A forward osmosis unit for lithium extraction from salt lakes and its safety monitoring system

Abstract

This invention relates to lithium extraction equipment technology from salt lakes, proposing a forward osmosis device and its safety monitoring system, including a pretreatment component, a lithium-based adsorption tower, and a forward osmosis unit. The pretreatment component reduces suspended solids in the salt lake brine, and the treated brine is then fed into the lithium-based adsorption tower and the forward osmosis unit. The lithium-based adsorption tower has outlets for the adsorbed raw solution, desorbed water, and desorbed liquid, and uses an aluminum-based adsorbent. The forward osmosis unit incorporates a forward osmosis membrane module, employing a non-woven fabric base membrane coated with cellulose acetate and polyamide. This invention replaces the high-pressure reverse osmosis component with a forward osmosis unit, achieving atmospheric pressure concentration and lithium extraction, reducing energy consumption and safety risks. The forward osmosis unit uses saturated brine as the draw solution, ensuring osmotic pressure differences and increasing desorbed liquid yield. Conventional systems require separate treatment of the diluted draw solution; in this invention, the diluted draw solution is directly returned to the salt lake, utilizing the high salinity of the salt lake to slow the decrease in draw solution concentration and maintain a long-term stable osmotic pressure gradient.

Description

Technical Field

[0001] This invention relates to the field of lithium extraction equipment technology from salt lakes, and in particular to a forward osmosis device for lithium extraction from salt lakes and its safety monitoring system. Background Technology

[0002] The main process flow in the lithium extraction system from salt lakes is: adsorption → high-pressure reverse osmosis → nanofiltration → boron removal → lithium precipitation → drying. In this process, the lithium adsorption tower adsorbs lithium ions from the brine. After adsorption, desorption is performed using fresh water, which is unsaturated brine. The desorbed water first enters the high-pressure reverse osmosis unit for concentration. The concentrate then enters the nanofiltration unit to remove divalent ions. In the high-pressure reverse osmosis and nanofiltration systems, the number of cycles often needs to be adjusted according to the actual influent water parameters. However, high-pressure (influent water pressure can reach 100 bar) reverse osmosis has disadvantages such as high energy consumption (the high-pressure reverse osmosis pump is one of the main energy-consuming components), short lifespan, concentration limitations leading to water production failure, and easy scaling. Summary of the Invention

[0003] To address one of the aforementioned technical problems, the present invention adopts the following technical solution:

[0004] According to one aspect of the present invention, a forward osmosis apparatus for lithium extraction from salt lakes is provided, comprising: a pretreatment component, a lithium adsorption tower, and a forward osmosis unit.

[0005] The pretreatment unit is used to reduce the suspended solids content in the initial brine of the salt lake. The outlet of the pretreatment unit is connected to the brine inlet of the lithium adsorption tower and the draw liquid inlet of the forward osmosis unit, respectively, so that the treated secondary brine of the salt lake can be fed into the lithium adsorption tower and the forward osmosis unit.

[0006] The lithium-based adsorption tower is also equipped with a post-adsorption solution outlet, a desorption water inlet, and a desorption liquid outlet. The desorption liquid outlet is connected to the feed water inlet of the forward osmosis unit. The post-adsorption solution outlet is used to transport the post-adsorption solution to the brine lake. The desorption water inlet is connected to the desorption water supply equipment. The adsorbent filled in the lithium-based adsorption tower is an aluminum-based adsorbent.

[0007] The forward osmosis unit contains a forward osmosis membrane module and also has a diluted draw solution outlet. The diluted draw solution outlet is used to transport the diluted draw solution to the brine lake.

[0008] The permeation membrane in the forward osmosis membrane module uses non-woven fabric as the base membrane, which is coated with cellulose acetate and polyamide.

[0009] According to a second aspect of the present invention, a forward osmosis safety monitoring system for lithium extraction from salt lakes is provided, comprising a forward osmosis device for lithium extraction from salt lakes, an infrared image acquisition device, and a processor.

[0010] The infrared image acquisition device is used to acquire temperature images of the permeation membrane surface. The processor is communicatively connected to the infrared image acquisition device.

[0011] The processor is used to perform the following steps:

[0012] The temperature image of the permeate membrane surface is preprocessed to generate a segmented temperature image of the permeate membrane surface.

[0013] Based on the temperature information corresponding to each pixel in the temperature image to be segmented, an image segmentation threshold P is generated. P satisfies the following condition:

[0014] P = μ + Kσ. ​​Where μ is the average temperature of all pixels in the temperature image to be segmented. σ is the standard deviation of the temperature of all pixels in the temperature image to be segmented. K is a preset segmentation coefficient.

[0015] Based on P, image segmentation techniques are used to segment the high-temperature regions from the temperature image to be segmented. High-temperature regions are images whose temperature is greater than or equal to the image segmentation threshold.

[0016] The scaling coefficient S is generated based on the high-temperature region image and the temperature image to be segmented. S satisfies the following condition:

[0017] S=S G / S Z Among them, S G S represents the number of pixels contained in the image of the high-temperature region. Z The number of pixels contained in the temperature image to be segmented.

[0018] If S > Y, a scaling warning message is generated. Y is the preset scaling threshold.

[0019] This invention has at least one of the following beneficial effects:

[0020] In the forward osmosis device for lithium extraction from salt lakes of the present invention, the high-pressure reverse osmosis component is replaced with a forward osmosis unit, thereby enabling the extraction of lithium from salt lakes via a process route of atmospheric pressure concentration. Furthermore, this process system eliminates the need for a high-pressure pump, significantly reducing operating energy consumption and minimizing safety risks in the workshop.

[0021] Meanwhile, by using saturated brine (i.e., salt lake water) as the draw solution in the forward osmosis unit, a significant difference in osmotic pressure between the solutions on both sides of the membrane can be maintained, thereby greatly increasing the yield of the concentrated desorbate. Furthermore, conventional forward osmosis systems require a separate draw solution treatment unit to process the diluted draw solution and restore it to a high concentration for recycling in order to maintain the osmotic pressure difference and prevent system efficiency degradation. This necessitates the use of reverse osmosis or multi-effect evaporation equipment. However, in the salt lake lithium extraction process of this invention, the diluted draw solution can be directly returned to the salt lake. Since salt lakes are mostly supersaturated solutions containing a large amount of crystalline salt, the diluted draw solution, when discharged back into the salt lake, will dissolve the solid salt to restore saturation and form a dynamic equilibrium. In this invention, the draw solution is recycled, and combined with the natural high-salt environment of the salt lake, the rate of decrease in draw solution concentration can be slowed down, maintaining a long-term stable osmotic pressure gradient.

[0022] Furthermore, the forward osmosis safety monitoring system for lithium extraction from salt lakes of the present invention acquires the surface temperature distribution of the permeate membrane through infrared images and identifies high-temperature areas using image segmentation algorithms. This allows for the quantification of the scaling coefficient S, enabling an objective assessment of the degree of membrane scaling. An early warning is triggered when S exceeds a preset threshold Y, effectively avoiding the lag of traditional manual detection and further improving the system's operational stability. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 A schematic diagram of the structural connection of the front part of a forward osmosis device for lithium extraction from salt lakes provided in an embodiment of the present invention includes: a pretreatment component, a lithium adsorption tower, and a forward osmosis unit;

[0025] Figure 2 This is a schematic diagram of the structural connection of the downstream part of a forward osmosis device for lithium extraction from salt lakes provided in an embodiment of the present invention, including: a nanofiltration membrane module unit, an electrostatic boron removal unit, a multi-effect evaporator, a lithium precipitation unit, and a condenser;

[0026] Figure 3 This is a schematic diagram of the execution steps of a processor in a forward osmosis safety monitoring system for lithium extraction from salt lakes, provided as an embodiment of the present invention.

[0027] Figure Labels

[0028] 1. Pretreatment components; 2. Lithium-based adsorption tower; 3. Forward osmosis unit; 4. Nanofiltration membrane unit; 5. Electrostatic boron removal unit; 6. Multi-effect evaporator; 7. Lithium deposition unit; 8. Condenser. Detailed Implementation

[0029] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] As one possible embodiment of the present invention, such as Figure 1 As shown, a forward osmosis device for lithium extraction from salt lakes is provided, comprising: a pretreatment component 1, a lithium adsorption tower 2, and a forward osmosis unit 3.

[0031] The pretreatment component 1 is used to reduce the content of suspended solids in the initial brine of the salt lake. The outlet of the pretreatment component 1 is connected to the brine inlet of the lithium adsorption tower 2 and the draw liquid inlet of the forward osmosis unit 3, respectively, so as to input the treated secondary brine of the salt lake into the lithium adsorption tower 2 and the forward osmosis unit 3.

[0032] The high content of suspended solids in the brine (i.e., the original salt lake water) can damage the adsorbent packed in the downstream lithium-based adsorption tower 2, leading to shorter cleaning cycles and a shorter lifespan. After treatment by the pretreatment equipment, the suspended solids content (SS) is reduced from about 200 ppm to 10 ppm, which can protect the aluminum-based adsorbent packed in the downstream lithium-based adsorption tower 2.

[0033] The lithium-based adsorption tower 2 is also equipped with a post-adsorption solution outlet, a desorption water inlet, and a desorption liquid outlet. The desorption liquid outlet is connected to the feed water inlet of the forward osmosis unit 3. The post-adsorption solution outlet is used to transport the post-adsorption solution to the salt lake. The desorption water inlet is connected to the desorption water supply equipment. The adsorbent filled in the lithium-based adsorption tower 2 is an aluminum-based adsorbent.

[0034] The forward osmosis unit 3 is equipped with a forward osmosis membrane module and a diluted draw solution outlet. The diluted draw solution outlet is used to transport the diluted draw solution to the salt lake.

[0035] The pretreated brine enters lithium adsorption tower 2 for lithium ion adsorption. After adsorption, fresh water is used to desorb the adsorption tower. The desorbed liquid is then used as feed water to enter forward osmosis unit 3. The lithium ion content of the desorbed liquid entering forward osmosis unit 3 will be higher than that of the original brine in the salt lake. Specifically, this can be determined based on the lithium ion content of the salt lake. For example, if the lithium ion content of the original brine in the salt lake is around 50-100 ppm, the lithium ion content in the desorbed liquid can generally reach 200-300 ppm.

[0036] The feed water, consisting of a desorption solution, and the draw solution, consisting of raw brine treated by the pretreatment component 1, are injected into both sides of the forward osmosis membrane module. The feed water, being unsaturated brine, is desorbed from the adsorption tower using fresh water. The raw brine from the salt lake, however, is saturated due to the presence of crystalline salts. The forward osmosis membrane utilizes the osmotic pressure created by the concentration difference between the brine on both sides to concentrate the brine. Fresh water moves from the low-concentration side (feed water) to the high-concentration side (raw brine). This process is at atmospheric pressure, unlike high-pressure reverse osmosis which requires high-pressure pressurization. Furthermore, existing high-pressure reverse osmosis systems typically produce water with a lithium ion content of 3 g / L under these conditions, while the forward osmosis process of this invention achieves a lithium ion content of up to 8 g / L.

[0037] Furthermore, in conventional applications of existing forward osmosis systems, the diluted draw solution requires additional high-pressure reverse osmosis treatment or multi-effect evaporation to achieve freshwater reuse and restore the draw solution saturation. However, in this process system, the diluted draw solution requires no treatment and can be directly discharged back into the salt lake. Since the salt lake contains a large amount of continuously generated crystalline salt, the diluted draw solution can improve the solubility of the crystalline salt in the salt lake, reducing the processing work for solid ore. This further improves the energy efficiency of the forward osmosis device used for lithium extraction from salt lakes in this invention.

[0038] In this embodiment, the permeation membrane in the forward osmosis membrane module uses non-woven fabric as the base membrane, and the base membrane is coated with cellulose acetate and polyamide.

[0039] The functions of nonwoven fabric-based membranes include: providing a porous support structure, enhancing the membrane's mechanical strength, preventing membrane deformation or damage, and extending the service life of the permeable membrane. Additionally, the three-dimensional pore structure of nonwoven fabrics can reduce water flow resistance and increase water flux.

[0040] The role of cellulose acetate: as a base coating, it provides a uniform pore size distribution, further balancing rejection rate and permeability.

[0041] Polyamide is used as the active layer in reverse osmosis / forward osmosis membranes. It has high hydrophilicity and selectivity and can optimize salt rejection.

[0042] Specifically, polyamide can also be replaced by one or more of polysulfone, polyvinylidene fluoride, or polyvinyl alcohol.

[0043] Polysulfone (PSF) or polyethersulfone (PES): As a support layer material, it provides mechanical strength and chemical stability.

[0044] Polyvinylidene fluoride (PVDF): It has strong antifouling properties, is suitable for high-salt environments, and can reduce fouling on the membrane surface.

[0045] Polyvinyl alcohol (PVA) or polydopamine (PDA): enhances the hydrophilicity of the membrane surface and strengthens the driving force for water molecule penetration.

[0046] Therefore, based on actual needs and the properties of the other polymer materials mentioned above, one or more combinations of polymer materials can be used as the coating layer of the base film.

[0047] Furthermore, such as Figure 2 As shown, the forward osmosis unit for lithium extraction from salt lakes also includes: nanofiltration membrane module 4, electro-boron removal unit 5, multi-effect evaporator 6, lithium precipitation unit 7, and condenser 8.

[0048] The forward osmosis unit 3, nanofiltration membrane module unit 4, electro-boron removal unit 5, multi-effect evaporator 6, and lithium precipitation unit 7 are connected in series. This is used to increase the lithium ion content in the concentrated feed water discharged from the forward osmosis unit 3.

[0049] The fresh water outlet of the multi-effect evaporator 6 is connected to the liquid inlet of the condenser 8, and the liquid outlet of the condenser 8 is connected to the desorption water inlet of the lithium adsorption tower 2.

[0050] The forward osmosis unit for lithium extraction from salt lakes also includes: a centrifugal drying unit, a drying kiln, and a pneumatic conveying unit.

[0051] The mother liquor outlet of lithium precipitation unit 7 is connected to the centrifugal drying unit. The centrifugal drying unit, drying kiln, and pneumatic conveying unit are arranged in series.

[0052] Nanofiltration membranes are mainly used to remove divalent ions. Monovalent ions can pass through the nanofiltration membrane to reach the next process. However, the high content of magnesium and calcium ions in the salt lake will be intercepted and cannot enter the next process. The water produced here is high-lithium water 1, with a lithium ion content of about 15g / L.

[0053] The electro-boron removal device mainly treats the high-lithium water 1 produced by the nanofiltration membrane module. The main ions in high-lithium water 1 are lithium ions and boron ions. After electro-boron removal treatment, high-lithium water 2 is produced. At this time, there are basically only single lithium ions and chloride ions, which is close to the state of lithium chloride solution.

[0054] The high-lithium water 2 enters the multi-effect evaporator 6 through the electro-boron removal device, where the lithium ion content can be further increased to about 35 g / L after evaporation. Furthermore, the water vapor produced in the multi-effect evaporator 6, after being condensed by the condenser 8, produces fresh water that can be used as desorption water in the lithium-based adsorption tower 2.

[0055] High-lithium water 3 enters the lithium precipitation unit through the multi-effect evaporation system. Here, excess sodium carbonate needs to be added to react and generate lithium carbonate. Since lithium carbonate is slightly soluble in water, the precipitated lithium carbonate (lithium precipitation mother liquor) is discharged from the bottom of the lithium precipitation unit to the next process.

[0056] The precipitated lithium mother liquor is then dried by centrifugation, then dried in a drying kiln, and finally conveyed by pneumatic conveying to produce lithium carbonate products, which can then be packaged.

[0057] As another possible embodiment of the present invention, such as Figure 3 As shown, a forward osmosis safety monitoring system for lithium extraction from salt lakes is provided, including the aforementioned forward osmosis device, infrared image acquisition device, and processor.

[0058] An infrared image acquisition device is used to acquire temperature images of the permeate membrane surface. The processor is communicatively connected to the infrared image acquisition device. Specifically, in this embodiment, the infrared image acquisition device can be an infrared thermal imager. During the design phase of the forward osmosis unit or through modification, an infrared transparent window (e.g., a window made of germanium or silicon) is installed at a suitable location on the unit. This allows the infrared thermal imager to directly observe the internal permeate membrane area. A standard infrared thermal imager is used to photograph the membrane surface from the outside through the window to obtain a temperature image of the permeate membrane surface. Alternatively, existing equipment suitable for underwater infrared imaging can also be used to acquire temperature images of the permeate membrane surface.

[0059] The processor is used to perform the following steps:

[0060] S100: Perform image preprocessing on the temperature image of the permeate membrane surface to generate a segmented temperature image of the permeate membrane surface.

[0061] S100 includes:

[0062] S101: Using image recognition technology, obtain an image of the area corresponding to the permeate membrane in the temperature image of the permeate membrane surface.

[0063] This step can further determine the target image processing area, thereby reducing the amount of data processing. Furthermore, in this embodiment, if the orientation relationship between the infrared thermal imager and the permeation membrane remains fixed, a fixed range of pixel coordinates can be defined to quickly select the image area corresponding to the permeation membrane from the infrared image.

[0064] S102: Perform image denoising processing on the image corresponding to the permeation membrane region. Image denoising processing includes Gaussian blur denoising. Apply Gaussian blur or other denoising methods to reduce noise in the image.

[0065] S103: Convert the denoised image into a grayscale image to generate the temperature image to be segmented.

[0066] Use an appropriate library to read the infrared image file. Infrared images usually come with temperature data, which also needs to be imported. To retain only temperature information in the image, the infrared image needs to be converted to grayscale, thus containing only information from one channel (i.e., temperature).

[0067] In a forward osmosis system, the temperature of the fouled portion of the membrane is slightly higher than that of the non-scaled portion, mainly due to the following reasons:

[0068] First, scale deposits are typically composed of mineral deposits, organic matter, or microorganisms, which often have lower thermal conductivity than membrane materials. This means that scale increases local thermal resistance. When heat is generated within the system (e.g., frictional heat due to water flux), the heat from the scaled area is more difficult to dissipate, causing the temperature in that area to rise.

[0069] Secondly, scaling can affect the efficiency of water flow through the membrane surface, causing a decrease in local flow velocity. This phenomenon is called concentration polarization, where the solute concentration near the membrane surface is significantly higher than that in the bulk solution. This flow non-uniformity can lead to localized temperature rises.

[0070] Third, scaling increases the mass transfer resistance on the membrane surface, reduces the effective filtration area, and makes water molecules require more energy to pass through the membrane, which may cause local temperature rise.

[0071] Due to the influence of the above factors, the temperature of the scaled part of the permeable membrane will be slightly higher than that of the non-scaled area, usually by 1-2℃. Therefore, this characteristic will also be reflected in the temperature image to be segmented, and the high-temperature area and the non-high-temperature area (i.e., the scaled area and the non-scaled area) can be determined by image segmentation.

[0072] S200: Generate an image segmentation threshold P based on the temperature information corresponding to each pixel in the temperature image to be segmented. P satisfies the following condition:

[0073] P = μ + Kσ. ​​Where μ is the average temperature of all pixels in the temperature image to be segmented. σ is the standard deviation of the temperature of all pixels in the temperature image to be segmented. In this embodiment, σ can also be directly replaced by the temperature difference between the scaled and non-scaled areas, such as any value within the range of 0.8℃ to 1.3℃. K is a preset segmentation coefficient, K = 1.

[0074] In addition, to further improve the accuracy of recognition, the temperature image to be segmented can be divided into different temperature regions, and then P can be calculated for each small region.

[0075] The safety monitoring system also includes an osmotic pressure sensor. The osmotic pressure sensor is used to acquire the osmotic pressure values ​​of the desorption solution and the draw solution on both sides of the permeation membrane, respectively. The osmotic pressure sensor is communicatively connected to the processor.

[0076] The processor is also used to perform the following steps:

[0077] S201: Control the osmotic pressure sensor to acquire the osmotic pressure change sequences of the desorption solution and the absorption solution in each update cycle. The update cycle can be 1 hour or 0.5 hours, and the sensor's acquisition cycle can also be adjusted according to actual needs, such as 30 seconds.

[0078] S202: Based on the osmotic pressure change sequence of the desorption solution and the osmotic pressure change sequence of the draw solution, generate the actual osmotic pressure difference change coefficient ΔR and the mean osmotic pressure R of the desorption solution for the corresponding renewal cycle. tf and the mean osmotic pressure R of the extraction fluid jq ΔR satisfies the following condition: Where t1 and t2 are the first and last data collection times in the update cycle, respectively. R t1 jq and R t2 jq R represents the osmotic pressure values ​​obtained at t1 and t2 in the osmotic pressure change sequence of the extraction fluid. t1 tf and R t2 tf These are the osmotic pressure values ​​obtained at t1 and t2 in the osmotic pressure change sequence of the desorption solution, respectively.

[0079] S203: According to R tf and R jq The standard osmotic pressure difference change coefficient W for the update cycle is obtained from the preset osmotic pressure difference mapping table.

[0080] The preset osmotic pressure difference mapping table includes the rate of change of osmotic pressure difference during the time period corresponding to the renewal cycle, under the condition that there is no scaling on the permeation membrane in the forward osmosis unit 3, for different combinations of desorption liquid osmotic pressure and draw liquid osmotic pressure.

[0081] S204: Based on W and ΔR, generate a segmentation adjustment coefficient K1 to replace K. K1 satisfies the following condition:

[0082] .

[0083] When there is no scaling on the permeable membrane, the rate of change of osmotic pressure difference is mainly determined by the concentration difference of the solution on both sides of the membrane. Driven by the osmotic pressure on both sides, water passes through the membrane smoothly, which can change the osmotic pressure difference between the solutions on both sides at a certain rate.

[0084] When the permeate membrane is fouled, the increased mass transfer resistance, reduced effective filtration area, and decreased water flux result in a slower rate of increase in solute concentration on the feed side and a slower rate of decrease in solute concentration on the draw side. Consequently, the rate of change of osmotic pressure difference (W) when the membrane is free of fouling will be greater than the rate of change of osmotic pressure difference (ΔR) when the membrane is fouled. Therefore, in this step, K is adjusted in real time based on the difference between W and ΔR. Specifically, the smaller ΔR is than W, the smaller K1 will be than the original K, which can lower the image segmentation threshold P, thereby identifying areas in the image with temperatures slightly above the average as high-temperature areas.

[0085] Typically, the size of a scaled area is positively correlated with the temperature rise in that local area. Therefore, the temperature difference between a smaller scaled area and its surrounding unscaled area is smaller. Thus, in this step, by adjusting the K value in real-time in S204, the sensitivity for identifying small scaled areas can be improved, thereby increasing the area of ​​the high-temperature region, i.e., the accuracy of identifying the area of ​​suspected scale.

[0086] S300: Based on P, use image segmentation technology to segment the high-temperature region image from the temperature image to be segmented. The high-temperature region image is the image with a temperature greater than or equal to the image segmentation threshold.

[0087] Image segmentation techniques include fixed thresholding or the Otsu method. Using fixed thresholding, the Otsu method, or other adaptive thresholding techniques, an image is transformed into a binary image (high-temperature region and non-high-temperature region). In image segmentation, the determination of the image segmentation threshold is extremely important for the accuracy of the subsequent segmentation results. In this step, the image segmentation threshold P is determined by μ and σ, which can achieve greater precision. Furthermore, the accuracy of segmentation can be further improved by dynamically adjusting the value of K.

[0088] S400: The scaling coefficient S is generated based on the high-temperature region image and the temperature image to be segmented. S satisfies the following condition:

[0089] S=S G / S Z Among them, S G S represents the number of pixels contained in the image of the high-temperature region. Z The number of pixels contained in the temperature image to be segmented.

[0090] S500: If S>Y, a scaling warning message is generated. Y is the preset scaling threshold, such as Y=0.1.

[0091] The safety monitoring system also includes a flow sensor for acquiring the flow rate of the concentrated desorbent produced by the forward osmosis unit 3. The flow sensor is communicatively connected to the processor.

[0092] The processor is also used to perform the following steps:

[0093] S501: Control the flow sensor to obtain the total flow rate L1 of the concentrated desorbent generated by the forward osmosis unit 3 in the current update cycle.

[0094] S502: Obtain the total flow rate L2 of the standard concentrated desorption solution generated by the forward osmosis unit 3 in the current update cycle.

[0095] Correspondingly, the method for obtaining L2 in S502 can be referenced from that in S203 based on R. tf and R jq The L2 of the update cycle is obtained from the preset desorption fluid flow rate mapping table. The preset desorption fluid flow rate mapping table here includes the total flow rate of the standard concentrated desorption fluid generated by the forward osmotic unit 3 within the time period corresponding to the update cycle, under the condition that there is no scaling on the permeation membrane in the forward osmotic unit 3.

[0096] S503: Based on L1 and L2, generate a scaling adjustment threshold Y1 to replace Y. Y1 satisfies the following condition: .

[0097] In this embodiment, the preset scaling threshold Y is adaptively adjusted by monitoring the flow rate of the concentrated desorbent produced by the forward osmosis unit 3. Typically, membrane scaling reduces water flux, thereby reducing the flow rate of the produced concentrated desorbent. Therefore, in this embodiment, Y can be adjusted in real time based on the difference between L1 and L2. Specifically, the smaller L1 is than L2, the smaller Y1 will be than the original Y, which lowers the scaling warning threshold and allows for earlier warnings. This enables relevant personnel to clean and maintain the permeate membrane more promptly, ensuring the long-term safe operation of the entire system.

[0098] Furthermore, although the steps of the method in this disclosure are described in a specific order in the accompanying drawings, this does not require or imply that the steps must be performed in that specific order, or that all the steps shown must be performed to achieve the desired result. Additional or alternative steps may be omitted, multiple steps may be combined into one step, and / or a step may be broken down into multiple steps.

[0099] From the above description of the embodiments, those skilled in the art will readily understand that the exemplary embodiments described herein can be implemented by software or by combining software with necessary hardware. Therefore, the technical solutions according to the embodiments of this disclosure can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (such as a CD-ROM, USB flash drive, external hard drive, etc.) or on a network, including several instructions to cause a computing device (such as a personal computer, server, mobile terminal, or network device, etc.) to execute the methods according to the embodiments of this disclosure.

[0100] In an exemplary embodiment of this disclosure, an electronic device capable of implementing the above-described method is also provided.

[0101] Those skilled in the art will understand that various aspects of the present invention can be implemented as systems, methods, or program products. Therefore, various aspects of the present invention can be specifically implemented in the following forms: entirely in hardware, entirely in software (including firmware, microcode, etc.), or in a combination of hardware and software, collectively referred to herein as “circuit,” “module,” or “system.”

[0102] An electronic device according to this embodiment of the invention. The electronic device is merely an example and should not be construed as limiting the functionality or scope of the embodiments of the invention.

[0103] Electronic devices are manifested in the form of general-purpose computing devices. Components of an electronic device may include, but are not limited to: at least one processor, at least one memory, and buses connecting different system components (including memory and processor).

[0104] The memory stores program code that can be executed by a processor, causing the processor to perform the steps described in the "Exemplary Methods" section above, according to various exemplary embodiments of the present invention.

[0105] The storage may include readable media in the form of volatile storage, such as random access memory (RAM) and / or cache memory, and may further include read-only memory (ROM).

[0106] The storage may also include programs / utilities having a set (at least one) of program modules, including but not limited to: an operating system, one or more applications, other program modules, and program data, each or some combination of these examples may include an implementation of a network environment.

[0107] A bus can be one or more of several types of bus architectures, including a memory bus or memory controller, a peripheral bus, a graphics acceleration port, a processor, or a local bus that uses any of a variety of bus architectures.

[0108] The electronic device can also communicate with one or more external devices (e.g., keyboards, pointing devices, Bluetooth devices, etc.), one or more devices that enable a user to interact with the electronic device, and / or any device that enables the electronic device to communicate with one or more other computing devices (e.g., routers, modems, etc.). This communication can be performed via input / output (I / O) interfaces. Furthermore, the electronic device can communicate with one or more networks (e.g., local area networks (LANs), wide area networks (WANs), and / or public networks, such as the Internet) via a network adapter. The network adapter communicates with other modules of the electronic device via a bus. It should be understood that, although not shown in the figures, other hardware and / or software modules can be used in conjunction with the electronic device, including but not limited to: microcode, device drivers, redundant processors, external disk drive arrays, RAID systems, tape drives, and data backup storage systems.

[0109] From the above description of the embodiments, those skilled in the art will readily understand that the exemplary embodiments described herein can be implemented by software or by combining software with necessary hardware. Therefore, the technical solutions according to the embodiments of this disclosure can be embodied in the form of a software product, which can be stored in a non-volatile storage medium (such as a CD-ROM, USB flash drive, external hard drive, etc.) or on a network, including several instructions to cause a computing device (such as a personal computer, server, terminal device, or network device, etc.) to execute the methods according to the embodiments of this disclosure.

[0110] In exemplary embodiments of this disclosure, a computer-readable storage medium is also provided, on which a program product capable of implementing the methods described above is stored. In some possible embodiments, various aspects of the present invention may also be implemented as a program product comprising program code that, when the program product is run on a terminal device, causes the terminal device to perform the steps of the various exemplary embodiments of the present invention described in the "Exemplary Methods" section above.

[0111] The program product may employ any combination of one or more readable media. A readable medium may be a readable signal medium or a readable storage medium. A readable storage medium may be, for example, but not limited to, an electrical, magnetic, optical, electromagnetic, infrared, or semiconductor system, apparatus, or device, or any combination thereof. More specific examples of readable storage media (a non-exhaustive list) include: electrical connections having one or more wires, portable disks, hard disks, random access memory (RAM), read-only memory (ROM), erasable programmable read-only memory (EPROM or flash memory), optical fiber, portable compact disk read-only memory (CD-ROM), optical storage devices, magnetic storage devices, or any suitable combination thereof.

[0112] Computer-readable signal media may include data signals propagated in baseband or as part of a carrier wave, carrying readable program code. Such propagated data signals may take various forms, including but not limited to electromagnetic signals, optical signals, or any suitable combination thereof. A readable signal medium may also be any readable medium other than a readable storage medium, capable of sending, propagating, or transmitting programs for use by or in conjunction with an instruction execution system, apparatus, or device.

[0113] The program code contained on the readable medium may be transmitted using any suitable medium, including but not limited to wireless, wired, optical fiber, RF, etc., or any suitable combination thereof.

[0114] Program code for performing the operations of this invention can be written in any combination of one or more programming languages, including object-oriented programming languages ​​such as Java and C++, and conventional procedural programming languages ​​such as C or similar languages. The program code can execute entirely on the user's computing device, partially on the user's device, as a standalone software package, partially on the user's computing device and partially on a remote computing device, or entirely on a remote computing device or server. In cases involving remote computing devices, the remote computing device can be connected to the user's computing device via any type of network, including a local area network (LAN) or a wide area network (WAN), or it can be connected to an external computing device (e.g., via the Internet using an Internet service provider).

[0115] Furthermore, the above figures are merely illustrative of the processes included in the method according to exemplary embodiments of the present invention, and are not intended to be limiting. It is readily understood that the processes shown in the above figures do not indicate or limit the temporal order of these processes. Additionally, it is readily understood that these processes may be executed synchronously or asynchronously, for example, in multiple modules.

[0116] It should be noted that although several modules or units for the device used to perform actions have been mentioned in the detailed description above, this division is not mandatory. In fact, according to embodiments of this disclosure, the features and functions of two or more modules or units described above can be embodied in one module or unit. Conversely, the features and functions of one module or unit described above can be further divided and embodied by multiple modules or units.

[0117] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A forward osmosis safety monitoring system for lithium extraction from salt lakes, characterized in that, It includes a forward osmosis device for lithium extraction from salt lakes, an infrared image acquisition device, and a processor; A forward osmosis system for lithium extraction from salt lakes includes: a pretreatment component, a lithium adsorption tower, and a forward osmosis unit; The pretreatment component is used to reduce the content of suspended solids in the initial salt lake brine; the outlet of the pretreatment component is connected to the brine inlet of the lithium adsorption tower and the draw liquid inlet of the forward osmosis unit, respectively, so as to input the treated secondary salt lake brine into the lithium adsorption tower and the forward osmosis unit. The lithium-based adsorption tower is also equipped with an adsorption solution outlet, a desorption water inlet, and a desorption liquid outlet. The desorption liquid outlet is connected to the feed water inlet of the forward osmosis unit. The adsorption solution outlet is used to transport the adsorption solution to the salt lake. The desorption water inlet is connected to the desorption water supply equipment. The adsorbent filled in the lithium-based adsorption tower is an aluminum-based adsorbent. The forward osmosis unit is equipped with a forward osmosis membrane module, and the forward osmosis unit is also equipped with a diluted draw solution outlet; the diluted draw solution outlet is used to transport the diluted draw solution to the salt lake. The permeation membrane in the forward osmosis membrane module uses non-woven fabric as the base membrane, and the base membrane is coated with cellulose acetate and polyamide. The infrared image acquisition device is used to acquire temperature images of the surface of the permeation membrane; the processor is communicatively connected to the infrared image acquisition device. The processor is used to perform the following steps: The temperature image of the permeate membrane surface is preprocessed to generate a segmented temperature image of the permeate membrane surface. Based on the temperature information corresponding to each pixel in the temperature image to be segmented, an image segmentation threshold P is generated; P satisfies the following condition: P = μ + Kσ; where μ is the average temperature of all pixels in the temperature image to be segmented; σ is the standard deviation of temperature of all pixels in the temperature image to be segmented; and K is the preset segmentation coefficient. Based on P, image segmentation technology is used to segment the high-temperature region image in the temperature image to be segmented; the high-temperature region image is an image with a temperature greater than or equal to the image segmentation threshold. Based on the high-temperature region image and the temperature image to be segmented, a scaling coefficient S is generated; S satisfies the following condition: S=S G / S Z Among them, S G S represents the number of pixels contained in the image of the high-temperature region. Z The number of pixels contained in the temperature image to be segmented; If S>Y, a scaling warning message is generated; Y is the preset scaling threshold.

2. The forward osmosis safety monitoring system for lithium extraction from salt lakes according to claim 1, characterized in that, It also includes an osmotic pressure sensor; the osmotic pressure sensor is used to obtain the osmotic pressure values ​​of the desorption solution and the draw solution on both sides of the permeation membrane, respectively; the osmotic pressure sensor is communicatively connected to the processor; The processor is also configured to perform the following steps: The osmotic pressure sensor is controlled to acquire the osmotic pressure change sequence of the desorption solution and the osmotic pressure change sequence of the draw solution in each update cycle; Based on the osmotic pressure change sequences of the desorption solution and the draw solution, the actual osmotic pressure difference change coefficient ΔR and the mean osmotic pressure R of the desorption solution for the corresponding renewal cycle are generated. tf and the mean osmotic pressure R of the extraction fluid jq ΔR satisfies the following condition: Where t1 and t2 are the first and last data collection times in the update cycle, respectively; R t1 jq and R t2 jq These are the osmotic pressure values ​​obtained at t1 and t2 in the osmotic pressure change sequence of the extractant, respectively; R t1 tf and R t2 tf These are the osmotic pressure values ​​obtained at t1 and t2 in the osmotic pressure change sequence of the desorption solution, respectively. According to R tf and R jq Obtain the standard osmotic pressure difference change coefficient W for the update cycle from the preset osmotic pressure difference mapping table; Based on W and ΔR, a segmentation adjustment coefficient K1 is generated to replace K; K1 satisfies the following condition: 。 3. The forward osmosis safety monitoring system for lithium extraction from salt lakes according to claim 2, characterized in that, It also includes a flow sensor for obtaining the flow rate of the desorbent produced by the forward osmosis unit after concentration; The flow sensor is communicatively connected to the processor; The processor is also configured to perform the following steps: The flow sensor is used to obtain the total flow rate L1 of the concentrated desorbent produced by the forward osmosis unit in the current update cycle. Obtain the total flow rate L2 of the standard concentrated desorbent generated by the forward osmosis unit in the current update cycle from the preset desorbent flow rate mapping table; Based on L1 and L2, a scaling adjustment threshold Y1 is generated to replace Y; Y1 satisfies the following condition: .

4. The forward osmosis safety monitoring system for lithium extraction from salt lakes according to claim 1, characterized in that, Image preprocessing is performed on the temperature image of the permeate membrane surface to generate a segmented temperature image of the permeate membrane surface, including: Image recognition technology is used to obtain images of the corresponding areas of the permeate membrane from the temperature images on the surface of the permeate membrane; Image denoising processing is performed on the image of the corresponding area of ​​the permeation membrane; The denoised image is converted into a grayscale image to generate the temperature image to be segmented.

5. A forward osmosis safety monitoring system for lithium extraction from salt lakes according to claim 4, characterized in that, The image denoising process includes Gaussian blur denoising.

6. A forward osmosis safety monitoring system for lithium extraction from salt lakes according to claim 1, characterized in that, Image segmentation techniques include the fixed threshold method or the Otsu method.

7. A forward osmosis safety monitoring system for lithium extraction from salt lakes according to claim 1, characterized in that, The forward osmosis unit for lithium extraction from salt lakes also includes: nanofiltration membrane module unit, electro-boron removal unit, multi-effect evaporator, lithium precipitation unit and condenser; The forward osmosis unit, nanofiltration membrane unit, electro-boron removal unit, multi-effect evaporator, and lithium precipitation unit are arranged in series to increase the lithium ion content in the concentrated feed water discharged from the forward osmosis unit. The freshwater outlet of the multi-effect evaporator is connected to the liquid inlet of the condenser, and the liquid outlet of the condenser is connected to the desorption water inlet of the lithium adsorption tower.

8. A forward osmosis safety monitoring system for lithium extraction from salt lakes according to claim 7, characterized in that, The forward osmosis unit for lithium extraction from salt lakes also includes: a centrifugal drying unit, a drying kiln, and a pneumatic conveying unit; The mother liquor outlet of the lithium precipitation unit is connected to the centrifugal drying unit; the centrifugal drying unit, the drying kiln, and the pneumatic conveying unit are arranged in series.

9. A forward osmosis safety monitoring system for lithium extraction from salt lakes according to claim 1, characterized in that, The polyamide is replaced by one or more of polysulfone, polyvinylidene fluoride, or polyvinyl alcohol.

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