and population growth. For this purpose, it is important to reuse wastewater such as industrial wastewater. In order to reuse wastewater, it is necessary to purify water, that is, to separate other substances from the water. As a method for separating other substances from water, there are various methods such as a membrane separation method, a centrifugal separation method, an activated carbon adsorption method, an ozone treatment method, and a removal method of suspended substances by aggregation. Using these methods, it is possible to remove substances having a large environmental impact such as phosphorus and nitrogen contained in water, and to remove oils and clays dispersed in water.

  Among these various water treatment methods, the membrane separation method is one of the most commonly used methods for removing insoluble substances in water. When cleaning the separation membrane after the membrane separation is performed, if the separation between the separated insoluble substance and the separation membrane is poor, the cleaning efficiency of the separation membrane is reduced, and the consumption of cleaning water is increased and the performance of the membrane is decreased. cause. When the insoluble substance is fine particles, it is necessary to add an aggregating agent for aggregating the fine particles in advance. When recovering valuable metals such as rare metals in water by a membrane separation method, impurities derived from the flocculant may be mixed.

JP 2008-180206 A

  The problem to be solved by the present invention is to provide a metal recovery apparatus and a metal recovery method capable of recovering valuable metals without using a flocculant.

The metal collection | recovery apparatus of embodiment has a precipitation tank and a filter.
In the precipitation tank, water to be treated containing metal ions is made basic to deposit metal ions as metal compounds.
A filter has a filter which isolate | separates and collects the metal compound in to-be-processed water.
The filter has a filter base and a plating layer that covers the surface of the filter base.
At least on the surface of the plating layer on the primary surface side of the filter substrate, there is an aggregate of polyhedral precipitates or an aggregate of a plurality of needle-like precipitates.

The schematic diagram which shows the metal collection | recovery apparatus of 1st Embodiment. The plane schematic diagram of a filter. The partial cross section schematic diagram of a filter. The expanded cross-section schematic diagram of the principal part of a filter. An electron micrograph of the surface of the plating layer of the filter. An electron micrograph of the surface of the plating layer of the filter. The block diagram explaining the metal collection | recovery method of 1st Embodiment. The schematic diagram which shows the metal collection | recovery apparatus of 2nd Embodiment. The block diagram explaining the metal collection | recovery method of 2nd Embodiment. The external appearance perspective view which showed the filter other example. Sectional drawing when the filter shown in FIG. 10 is seen from the end face side. The plane schematic diagram which showed the other example of the filter. The plane schematic diagram which showed the other example of the filter. The plane schematic diagram which showed the other example of the filter. Schematic which showed the other example of the filter formed in the cylindrical shape. Sectional drawing when the filter shown in FIG. 15 is seen from the end surface side. The principal part expanded sectional view which shows the internal peripheral surface side of the filter shown in FIG. The principal part expanded sectional view which shows the internal peripheral surface side in the other example of a filter. The external appearance perspective view which shows the other example of a filter. The external appearance perspective view which shows the other example of a filter.

  Hereinafter, the metal collection | recovery apparatus and metal collection | recovery method of embodiment are demonstrated with reference to drawings.

(First embodiment)
As shown in FIG. 1, the metal recovery apparatus 1 of the present embodiment includes a precipitation tank 2 that precipitates metal ions in the water to be treated as a metal compound, and a filter that includes a filter 3 that recovers the metal compound from the water to be treated. 4, a cleaning mechanism 5 that supplies cleaning water to the filter 3, a recovery tank 6 that stores the cleaning water after cleaning, and a treated water tank 7 that stores the water to be treated that has passed through the filter 3. . Further, the metal recovery apparatus 1 shown in FIG. 1 is further provided with a filter heating apparatus 8 for heating the filter 3.

  The to-be-processed water processed by the metal collection | recovery apparatus 1 of this embodiment can illustrate the acidic thru | or neutral water containing various metal ions, for example, More desirably, it is acidic water containing various metal ions. Examples of the metal species of the metal ion include Cu, Cr, Ni, Zn, Al, Cd, Ga, Au, Ag, Co, Fe, Pb, Be, Mg, and Mn. The water to be treated may contain one or more of these metal ions. The concentration of metal ions is not particularly limited.

  To the precipitation tank 2, water to be treated containing metal ions is supplied from a raw water supply source (not shown) via a line L 1, and this is temporarily stored in the precipitation tank 2. The line L1 has a shut-off valve S1 so that the supply of raw water to the precipitation tank 2 can be controlled. The precipitation tank 2 is equipped with a stirrer 2a for stirring the water to be treated and a pH adjusting device 2b for making the water to be treated basic. The pH adjusting device 2b adds acid or alkali to the water to be treated. By adding alkali from the pH adjusting device 2b, the water to be treated is made basic at pH 9 or higher. Moreover, you may add an acid from the pH adjuster 2b for pH adjustment. Sodium hydroxide can be illustrated as an alkali. An example of the acid is sulfuric acid. The precipitation tank 2 deposits metal ions in the water to be treated as a metal compound by making the water to be treated basic.

  The filter 4 incorporates a filter 3 that partitions the interior into a primary space 4a and a secondary space 4b. The primary space 4 a is a space into which the water to be treated before passing through the filter 3 is introduced, and the secondary space 4 b is a space into which the water to be treated that has passed through the filter 3 flows. The filter 3 has a filter base material made of metal and a plating layer that covers the surface of the filter base material. The surface of the plating layer of the filter 3 is provided with a polyhedral precipitate aggregate or a plurality of acicular precipitate aggregates. The filter 3 will be described later.

  The primary space 4a of the filter 4 is connected to the precipitation tank 2 via a supply line L2 having a pressure pump P1. The supply line L2 is provided with a shutoff valve S2. The primary space 4a is connected to a cleaning line L3 for supplying cleaning water to the primary space 4a and a recovery line L4 for recovering the cleaning water after cleaning. The cleaning line L3 and the recovery line L4 are provided with shutoff valves S3 and S4, respectively. Further, the cleaning line L3 is provided with a pressure pump P2 for sending the cleaning water to the primary space 4a. A cleaning mechanism 5 is configured by the cleaning line L3 and the pressure pump P2.

  The cleaning line L3 supplies cleaning water from the side to the primary side space 4a and peels and removes the deposited layer from the filter 3. A sufficient amount of cleaning water is introduced from the side into the primary space 4a of the filter 4 through the cleaning line L3, and the deposited layer is peeled off from the filter 3 by hydraulic power and removed. The flow rate and water pressure of the washing water are controlled by the pressurizing pump P2. Moreover, if an injection nozzle is attached to the connection part of the washing line L3 and the filter 4 and water is ejected vigorously from the nozzle, the peeling effect of the deposited layer is enhanced and the removal efficiency is further improved.

  The recovery line L4 discharges the washing water used for washing the filter 3 from the side of the filter 4. A recovery tank 6 is connected to the end of the recovery line L4.

  The recovery tank 6 stores the wash water discharged from the filter 4 via the recovery line L4. The stored washing water contains the metal compound peeled off from the filter 3.

  Moreover, the secondary side space 4b of the filter 4 is connected to the treated water tank 7 via the discharge line L5. The drain line L5 is provided with a shutoff valve S5.

  The treated water that has passed through the filter 3 is stored in the treated water tank 7. Further, a cleaning line L3 is connected to the treated water tank 7. The cleaning line L3 branches off from the treated water discharge line L6 on the upstream side of the shutoff valve S3. The treated water discharge line L6 is provided with a shutoff valve S6.

  Furthermore, the metal recovery device 1 of the present embodiment is provided with a filter heating device 8. The filter heating device 8 may be any device that can heat the filter 3. For example, an electric heater that heats the filter 3, a steam injection device that heats the filter 3 by spraying high-temperature steam, or a high-temperature combustion gas on the filter 3. For example, a high-temperature gas injection device that sprays the like can be used. The filter heating device 8 can heat the filter 3 up to 500 ° C.

Next, the filter 3 provided in the filter 4 will be described. FIG. 2 shows a schematic plan view of the filtration filter, and FIG. 3 shows a partial sectional view of the filtration filter. Figure 3 is a cross-sectional view along line A-A 'of FIG.

  The filter 3 for filtration shown in FIG.2 and FIG.3 has the filter base material 16 and the plating layer 13 formed in the surface of the filter base material 16 by the electroplating process etc. FIG. In the example shown in FIGS. 2 and 3, the filter base 16 is formed of a wire mesh in which a wire 12 made of metal is twilled. As shown in FIG. 3, a base layer 14 is formed on the surface of the wire 12 constituting the filter base material 16, and a plating layer 13 is formed on the base layer 14. On the surface of the plating layer 13, a polyhedral precipitate aggregate or a plurality of acicular precipitate aggregates (not shown) is provided.

  The filter substrate 16 has a mesh shape in which the wire 12 is twilled, and a gap is formed by overlapping the wire 12 at a portion where the wires 12 intersect with each other, and the gap becomes a plurality of through holes 18. The long diameter of the through hole 18 is preferably in the range of 0.5 μm to 20 μm, and more preferably in the range of 1 μm to 10 μm. When the long diameter of the through hole 18 is 0.5 μm or more, an appropriate filtration flow rate is easily secured. If the long diameter of the through-hole 18 is 20 μm or less, the metal compound can be easily supplemented.

  The material of the wire 12 is preferably a metal in order to easily form only the plating layer 13 or the plating layer 13 and the base layer 14 by plating. For example, iron, nickel, copper, and alloys thereof are preferably used as the metal used for the wire 12. In particular, it is preferable to use a stainless steel wire that is excellent in corrosion resistance, low cost, and easy to process as the wire 12.

  The underlayer 14 is provided as necessary in order to improve the adhesion of the plating layer 13 to the wire 12. As the material of the underlayer 14, for example, when the plating layer 13 made of a nickel alloy is formed on the surface of the wire 12, it is preferable to use nickel or a nickel alloy. Examples of the nickel alloy include those containing one or more elements selected from boron, phosphorus, and zinc.

  The thickness of the foundation layer 14 should just be more than the thickness which can improve the adhesiveness to the wire 12 of the plating layer 13. FIG. Further, when the underlayer 14 is formed, the length of the through-hole 18 is determined by the thickness of the underlayer 14. Therefore, the thickness of the underlayer 14 may be determined in consideration of the long diameter of the through-hole 18.

  As shown in FIG. 3, the plating layer 13 may be formed on the surface of the base layer 13, or may be directly formed on the surface of the wire 12 when the base layer 14 is omitted. The plating layer 13 is provided with a polyhedral precipitate aggregate or a plurality of acicular precipitate aggregates (not shown). These assemblies will be described in detail later.

  As the metal used for the plating layer 13, a metal capable of depositing a polyhedral precipitate aggregate or a plurality of acicular precipitate aggregates on the surface of the filter base 12 by a process such as electroplating is used. Examples of such a metal include iron, nickel, copper, and alloys thereof. The metal used for the plating layer 13 is a metal that is easy to control the shape of a polyhedral precipitate aggregate or a plurality of acicular precipitate aggregates among the above metals, and that has excellent corrosion resistance. It is preferable to use nickel or a nickel alloy. Examples of the nickel alloy include those containing one or more elements selected from boron, phosphorus, and zinc.

  Next, details of the plating layer 13 will be described. In the present embodiment, a plating layer including a plurality of acicular precipitate aggregates or a plating layer including polyhedral precipitate aggregates can be used.

  First, the plating layer provided with the aggregate | assembly of several acicular precipitates is demonstrated. FIG. 4 shows an aggregate of a plurality of needle-like precipitates. FIG. 4 also shows a metal compound captured on the surface of the plating layer during the filtration process.

  As shown in FIG. 4, the plating layer 13 including a plurality of acicular precipitate aggregates is a composite body in which a plurality of acicular structures 15 are aggregated on the surface of the base layer 14. In each needle-like structure 15, the base 15 a on the wire 12 side of each needle-like structure 15 and the base 15 a of another adjacent needle-like structure 15 are integrated. The base portion 15 a of the needle-like structure 15 is continuously formed on the surface of the base layer 14. Each needle-like structure 15 has, for example, a polygonal pyramid shape or a conical shape. Each needle-like structure 15 having such a conical shape has a tapered shape from the proximal end 153a toward the distal end 152, as shown in FIG. A valley 153 is formed between the adjacent needle-like structures 15, and the width becomes narrower as the base end 153 a is approached in a cross-sectional view. The valley 153 is formed so as to surround each needle-like structure 15 in plan view. The valley 153 surrounding each needle-like structure 15 is formed to be connected to the valley 153 surrounding another adjacent needle-like structure 15 in plan view. As shown in FIG. 4, the metal compound captured from the liquid to be treated is attached to a part of the plurality of needle-like structures 15.

The number of needle-like structure 15 of the unit area (1 [mu] m ²⁾ per filter medium 16 is preferably 1.2 to 10.0 units / [mu] m ^2, more preferably 3.0 to 7.0 pieces / [mu] m ² .

When the number of needle-like structures 15 per unit area is 1.2 pieces / μm ² or more, the surface area of the filter 3 is sufficiently large, and the metal compound is easily captured between the adjacent needle-like structures 15. .
If the number of needle-like structures 15 per unit area is 10.0 pieces / μm ² or less, the gap between adjacent needle-like structures 15 does not become too narrow. Therefore, a sufficiently wide space 131 surrounded by the valleys 153 formed between the adjacent needle-like structures 15 and the metal compound formed on the plating layer 13 is formed. The space 131 functions as a flow path through which water to be treated flows when a metal compound is formed. Compared with a filter that does not have the needle-like structure 15, the area of the treatment liquid that has passed through the metal compound is increased, so that the filtration flow rate can be increased. Therefore, the filter 3 is easy to remove the metal compound and has a large filtration flow rate.

The number of needle-like structures 15 per unit area (1 μm ² ) of the filter substrate 16 can be measured by the following method.
The filter 3 is observed with an electron microscope, and the number of apexes of a needle-like structure existing in a square region having a length of 2 μm, a width of 2 μm, and an area of 4 μm ² is measured at four points. Then, the number of apexes of the needle-like structures measured at four locations is averaged, and the number of needle-like structures per unit area (1 μm ² ) is calculated.

  The number of needle-like structures 15 per unit length (1 μm) in the cross section of the filter substrate 16 is preferably 1.0 to 4.0 / μm, more preferably 1.5 to 3.0 / μm. preferable.

When the number of needle-like structures 15 per unit length is 1.0 piece / μm or more, similarly to the case where the number of needle-like structures 15 per unit area is 1.2 pieces / μm ² or more. And an excellent removal function capable of capturing the metal compound.

When the number of needle-like structures 15 per unit length is 4.0 pieces / μm or less, as in the case where the number of needle-like structures 15 per unit area is 10.0 pieces / μm ² or less. The gap between adjacent needle-like structures 15 is prevented from becoming too narrow. For this reason, a sufficiently wide space 131 surrounded by the valleys 153 formed between the adjacent needle-like structures 15 and the metal compound formed on the plating layer 13 is formed, The filter 3 has a large filtration flow rate.

The number of needle-like structures 15 per unit length (1 μm) in the cross section of the filter substrate 16 can be measured by the following method.
The filter 13 is fixed with an embedded resin and cut, and the cut surface is smoothed by ion milling and photographed using a scanning electron microscope (SEM). Thereafter, the number of needle-like structures per 10 μm is measured along the substantially extending direction of the surface of the filter substrate 16 in the photograph of the photographed cross section of the filter substrate. Then, the number of needle-like structures per unit length (1 μm) is calculated from the measured number of needle-like structures.

In the present embodiment, the average height H of the needle-like structure 15 and the average width D of the base end portion in the cross section of the filter base 16 are measured by the following measuring method.
As shown in FIG. 4, valleys 153 are formed between adjacent needle-like structures 15 in the cross section of the filter base 16. In the cross section of the filter base material 16, the base ends 153 a and 153 a that are the valley bottoms facing each other with the needle-like structure 15 interposed therebetween are connected by a straight line 151, and the length is the width D1 of the base end portion of the needle-like structure 15. , D2. The shortest distance between the tip 152 of the needle-like structure 15 and the straight line 151 is defined as the heights H1 and H2 of the needle-like structure 15.

  When the two needle-like structures 157 and 158 are integrated in the cross section of the filter base 16 (the needle-like structure indicated by reference numeral 159 in FIG. 3), the dimensions of the following parts are indicated by needle-like structures. The heights H3 and H4 of the structures 157 and 158 and the widths D3 and D4 of the base ends of the needle-like structures 157 and 158 are set.

  First, a straight line 154 connects the base ends 153a and 153a, which are valley bottoms facing each other across the needle-like structure 159 in which the needle-like structures 157 and 158 are integrated. Next, a perpendicular line 156 is drawn from the bottom of the valley 155 between the two needle-like structures 157 and 158 toward the straight line 154. The distances from the intersection of the perpendicular 156 and the straight line 154 to the base ends 153a and 153a are defined as the widths D3 and D4 of the base ends of the needle-like structures 157 and 158, respectively. Further, the shortest distances between the tips 152a and 152b of the needle-like structures 157 and 158 and the straight line 154 are defined as the heights H3 and H4 of the needle-like structures 157 and 158, respectively. In addition, when the length of the perpendicular line 156 is less than 3/4 of the heights H3 and H4 of the needle-like structures 157 and 158, it is regarded as two independent needle-like structures. Further, the reference that the two needle-like structures 157 and 158 are integrated is a case other than the case where the two needle-like structures are regarded as independent.

  In order to measure the height of the needle-like structure 15 and the width of the base end portion of the needle-like structure 15, the filter 3 is fixed with embedded resin and cut, and the cut surface is polished by ion milling and scanned. Photograph using a scanning electron microscope (SEM). Thereafter, a range of 10 μm in length along the substantially extending direction of the surface of the filter base material in the enlarged photograph of the cross section of the photographed filter base material 16 is defined as one measurement region, and all the above-described ones existing in the four measurement regions. The height of the needle-like structure 15 and the width of the base end are measured. Then, the average value of the measured heights of the four needle-like structures 15 is defined as an average height H of the needle-like structures 15. Further, an average value of the widths of the base end portions of the four needle-like structures 15 measured is defined as an average width D of the base end portions of the needle-like structures 15.

  The variation coefficient of the height of the needle-like structure 15 in the cross section of the filter base 16 is preferably 0.15 to 0.50, and more preferably 0.18 to 0.36. The variation coefficient is obtained by dividing the standard deviation of the height distribution of the needle-like structures 15 in the cross section of the filter base 16 described above by the arithmetic average value of the heights of the needle-like structures 15.

  When the variation coefficient is 0.15 or more, the variation in the height of the needle-like structure 15 is sufficiently large. For this reason, when the water to be treated is passed through the filter 3, the flow of the water to be treated containing the metal compound on the surface of the filter 3 is complicated, and the metal compound is caught on the needle-like structure 15 having a high height. It becomes easy. As a result, the metal compound is easily captured.

  When the coefficient of variation is 0.50 or less, the metal compound formed on the surface of the plating layer 13 is supported between the needle-like structures 15 having a low height, so that the metal compound is formed between the adjacent needle-like structures 15. The space 131 surrounded by the valley 153 and the metal compound is easily secured. For this reason, to-be-processed water becomes easy to flow through the space 131, and the filtration flow volume increases.

  The average height H of the needle-like structures 15 in the cross section of the filter substrate 16 is preferably 0.2 to 2.5 μm, and more preferably 0.4 to 1.8 μm. When the average height H is 0.2 μm or more, the height H is sufficiently high surrounded by the valleys 153 formed between the adjacent needle-like structures 15 and the metal compound formed on the plating layer 13. A space 131 is formed. For this reason, after a metal compound is formed at the time of filtration, the water to be treated easily flows in the space 131, and the filtration flow rate is excellent.

Moreover, it is prevented that the clearance gap between the adjacent acicular structures 15 becomes too narrow as average height H is 2.5 micrometers or less. For this reason, it becomes the filter 3 excellent in the filtration flow rate with which the space 131 was fully ensured similarly to the case where it is 10.0 piece / micrometer < ² > or less.

In order to manufacture the filter 3 shown in FIG. 4, first, a wire 12 that is twilled to have a mesh shape is prepared.
Next, the base layer 14 is formed on the entire surface of the wire 12 using a plating process. A conventionally known method can be used as the plating treatment for forming the underlayer 14. For example, when the base layer 14 is formed on the surface of the wire 12 made of stainless steel before the plating layer 13 made of nickel or a nickel alloy is formed, the nickel is plated by electrolytic nickel plating or electroless nickel plating. Alternatively, it is preferable to form the underlayer 14 made of a nickel alloy.

  Next, a plurality of needle-like structures 15 are deposited on the entire surface of the wire 12 provided with the base layer 14 by electroplating, and the wire 12 is covered with the plating layer 13. As an electroplating process for forming the plating layer 13, a conventionally known method can be used. For example, when the underlayer 14 and the plating layer 13 are made of nickel or a nickel alloy, an additive is added to the plating bath after the formation of the underlayer 14 to continuously perform electrolytic nickel plating treatment or electroless nickel plating. It is preferable to form the plating layer 13 using a process.

  In the electroplating process for depositing a plurality of needle-like structures 15, the shape and size of the needle-like structures 15 can be changed by changing the type, concentration, and plating time of the additive added to the plating bath. it can. Examples of the additive include ethylenediamine dihydrochloride and ethylenediamine (EDA).

  After performing the plating process for forming the plating layer 13, heat treatment may be performed as necessary to promote crystallization of the plating layer 13.

  Next, as another example of the plating layer, a plating layer including an aggregate of polyhedral precipitates will be described. 5 and 6 show SEM photographs of the plating layer provided with the polyhedral precipitate aggregate.

  The plating layer shown in FIGS. 5 and 6 is formed of an aggregate in which a plurality of polyhedral precipitates are aggregated on the surface of the underlayer. In the aggregate shown in FIG. 5, a plurality of polyhedrons are coupled to each other and share a part of the volume. Each of the plurality of polyhedral precipitates has a plurality of vertices where three or more planes intersect. As shown in FIGS. 5 and 6, each precipitate has a different shape and a different size, and is formed densely on the surface of the underlayer. As a result, the portion corresponding to the side of the polyhedron shape faces an irregular direction.

  The average value of the maximum outer dimensions of the polyhedral precipitate is preferably 0.5 to 10 μm, and more preferably 2 to 8 μm. When the average maximum outer dimension of the precipitate is within the above range, the metal compound in the water to be treated is easily caught. In particular, when the average particle diameter of the metal compound in the water to be treated is 0.1 to 10 μm, the metal compound is easily caught on the plating layer. Therefore, when the average particle diameter of the metal compound in the water to be treated is within the above range, the metal compound can be captured efficiently. Further, when the average maximum outer dimension of the precipitate is within the above range, the metal compound is easily caught on the plating layer, and the filter 3 having a high function of removing the metal compound is obtained.

The average maximum outer dimension of the polyhedral precipitate is measured by the following measurement method.
That is, a photograph of the enlarged filter is taken using a scanning electron microscope (SEM), and image processing is performed. Specifically, the outer dimensions of the largest portion of the polyhedral precipitate are measured by selecting ten representative locations for one photograph, and the average value is taken as the average maximum outer dimension. Define.

In plan view, the long diameter of the through hole covered with the plating layer is preferably 1 to 20 μm on average when approximate to the diameter of the inscribed circle in contact with the inner wall of the through hole. The average value of the diameter of the inscribed circle determines the size of the through hole and the aperture ratio of the filter 3. In the filter, the average value of the diameter of the inscribed circle changes at least one of the spacing between the wires before forming the base layer and the plating layer, the thickness of the base layer, and the thickness of the plating layer. Can be adjusted. Moreover, it is preferable that the area of the through-hole with which the plating layer was coat | covered with respect to the area of a filter base material is 0.04-5.00%.

  In plan view, when the long diameter of the through hole covered with the plating layer is 1 to 20 μm, particularly when the average particle diameter of the metal compound in the water to be treated is 0.1 to 10 μm, the size of the through hole Is appropriate.

The average value of the diameter of the inscribed circle in contact with the inner wall of the through hole is measured by the following measuring method.
That is, a photograph of the enlarged filter is taken using a scanning electron microscope (SEM), and image processing is performed. Specifically, in plan view, the diameter of the inscribed circle in contact with the inner wall of the through hole covered with the plating layer is measured by selecting 10 representative positions for one photograph, and the average value thereof. Is defined as the average value of the diameter of the inscribed circle.

Next, a method for manufacturing the filter shown in FIG. 5 or 6 will be described.
It is the same as the plating layer in the example described above until the base layer is formed on the entire surface of the wire using plating.

  Next, precipitates having a plurality of polyhedral shapes are deposited on the entire surface of the wire provided with the base layer by plating, and the wire is covered with the plating layer. As the plating treatment for forming the plating layer, a conventionally known method can be used. For example, when the underlayer and the plating layer are made of nickel or a nickel alloy, an additive is added to the plating bath after the formation of the underlayer, and continuous electrolytic nickel plating or electroless nickel plating is used. It is preferable to form a plating layer.

  In the plating process for forming a plating layer formed of precipitates having a plurality of polyhedral shapes, the shape and size of the polyhedral precipitates are changed by changing the type and concentration of the additive added to the plating bath. It can be changed. Examples of the additive include 2-butyne-1,4-diol.

  After performing the plating treatment for forming the plating layer, heat treatment may be performed as necessary to promote crystallization (polyhedralization) of the plating layer.

Next, a metal recovery method using the metal recovery apparatus 1 will be described with reference to FIGS.
The metal recovery method of the present embodiment includes a precipitation process in which water to be treated containing metal ions is made basic to precipitate metal ions as a metal compound, and a recovery in which the metal compound precipitated in the water to be treated is separated and recovered by the filter 3. And a process. Moreover, the heating process which heats a metal compound is further performed after a collection | recovery process. The heating step is a step of heating the filter 3 with the metal compound attached to the filter 3. Further, after the heating process, a cleaning process for cleaning the filter is performed.

In FIG. 1, it is assumed that all shut-off valves are closed in the initial stage.
First, in the precipitation process, the shutoff valve S1 of the line L1 is opened, and the water to be treated containing metal ions is caused to flow into the precipitation tank 2. Then, the pH adjusting device 2b is operated to adjust the pH of the water to be treated to basic. What is necessary is just to change pH of to-be-processed water with the kind of metal which it is going to collect | recover. For example, when recovering copper, the pH of the water to be treated may be about 9-11. Thereby, the metal ion in to-be-processed water precipitates as a metal hydroxide (metal compound). For example, in the case of copper, it is deposited as copper hydroxide (Cu (OH) ₂ ), which is a kind of metal compound.

  Next, in the recovery step, the shutoff valve S2 and the shutoff valve S5 are opened, and the pressurizing pump P1 is operated to supply the treated water adjusted to basicity to the primary space 4a of the filter 4. The water to be treated is filtered by the filter 3. During the filtration, the metal hydroxide (metal compound) in the water to be treated is captured by the acicular precipitates or polyhedral precipitates on the plating layer of the filter 3, and attached to the plating layer of the filter 3. Collected. The treated water that has passed through the filter 3 is stored in the treated water tank 7 via the drain line L5.

  The order of performing the precipitation step and the recovery step is not particularly limited, and the recovery step may be performed after the precipitation step, or the recovery step may be started during the continuation of the precipitation step. You may perform a collection | recovery process, making it pause.

Next, in the heating step, the pressure pump P1 is stopped and the shutoff valve S2 is closed. Thereby, supply of the to-be-processed water to the filter 4 is stopped. The shut-off valve S5 may be opened or closed. Then, the filter heating device 8 is operated to heat the filter 3. By heating the filter 3, the metal compound adhering to the filter 3 is heated. The heating temperature of the filter 3 varies depending on the metal species to be collected, but the lower limit may be 60 ° C. or higher. Moreover, an upper limit should just be 500 degrees C or less. The metal compound adhering to the filter 3 is a metal hydroxide, and when this metal hydroxide is heated, a dehydration reaction occurs and a metal oxide is generated. For example, in the case of copper, copper hydroxide (Cu (OH) ₂ ) becomes copper oxide (CuO). In order to change copper hydroxide to copper oxide, the heating temperature is sufficient in the range of 60 to 80 ° C. In the case of a metal other than copper, an optimum heating temperature for changing the metal hydroxide to an oxide may be employed.

  In general, the metal hydroxide is precipitated in a hydrated state, so that the metal content is low. However, by changing this to a metal oxide, the metal content can be increased. Also, depending on the type of metal, some metal oxides can easily adhere to the plating layer on the outermost surface of the filter 3, but by changing to a metal oxide, it can be easily peeled off from the filter surface. Become.

  Next, a cleaning process for cleaning the surface of the filter 3 is performed. First, when the shut-off valve S5 has been opened, it is closed. Subsequently, the pressurization pump P2 of the washing line L3 is operated, and the shutoff valve S3 and the shutoff valve S4 are opened. As a result, the filtered water to be treated stored in the treated water tank 7 flows into the primary space 4a of the filter 4 as the washed water through the washing line L3. The washing water that has flowed in causes the metal oxide attached to the filter 3 to peel off from the filter 3. The metal oxide peeled off by the cleaning water is sent to the recovery tank 6 through the recovery line L4 together with the cleaning water.

  The amount of cleaning water used in the cleaning step is significantly smaller than the amount of water to be treated that has passed through the filter 3 in the recovery step. Therefore, the metal hydroxide is changed to a metal oxide through the washing process from the collecting process, and the concentration of the metal oxide in the washing water after the washing process is changed to the metal hydroxide in the treated water before the collecting process. It becomes higher than the concentration of things.

  The metal oxide recovered in the recovery tank 6 is settled and separated in the tank, or is further solid-liquid separated by another filter device. In this way, metal ions in the water to be treated are recovered in the form of metal oxide.

  The treated water stored in the treated water tank 7 is partly used as washing water, and the remaining is treated water, and is discharged to the outside through the treated water discharge line L6 with the shut-off valve S6 opened.

According to the metal recovery apparatus 1 of the present embodiment, the filter 3 includes the precipitation tank 2 that precipitates metal ions in the water to be treated as a metal compound, and the filter 4 that includes the filter 3 that separates and recovers the metal compound. Since a polyhedral precipitate aggregate or a plurality of acicular precipitate aggregates is provided, the filtration rate of the water to be treated is increased while capturing the precipitated metal compound by these aggregates. The metal in the water to be treated can be efficiently recovered, and an addition device such as a flocculant is not necessary.
In addition, according to the metal recovery apparatus 1 of the present embodiment, the cleaning mechanism 5 that supplies the cleaning water to the filter 3 to which the metal compound is attached and the recovery tank 6 that stores the cleaning water containing the metal compound are further provided. Therefore, the metal compound can be easily recovered.
Furthermore, according to the metal recovery apparatus 1 of the present embodiment, since the filter heating apparatus 8 that heats the filter 3 to which the metal compound is attached is further provided, the metal compound can be stabilized and recovered easily. In particular, when metal ions in the water to be treated are precipitated as metal hydroxides, the metal hydroxides can be changed to metal oxides by heating the filter 3. The metal oxide has a higher metal content per unit mass than the metal hydroxide, and is easily peeled off from the filter 3. Therefore, by heating the metal hydroxide adhering to the filter 3 to form a metal oxide, it can be recovered as a high-quality metal compound, and the recovery rate of the metal compound and the cleaning efficiency of the filter can be increased.
Moreover, since the filter base material and the plating layer which comprise the filter 3 are comprised with a metal, even if the filter 3 is heated, a filter will not change and the filter 3 can be used repeatedly.
Furthermore, by constituting the filter 3 with a metal having excellent corrosion resistance such as stainless steel or nickel, it is possible to sufficiently withstand the basic water to be treated.

Next, according to the metal recovery method of the present embodiment, when the metal compound is separated and recovered by depositing metal ions in the water to be treated as a metal compound and filtering the water to be treated through the filter 3, the filter 3. As described above, by using the filter 3 having a polyhedral precipitate aggregate or a plurality of acicular precipitate aggregates on the surface, the deposited metal compound is captured by these aggregates, and the target object is treated. The filtration flow rate of water can be increased, metals in the water to be treated can be efficiently recovered, and the addition of a flocculant and the like is not necessary.
Further, according to the metal recovery method of the present embodiment, the metal compound is heated after the metal compound is recovered, so that the metal compound can be stabilized and recovered easily. In particular, when metal ions in the water to be treated are deposited as metal hydroxides, the metal hydroxides can be heated and converted into metal oxides. The metal oxide has a higher metal content per unit mass than the metal hydroxide. Therefore, it can collect | recover as a high quality metal compound by heating a metal hydroxide to make a metal oxide.
Further, according to the metal recovery method of the present embodiment, the filter 3 is heated while the metal hydroxide (metal compound) is attached to the filter 3, so that the metal hydroxide can be easily separated from the filter 3. The metal oxide can be changed. Thereby, the recovery rate of the metal compound and the cleaning efficiency of the filter 3 can be increased.

(Second Embodiment)
Next, a metal recovery apparatus and a metal recovery method according to the second embodiment will be described with reference to FIGS.

  The metal recovery device 101 of the present embodiment is not provided with the filter heating device 8, but instead is provided with a water heating device 108 for heating the cleaning water containing the metal compound in the recovery tank 6. It is different from the metal recovery apparatus 1 of the embodiment. There is no difference between the other configurations. The same components as in FIG. 1 are denoted by the same reference numerals in FIG. 8 and description thereof is omitted.

  As shown in FIG. 8, the metal recovery apparatus 101 according to the present embodiment includes a precipitation tank 2, a filter 4 including a filter 3, a cleaning mechanism 5, a recovery tank 6, and a treated water tank 7. ing. Further, the metal recovery apparatus 101 shown in FIG. 8 is further provided with a water heating apparatus 108 for heating the cleaning water containing the metal compound stored in the recovery tank 6.

  The recovery tank 6 stores the wash water discharged from the filter 4 via the recovery line L4. The stored washing water contains the metal compound peeled off from the filter 3.

  Further, the water heating device 8 may be any device that can heat the cleaning water stored in the recovery tank. For example, the water heating device 8 heats the cleaning water directly or indirectly, and heats the cleaning water by spraying high temperature steam. A steam injection device or a high-temperature gas injection device that blows high-temperature combustion gas or the like onto the cleaning water can be used. The water heating device 108 can heat the cleaning water to about 100 ° C.

Next, the metal recovery method of this embodiment is demonstrated with reference to FIG.8 and FIG.9.
The metal recovery method according to the present embodiment includes a precipitation process in which metal ions are precipitated as a metal compound, and a recovery process in which the metal compound is separated and recovered by the filter 3. Further, after the recovery process, a cleaning process and a heating process for heating the metal compound are further performed. In the washing step and the heating step, the washing water that has washed the filter 3 is collected in the collection tank 6, and then the washing water containing the metal compound is heated in the collection tank 6.

  Since the deposition step and the recovery step are the same as those in the first embodiment, description thereof is omitted.

  After the metal hydroxide (metal compound) in the water to be treated is solid-liquid separated by the recovery process, a cleaning process for cleaning the surface of the filter 3 is performed. First, if the shut-off valve S5 has been opened in the recovery process, it is closed. Next, the pressure pump P2 of the cleaning line L3 is operated, and the shutoff valve S3 and the shutoff valve S4 are opened. As a result, the filtered water to be treated stored in the treated water tank 7 flows into the primary space 4a of the filter 4 as the washed water through the washing line L3. The washing water that has flowed in causes the metal hydroxide adhering to the filter 3 to peel off from the filter 3. The metal hydroxide peeled off by the cleaning water is sent to the recovery tank 6 through the recovery line L4 together with the cleaning water.

Next, in the heating step, the pressure pump P2 is stopped and the shutoff valves S3 and S4 are closed. Next, the water heating device 108 is operated to heat the cleaning water in the collection tank 6. By heating the washing water, the metal hydroxide contained in the washing water is heated. The heating temperature varies depending on the metal species to be collected, but the lower limit may be 60 ° C. or higher. Moreover, an upper limit should just be 100 degrees C or less. The metal compound recovered in the recovery tank 6 is a metal hydroxide, and by heating the metal hydroxide, a dehydration reaction occurs and a metal oxide is generated. For example, in the case of copper, copper hydroxide (Cu (OH) ₂ ) becomes copper oxide (CuO). In order to change copper hydroxide to copper oxide, the heating temperature is sufficient in the range of 60 to 80 ° C. In the case of a metal other than copper, an optimum heating temperature for changing the metal hydroxide to an oxide may be employed.

  Since the metal hydroxide precipitates in a hydrated state, the metal content is low, but the metal content can be increased by changing this to a metal oxide.

  The amount of cleaning water used in the cleaning step is significantly smaller than the amount of water to be treated that has passed through the filter 3 in the recovery step. Therefore, through the heating process from the recovery process, the metal hydroxide changes to the metal oxide, and the concentration of the metal oxide in the cleaning water after the cleaning process is changed to metal hydroxide in the water to be treated before the recovery process. It becomes higher than the concentration of things.

  The metal oxide generated by heating in the recovery tank 6 is settled and separated in the tank, or is solid-liquid separated by another filter. In this way, metal ions in the water to be treated are recovered in the form of metal oxide.

  The treated water stored in the treated water tank 7 is partially used as washing water, and the remaining is treated water, and is discharged to the outside through the treated water discharge line L6 with the shut-off valve S6 opened.

The metal recovery apparatus 101 of this embodiment can obtain the same effects as those of the first embodiment, and also the following effects.
According to the metal recovery apparatus 101 of the present embodiment, since the water heating apparatus 108 for heating the cleaning water recovered in the recovery tank 6 is provided, the metal compound can be stabilized and recovered easily. In particular, when metal ions in the water to be treated are deposited as metal hydroxides, the metal hydroxides can be changed to metal oxides by heating the washing water. The metal oxide has a higher metal content per unit mass than the metal hydroxide. Therefore, it can collect | recover as a high quality metal compound by heating the metal hydroxide in washing water to make a metal oxide.

Further, the metal recovery method of the present embodiment can obtain the same effects as those of the first embodiment, and also the following effects.
According to the metal recovery method of the present embodiment, since the wash water recovered in the recovery tank 6 is heated, the metal compound can be stabilized and recovered easily. In particular, when metal ions in the water to be treated are deposited as metal hydroxides, the metal hydroxides can be heated and converted into metal oxides. The metal oxide has a higher metal content per unit mass than the metal hydroxide. Therefore, it can collect | recover as a high quality metal compound by heating a metal hydroxide to make a metal oxide.

  In each of the above embodiments, the filter 3 including the filter base material 16 made of the twill-woven mesh-like wire 12 has been described as an example. However, the filter base material of the filter 3 is limited to the above example. is not.

  For example, a filter having a plate-like substrate having a plurality of through holes may be used as the filter substrate.

FIG. 10 is an external perspective view showing another example of the filter. FIG. 11 is a cross-sectional view of the filter shown in FIG. 10 when viewed from the end surface side.
The plate-like base material 211 included in the filter 212 is formed of the same material as the mesh-like base material 11 in each of the above embodiments. Hereinafter, in the description of the filter 212, the description of the same configuration as the filter 10 in each of the above embodiments is omitted.

  A plurality of through holes 213, 213... Penetrating in the thickness direction are formed in the plate-shaped filter base material 211. The through holes 213, 213,... Are cylindrical holes that connect the primary surface 211a and the secondary surface 211b of the filter base material 211. The through holes 213, 213,... Are arranged in a staggered arrangement along the primary surface 211a.

The average pore diameter of the through holes 213 is preferably 0.1 to 100 μm. When the average pore diameter of the through holes 213, 213,... Is 0.1 μm or more, the filtration flow rate is easily secured in the filter having the filter 212, and the liquid to be treated can be efficiently filtered. When the average pore diameter of the through holes 213, 213,... Is 100 μm or less, the metal compound is easily captured.
The average hole diameter of the through holes 213, 213,... Means the average value of the diameters of the inscribed circles of the plurality of through holes 213, 213,.

  A plurality of fine structures 205 are formed on the entire surface of the filter 212. That is, the fine structure 205 is formed so as to cover the primary surface (inflow surface) 211a of the filter 212, the secondary surface (outflow surface) 211b through which the liquid to be processed flows out, and the inner wall surface of the through hole 213. Yes. As the fine structure 205, the needle-like structure or the polyhedral structure in each of the above embodiments is formed. The fine structure 205 has a maximum outer dimension smaller than the average hole diameter of the through holes 213.

  The filter 212 shown in FIG. 10 can be manufactured in the same manner as the filter 3 in the above embodiments except that the filter base material 211 is used instead of the filter base material in the above embodiments.

In the filter 212 shown in FIG. 10, the through holes 213 having a circular shape in plan view are arranged in the filter base material 211 in a staggered arrangement, but the shape and arrangement of the individual through holes are not limited.
12 to 14 are schematic plan views illustrating other examples of the filter. In the filter 291 shown in FIG. 12, the through holes 292 having a rectangular planar shape are arranged at regular intervals in a lattice shape. In the filter 294 shown in FIG. 13, the through holes 295 having a rectangular planar shape are formed in a staggered arrangement. In the filter 297 shown in FIG. 14, the through holes 298 having a hexagonal plan shape are formed in a staggered arrangement.

In addition to this, the planar shape of the through-hole formed in the base material can be various shapes such as a polygonal shape such as a triangle and a pentagon, an elliptical shape, and a cross shape, and is not particularly limited.
Further, regarding the arrangement form of the plurality of through holes, for example, the filters 291 shown in FIG. 12 may be equally arranged, or the filters 212, 294, and 297 shown in FIG. 10, FIG. 13, and FIG. Like this, it may be a staggered arrangement, or may be arranged at random, and is not particularly limited.
The average hole diameter of the through holes having these planar shapes means an average value of the diameters of the inscribed circles of the plurality of through holes penetrating the filter.

  Similar to the filter 212 shown in FIG. 10, a plurality of fine structures 205 are formed on the entire surface of the filters 291, 294, and 297. As the fine structure 205, the needle-like structure or the polyhedral structure in each of the above embodiments is formed. The fine structure 205 has a maximum outer dimension smaller than the average hole diameter of the through holes 213.

  The filters 212, 291, 294, and 297 shown in FIGS. 10 to 14 may be used in the form of a plate, or may be formed in a cylindrical shape, for example.

  Further, as a filter base material, it has a filter body in which wire rods are arranged in a planar shape, and a support member that supports the wire rod, a gap is formed between the wire rods adjacent to each other, and the filter body Among these, a filter having a base material that forms a flat surface may be used as the wire facing the primary surface into which the liquid to be treated flows.

  FIG. 15 is a schematic view showing another example of a filter formed in a cylindrical shape. 16 is a cross-sectional view of the filter shown in FIG. 15 when viewed from the end surface side. 17 is an enlarged cross-sectional view of a main part showing the inner peripheral surface side of the filter shown in FIG.

  The filter base material 310 of the filter 300 is formed of a filter body 312 in which the wire materials 311 are arranged in a planar shape, and a support member 313 that supports the wire material 311. The filter body 312 is formed by winding a long wire 311 into a coil shape and forming it into a hollow cylindrical body.

  The wire 311 has a triangular cross section perpendicular to the extending direction. The wire 311 is supported by the support member 313 so as to be separated from each other while maintaining a gap having a predetermined width between adjacent wires. Thus, a slit-shaped gap 316 is formed in the cylindrical filter body 312 so as to penetrate between the inner peripheral surface 312a and the outer peripheral surface 312b.

  The support member 313 is a wire having a square cross section. The support member 313 is joined to the wire 311 on the outer peripheral surface 312 b side of the filter body 312. For example, four support members 313 are formed at equal intervals along the circumferential direction of the wire 311. The support member 313 extends in parallel to the central axis of the filter body 312 and supports the wound wire 311 from the outer peripheral surface 312b side. The support member 313 and the wire 311 are joined by, for example, sintering.

  The wire 311 facing the inner peripheral surface 312a side of the filter body 312 has a flat surface 311f. That is, one side of the triangle of the wire 311 having a triangular cross-sectional shape is arranged along the inner peripheral surface 312a. The wire 311 is joined to the support member 313 at the apex of the triangle facing one side of the triangle along the inner peripheral surface 312a of the wire 311.

  In the filter 300 shown in FIG. 15, the water to be treated flows into the inner peripheral surface 312a of the filter body 312 and the water to be treated is filtered through the gap 316, and the treated water is filtered from the outer peripheral surface 312b. Spill. The gaps 316 between the wire rods 311 and 311 adjacent to each other with different circulations are formed by using the wire rod 311 having a triangular cross-sectional shape. It is formed so that the width increases toward the surface (secondary surface) 312b side.

  In the filter 300 shown in FIG. 15, the average hole diameter of the through holes means the average distance of the narrowest portion in the gap 316 between the wire rods 311. In other words, the average hole diameter of the through holes in the filter 300 means a distance between adjacent flat surfaces 311f facing the inner peripheral surface 312a.

In the filter 300, a plurality of fine structures 305 are formed on the inner peripheral surface 312a side into which the liquid to be treated flows (in other words, on the flat surface 311f (see FIG. 17) of the wire 311 facing the inner peripheral surface 312a). Yes. As the plurality of fine structures 305 included in the filter 300, the needle-like structure or the polyhedron structure in each of the above embodiments is formed. The fine structure 305 has a maximum outer dimension smaller than the average hole diameter of the through holes.
The fine structure 305 may be formed on the entire surface of the filter 300.

  A filter 300 shown in FIG. 15 uses a filter base material 310 in which a wire 311 wound in a coil shape and a support member 313 are sintered and bonded instead of the filter base material 16 of the filter 3 in each of the above embodiments. Except for this, it can be manufactured in the same manner as the filter 3 in each of the above embodiments.

  In the filter 300 shown in FIG. 15, a plurality of fine structures 305 are formed on the flat surface 311f of the wire 311 constituting the inner peripheral surface 312a into which the liquid to be treated flows. Therefore, the water pressure to the filter 300 at the time of inflow of the water to be treated becomes uniform, and the water pressure does not concentrate locally on the surface of the filter 300. For this reason, in the filter 300 shown in FIG. 15, the durability of the filter 300 against the water pressure at the time of inflow of the water to be treated is enhanced, and the formation of cake is promoted.

In the filter 300 illustrated in FIG. 15, an example in which a wire having a triangular cross section is used. However, the cross sectional shape of the wire is not limited to a triangle, and may be, for example, a trapezoid.
FIG. 18 is an enlarged cross-sectional view of the main part showing the inner peripheral surface side in another example of the filter. A filter 370 shown in FIG. 18 includes a filter body 372 in which a wire 371 having a trapezoidal cross-sectional shape perpendicular to the extending direction is wound in a coil shape to form a hollow cylindrical body. The wire 371 is supported by the support member 373 on the outer peripheral surface 372b side so as to be separated with a gap 376 having a predetermined width between adjacent wire members 371.

  In the filter 370 shown in FIG. 18, the inner peripheral surface 372a of the filter body 372 is a primary surface into which the water to be treated flows, and the outer peripheral surface 372b is a secondary surface from which the treated water filtered by the filter body 372 flows out. Is done. Of the filter 372, the wire 371 facing the inner peripheral surface 372a has a flat surface 371f. The wire 371 having a trapezoidal cross-sectional shape is arranged so that one of the longer parallel sides of the trapezoid is along the inner peripheral surface 372a, and the shorter one of the two parallel sides is joined to the support member 313. ing.

  In the filter 370, a plurality of fine structures 305 are formed on the flat inner peripheral surface 372 a side into which the water to be treated flows and the inner surface of the gap 376. The fine structure 305 is only required to be formed on the inner peripheral surface 372a (primary surface) side of the filter body 372, and may be formed on the entire surface of the filter 370.

In the filters 300 and 370 shown in FIG. 15 and FIG. 18, an example in which a wire is wound in a coil shape to form a hollow cylindrical body has been shown. However, a plurality of wires may be arranged on one surface to form a flat plate shape. Good. FIG. 19 is an external perspective view showing another example of the filter.
A filter 390 shown in FIG. 19 includes a filter body 392 in which a plurality of wire rods 391 are arranged in a planar shape, and a support member 393 that supports the wire rod 391 as a base material. The filter body 392 is formed by arranging a plurality of wire rods 391 having a triangular cross-sectional shape perpendicular to the extending direction on a flat surface and forming it into a flat plate shape.

  The wire 391 is fixed to the support member 393 so as to maintain a slit-shaped gap 396 having a predetermined width between the adjacent wires 391 and 391. In the filter 390, the wire 391 facing the one surface 392a that is the upper side in FIG. 19 forms a flat surface 391f. In the case of a wire rod 391 having a triangular cross-sectional shape, one side of the triangle is disposed along one surface 392a, and is joined to the support member 393 at the apex of the triangle facing this one side.

  The support member 393 is made of, for example, a wire having a rectangular or triangular cross section, and is joined to the wire 391 on the other surface 392b side of the filter body 392. The support member 393 extends along the arrangement direction of the wires 391 and is joined to the plurality of wires 391. The support member 393 and the wire 391 are joined by, for example, sintering.

In the filter 390, the water to be treated flows from the upper surface (primary surface) 392a side in FIG. 19, and the treated water after filtration flows out from the other surface (secondary surface) 392b.
In the filter 390, a plurality of fine structures 305 are formed on a flat surface 392a into which the water to be treated flows. The fine structure 305 only needs to be formed on the one surface 392a (primary surface) side of the filter body 392, and may be formed on the entire surface of the filter 390.

In the filters 300, 370, and 390 shown in FIG. 15, FIG. 18, and FIG. 19, the example in which a gap is formed between adjacent wires by the support member that supports the wire has been shown. It is also possible to use adjacent wires to separate them while maintaining a gap of a predetermined width.
FIG. 20 is an external perspective view showing another example of the filter.

A filter 90 shown in FIG. 20 includes, as a filter base material, a filter body 92 in which a plurality of wire rods 91 are arranged on a plane and formed into a flat plate shape, and a support member 93 that supports the wire rod 91.
The wire 91 has a rectangular cross section, and convex portions 95 are formed at predetermined intervals on one side of the rectangle. The convex portion is configured to separate adjacent wire rods 91 while maintaining a gap having a predetermined width. For example, when the filter body 92 is viewed in plan, the convex portions 95 are formed by shifting the positions of the adjacent wire rods 91 so as to form a staggered arrangement along the arrangement direction of the wire rods 91.

In the flat filter body 92 of the filter 90 shown in FIG. 20, a slit-like gap 96 penetrating between the one surface 92a and the other surface 92b is formed by a convex portion 95 formed on the wire 91.
In the filter 90 shown in FIG. 20, the average hole diameter of the through holes means an average distance of the gaps 96 between the wire rods 91.

  The support member 93 is, for example, a wire having a rectangular or triangular cross section (rectangular in FIG. 20). The support member 93 is formed, for example, so as to extend along the arrangement direction of the wires 91. The support member 93 is joined to the plurality of wires 91 on the other surface 92 b side of the filter body 92. The support member 93 and the wire 91 are joined by, for example, sintering.

The filter base material of the filter 90 shown in FIG. 20 (filter body 92 and support member 93 in FIG. 20) is formed of the same material as the net-like base material 11 in each of the above embodiments.
In the filter 90, a plurality of fine structures 305 are formed on the one surface (primary surface) 92 a side into which the water to be treated flows and the inner surface of the gap 96. As the plurality of fine structures 305 included in the filter 90, the needle-like structure or the polyhedral structure in each of the above embodiments is formed. The fine structure 305 has a maximum outer dimension smaller than the average hole diameter of the through holes.
The fine structure 305 may be formed on the entire surface of the filter 90.

The filter 90 shown in FIG. 20 is the same as that in each of the above embodiments except that instead of the filter base 16 of the filter 3 in each of the above embodiments, a support member 93 and a wire 91 are sintered and combined. It can be manufactured in the same manner as the filter 10.
The filter 90 shown in FIG. 20 may be used in the form of a plate, or may be used in the form of a cylinder, for example.

  According to at least one embodiment described above, a precipitation tank for depositing metal ions in water to be treated as a metal compound, and a filter equipped with a filter for separating and recovering the metal compound, the polyhedral precipitation on the filter. By having an aggregate of objects or an aggregate of a plurality of needle-like precipitates, it is possible to increase the filtration flow rate of water to be treated while capturing the precipitated metal compound by these aggregates. The metal can be efficiently recovered, and an addition device such as a flocculant becomes unnecessary.

  Although several embodiments of the present invention have been described, these embodiments are presented by way of example and are not intended to limit the scope of the invention. These embodiments can be implemented in various other forms, and various omissions, replacements, and changes can be made without departing from the spirit of the invention. These embodiments and their modifications are included in the scope and gist of the invention, and are also included in the invention described in the claims and the equivalents thereof.

  DESCRIPTION OF SYMBOLS 1,101 ... Metal recovery apparatus, 2 ... Deposition tank, 3 ... Filter, 4 ... Filter, 5 ... Cleaning mechanism, 6 ... Recovery tank, 8 ... Filter heating apparatus, 13 ... Plating layer, 16 ... Filter base material, 108 ... water heater.

Claims (20)

A deposition tank in which water to be treated containing metal ions is made basic to precipitate the metal ions as a metal compound;
A filter equipped with a filter for separating and recovering the metal compound in the treated water,
It said filter comprises a filter substrate, wherein and a plating layer covering the surface of the filter substrate, a collection of at least the the surface of the plating layer of the primary side of the filter medium precipitates polyhedral Or the metal collection | recovery apparatus provided with the aggregate | assembly of several acicular precipitates. A cleaning mechanism for supplying cleaning water to the filter to which the metal compound is attached;
The metal recovery apparatus according to claim 1, further comprising: a recovery tank that stores the cleaning water containing the metal compound.   The metal recovery device according to claim 2, further comprising a water heating device that heats the cleaning water containing the metal compound in the recovery tank.   The metal recovery apparatus according to claim 1, further comprising a filter heating device that heats the filter to which the metal compound is attached.   The metal recovery apparatus according to any one of claims 1 to 4, wherein the needle-like precipitate has a tapered shape from a proximal end toward a distal end. The number of the acicular precipitates per unit area of the filter substrate is 1.2 to 10.0 / μm ² , or
Metal recovery apparatus according to any one of the number of the needle-like precipitates per unit length in the filter substrate of section 1.0 to 4.0 pieces / [mu] m in a claims 1 to 5 .   The metal recovery apparatus according to any one of claims 1 to 6, wherein an average height of the needle-like precipitates in a cross section of the filter base material is 0.2 to 2.5 µm. Metal recovery apparatus according to any one of the maximum external dimension averages claims 1 to 4 Ru 0.5~10μm der of precipitates of the polyhedral shape. The metal recovery apparatus according to any one of claims 1 to 8, wherein an area of the through hole covered with the plating layer with respect to an area of the filter base is 0.04 to 5.00%. The metal recovery according to any one of claims 1 to 9 , wherein the plating layer including the polyhedral precipitate aggregate or the plurality of acicular precipitate aggregates is made of nickel or a nickel alloy. apparatus. The metal recovery apparatus according to claim 1, wherein the filter base material is a metal net. The metal recovery apparatus according to claim 11, wherein a polyhedral precipitate aggregate or a plurality of acicular precipitate aggregates is provided on the entire surface of the plating layer. The metal recovery apparatus according to claim 11 or 12, wherein an average of the long diameters of the through holes of the filter in a state where the plating layer is coated on the filter base is 1 to 20 µm. The metal recovery apparatus according to any one of claims 1 to 10 , wherein the filter base material is a metal plate provided with a plurality of through holes . The filter base is composed of a filter body in which a plurality of wires are arranged in parallel with a gap, and a support member that fixes and supports the plurality of wires.
Said filter body flat surface is provided wherein the wire facing the primary side of the treated water flows out of any one of claims 1 to 10 wherein the plating layer at least on the flat surface is formed The metal recovery device according to item. The filter base is composed of a filter body in which a wire is wound spirally with a gap, and a support member that fixes and supports the wire,
Said filter body flat surface is provided wherein the wire facing the primary side of the treated water flows out of any one of claims 1 to 10 wherein the plating layer at least on the flat surface is formed The metal recovery device according to item. A deposition step of making the water to be treated containing metal ions basic and depositing the metal ions as a metal compound;
A recovery step of separating and recovering the metal compound in the treated water with a filter,
As the filter, a filter substrate, wherein and a plating layer covering the surface of the filter substrate, aggregates or precipitates polyhedral at least on the surface of the plating layer of the primary side of the filter base Metal recovery method using what is provided with the aggregate | assembly of a some acicular deposit. The metal recovery method according to claim 17 , further comprising a heating step of heating the metal compound after the recovery step. The metal recovery method according to claim 18 , wherein the heating step is a step of heating the filter while the metal compound is attached to the filter. The metal recovery method according to claim 18 , wherein the heating step is a step of washing the metal compound adhering to the filter with washing water and heating the washing water containing the washed metal compound.