Valuable metal recovery system and method for recovering valuable metals

Abstract

To provide a valuable metal recovery system that enables optimal recovery of valuable metals by using functional materials capable of selectively adsorbing target valuable metals such as adsorbents and extractants and capable of being recycled, and by efficiently utilizing the functional materials and accurately controlling their replacement.SOLUTION: A valuable metal recovery system includes a waste liquid treatment device and a valuable metal recovery device. The waste liquid treatment device consists of a tank, a coagulation sedimentation tank, a membrane filtration device, and a valuable metal adsorption device 24, each of which constitutes a water treatment unit. The valuable metal adsorption device 24 has a supply pipe 42 connected to a supply source 41 of waste liquid W. Functional material elements 43A, 43B, and 43C are detachably provided in series in the supply pipe 42, and a storage tank 44 for treated water W1 is provided at the downstream end. The functional material elements 43A, 43B, and 43C are interconnected and configured to be circulated in a merry-go-round manner.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a system and method for recovering valuable metals in waste liquid, and in particular to a system and method for recovering valuable metals that uses functional materials such as adsorbents and extractants that can selectively adsorb or concentrate the target valuable metals and can be recycled and reused by methods such as elution regeneration and stripping, and that efficiently utilizes these functional materials while accurately controlling their exchange, thereby enabling the system and method to optimally recover valuable metals. [Background technology]

[0002] Traditionally, valuable metals that can be recovered with a profit have been recovered, but valuable metals that cannot be recovered with a profit have been discarded as industrial waste, etc. However, with the recent rise in expectations for the creation of a circular economy and the rise in the value of valuable metals such as rare metals and precious metals, there is a demand for further reuse of valuable metals.

[0003] As a method for recovering such valuable metals, Patent Document 1 discloses a process that includes a step of bringing an adsorbent into contact with a solution in which precious metals are dissolved, thereby causing the adsorbent to adsorb the precious metal ions in the solution, and a step of bringing a reducing agent into contact with the precious metal ions adsorbed on the adsorbent, thereby reducing the precious metal ions and causing them to be desorbed from the adsorbent and form particles. [Prior art documents] [Patent documents]

[0004] [Patent Document 1] WO2023 / 276710 Summary of the Invention [Problem to be solved by the invention]

[0005] However, to recover the desired valuable metals from waste liquid containing valuable metals, equipment for recovering the valuable metals is required at each site where the waste liquid is generated. This equipment for recovering valuable metals requires a waste liquid treatment device that adsorbs and concentrates the valuable metals contained in the waste liquid, and a valuable metal recovery device that recovers the adsorbed and concentrated valuable metals. However, when the amount of waste liquid is small or the waste liquid is generated irregularly, such as at specific times, not only is the initial investment burden for the valuable metal recovery device large, but the operation and management of this equipment is also required. Therefore, there is little business benefit for users (dischargers) that discharge waste liquid containing valuable metals to recover the valuable metals, and this has been an obstacle to the progress of building a circular economy.

[0006] As a countermeasure, it is conceivable that users discharging waste liquid containing valuable metals could entrust this waste liquid containing valuable metals to a company that can refine these valuable metals. However, if the waste liquid containing valuable metals were to be transported from the site of the user discharging the waste liquid containing valuable metals to a refinery of these valuable metals without reducing its volume, the concentration of valuable metals contained in the waste liquid would be very low, so the volume of the waste liquid would increase, and transportation efficiency would decrease, resulting in very high transportation costs and making this an unrealistic approach.

[0007] Therefore, with the aim of solving these problems, the applicant has previously filed an application for a valuable metal recovery system (Patent Application No. 2023-136695) that includes a wastewater treatment device having a functional material element capable of adsorbing or concentrating valuable metals as a water treatment unit, and a valuable metal recovery device that recovers the adsorbed or concentrated valuable metals from the functional material element, wherein the functional material element is detachable from the wastewater treatment device, and the functional material element is removed from the wastewater treatment device, the valuable metals are recovered using the valuable metal recovery device, and the functional material is regenerated, and this regenerated functional material is reused as a functional material element.

[0008] This valuable metal recovery system solves the above-mentioned problems, but in the recovery of valuable metals, there are often no regulations on the outlet concentration of treated water from wastewater treatment equipment, except for the removal of harmful substances. Furthermore, frequent regeneration of functional materials leads to deterioration of the functional materials themselves. Therefore, it is desirable to regenerate the functional materials only after they have sufficiently captured valuable metals.

[0009] However, in the past, the timing of functional material regeneration was determined based on the amount of wastewater treated, the time it took for the water to pass through, and other factors. This meant that the functional material was sometimes regenerated before it had fully adsorbed valuable metals. When the functional material was a solid adsorbent, this regeneration process led to deterioration of the adsorbent due to wear or the chemical action of the regenerated eluent. Furthermore, when the functional material was an extractant, there was a problem of the material leaking to the subsequent stage. On the other hand, continuous use of a functional material for a long period of time could lead to water passing through the functional material in a breakthrough state, which could result in insufficient capture of valuable metals by the functional material and a decrease in the recovery rate.

[0010] Furthermore, functional materials deteriorate over long periods of use, reducing their capture efficiency for valuable metals compared to unused materials and shortening the time until breakthrough, which can make it impossible to efficiently recover valuable metals.

[0011] The present invention has been made in consideration of the above-mentioned problems, and aims to provide a valuable metal recovery system and a valuable metal recovery method that can efficiently recover valuable metals by using functional materials such as adsorbents and extractants that can selectively adsorb or concentrate target valuable metals and can be recycled and reused by methods such as elution regeneration and back-extraction, and by accurately controlling the exchange of these functional materials. [Means for solving the problem]

[0012] In order to solve the above problems, the present invention first provides a valuable metal recovery system that recovers valuable metals from waste liquid containing the valuable metals, comprising: a waste liquid treatment apparatus having, as a water treatment unit, functional material elements capable of adsorbing or concentrating the valuable metals; and a valuable metal recovery apparatus that recovers the adsorbed or concentrated valuable metals from the functional material elements, regenerates the functional material, and reuses the regenerated functional material as a functional material element. The functional material elements are detachably installed in two or more stages from the waste liquid treatment apparatus so that water can pass through them in series, and each functional material element has sensors on the inlet and outlet sides that measure the concentration of the valuable metal to be recovered. The system is equipped with a control means that controls the switching of the water flow order of the functional material elements in the multiple stages based on the output data of the inlet and outlet sensors and the amount of water passing through, and that determines when to replace the functional material elements. The control means instructs the first functional material element to be removed and regenerated in the water flow treatment process of the functional material elements, and sequentially repeats this control to switch the first functional material element that has been regenerated to become the last stage (Invention 1).

[0013] According to the above invention (Invention 1), the valuable metals in a waste liquid containing valuable metals can be adsorbed or concentrated by a functional material element in a waste liquid treatment device. Once the volume of the valuable metals in the waste liquid has been sufficiently reduced, the functional material element can be detached from the waste liquid treatment device and the valuable metals can be recovered in a valuable metal recovery device. In this case, by sufficiently reducing the volume of the waste liquid containing valuable metals in the waste liquid treatment device, the valuable metals can be easily transported by detaching the functional material element. This makes it suitable to have the waste liquid treatment device for the valuable metal-containing waste liquid and the valuable metal recovery device for recovering the valuable metals adsorbed or concentrated on the functional material element in different locations. This allows the waste liquid treatment and valuable metal recovery of the waste liquid containing valuable metals to be performed separately from the entity that discharges the waste liquid containing valuable metals. Furthermore, by recovering the valuable metals and regenerating the functional material, and then reusing the regenerated functional material as a functional material element, a valuable metal recovery system that is excellent in terms of circular economy can be achieved. In this valuable metal recovery process, multiple stages of functional material elements are arranged in series to allow water to pass through. For example, in a three-stage configuration, if the first (initial) functional material element is deemed to have broken through based on the concentration of valuable metals at the inlet and outlet sides of each functional material element and the amount of water passing through, the first-stage functional material element is removed and regenerated, the second-stage functional material element is moved up to continue processing as the first functional material element, and the water flow order is controlled to switch so that the regenerated first-stage functional material element becomes the last stage. Next, if the second functional material element, which has now become the first, is deemed to have broken through, it is removed and regenerated, the third-stage functional material element is moved up to continue processing as the first functional material element, and the water flow order is controlled to switch so that the regenerated second-stage functional material element becomes the last stage. This so-called merry-go-round process, in which the control to switch the water flow order is repeated sequentially, allows for efficient use of functional materials.

[0014] In the above invention (Invention 1), it is preferable that the control means assumes that the functional material has broken through when the valuable metal concentration at the outlet side / valuable metal concentration at the inlet side of the first functional material element exceeds a predetermined value, and controls the switching of the water flow order of the multiple stages of functional material elements (Invention 2).

[0015] According to the above invention (Invention 2), the permeability of valuable metals through the first functional material element (concentration of valuable metals at the outlet side of the first functional material element / concentration of valuable metals at the outlet side) is preset according to the flow rate of the waste liquid, and when this permeability becomes large, it is assumed that the first functional material element has broken through, and a notification is sent to regenerate the functional material element, thereby making it possible to use the functional material more efficiently.

[0016] In the above invention (Invention 1), it is preferable that the control means determines that the functional material has deteriorated when the mass of valuable metal (Mn) when water is passed until breakthrough of the functional material is assumed / the mass of valuable metal (M0) when water is passed until breakthrough of the initial functional material becomes smaller than a predetermined value, and determines that it is time to replace the functional material element and issues an instruction to do so (Invention 3).

[0017] According to the above invention (Invention 3), if the amount of water passed through the functional material before it breaks through becomes small, it is determined that the functional material itself has deteriorated, and a notification is sent to notify the user that the functional material element needs to be replaced, thereby making it possible to efficiently utilize the functional material element and maintain a high recovery capacity for valuable metals.

[0018] In the above invention (Invention 1), it is preferable that the waste liquid treatment device is composed of one or more water treatment units, and that the water treatment units are portable (Invention 4).

[0019] According to the above invention (Invention 4), the waste liquid of a specific user can be transported to the water treatment unit that constitutes the waste liquid treatment device to the discharge point thereof, so the user does not need to construct the waste liquid treatment device as a fixed structure, and a valuable metal recovery system can be created that reduces the user's initial costs.

[0020] In the above invention (Invention 1), it is preferable that the waste liquid treatment device and the valuable metal recovery device are installed in different locations (Invention 5).

[0021] According to the above invention (Invention 5), the functional material element is detachable from the waste liquid treatment device, and by removing the functional material element from the waste liquid treatment device, the waste liquid treatment device and the valuable metal recovery device, which are installed at the user's waste liquid discharge point, can be located in different places, and the functional material element can be transported to the installation location of the valuable metal recovery device.This allows the user to install only the waste liquid treatment device at the user's waste liquid discharge point, thereby reducing the space required on the user's side.In addition, by selecting the recovery entity using the valuable metal recovery device depending on the valuable metal to be recovered, optimal recovery processing can be performed.

[0022] In the above invention (Invention 1), it is preferable that the functional material element comprises a functional material selected corresponding to the valuable metals in the waste liquid containing the valuable metals to be recovered (Invention 6).

[0023] According to the above invention (Invention 6), by selecting a functional material depending on the valuable metal to be recovered, the valuable metal to be recovered can be preferentially recovered.

[0024] In the above inventions (Inventions 1 to 6), it is preferable that the control means calculates the cost of valuable metal recovery treatment in accordance with the market price of valuable metals (Invention 7).

[0025] According to the above invention (Invention 7), the processing cost can be calculated appropriately according to the market price of valuable metals.

[0026] In a second aspect, the present invention provides a method for recovering valuable metals from waste liquid containing the valuable metals, comprising: a waste liquid treatment process in which the valuable metals in the waste liquid are adsorbed or concentrated by a waste liquid treatment device having, as a water treatment unit, functional material elements capable of adsorbing or concentrating the valuable metals; and a valuable metal recovery process in which the valuable metals are recovered from the functional material elements, the functional material is regenerated, and the regenerated functional material is reused as a functional material element by a valuable metal recovery device, wherein the functional material elements are arranged in two or more stages so as to be detachable from the waste liquid treatment device. and a control means for controlling the switching of the order in which water passes through the functional material elements in the plurality of stages based on the output data of the sensors on the inlet and outlet sides and the amount of water passing through, and for determining the timing of replacing the functional material elements, wherein the control means instructs that the first functional material element be removed and regenerated in the water passing process of the functional material elements, and sequentially repeats control of switching so that the first functional material element that has been regenerated becomes the last stage (Invention 8).

[0027] According to the above invention (Invention 8), the valuable metals in a waste liquid containing valuable metals can be adsorbed or concentrated by a functional material element in a waste liquid treatment device. Once the volume of the valuable metals in the waste liquid has been sufficiently reduced, the functional material element can be detached from the waste liquid treatment device and the valuable metals can be recovered in a valuable metal recovery device. In this case, by sufficiently reducing the volume of the waste liquid containing valuable metals in the waste liquid treatment device, the valuable metals can be easily transported by detaching the functional material element. This makes it suitable to have the waste liquid treatment device for the valuable metal-containing waste liquid and the valuable metal recovery device for recovering the valuable metals adsorbed or concentrated on the functional material element in different locations. This allows the waste liquid treatment and valuable metal recovery of the waste liquid containing valuable metals to be performed separately from the entity that discharges the waste liquid containing valuable metals. Furthermore, by recovering the valuable metals and regenerating the functional material, and then reusing the regenerated functional material as a functional material element, a valuable metal recovery system that is excellent in terms of circular economy can be achieved. In this valuable metal recovery process, multiple stages of functional material elements are arranged in series to allow water to pass through. For example, in a three-stage configuration, if the first (initial) functional material element is deemed to have broken through based on the concentration of valuable metals at the inlet and outlet sides of each functional material element and the amount of water passing through, the first-stage functional material element is removed and regenerated, the second-stage functional material element is moved up to continue processing as the first functional material element, and the water flow order is controlled to switch so that the regenerated first-stage functional material element becomes the last stage. Next, if the second functional material element, which has now become the first, is deemed to have broken through, it is removed and regenerated, the third-stage functional material element is moved up to continue processing as the first functional material element, and the water flow order is controlled to switch so that the regenerated second-stage functional material element becomes the last stage. This so-called merry-go-round process, in which the control to switch the water flow order is repeated sequentially, allows for efficient use of functional materials.

[0028] In the above invention (Invention 8), it is preferable that the control means assumes that the functional material has broken through when the valuable metal concentration at the outlet side / the valuable metal concentration at the outlet side of the first functional material element exceeds a predetermined value, and controls the switching of the water flow order of the multiple stages of functional material elements (Invention 9).

[0029] According to the above invention (Invention 9), the permeability of valuable metals through the first functional material element (concentration of valuable metals at the outlet side of the first functional material element / concentration of valuable metals at the outlet side) is preset according to the flow rate of the waste liquid, and when this permeability becomes large, it is assumed that the first functional material element has broken through, and a notification is sent to regenerate the functional material element, thereby making it possible to use the functional material more efficiently.

[0030] In the above invention (Invention 9), it is preferable that the control means determines that the functional material has deteriorated when the mass of valuable metals (Mn) when water is passed before breakthrough of the functional material is assumed / the mass of valuable metals (M0) when water is passed before breakthrough of the initial functional material becomes smaller than a predetermined value, and determines that it is time to replace the functional material element and issues an instruction (Invention 3).It is preferable that the control means determines that the functional material has deteriorated when the mass of valuable metals (Mn) when water is passed before breakthrough of the functional material is assumed / the mass of valuable metals (M0) when water is passed before breakthrough of the initial functional material becomes smaller than a predetermined value, and determines that it is time to replace the functional material element and issues an instruction (Invention 10).

[0031] According to the above invention (Invention 10), if the amount of water passed through the functional material before it breaks through becomes small, it is determined that the functional material itself has deteriorated, and a notification is sent to notify the user that the functional material element needs to be replaced, thereby making it possible to efficiently utilize the functional material element and maintain a high recovery capacity for valuable metals.

[0032] In the above invention (Invention 8), it is preferable that the waste liquid treatment device is composed of one or more water treatment units, and that the water treatment units are portable (Invention 11).

[0033] According to the above invention (Invention 11), the waste liquid of a specific user can be transported to the water treatment unit constituting the waste liquid treatment device up to the discharge point thereof, so the user does not need to construct the waste liquid treatment device as a fixed structure, and a valuable metal recovery system can be created that reduces the user's initial costs.

[0034] In the above invention (Invention 11), it is preferable that the waste liquid treatment device and the valuable metal recovery device are installed in different locations (Invention 12).

[0035] According to the above invention (Invention 12), the functional material element is detachable from the waste liquid treatment device, and by removing the functional material element from the waste liquid treatment device, the waste liquid treatment device and the valuable metal recovery device, which are installed at the user's waste liquid discharge location, can be located in different places. By transporting the functional material element to the installation location of the valuable metal recovery device, the system installed at the user's waste liquid discharge location can be used as the waste liquid treatment device, thereby reducing the space required on the user's side. In addition, by selecting the recovery entity by the valuable metal recovery device depending on the valuable metal to be recovered, optimal recovery processing can be performed.

[0036] In the above invention (Invention 8), it is preferable that the functional material element comprises a functional material selected corresponding to the valuable metals in the waste liquid containing the valuable metals to be recovered (Invention 13).

[0037] According to the above invention (Invention 13), by selecting a functional material depending on the valuable metal to be recovered, the valuable metal to be recovered can be preferentially recovered.

[0038] In the above inventions (Inventions 8 to 13), it is preferable that the control means calculates the cost of valuable metal recovery treatment in accordance with the market price of valuable metals (Invention 14).

[0039] According to the above invention (Invention 14), the processing cost can be calculated appropriately according to the market price of valuable metals. [Effects of the Invention]

[0040] According to the valuable metal recovery system of the present invention, multiple stages of functional material elements are arranged in series to allow water to pass through, and when it is determined that the first stage functional material element has broken through based on the concentration of valuable metals at the inlet and outlet sides of each functional material element and the amount of water passing through, the first stage functional material element is removed and regenerated, and the second and subsequent stages of functional material elements are moved up to be processed, and the first regenerated functional material element is reinstalled and placed at the rear of the flow order, and this control is repeated sequentially in a so-called merry-go-round style of processing, allowing for efficient use of functional materials. [Brief explanation of the drawings]

[0041] [Figure 1] 1 is a schematic diagram showing the configuration of a valuable metal recovery system according to one embodiment of the present invention. [Figure 2] 1 is a schematic diagram showing a processing flow of a valuable metal recovery system according to an embodiment of the present invention. [Figure 3] 1 is a schematic diagram showing a processing flow of a valuable metal recovery system according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0042] Hereinafter, an embodiment of the valuable metal recovery system of the present invention will be described in detail with reference to the accompanying drawings.

[0043] [Valuable metal recovery system] As the valuable metal recovery system of this embodiment, for example, one having the configuration shown in FIG. 1 can be used.

[0044] In FIG. 1, a valuable metal recovery system 1 comprises a waste liquid treatment device 2 and a valuable metal recovery device 3 .

[0045] <Waste liquid treatment equipment> The waste liquid treatment device 2 comprises water treatment units: a tank 21 for storing waste liquid W containing valuable metals; a coagulation and sedimentation tank 22 as pretreatment means; a membrane filtration device 23 such as MF or UF; and a valuable metal adsorption device 24. This valuable metal adsorption device 24 is equipped with a detachable adsorbent column (functional material element), which is a functional material capable of adsorbing valuable metals. Each of these water treatment units is unitized by installing the necessary equipment and piping on a pallet that can be loaded onto a transport means such as a trailer T. The unit is then loaded onto one or more trailers T and transported to the customer's waste liquid discharge site containing valuable metals, where it can be unloaded from the trailer T or installed at the site while still mounted on the trailer T.

[0046] (liquid waste containing valuable metals) In this embodiment, valuable metals to be recovered include, but are not limited to, Li, Rb, Cs, Ti, Mo, Ni, In, Cu, Co, Ga, and V. When two or more valuable metals are present in the waste liquid W, only one type may be recovered, two or more types may be recovered separately, or two or more types may be recovered simultaneously. The valuable metals in the waste liquid may be dissolved by immersion in water, acid, or alkali. Furthermore, elution water from the waste may be used as the waste liquid W. In this case, the waste 25 may be immersed and washed in pure water to remove dirt and impurities, and then the valuable metals may be eluted from the waste using chemicals such as acid or alkali. This elution water may be used as the waste liquid W, or the elution water may be combined with the waste liquid W. Valuable metals exist in the waste liquid W in the form of ions, and this method is suitable for waste liquid W with a concentration of 10 to 10,000 mg / L.

[0047] (Pre-processing means) In the coagulation settling tank 22 and membrane filtration device 23, pretreatment such as removal of suspended solids by solid-liquid separation and removal (rough removal) of coexisting substances that inhibit adsorption / extraction is carried out. In addition to these, one or more pretreatment means selected from sand filtration, activated carbon, coagulation filtration, coagulation pressure flotation, etc. may be used.

[0048] (Valuable metal adsorption device) The valuable metal adsorption device 24 is configured by detachably accommodating one or more functional material elements arranged in series or parallel, each of which is a column filled with a functional material (adsorbent) capable of adsorbing valuable metals contained in the waste liquid W containing the valuable metals. The shape and size of the column as the functional material element may be selected appropriately depending on the amount of waste liquid W to be treated.

[0049] Examples of adsorbents that can be used include, but are not limited to, ion exchange resins (cation exchange resins, anion exchange resins), chelating resins, various composite oxides including zeolites, activated carbon, porous silica, and porous titania.

[0050] Cation exchange resins adsorb ionic substances in wastewater by exchanging cations in the resin with cations in the wastewater. For example, they are suitable for adsorbing valuable metals such as Li, Rb, Cs, Ni, Cu, and Co that exist as cations in the solution. Anion exchange resins adsorb ionic substances in wastewater by exchanging anions in the resin with anions in the wastewater. For example, they are suitable for adsorbing metal ions that exist as oxoanions.

[0051] Chelate resins are resins that have been introduced with functional groups that form chelates (complexes) with specific metal ions, and can adsorb metal ions by forming chelates with the specific metals. The most commonly used chelate resins, which have iminodiacetic acid as a functional group, are suitable for adsorbing Cu, Ni, and Co.

[0052] Zeolites can selectively adsorb cations in aqueous solutions through ion exchange. The selectivity for cations depends on the crystalline structure of the zeolite, but it is suitable for adsorbing Cs and Rb. In addition to these, lithium manganese oxide, lithium titanate, layered double hydroxides, etc. can also be used as Li adsorbents.

[0053] Such adsorbents can be selected appropriately depending on the valuable metals to be recovered to form the functional material element, and it is preferable to use an adsorbent that exhibits a high partition coefficient for the valuable metals to be recovered. Specifically, the partition coefficient is preferably 100 mL / g (mg / mL solution / mg / mL adsorbent) or more, and more preferably 10,000 mL / g (mg / mL solution / mg / mL adsorbent) or more.

[0054] These functional materials may be appropriately selected depending on the valuable metals contained in the waste liquid to be recovered.

[0055] The valuable metal adsorption device 24 described above has a configuration as shown in Fig. 2. In Fig. 2, the valuable metal adsorption device 24 has a supply pipe 42 connected to a supply source 41 of waste liquid W. After passing through a pretreatment means, this supply pipe 42 has two or more stages (three stages in this embodiment) of functional material elements (the first stage is a first functional material element 43A, the second stage is a second functional material element 43B, and the third stage is a third functional material element 43C) detachably attached in series, with a storage tank 44 for treated water W1 attached at the end of the pipe. The functional material elements 43A, 43B, and 43C are interconnected, and the order of water flow can be changed by switching means such as valves (not shown) in a so-called merry-go-round manner: 43A → 43B → 43C, 43B → 43C → 43A, or 43C → 43A → 43B.

[0056] The system is also provided with a first valuable metal concentration sensor 45A that measures the concentration of valuable metals in the wastewater W (i.e., the initial valuable metal concentration (C0) flowing into the functional material element 43A), a second valuable metal concentration sensor 45B that measures the concentration of valuable metals in the treated water of the first functional material element 43A, a third valuable metal concentration sensor 45C that measures the concentration of valuable metals in the treated water of the second functional material element 43B, and a fourth valuable metal concentration sensor 45D that measures the concentration of valuable metals in the treated water of the third functional material element 43C. Furthermore, the first valuable metal concentration sensor 45A, the second valuable metal concentration sensor 45B, the third valuable metal concentration sensor 45C, and the fourth valuable metal concentration sensor 45D are each capable of transmitting measurement data to a control means such as a personal computer (not shown). Examples of valuable metal concentration sensors that can be used include, but are not limited to, ion chromatography, inductively coupled plasma optical emission spectroscopy (ICP-OES), inductively coupled plasma atomic emission spectroscopy (ICP-AES), inductively coupled plasma mass spectroscopy (ICP-MS), atomic absorption spectroscopy (AAS), conductivity meters, and pH meters.

[0057] This control means switches the water flow order by controlling switching means such as valves of the functional material elements 43A, 43B, and 43C. For example, if the ratio (= transmittance: (Cn) / (C0)) of the valuable metal concentration (Cn) at the outlet side of the functional material element through which water is first passed to the initial valuable metal concentration (C0) at the inlet side exceeds a predetermined value, it is assumed that the functional material has broken through, and the control means switches the water flow order of the multiple stages of functional material elements, and can also notify the administrator that the functional material element needs to be regenerated.

[0058] Furthermore, the control means is capable of acquiring flow rate data from a timer and a flow meter, and calculates the ratio (= maintenance rate: (Mn) / (M0)) of the mass of valuable metal (Mn) when water is passed until the functional material is assumed to have broken through, based on the time until the functional material breaks through and the concentration data of the valuable metal, to the mass of valuable metal (M0) when water is passed until the initial functional material is assumed to have broken through. If this maintenance rate: (Mn) / (M0) becomes smaller than a predetermined value, it is determined that the functional material itself has deteriorated, and it is possible to notify the administrator that it is time to replace the functional material element.

[0059] <Valuable metal recovery equipment> The valuable metal recovery device 3 elutes or strips out the target valuable metals from the functional material elements filled with the adsorbent. This valuable metal recovery device 3 is preferably installed in a location different from the waste liquid treatment device 2, and receives and treats the functional material elements. This valuable metal recovery device 3 may be configured according to the valuable metals to be recovered.

[0060] In this embodiment, the waste liquid treatment device 2 and the valuable metal recovery device 3 are installed in different locations.

[0061] [Valuable metal recovery method] Next, a valuable metal recovery method using the valuable metal recovery system described above will be described.

[0062] <Waste liquid storage process> First, waste liquid W containing valuable metals to be treated is stored in tank 21. This waste liquid W containing valuable metals may be waste liquid discharged from various factories, or it may be elution water from waste discarded at various factories. In the case of elution water from waste, the waste is immersed and washed in pure water to remove dirt and impurities, and then the valuable metals are eluted from the waste using chemicals such as acids or alkalis to obtain elution water. In this waste liquid W, the valuable metals exist in the form of ions.

[0063] <Waste liquid treatment process> (Pretreatment process) The waste liquid W containing valuable metals stored in the tank 21 as described above is transferred to the coagulation and sedimentation tank 22 and subjected to coagulation and sedimentation treatment. This coagulation and sedimentation treatment removes suspended solid matter in the waste liquid W and removes (roughly removes) coexisting substances that inhibit adsorption / extraction. Subsequently, fine suspended solid matter contained in the waste liquid W is removed by filtration using a membrane filtration device 23.

[0064] (Valuable metal adsorption process) The waste liquid W thus pretreated is treated in a valuable metal adsorption device 24. In this valuable metal adsorption device 24, ionized valuable metals are adsorbed by an adsorbent. In this valuable metal adsorption step, an upper limit of the ion concentration of valuable metals in treated water obtained by treating the waste liquid W in the valuable metal adsorption device 24 is determined in advance depending on the ion concentration of valuable metals contained in the waste liquid W to be treated, the amount of waste liquid W to be treated, and the amount of adsorbent used in the adsorbent column of the valuable metal adsorption device 24, and the SV of the waste liquid W can be set so that the ion concentration of valuable metals in the treated water W falls below this upper limit. Alternatively, the waste liquid W may be circulated in the valuable metal adsorption device 24 until the ion concentration of valuable metals in the treated water falls below this predetermined upper limit.

[0065] By using the valuable metal adsorption process described above, waste liquid W having a valuable metal concentration of 10 to 10,000 mg / L can be reduced in volume to 0.01 to 10% by volume of the waste liquid W by treating it with an adsorbent having a distribution coefficient for the valuable metal of 100 mL / g or more, particularly 10,000 mL / g or more.

[0066] (Valuable metal recovery process) Next, valuable metals are recovered from the adsorbent in the column removed from the valuable metal adsorption device 24. This recovery can be achieved by immersing the adsorbent in a solvent appropriate for the valuable metal to be recovered, eluting the valuable metal, and then precipitating the valuable metal from the solvent, which can then be dried and purified. The solvent used for elution can be selected appropriately depending on the valuable metal to be recovered, such as hydrochloric acid, nitric acid, sodium chloride, potassium chloride, or other solvents that form complexes with the eluted metal ions. Note that different valuable metals can also be recovered separately by sequentially immersing the adsorbent in different solvents.

[0067] In addition, the adsorbent can be regenerated by removing adsorbates other than valuable metals and further removing crushed adsorbent, and then drying it, allowing it to be reused as an adsorbent again (regeneration process).

[0068] The volume of the valuable metals to be treated in this valuable metal recovery process is reduced to about 0.01 to 10% by volume of the valuable metal waste liquid volume W by the valuable metal adsorption process, making it easy to transport the column as valuable metal recovery material. Therefore, by transporting the column to a company that elutes and recovers valuable metals, it is possible to process the valuable metals at a location other than the waste liquid treatment process.

[0069] As described above, the valuable metal recovery system 1 of this embodiment makes it possible to facilitate the transportation of the media for valuable metal recovery by sufficiently reducing the volume of the media for valuable metal recovery in the waste liquid treatment device 2 compared to the waste liquid W. This not only makes it possible to operate the waste liquid treatment device 2 at a different location from the valuable metal recovery device 3, but also makes it possible to arbitrarily select an operator of the valuable metal recovery device 3 and entrust the valuable metal recovery process to that operator.

[0070] Furthermore, the user U not only does not need to incur the initial costs for either the waste liquid treatment device 2 or the valuable metal recovery device 3, but also does not need to install these devices at the location where the user U discharges the waste liquid W, and can enjoy the benefit of only paying the appropriate treatment costs. On the other hand, by applying the operation method of this valuable metal recovery system, valuable metals can be recovered and reused, and the adsorbent material (functional material element) can also be reused, which is also advantageous in terms of circular economy.

[0071] (Valuable metal adsorption step of this embodiment) In the waste liquid treatment process described above, the valuable metal adsorption process is carried out using a valuable metal adsorption device 24 having the configuration shown in FIG. 2 and controlled by a merry-go-round method according to the flow shown in FIG.

[0072] First, the waste liquid W is passed through the functional material elements 43A, 43B, and 43C in this order to adsorb the valuable metals in the waste liquid W. At this time, the first valuable metal concentration sensor 45A measures the initial valuable metal concentration (C0) of the waste liquid W, and the second valuable metal concentration sensor 45B measures the valuable metal concentration (Cn) of the treated liquid after treatment in the first functional material element 43A, through which the waste liquid W initially passes. The control means then calculates the valuable metal transmittance (Cn / C0) based on these data. A preset value (e.g., 0.90) is set for this transmittance, and it is determined whether this transmittance (Cn / C0) exceeds the preset value. If the permeability (Cn / C0) is below the set value (No), the treatment continues as is, whereas if the permeability (Cn / C0) exceeds the set value (Yes), the first functional material element 43A is assumed to have broken through, and the first functional material element 43A is removed and sent to a valuable metal recovery process to recover the valuable metals adsorbed on the first functional material element 43A, after which the first functional material element 43A is regenerated. Note that Cn is the valuable metal concentration after treatment with the nth (n is an integer greater than or equal to 1) functional material element, and C0 is the valuable metal concentration in the raw water (wastewater W), which is the average concentration (=Σ(Q×C0) / Qtotal) from the start of the flow of wastewater W (Q is the total amount of raw water flowing).

[0073] Next, while the first functional material element 43A is being regenerated, the water flow order is switched so that the second functional material element 43B comes first, i.e., the flow order is changed from 43B to 43C. Similarly, when the second functional material element 43B is deemed to have broken through, the second functional material element 43B is removed and sent to the valuable metal recovery process to recover the valuable metals adsorbed by the second functional material element 43B, and then the first functional material element 43A is regenerated. At this time, the regenerated first functional material element 43A is attached to the valuable metal adsorption device 24. At this time, the water flow order is switched so that the regenerated first functional material element 43A is the last stage and the third functional material element 43C comes first, i.e., the flow order is changed from 43C to 43A. Next, when it is determined that the third functional material element 43C has broken through, the third functional material element 43C is removed, the regenerated second functional material element is attached, and the water flow order is switched so as to change the flow order from 43A to 43B. By repeating this process, valuable metals can be recovered while efficiently regenerating the functional material elements 43A to 43C.

[0074] In this water flow control, repeated regeneration of the functional material elements 43A-43C gradually deteriorates the functional material, reducing the valuable metal capture efficiency compared to when the functional material elements were unused. This shortens the time it takes for the permeability (Cn / C0) to exceed a set value. Therefore, the control unit calculates a maintenance rate by calculating the ratio (Mn / M0) of the mass of valuable metal (Mn) when water is passed through the functional material element until the permeability (Cn / C0) exceeds the set value to the mass of valuable metal (M0) when water is passed through the initial functional material element until the permeability (Cn / C0) exceeds the set value. A preset value (e.g., 0.75) is set for this maintenance rate (Mn / M0), and a determination is made as to whether or not this set value has been exceeded. If the maintenance rate (Mn / M0) is equal to or greater than the set value (No), the regeneration of the functional material element and the change of the water flow route are continued. On the other hand, if the maintenance rate (Mn / M0) falls below the set value (Yes), it is determined that the functional material element itself has deteriorated, and the administrator is notified to replace the functional material element, or if the analysis results are entered and fall below the set judgment value, the information is automatically communicated to the administrator via the Internet. Note that M = Σ(Q × C) (Q = total amount of raw water flowing, C = average concentration of valuable metals in the raw water).

[0075] [Operation method of valuable metal recovery system] The valuable metal adsorption process flow of this embodiment, as described above, utilizes valuable metal concentration sensors 45A, 45B, 45C, and 45D to automatically determine whether to regenerate the functional material elements 43A, 43B, and 43C and control their flow paths, thereby maintaining the performance of the functional materials and maintaining the valuable metal recovery rate. Furthermore, by determining when to replace the functional material elements 43A, 43B, and 43C, deteriorated functional materials can be promptly replaced, maintaining high valuable metal recovery efficiency and efficiently utilizing the functional material elements. Furthermore, by communicating the decision to regenerate the functional material elements 43A, 43B, and 43C following breakthrough or the decision to replace the functional material elements themselves via electronic mail or other means to a manager, such as a service provider, this not only reduces the burden on the operator operating the wastewater treatment device 2 but also provides assistance to less experienced operators. Furthermore, by calculating the basic costs of the valuable metal recovery method of the present invention in advance and allowing the control means to obtain market price data for valuable metals as appropriate, it becomes possible to calculate the valuable metal recovery processing costs taking into account the reuse of the recovered valuable metals, thereby enabling the optimization of processing costs.

[0076] The present invention has been described above based on the above-described embodiments with reference to the accompanying drawings. However, the present invention is not limited to these embodiments and various modifications are possible. For example, in the above-described embodiments, when one of the functional material elements 43A, 43B, or 43C is regenerated, treatment is performed using the remaining two functional material elements. However, treatment may be stopped when one of the functional material elements 43A, 43B, or 43C is regenerated, and once the functional material element is regenerated, the flow path may be changed to make the regenerated element the last element. Furthermore, although three or more functional material elements are preferably arranged in series, even in a two-stage configuration, treatment may be stopped when a functional material element that has simulated breakthrough is regenerated, and once the functional material element is regenerated, the flow path may be changed to make the regenerated element the last element. Furthermore, while the above-described embodiments have been described as recovering valuable metals by adsorption, treatment may be performed by reducing the volume of the wastewater W by concentrating valuable metal ions using a reverse osmosis membrane or an electrodeionization device. Furthermore, if the user U has a short treatment period for the waste liquid W containing valuable metals, the waste liquid treatment device 2 can be transported, and the operating rate of the waste liquid treatment device 2 can be improved by transporting the waste liquid treatment device 2 to the discharge location of the waste liquid W containing other valuable metals. [Example]

[0077] The present invention will be further illustrated by the following specific examples.

[0078] [Example 1] Wastewater W containing approximately 100 mg / L of lithium was prepared as simulated raw water (simulated wastewater). Valuable metals in this wastewater W were adsorbed using a merry-go-round system in a valuable metal adsorption device 24 consisting of a three-stage series adsorption tower (functional material elements 43A, 43B, and 43C) as shown in Figure 2. The adsorption capacity of the adsorbent filled in the adsorption tower was set to 0.01 kg of valuable metal / kg of adsorbent. The adsorption tower was filled with 1,000 kg of this adsorbent, and the valuable metal adsorption capacity of the adsorption tower without water flow was set to 10 kg. The concentration of valuable metals in the wastewater W was determined to be 100 mg / L using the arithmetic average concentration from the start of water flow until the breakthrough of the adsorption tower was determined. A cation exchange resin was used as the adsorbent.

[0079] In the valuable metal adsorption device 24 described above, water was first passed through the functional material elements 43A, 43B, and 43C in that order. When the valuable metal concentration at the outlet of the first functional material element 43A exceeded 90 mg / L (permeability (Cn) / (C0)=0.90), it was assumed that the first functional material element 43A had broken through, and the first functional material element 43A was removed and sent to the regeneration process.

[0080] Next, the flow route was changed so that the second functional material element 43B was first, and the wastewater W was passed through the functional material elements 43B → 43C in that order. When the valuable metal concentration at the outlet of the functional material element 43B exceeded 90 mg / L (transmittance (Cn) / (C0) = 0.90), the second functional material element 43B was assumed to have broken through, and the second functional material element 43B was removed and sent to the regeneration process. The regenerated first functional material element 43A was then reattached.

[0081] Furthermore, the flow route was changed so that the third functional material element 43C was first, and the wastewater W was passed through the functional material element 43C → 43A in that order. When the valuable metal concentration at the outlet of the functional material element 43C exceeded 90 mg / L (permeability (Cn) / (C0) = 0.90), it was assumed that the third functional material element 43C had broken through, and the third functional material element 43C was removed and sent to the regeneration process.

[0082] The functional material elements were judged to have deteriorated when the ratio (maintenance rate (Mn / M0)) of the mass of valuable metals (Mn) that had actually passed through the unregenerated adsorption towers (functional material elements 43A to 43C) before breakthrough to the mass of valuable metals (10 kg (M0) that could pass through the unregenerated adsorption towers before breakthrough) became less than 0.75 (in this example, Mn = 7.5 kg). At this point, it was determined that it was time to replace the functional material elements themselves. [Explanation of symbols]

[0083] 1 Valuable metal recovery system 2. Waste liquid treatment equipment 21 Tank 22 Coagulation and settling tank (pretreatment means) 23 Membrane filtration device (pretreatment means) 24 Valuable metal adsorption equipment 25 Waste 3 Valuable metal recovery equipment 41 Source 42 Supply pipe 43A First functional material element 43B Second functional material element 43C Third functional material element 44 Storage tank 45A First Valuable Metal Concentration Sensor 45B Secondary valuable metal concentration sensor 45C Third valuable metal concentration sensor 45D Fourth valuable metal concentration sensor W Waste liquid containing valuable metals W1 treated water T Trailer (vehicle)

Claims

1. A system for recovering valuable metals from waste liquid containing the valuable metals, a waste liquid treatment device having a functional material element capable of adsorbing or concentrating the valuable metals as a water treatment unit; a valuable metal recovery device that recovers the adsorbed or concentrated valuable metals from the functional material elements, regenerates the functional material, and reuses the regenerated functional material as a functional material element; the functional material elements are detachably provided in two or more stages from the waste liquid treatment device so as to allow water to pass through in series, Each functional material element has a sensor at its inlet and outlet for measuring the concentration of valuable metals to be recovered, a control means for controlling the switching of the water flow order of the functional material elements in the plurality of stages based on the output data of the inlet and outlet sensors and the amount of water flowing, and for determining the time to replace the functional material elements; The control means instructs the removal and regeneration of the first functional material element during the water flow treatment of the functional material elements, and sequentially repeats control to switch the first functional material element that has been regenerated to become the last stage.

2. 2. The valuable metal recovery system according to claim 1, wherein the control means determines that the functional material has broken through when the concentration of valuable metals at the outlet side / the concentration of valuable metals at the inlet side of the first functional material element exceeds a predetermined value, and controls the switching of the order in which water passes through the functional material elements in multiple stages.

3. The valuable metal recovery system according to claim 2, wherein the control means determines that the functional material has deteriorated when the ratio of the mass of valuable metal (Mn) when water is passed until breakthrough of the functional material is assumed to have occurred to the mass of valuable metal (M0) when water is passed until breakthrough of the initial functional material occurs becomes smaller than a predetermined value, and determines that it is time to replace the functional material element and issues an instruction to do so.

4. 2. The valuable metal recovery system according to claim 1, wherein the waste liquid treatment device is composed of one or more water treatment units, and the water treatment units are portable.

5. 2. The valuable metal recovery system according to claim 1, wherein the waste liquid treatment device and the valuable metal recovery device are installed in different locations.

6. 2. The valuable metal recovery system according to claim 1, wherein the functional material element comprises a functional material selected corresponding to the valuable metal contained in the waste liquid containing the valuable metal to be recovered.

7. The valuable metal recovery system according to any one of claims 1 to 6, wherein the control means calculates the valuable metal recovery processing cost according to the market price of the valuable metal.

8. A method for recovering valuable metals from a waste liquid containing the valuable metals, comprising: a waste liquid treatment process in which valuable metals in the waste liquid are adsorbed or concentrated by a waste liquid treatment device having, as a water treatment unit, the functional material element capable of adsorbing or concentrating valuable metals; a valuable metal recovery step of recovering the adsorbed or concentrated valuable metals from the functional material elements and regenerating the functional material, using a valuable metal recovery device that recycles the regenerated functional material as a functional material element; The functional material elements are detachably mounted in two or more stages in series so as to allow water to pass through them from the waste liquid treatment device, and each functional material element has a sensor at the inlet and outlet sides for measuring the concentration of valuable metals to be recovered, and the system is equipped with a control means for switching and controlling the order in which water passes through the functional material elements at the multiple stages based on the output data of the sensors at the inlet and outlet sides and the amount of water passing through, and for determining when to replace the functional material elements. The control means instructs the removal and regeneration of the first functional material element during the water flow treatment of the functional material elements, and sequentially repeats control to switch the first functional material element that has been regenerated to become the last stage.

9. The valuable metal recovery method according to claim 8, wherein the control means determines that the functional material has broken through when the valuable metal concentration at the outlet side of the first functional material element / the valuable metal concentration at the outlet side exceeds a predetermined value, and controls the switching of the order in which water passes through the functional material elements in multiple stages.

10. The valuable metal recovery method according to claim 9, wherein the control means determines that the functional material has deteriorated when the ratio of the mass of valuable metal (Mn) when water is passed until breakthrough of the functional material is assumed to have occurred to the mass of valuable metal (M0) when water is passed until breakthrough of the initial functional material occurs becomes smaller than a predetermined value, and determines that it is time to replace the functional material element and issues an instruction to do so.

11. 9. The valuable metal recovery method according to claim 8, wherein the waste liquid treatment device is composed of one or more water treatment units, and the water treatment units are portable.

12. The valuable metal recovery method according to claim 11, wherein the waste liquid treatment device and the valuable metal recovery device are installed in different locations.

13. 9. The valuable metal recovery method according to claim 8, wherein the functional material element comprises a functional material selected corresponding to the valuable metal in the waste liquid containing the valuable metal to be recovered.

14. The valuable metal recovery method according to any one of claims 8 to 13, wherein the control means calculates the valuable metal recovery processing cost according to the market price of the valuable metal.

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