A method for sampling and pretreating salt lake brine and concentrated brine

Abstract

The application relates to a method for sampling and pretreating salt lake brine and concentrated brine, which is realized based on a sampler and an isolation pipe which can be inserted into a brine pool and comprises the following steps: S1, brine mixing: inserting the sampler into the isolation pipe and setting the distance between the sampler and the bottom of the brine pool, driving the driving mechanism to be in transmission connection with the driven mechanism through the air supply end of the piston piece, driving the driven mechanism to drive the movable pipe to move up and down, and mixing the brine in the isolation pipe; S2, mode changing: disconnecting the driving mechanism from the driven mechanism and realizing the connection between the driving mechanism and the piston piece, and meanwhile, the air supply end of the piston piece is closed; S3, brine extraction: driving the piston piece to move upwards through the driving mechanism, reducing the air pressure in the sampler to form a pressure difference, and extracting the brine to be detected into the sampler. The application realizes the rapid acquisition of a representative sample of the brine solution, prevents the occurrence of sample salt deposition, and improves the work efficiency and the accuracy of the detection result.

Description

Technical Field

[0001] This invention relates to the field of analytical testing technology, specifically to a method for sampling and pretreatment of salt lake brine and concentrated brine, particularly to a sampling method for representative samples of high-salinity brine and crystalline brine, and a pretreatment method for easily crystallizing high-salinity brine samples. Background Technology

[0002] Research and development on lithium extraction from salt lakes began in the 1970s. By the 1990s, foreign companies had made breakthroughs in the technology, leading to the comprehensive utilization of salt lake resources. The production cost of lithium carbonate from salt lakes is much lower than that from ore, which has promoted the development of lithium extraction from salt lakes. In addition, salt lake projects have large individual resource scales, low operating costs, and great potential for technological advancements, and are expected to become an ideal major source of global lithium resources in the future.

[0003] Intercrystalline brine in salt lakes exists in the intercrystalline pores of chemically deposited layers such as halite and mirabilite. It is a highly mineralized salt solution remaining from the long-term development and evolution of the salt lake. The main ions and salt minerals in the brine have reached equilibrium, essentially reaching saturation. When the brine is brought to the surface, due to changes in the surrounding environment, especially at low temperatures, salt crystallization occurs in the sample bottle, sometimes quite severely, resulting in a large amount of salt crystals. For crystallized samples of salt lake brine and concentrated brine, laboratories typically place the sample bottle in an artificially heated environment of 50–60°C to allow the sample crystals to redissolve into the liquid before sampling and testing. However, increasing the sample temperature affects the accuracy of sample transfer to some extent; and concentrated brine is prone to recrystallization at slightly lower temperatures, potentially containing undissolved crystal nuclei; while some concentrated brine crystallized samples are difficult to redissolve or have very long redissolution and crystallization times, and high sample temperatures affect the detection of certain parameters, such as pH and density.

[0004] Therefore, the research objective of this invention is to design a method for sampling and pretreatment of salt lake brine and concentrated brine that effectively prevents crystallization of samples, ensures the stability of the physicochemical properties of the samples, avoids affecting the quality of sample testing, effectively improves the testing efficiency of such samples, and is simple to operate, low in cost, and can quickly obtain representative samples of salt lake brine and concentrated brine. Summary of the Invention

[0005] In view of the technical problems existing in the prior art, the present invention provides a method for sampling and pretreatment of salt lake brine and concentrated brine, which can effectively solve the technical problems existing in the prior art.

[0006] The technical solution of this invention is:

[0007] A method for sampling and pretreatment of salt lake brine and concentrated brine, the sampling and pretreatment method being based on a sampler and an isolation tube that can be inserted into a brine tank. The sampler consists of a fixed tube and a movable tube that are movably connected. A driving mechanism and a piston are movably installed inside the fixed tube, and a driven mechanism is fixedly installed inside the movable tube. The driving mechanism can drive the piston and the movable tube separately. The movable tube is sleeved on the outside of the fixed tube and moves up and down in a directional manner through corresponding grooves and protrusions. A rubber ring is fixedly installed on the inner wall of the end of the movable tube that connects to the fixed tube by adhesive. The rubber ring is pressed between the movable tube and the fixed tube in an interference fit. A flange seat is fixedly installed on the end of the movable tube that is not connected to the fixed tube, and an inlet communicating with the movable tube is provided in the middle of the flange seat. A corresponding one-way valve is detachably installed at the inlet, and a filter layer is fixedly installed on the outside of the one-way valve. The sampling and pretreatment method includes:

[0008] Step S0: Prepare materials: Fill the sampler with a certain amount of pure water, and the amount of brine extracted in step S3 is equal to the amount of pure water in step S0.

[0009] Step S1, brine mixing: The sampler is inserted into the isolation tube and spaced apart from the bottom of the brine tank. The drive mechanism is connected to the driven mechanism through the air supply end of the piston and drives the driven mechanism to move the movable tube up and down to mix the brine in the isolation tube.

[0010] Step S2, mode change: disconnect the drive mechanism from the driven mechanism, and connect the drive mechanism to the piston, while sealing off the air supply end of the piston.

[0011] Step S3, brine extraction: The piston is moved upward by the drive mechanism, which reduces the air pressure in the sampler to create a pressure difference and draw the brine to be tested into the sampler.

[0012] Step S4, sample mixing: The lower end of the driving mechanism disengages from the piston, and the driving mechanism moves up and down to mix equal amounts of pure water and brine.

[0013] Step S5, Mixture Transfer: The drive mechanism is reconnected to the piston and drives the piston to disengage from the fixed tube, pouring the mixture from the end of the fixed tube into a capped sample bottle.

[0014] The piston is installed in the fixed tube with an interference fit, and the air supply end is a through hole located in the middle of the piston.

[0015] The driving mechanism includes a connecting rod that passes through the through hole. The outer end of the connecting rod is fixed with a corresponding handle, and the inner end is fixed with a closing ring that can be used to close the through hole. The connecting rod is provided with a corresponding internal threaded hole at one end of the closing ring.

[0016] The driven mechanism is a connecting seat fixed inside the movable tube. The distance between the connecting seat and the liquid inlet is set. A screw with evenly distributed external threads is provided in the middle of the connecting seat. The screw and the connecting rod are connected by a threaded connection. The driven mechanism and the driving mechanism are adjustablely connected. By rotating the connecting rod, the smaller the connection part between the connecting rod and the screw, the greater the stretching distance between the movable tube and the fixed tube.

[0017] At least one spring is installed on the outside of the fixed tube via a positioning ring. A pressing component with a cross-section in the shape of an "[" is fixedly installed on the outside of the top of the movable tube. When the driving mechanism drives the driven mechanism to move up and down, the maximum stroke of the movable tube is determined and controlled by the extension force of the spring.

[0018] In step S1, when the drive mechanism is connected to the driven mechanism and drives the movable tube to move outward, the outward movement of the movable tube is controlled by judging the extension force of the spring.

[0019] Advantages of this invention:

[0020] 1) This invention overcomes the problems of layering in salt lake brine and concentrated brine solutions, the presence of a large number of crystal particles in the solution, and the difficulty in obtaining representative samples. It also overcomes the problem of easy crystallization in obtaining representative samples, which affects the quality and efficiency of detection and analysis. This invention enables the rapid acquisition of representative samples from salt lake brine and concentrated brine solutions, prevents salt formation in salt lake brine and concentrated brine samples, and improves work efficiency and the accuracy of detection results.

[0021] 2) This invention provides a simple, rapid, and low-cost way to obtain representative samples of easily crystallizing solutions such as salt lake brine and concentrated brine. Utilizing a drive mechanism and a driven mechanism connected by a transmission link, the driven mechanism moves up and down, causing the movable tube to move along the fixed tube. This, in turn, moves the raised edge seat up and down, creating turbulence to mix the brine within the isolation tube. This effectively solves the problems of stratification in salt lake brine and concentrated brine solutions, differences in solution at different locations in the brine pool, and the difficulty and cumbersome operation of obtaining representative samples. Compared to using a simple stirrer to mix the brine, which requires removing the sampler and then replacing it for sampling, and where the stirrer may carry some crystals, affecting sampling accuracy, this invention only requires changing the sampler mode during sampling. This achieves uniformity in mixing and sampling equipment, further effectively avoiding the carry-out of crystals when the equipment is removed, thus preventing impact on sample accuracy.

[0022] The connecting rod and screw are connected by a threaded connection. By rotating the connecting rod in both directions, the screw moves up and down, which in turn moves the movable tube up and down along the fixed tube, thereby stirring the sample and making the brine sample more representative.

[0023] 3) Because the concentration of main ions and salt minerals in salt lake brine and concentrated brine is very high and basically saturated, when salt lake brine and concentrated brine are taken out of the brine pool, the environmental temperature, air pressure and other factors change, which can easily cause severe salt formation. This invention, without replacing the sampler or equipment, disconnects the driven mechanism from the driven mechanism by changing the mode, and connects the drive mechanism to the piston. Simultaneously, it seals the gas supply end of the piston, allowing the drive mechanism to move the piston outward, creating a pressure difference inside and outside the sampler for sampling. This effectively avoids contamination caused by equipment replacement and prevents crystals from detaching from the brine during equipment removal, thus ensuring accurate detection. Furthermore, the sampler is pre-filled with a fixed amount of pure water, and a negative pressure is artificially created during sampling. The sample is immediately mixed with the pure water, ensuring the sample is in an unsaturated state. The ion concentration in the sample remains far below the saturation value, effectively preventing crystallization that can occur during storage and transportation of brine and concentrated brine due to environmental changes after sampling. This effectively solves the salt formation problem in brine and concentrated brine, obtaining accurate and representative samples, avoiding the time wasted on salt re-dissolution and its impact on detection accuracy. It improves the efficiency and accuracy of chemical component detection in brine and concentrated brine, while also better guiding production monitoring.

[0024] 4) Since the extractor can extract samples, it can mix high-concentration samples with pure water to keep them in an unsaturated state and avoid crystallization. However, it is difficult to mix pure water and samples evenly by the extraction force alone. Therefore, this invention further separates the closed ring, which is fixed to the connecting rod at the lower end of the drive mechanism, from the piston body. The closed ring is driven up and down and rotated by rotating the connecting rod, which creates turbulence and agitation in the liquid, allowing the pure water and sample to be fully mixed. Furthermore, the drive mechanism is reconnected to the driven mechanism, and the connecting rod is rotated in both directions, causing the movable tube to move up and down. This pushes the liquid in the movable tube upward, and the liquid in the container will further flow due to pressure changes, thereby breaking the original static equilibrium and forming convection or turbulence, promoting liquid mixing and further improving the practical effect of this invention.

[0025] 5) This invention requires the rotation of a connecting rod with an internal thread and a screw to drive the movable tube up and down, creating turbulence to mix the brine sample. However, the stroke needs to be properly controlled to prevent the screw from disengaging from the connecting rod, thus preventing the movable tube from moving up and down. Therefore, this invention further installs a corresponding spring between the movable tube and the fixed tube. Before the connecting rod and the screw disengage, the spring compression force increases. Before the compression reaches its maximum, the connecting rod needs to be rotated in the opposite direction. Otherwise, the connecting rod will disengage from the screw, and the driving mechanism and the driven mechanism will also disengage from the transmission connection, thus preventing the movable tube from moving up and down. This invention, through the control of the spring's extension and contraction, can easily ensure the specific stroke of the movable tube, avoid excessive rotation of the connecting rod, prevent the driving mechanism and the driven mechanism from disconnecting, and further ensure the practical effect of this invention. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the process of the present invention.

[0027] Figure 2 This is a diagram showing the sampling point layout of the brine tank in this invention.

[0028] Figure 3 This is a schematic diagram of the sampler of the present invention.

[0029] Figure 4 for Figure 3 A cross-sectional diagram.

[0030] Figure 5 for Figure 4 An enlarged schematic diagram of part A in the middle.

[0031] Figure 6 for Figure 4 An enlarged schematic diagram of section B.

[0032] Figure 7 for Figure 4 An enlarged schematic diagram of section C.

[0033] Figure 8 for Figure 3 A diagram illustrating the usage state during material mixing.

[0034] Figure 9 for Figure 3 A schematic diagram showing the usage status during sampling.

[0035] Figure 10 for Figure 9 An enlarged schematic diagram of section D.

[0036] Figure 11 This is a schematic diagram of the sampler in Example 2.

[0037] Figure 12 for Figure 11 A cross-sectional diagram.

[0038] Figure 13 for Figure 11 A diagram illustrating the usage status.

[0039] Figure 14 for Figure 13 An enlarged schematic diagram of section E in the middle.

[0040] In the attached diagram: 1. Isolation tube; 2. Fixed tube; 201. Protrusion; 3. Movable tube; 301. Slide groove; 4. Drive mechanism; 401. Connecting rod; 401. Internal threaded hole; 402. Handle; 403. Closing ring; 404. Reset ring; 5. Piston; 501. Through hole; 6. Driven mechanism; 601. Connecting seat; 602. Screw; 7. Rubber ring; 8. Protruding edge seat; 9. One-way valve; 10. Filter layer; 11. Positioning ring; 12. Spring; 13. Pressing part. Detailed Implementation

[0041] To facilitate understanding by those skilled in the art, the structure of the present invention will now be described in further detail with reference to the accompanying drawings:

[0042] Example 1

[0043] refer to Figure 1-10 A method for sampling and pretreatment of salt lake brine and concentrated brine, wherein the sampling and pretreatment method is based on a sampler and an isolation tube 1 that can be inserted into the brine tank. The sampler consists of a fixed tube 2 and a movable tube 3 that are movably connected. A driving mechanism 4 and a piston 5 are movably arranged inside the fixed tube 2, and a driven mechanism 6 is fixedly arranged inside the movable tube 3. The driving mechanism 4 can drive the piston 5 and the movable tube 3 separately. The sampling and pretreatment method includes:

[0044] Step S1, brine mixing: The sampler is inserted into the isolation tube 1 and spaced apart from the bottom of the brine tank. The drive mechanism 4 is connected to the driven mechanism 6 through the air supply end of the piston 5 and drives the driven mechanism 6 to move the movable tube 3 up and down to mix the brine in the isolation tube 1.

[0045] Step S2, mode change: disconnect the drive mechanism 4 from the driven mechanism 6, and connect the drive mechanism 4 to the piston 5, while sealing the air supply end of the piston 5.

[0046] Step S3, brine extraction: The piston 5 is moved upward by the drive mechanism 4, which reduces the air pressure in the sampler and creates a pressure difference to draw the brine to be tested into the sampler.

[0047] Before step S1, there is a step S0 for material preparation: a certain amount of pure water is filled into the sampler, and the amount of brine extracted in step S3 is equal to the amount of pure water in step S0; after step S3, there is a step S4 for sample mixing, where the lower end of the driving mechanism 4 is disengaged from the piston 5, and the driving mechanism 4 moves up and down to mix equal amounts of pure water and brine.

[0048] After step S4, there is a step S5 for transferring the mixed liquid: the driving mechanism 4 is reconnected to the piston 5 and drives the piston 5 to disengage from the fixed tube 2, so that the mixed liquid is poured from the end of the fixed tube 2 into the capped sample bottle.

[0049] This invention overcomes the problems of stratification and the presence of a large number of crystal particles in salt lake brine and concentrated brine solutions, making it difficult to obtain representative samples. It also overcomes the problem of crystallization in obtaining representative samples affecting the quality and efficiency of detection and analysis. This invention enables the rapid acquisition of representative samples from salt lake brine and concentrated brine solutions, prevents salt formation in salt lake brine and concentrated brine samples, and improves work efficiency and the accuracy of detection results.

[0050] The movable tube 3 is sleeved on the outside of the fixed tube 2 and moves up and down in a directional manner through the cooperation of the corresponding sliding groove 301 and protrusion 201. A rubber ring 7 is fixedly installed on the inner side wall of the end of the movable tube 3 that is connected to the fixed tube 2 by adhesive. The rubber ring 7 is pressed between the movable tube 3 and the fixed tube 2 in an interference fit.

[0051] The end of the movable tube 3 that is not connected to the fixed tube 2 is fixedly installed with a flange seat 8, and the middle part of the flange seat 8 is provided with an inlet that communicates with the movable tube 3. A corresponding one-way valve 9 is detachably installed at the inlet, and a filter layer 10 is fixedly provided on the outside of the one-way valve 9.

[0052] The piston 5 is installed in the fixed tube 2 in an interference fit, and the air supply end is a through hole 501 located in the middle of the piston 5.

[0053] The drive mechanism 4 includes a connecting rod 401 that passes through the through hole 501. The outer end of the connecting rod 401 is fixed with a corresponding handle 402, and the inner end is fixed with a closing ring 403 that can be used to close the through hole 501. The connecting rod 401 is provided with a corresponding internal thread hole 4011 at one end of the closing ring 403.

[0054] A corresponding reset ring 404 is also fixedly connected to the connecting rod 401 between the closing ring 403 and the handle 402. When installing the drive mechanism 4, as the connecting rod 401 and the screw 602 are screwed downwards, the reset ring 404 is driven downwards. At the same time, the reset ring 404 pushes the piston 5 into the fixed position inside the fixed tube 2. This allows for quick installation of the piston 5 and improves ease of use.

[0055] The driven mechanism 6 is a connecting seat 601 fixed inside the movable tube 3. The connecting seat 601 is spaced apart from the liquid inlet. A screw 602 with evenly distributed external threads is provided in the middle of the connecting seat 601. The screw 602 and the connecting rod 401 are connected by a threaded connection. The driven mechanism 6 and the driving mechanism 4 are adjustablely connected. By rotating the connecting rod 401, the smaller the connection part between the connecting rod 401 and the screw 602, the greater the stretching distance between the movable tube 3 and the fixed tube 2.

[0056] This invention provides a simple, rapid, and low-cost method for obtaining representative samples of easily crystallizing solutions such as salt lake brine and concentrated brine. An isolation tube 1 separates the sampling area from the brine tank, allowing for stirring of the brine within the isolation tube 1 without interfering with other sampling. A drive mechanism 4 and a driven mechanism 6 work together to drive the moving tube 3 up and down along the fixed tube 2, which in turn moves the convex seat up and down, creating turbulence to mix the brine within the isolation tube 1. This effectively solves the problems of stratification in salt lake brine and concentrated brine solutions, differences in solution at different locations in the brine tank, and the difficulty and cumbersome operation of obtaining representative samples. Compared to using a simple stirrer to mix the brine, which requires removing the sampler and then replacing it for sampling, and where the stirrer may carry some crystals, affecting sampling accuracy, this invention only requires changing the sampler mode during sampling. This achieves uniformity between mixing and sampling equipment, further effectively avoiding the carry-out of crystals when the equipment is removed, thus preventing impact on sample accuracy.

[0057] The connecting rod 401 and the screw 602 are connected by a threaded connection. By rotating the connecting rod 401 in both directions, the screw 602 moves up and down, which in turn drives the movable tube 3 to move up and down along the fixed tube 2, thereby stirring the sample and making the brine sample more representative.

[0058] Because the concentration of main ions and salt minerals in salt lake brine and concentrated brine is very high and basically saturated, when the salt lake brine and concentrated brine are taken out of the brine pool, the environmental temperature and air pressure change, which can easily cause severe salt formation. This invention, without replacing the sampler or equipment, disconnects the drive mechanism 4 and driven mechanism 6 by changing the mode, and connects the drive mechanism 4 to the piston 5. Simultaneously, it seals the gas supply end of the piston 5, allowing the drive mechanism 4 to move the piston 5 outward, creating a pressure difference inside and outside the sampler for sampling. This effectively avoids contamination caused by equipment replacement and prevents crystals from detaching from the brine when the equipment is removed, thus ensuring accurate detection. Furthermore, a fixed amount of pure water is pre-filled in the sampler, and a negative pressure is artificially created during sampling. The sample is immediately mixed with the pure water, ensuring the sample is in an unsaturated state. The ion concentration in the sample remains far below the saturation value, effectively preventing crystallization that can occur during sample storage and transportation due to environmental changes after sampling of salt lake brine and concentrated brine. This effectively solves the salt formation problem in salt lake brine and concentrated brine, obtaining accurate and representative samples, avoiding the time wasted on salt re-dissolution and its impact on detection accuracy. It improves the efficiency and accuracy of detecting various chemical components in salt lake brine and concentrated brine, while also better guiding production monitoring.

[0059] Since the extractor can extract samples, it mixes high-concentration samples with pure water to keep them in an unsaturated state and avoid crystallization. However, it is difficult to mix pure water and samples evenly by the extraction force alone. Therefore, this invention further separates the lower end of the drive mechanism 4, i.e., the closed ring 403 fixed to the connecting rod 401, from the piston body. By driving up and down and rotating the connecting rod 401, the closed ring 403 is moved up and down and rotated, creating turbulence and stirring of the liquid, so that the pure water and sample are fully mixed. Furthermore, the drive mechanism 4 is reconnected to the driven mechanism 6, and the connecting rod 401 is rotated in both directions, causing the movable tube 3 to move up and down, thereby pushing the liquid in the movable tube 3 upward. The liquid in the container will further flow due to pressure changes, thereby breaking the original static equilibrium and forming convection or turbulence, promoting liquid mixing, and further improving the practical effect of this invention.

[0060] Before sampling, sampling points need to be arranged. Multiple points of consistent depth within the brine pool should be selected as fixed sampling points, based on the average depth of the pool. Since sampling from the middle of the pool is inconvenient due to its large size, this step is omitted. See below for specific sampling point layout. Figure 2 .

[0061] Before sampling, all sampling equipment was cleaned three times with pure water and air-dried. The solution in the sampler during sampling is the sample for that sampling point, diluted by half. Samples from different sampling points were transferred to a large, dry container and stirred thoroughly to obtain the comprehensive brine sample, also diluted by half. The samples were then placed in sealed sample bottles with labels, and two copies were prepared: a primary sample and a secondary sample. The necessary information, including the sampling date, sampler, sample number, and analytical items, was noted and submitted for testing.

[0062] Application examples and method verification of this invention are as follows:

[0063] 1. Verification of sample representativeness and accuracy

[0064] Salt lake brine pools and concentrated brine pools have poor water flow and are open. The brine solution in different locations within the same brine pool varies. There are obvious temperature differences between the upper, middle, and lower layers at the same location, and there are also obvious gradients in ion concentration at the upper, middle, and lower layers at the same location (except for some metal ions that have reached saturation).

[0065] To verify the representativeness of the sampling in this invention, appropriate ions need to be selected to evaluate the sample solution. This invention uses brine samples from the lithium extraction and evaporation process at the 3Q Salt Lake in Argentina for verification; therefore, the 3Q brine sample is used for illustration. Natural brine is extracted from underground and concentrated through evaporation. At different stages of evaporation, different salts crystallize out sequentially due to their varying solubility: halite (sodium chloride), potassium halite (potassium chloride), carnallite (a mixture of potassium chloride and magnesium chloride), and antarcticite (calcium chloride), etc. Therefore, sodium, potassium, calcium, and magnesium ions cannot be used to evaluate the representativeness of the sample. Lithium chloride has high solubility, and no lithium chloride crystals precipitate during the evaporation stage; therefore, lithium ions are chosen to track and evaluate the brine sample.

[0066] Samples of brine from different stages of sun-drying were selected, based on... Figure 2 Sampling points were sampled using different sampling methods to verify the representativeness and accuracy of the sampling method used in this invention. To ensure the authenticity and validity of the data, five different sampling methods were used simultaneously. To avoid interference between different sampling methods, isolation tubes were used to isolate the solution (five sampling isolation tubes were simultaneously inserted into the sampling points), and then samples were taken simultaneously according to the different sampling methods. The average depth of the brine pool was 90 cm. Except for the method of this invention, all other different sampling methods used a "filter sampler," which was made by installing a one-way valve at the head of the sampler, with the same filter layer fixed to the outside of the one-way valve.

[0067] Comparative Example 1: Ignoring ion concentration gradients, random sampling was performed inside the water pipe.

[0068] Comparative Example 2: Two samples of the same volume were taken from the same sampling tube at a depth of 30 cm and 60 cm below the liquid surface, respectively.

[0069] Comparative Example 3: Three samples of the same volume were taken from the same sampling tube at depths of 25 cm, 45 cm, and 70 cm below the liquid surface.

[0070] Comparative Example 4: Five samples of the same volume were taken from the same sampling tube at depths of 15cm, 30cm, 45cm, 60cm and 75cm below the liquid surface.

[0071] When taking multiple samples at different depths from the same sampling point, the movements should be as gentle as possible to avoid affecting the accurate acquisition of samples at different depths. Multiple "filter samplers" can also be used for simultaneous sampling. Samples from different sampling points should be quickly mixed and bottled in a large container to prepare a composite sample. Samples obtained using methods other than this one need to be placed in an artificially heated environment of 50–60°C along with the sample bottle to allow the sample crystals to dissolve back into the liquid. The crystal dissolution time is approximately 1.0–2.0 hours.

[0072] Table 1 Comparison of comprehensive water sample test data from different sampling methods

[0073]

[0074] Due to the stratification of salt lake brine and concentrated brine, differences in sampling points within the same brine pool, and the tendency of the extracted samples to crystallize, Comparative Example 4, compared to other sampling methods besides the method of this invention, theoretically produces the most representative sample reflecting the true condition of the brine pool. The test data in Table 1 shows that Comparative Example 4 exhibits the best precision in lithium ion concentration compared to other sampling methods besides the method of this invention, further illustrating this point. The test data in Table 1 also shows a good comparison between the test results of the samples obtained in Example 1 and Comparative Example 4 using the method of this invention, indicating that the samples obtained using the method of this invention have good representativeness and accuracy.

[0075] 2.2 Precision Validation

[0076] Since multiple samples at different depths may be required at the same location, it is impractical to simultaneously verify the precision of the sampling method using many sets of samples (as the stratification of the brine solution in the brine tank would be disrupted). Therefore, only two sets of samples were verified for precision. Other sampling methods may be limited by the need for stratified sampling, making precision testing of multiple sets of samples difficult or impossible (as the stratification of the brine solution in the brine tank is easily disrupted). The method of this invention is simple to operate for verifying the precision of the sampling method; sampling only requires taking several sets of samples simultaneously. Specific precision test data are shown in the table below:

[0077] Table 2 Precision Test

[0078]

[0079] Since the sample was diluted by half during sampling in this invention, the data after testing needs to be calculated by 2 times. As can be seen from the test data in Table 2, the relative standard deviation (RSD) of the brine samples taken from brine tanks AP-CC31 and AP-CC23 is less than 1.00%, indicating that the test precision of the samples taken using the method of this invention is good.

[0080] If it is necessary to test parameters such as density and pH value of salt lake brine and concentrated brine, these parameters can be obtained through calculation. Taking density as an example, the sample is a 1:1 mixture of brine and pure water. Ignore the volume change during the mixing process (which is very small). The volume, density, and mass of pure water can be obtained by referring to tables or by calculation. The density of undiluted brine can be easily obtained through calculation.

[0081] Example 2

[0082] refer to Figure 11-14 The difference between this embodiment and embodiment one is that: at least one spring 12 is installed on the outside of the fixed tube 2 through the positioning ring 11, and a pressing part 13 with a cross section in the shape of "[" is fixedly installed on the outside of the top of the movable tube 3. When the driving mechanism 4 drives the driven mechanism 6 to move up and down, the maximum stroke of the movable tube 3 is determined and controlled by the extension force of the spring 12.

[0083] In step S1, when the drive mechanism 4 is connected to the driven mechanism 6 and drives the movable tube 3 to move outward, the outward movement of the movable tube 3 is controlled by judging the extension force of the spring 12.

[0084] This invention requires the rotation of the threaded connecting rod 401 and the screw 602 to drive the movable tube 3 to move up and down, creating turbulence to mix the brine sample. However, the stroke needs to be properly controlled to prevent the screw 602 from disengaging from the connecting rod 401, thus preventing the movable tube 3 from moving up and down. Therefore, this invention further installs a corresponding spring 12 between the movable tube 3 and the fixed tube 2. Before the connecting rod 401 and the screw 602 disengage, the spring 12 increases its compression force. Before the compression reaches its maximum, the connecting rod 401 needs to be rotated in the opposite direction. Otherwise, the connecting rod 401 will disengage from the screw 602, and the driving mechanism 4 and the driven mechanism 6 will also disengage from the transmission connection, thus preventing the movable tube 3 from moving up and down. This invention, through the control of the extension and retraction of the spring 12, can easily ensure the specific stroke of the movable tube 3, avoid excessive rotation of the connecting rod 401, prevent the driving mechanism 4 and the driven mechanism 6 from disengaging, and further ensure the practical effect of this invention.

[0085] It should be noted that this embodiment is implemented in the same way as the first embodiment in terms of principle and technical effect. For the sake of brevity, any parts not mentioned in this embodiment can be referred to the corresponding content in the first embodiment.

[0086] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for sampling and pretreatment of salt lake brine and concentrated brine, wherein the sampling and pretreatment method is based on a sampler and an isolation tube (1) that can be inserted into a brine tank. The sampler consists of a fixed tube (2) and a movable tube (3) that are movably connected. A driving mechanism (4) and a piston (5) are movably arranged inside the fixed tube (2), and a driven mechanism (6) is fixedly arranged inside the movable tube (3). The driving mechanism (4) can drive the piston (5) and the movable tube (3) separately. The movable tube (3) is sleeved on the outside of the fixed tube (2) and is connected by a corresponding sliding groove (301). The movable tube (3) and the protrusion (201) move up and down in a directional manner. A rubber ring (7) is fixedly installed on the inner side wall of the end connected to the fixed tube (2) by adhesive. The rubber ring (7) is pressed between the movable tube (3) and the fixed tube (2) in an interference fit. A flange seat (8) is fixedly installed on the end of the movable tube (3) that is not connected to the fixed tube (2). An inlet port communicating with the movable tube (3) is provided in the middle of the flange seat (8). A corresponding one-way valve (9) is detachably installed at the inlet port. A filter layer (10) is fixedly provided on the outside of the one-way valve (9). The feature is that... The sampling and sample pretreatment methods include: Step S0, material preparation: A certain amount of pure water is filled into the sampler, and the amount of brine extracted in step S3 is equal to the amount of pure water in step S0. Step S1, brine mixing: Insert the sampler into the isolation tube (1) and set it at a distance from the bottom of the brine tank. The drive mechanism (4) is connected to the driven mechanism (6) through the air supply end of the piston (5) and drives the driven mechanism (6) to move the movable tube (3) up and down to mix the brine in the isolation tube (1). Step S2, mode change: disconnect the drive mechanism (4) from the driven mechanism (6), and connect the drive mechanism (4) to the piston (5), while sealing the air supply end of the piston (5); Step S3, brine extraction: The piston (5) is dragged upward by the drive mechanism (4) to reduce the air pressure in the sampler and form a pressure difference to extract the brine to be tested into the sampler. Step S4, sample mixing: The lower end of the driving mechanism (4) disengages from the piston (5), and the driving mechanism (4) moves up and down to mix equal amounts of pure water and brine. Step S5, Mixture Transfer: The drive mechanism (4) is reconnected to the piston (5) and drives the piston (5) to disengage from the fixed tube (2), pouring the mixture from the end of the fixed tube (2) into the capped sample bottle.

2. The method for sampling and pretreatment of salt lake brine and concentrated brine according to claim 1, characterized in that, The piston (5) is installed in the fixed tube (2) in an interference fit, and the gas supply end is a through hole (501) located in the middle of the piston (5).

3. The method for sampling and pretreatment of salt lake brine and concentrated brine according to claim 2, characterized in that, The drive mechanism (4) includes a connecting rod (401) that passes through the through hole (501). The outer end of the connecting rod (401) is fixed with a corresponding handle (402), and the inner end is fixed with a closing ring (403) that can be used to close the through hole (501). The connecting rod (401) is provided with a corresponding internal thread hole (4011) at one end of the closing ring (403).

4. The method for sampling and pretreatment of salt lake brine and concentrated brine according to claim 3, characterized in that, The driven mechanism (6) is a connecting seat (601) fixed inside the movable tube (3). The distance between the connecting seat (601) and the liquid inlet is set. A screw (602) with evenly distributed external threads is provided in the middle of the connecting seat (601). The screw (602) and the connecting rod (401) are connected by a threaded connection. The driven mechanism (6) and the driving mechanism (4) are adjustablely connected. By rotating the connecting rod (401), the smaller the connection part between the connecting rod (401) and the screw (602), the greater the stretching distance between the movable tube (3) and the fixed tube (2).

5. The method for sampling and pretreatment of salt lake brine and concentrated brine according to claim 1, characterized in that, At least one spring (12) is installed on the outside of the fixed tube (2) through the positioning ring (11). A pressing part (13) with a cross section in the shape of "[" is fixedly installed on the top outside of the movable tube (3). When the driving mechanism (4) drives the driven mechanism (6) to move up and down, the maximum stroke of the movable tube (3) is determined by the extension force of the spring (12).

6. The method for sampling and pretreatment of salt lake brine and concentrated brine according to claim 5, characterized in that, In step S1, when the drive mechanism (4) is connected to the driven mechanism (6) and drives the movable tube (3) to move outward, the outward movement of the movable tube (3) is controlled by judging the extension force of the spring (12).

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