Low-cost high-salt mine well water treatment method and system

Abstract

The invention relates to the technical field of water treatment, in particular to a low-cost high-salt mine water treatment method and system. Comprising an adjusting pre-sedimentation tank, an induced crystallization device, a first-stage suspended matter pretreatment device, a first high-pressure pump, a first-stage energy recovery device, a first-stage membrane concentration device, a second-stage suspended matter pretreatment device, a second high-pressure pump, a second-stage energy recovery device, a second-stage membrane concentration device, a third-stage suspended matter pretreatment device and a third high-pressure pump, a third-stage energy recovery device and a third-stage membrane concentration device; the induced crystallization device is communicated with the adjusting pre-sedimentation tank and the first-stage suspension pretreatment device, the first high-pressure pump is arranged between the first-stage suspension pretreatment device and the first-stage membrane concentration device, and the first-stage energy recovery device is connected with the first-stage membrane concentration device. And heavy burden is brought to coal mine enterprises.

Description

Technical Field

[0001] The present invention relates to the technical field of water treatment, and in particular to a low-cost high-salt mine water treatment method and system. Background Art

[0002] At present, mine water is an important associated resource in the process of coal mining. Its water volume is large and its water quality is complex. Its treatment and utilization have always been widely concerned by the mining and environmental protection fields. In the process of coal mining, mine water will carry a large amount of dissolved solids, suspended matter and harmful substances. Among them, most mine water TDS content exceeds 1000mg / L, and it needs to be desalted to meet the requirements of reuse or discharge. The treatment cost of high-salt mine water is high, generally 8-20 yuan / m 3 The cost of high-salinity mine water treatment is mainly the cost of hardness removal agent, electricity and chemical sludge disposal, which account for about 80% of the total cost of high-salinity mine water. Reducing the cost of high-salinity mine water treatment mainly starts from reducing hardness removal costs and energy consumption.

[0003] In summary, in the prior art, the cost of mine water treatment is extremely high, which brings a heavy burden to coal mining enterprises. Summary of the invention

[0004] The purpose of the present invention is to provide a low-cost high-salt mine water treatment method and system, aiming to solve the technical problem in the prior art that the cost of mine water treatment is extremely high, resulting in a heavy burden on coal mining enterprises.

[0005] To achieve the above-mentioned purpose, the present invention adopts a low-cost high-salt mine water treatment system, which includes a regulating pre-sedimentation tank, an induced crystallization device, a primary suspended matter pretreatment device, a first high-pressure pump, a primary energy recovery device, a primary membrane concentration device, a secondary suspended matter pretreatment device, a second high-pressure pump, a secondary energy recovery device, a secondary membrane concentration device, a tertiary suspended matter pretreatment device, a third high-pressure pump, a tertiary energy recovery device and a tertiary membrane concentration device;

[0006] The induced crystallization devices are connected to the regulating pre-sedimentation tank and the first-level suspended pretreatment device, the first high-pressure pump is arranged between the first-level suspended matter pretreatment device and the first-level membrane concentrating device, the first-level energy recovery device is connected to the first-level membrane concentrating device, the second-level suspended matter pretreatment device is connected to the first-level energy recovery device, the second high-pressure pump is arranged between the second-level suspended matter pretreatment device and the second-level membrane concentrating device, the second-level energy recovery device is connected to the second-level membrane concentrating device, the third-level suspended matter pretreatment device is connected to the second-level energy recovery device, the third high-pressure pump is arranged between the third-level suspended matter pretreatment device and the third-level membrane concentrating device, and the third-level energy recovery device is connected to the third-level membrane concentrating device.

[0007] Among them, the low-cost high-salt mine water treatment system also includes a solid-liquid separator, which is used to separate the solid matter in the induced crystallization device.

[0008] Wherein, the first-stage energy recovery device, the second-stage energy recovery device and the third-stage energy recovery device all include a water inlet assembly, a fourth high-pressure pump, a control module, a boost flow meter, a boost regulating valve, an energy recovery device, a concentrated water flow meter and a concentrated water regulating valve;

[0009] The plurality of water inlet components are respectively connected to the first high-pressure pump, the second high-pressure pump and the third high-pressure pump, the fourth high-pressure pump and the energy recovery device are both connected to the corresponding water inlet components, the plurality of fourth high-pressure pumps are also respectively connected to the first-stage membrane concentrating device, the second-stage membrane concentrating device and the third-stage membrane concentrating device, the plurality of energy recovery devices are also respectively connected to the first-stage membrane concentrating device, the second-stage membrane concentrating device and the third-stage membrane concentrating device, the boost regulating valve is connected to the corresponding energy recovery device, the boost flowmeter is connected to the corresponding boost regulating valve, the plurality of boost flowmeters are respectively connected to the first-stage membrane concentrating device, the second-stage membrane concentrating device and the third-stage membrane concentrating device, the concentrated water flowmeter is connected to the corresponding energy recovery device, the concentrated water regulating valve is connected to the corresponding concentrated water flowmeter, and the concentrated water regulating valves in the first-stage energy recovery device and the second-stage energy recovery device are respectively connected to the second-stage suspended matter pretreatment device and the third-stage suspended matter pretreatment device.

[0010] Wherein, the water inlet component includes a booster pump and a water inlet flow meter, a plurality of the booster pumps are respectively connected to the first high-pressure pump, the second high-pressure pump and the third high-pressure pump, and the water inlet flow meter is connected to the corresponding booster pump.

[0011] Wherein, the water inlet component also includes a water quality monitoring instrument, and the water quality monitoring instrument is used to monitor the water quality.

[0012] The present invention also provides a low-cost high-salt mine water treatment method, which is applied to the low-cost high-salt mine water treatment system as described above.

[0013] The steps include:

[0014] The high-salt mine water is introduced into the regulating pre-sedimentation tank for preliminary precipitation to remove large particle impurities, and then enters the induced crystallization device to remove part of the calcium ions in the water and retain part of the magnesium ions;

[0015] The water after the crystallization treatment enters the first-stage suspension pretreatment device to remove suspended solids in the water, and then is pressurized by the first high-pressure pump and enters the first-stage membrane concentration device, where the water is concentrated using membrane separation technology to increase the salt concentration in the water, while the fresh water generated during the concentration process is discharged;

[0016] The energy generated by the primary membrane concentration device during operation is recovered by the primary energy recovery device, and the water after the recovery process enters the secondary suspended matter pretreatment device to further remove suspended matter in the water;

[0017] The water treated by the secondary suspended matter pretreatment device enters the secondary membrane concentration device after being pressurized by the second high-pressure pump, and the water is concentrated again to further increase the salt concentration in the water and recover more fresh water;

[0018] The energy generated during the operation of the secondary membrane concentration device is recovered by the secondary energy recovery device, and the water after the recovery process enters the tertiary suspended matter pretreatment device to further remove suspended matter in the water;

[0019] The water treated by the three-stage suspended matter pretreatment device enters the three-stage membrane concentration device after being pressurized by the third high-pressure pump for final concentration treatment;

[0020] The energy generated during the operation of the three-stage membrane concentration device is recovered by the three-stage energy recovery device, and the water after the recovery process is evaporated and crystallized.

[0021] The present invention discloses a low-cost high-salt mine water treatment method and system. The present invention uses an induction fine crystal nucleus small particle of about 0.05-0.1mm to allow calcium ions in the water to form calcium carbonate adsorbed on the induction particle ions to crystallize into small particles (about 1-2mm) at pH 9.5-10.5. Magnesium ions rarely participate in the reaction, thereby removing most of the calcium ions in the water and retaining most of the magnesium ions in the water. The first-level membrane concentration device then uses a double alkali method to adjust the pH value to above 11-11.5 to generate CaCO3 and Mg(OH)2 from calcium and magnesium in the water. At the same time, the magnesium remaining in the water reacts with silicon, and there is no need to specifically add magnesium agent or sodium aluminate for silicon removal.

[0022] The small particles formed by induced crystallization have high density and do not require a special sludge dewatering system. After simple solid-liquid separation by the solid-liquid separator, the solid content can reach more than 90%, and its water content is much lower than that of ordinary chemical sludge after plate and frame dehydration. The formed particles have a certain strength and can be used as building materials such as sand and gravel.

[0023] The present invention breaks the traditional system design of energy recovery only for desalinated seawater or water close to seawater quality. The three-stage membrane concentration of high-salinity mine water adopts energy recovery design from low-pressure reverse osmosis to high-pressure reverse osmosis. In order to cope with the changing characteristics of mine water quality and quantity, on the basis of traditional seawater desalination energy recovery technology, a water quality and flow linkage control system is added to ensure the stability of the system.

[0024] This method solves the technical problem in the prior art that the cost of mine water treatment is extremely high, which causes a heavy burden on coal mining enterprises. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 It is a principle block diagram of the low-cost high-salt mine water treatment system of the present invention.

[0027] Figure 2 It is a principle block diagram of the connection between the primary energy recovery device of the present invention and the secondary suspended matter pretreatment device.

[0028] Figure 3 It is a schematic diagram of the step-by-step hardness removal by induced crystallization of the present invention.

[0029] 1-regulating pre-sedimentation tank, 2-induced crystallization device, 3-primary suspended solids pretreatment device, 4-first high-pressure pump, 5-primary energy recovery device, 6-primary membrane concentration device, 7-secondary suspended solids pretreatment device, 8-second high-pressure pump, 9-secondary energy recovery device, 10-secondary membrane concentration device, 11-tertiary suspended solids pretreatment device, 12-third high-pressure pump, 13-tertiary energy recovery device, 14-tertiary membrane concentration device, 15-solid-liquid separator; 201-fourth high-pressure pump, 202-control module, 203-boosting flowmeter, 204-boosting regulating valve, 205-energy recovery equipment, 206-concentrated water flowmeter, 207-concentrated water regulating valve, 208-boosting pump, 209-water inlet flowmeter, 210-water quality monitoring instrument, 301-calcium carbonate induced crystal nucleus, 302-calcium carbonate microparticles, 303-calcium carbonate particles. DETAILED DESCRIPTION

[0030] Embodiments of the present invention are described in detail below. Examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, but should not be construed as limiting the present invention.

[0031] See also Figure 1 to Figure 3 ,in Figure 1 It is a principle block diagram of the low-cost high-salt mine water treatment system of the present invention. Figure 2 It is a principle block diagram of the connection between the primary energy recovery device of the present invention and the secondary suspended matter pretreatment device. Figure 3 It is a schematic diagram of the step-by-step hardness removal by induced crystallization of the present invention.

[0032] The present invention provides a low-cost high-salt mine water treatment system, comprising a regulating pre-sedimentation tank 1, an induced crystallization device 2, a primary suspended matter pretreatment device 3, a first high-pressure pump 4, a primary energy recovery device 5, a primary membrane concentration device 6, a secondary suspended matter pretreatment device 7, a second high-pressure pump 8, a secondary energy recovery device 9, a secondary membrane concentration device 10, a tertiary suspended matter pretreatment device 11, a third high-pressure pump 12, a tertiary energy recovery device 13 and a tertiary membrane concentration device 14;

[0033] The induced crystallization device 2 is connected to the regulating pre-sedimentation tank 1 and the first-level suspended pretreatment device, the first high-pressure pump 4 is arranged between the first-level suspended matter pretreatment device 3 and the first-level membrane concentrating device 6, the first-level energy recovery device 5 is connected to the first-level membrane concentrating device 6, the second-level suspended matter pretreatment device 7 is connected to the first-level energy recovery device 5, the second high-pressure pump 8 is arranged between the second-level suspended matter pretreatment device 7 and the second-level membrane concentrating device 10, the second-level energy recovery device 9 is connected to the second-level membrane concentrating device 10, the third-level suspended matter pretreatment device 11 is connected to the second-level energy recovery device 9, the third high-pressure pump 12 is arranged between the third-level suspended matter pretreatment device 11 and the third-level membrane concentrating device 14, and the third-level energy recovery device 13 is connected to the third-level membrane concentrating device 14.

[0034] The low-cost high-salt mine water treatment system further includes a solid-liquid separator 15 , which is used to separate the solid matter in the induced crystallization device 2 .

[0035] With respect to this specific embodiment, when it is used specifically, the present invention uses an induction fine crystal nucleus small particle of about 0.05-0.1mm, and at pH 9.5-10.5, calcium ions in the water are formed into calcium carbonate adsorbed on the induction particle ions and crystallized to form small particles (about 1-2mm), and magnesium ions rarely participate in the reaction, thereby removing most of the calcium ions in the water and retaining most of the magnesium ions in the water. The first-level membrane concentration device 6 then uses a double alkali method to adjust the pH value to above 11-11.5 to generate CaCO3 and Mg(OH)2 from calcium and magnesium in the water, and at the same time, the magnesium remaining in the water reacts with silicon, and there is no need to specifically add magnesium agent or sodium aluminate for silicon removal.

[0036] The small particles formed by induced crystallization have high density and do not require a special sludge dewatering system. After simple solid-liquid separation by the solid-liquid separator 15, the solid content can reach more than 90%, and its water content is much lower than that after ordinary chemical sludge plate and frame dehydration. The formed particles have a certain strength and can be used as building materials such as sand and gravel.

[0037] The primary energy recovery device 5, the secondary energy recovery device 9 and the tertiary energy recovery device 13 all include a water inlet assembly, a fourth high-pressure pump 201, a control module 202, a boost flow meter 203, a boost regulating valve 204, an energy recovery device 205, a concentrated water flow meter 206 and a concentrated water regulating valve 207;

[0038] The plurality of water inlet components are respectively connected to the first high-pressure pump 4, the second high-pressure pump 8 and the third high-pressure pump 12, the fourth high-pressure pump 201 and the energy recovery device 205 are both connected to the corresponding water inlet components, the plurality of fourth high-pressure pumps 201 are also respectively connected to the primary membrane concentrating device 6, the secondary membrane concentrating device 10 and the tertiary membrane concentrating device 14, the plurality of energy recovery devices 205 are also respectively connected to the primary membrane concentrating device 6, the secondary membrane concentrating device 10 and the tertiary membrane concentrating device 14, the boost regulating valve 204 is connected to the corresponding energy recovery device 2 05 is connected, the boost flowmeter 203 is connected to the corresponding boost regulating valve 204, a plurality of the boost flowmeters 203 are respectively connected to the primary membrane concentrating device 6, the secondary membrane concentrating device 10 and the tertiary membrane concentrating device 14, the concentrated water flowmeter 206 is connected to the corresponding energy recovery device 205, the concentrated water regulating valve 207 is connected to the corresponding concentrated water flowmeter 206, and the concentrated water regulating valve 207 in the primary energy recovery device 5 and the secondary energy recovery device 9 are respectively connected to the secondary suspended matter pretreatment device 7 and the tertiary suspended matter pretreatment device 11.

[0039] The water inlet assembly includes a booster pump 208 and a water inlet flow meter 209 . The multiple booster pumps 208 are respectively connected to the first high-pressure pump 4 , the second high-pressure pump 8 and the third high-pressure pump 12 . The water inlet flow meter 209 is connected to the corresponding booster pump 208 .

[0040] The water inlet assembly further includes a water quality monitoring instrument 210, and the water quality monitoring instrument 210 is used to monitor water quality.

[0041] With respect to this specific embodiment, when it is used, the recovery rate of the primary energy recovery device 5 and the secondary energy recovery device 9 is 68%, and the energy consumption of the high-pressure pump is reduced by 30% by using the adjustable energy recovery system. The reverse osmosis design recovery rate of the tertiary energy recovery device 13 is 47%, and the energy consumption of the high-pressure pump is reduced by 50% by using the adjustable energy recovery system. The use of full-process adjustable energy recovery can save 8.8 million degrees per year and reduce system power consumption by 9%.

[0042] The present invention also provides a low-cost high-salt mine water treatment method, which is applied to the low-cost high-salt mine water treatment system as described above.

[0043] The steps include:

[0044] S1, introducing high-salt mine water into the regulating pre-sedimentation tank 1 for preliminary precipitation to remove large particle impurities, and then entering the induced crystallization device 2 to remove part of the calcium ions in the water and retain part of the magnesium ions;

[0045] S2, the water after the crystallization treatment enters the first suspension pretreatment device to remove the suspended matter in the water, and then enters the first membrane concentration device 6 after being pressurized by the first high-pressure pump 4, and the water is concentrated by membrane separation technology to increase the salt concentration in the water, and the fresh water generated in the concentration process is discharged;

[0046] S3, the energy generated by the primary membrane concentration device 6 during operation is recovered by the primary energy recovery device 5, and the water after the recovery process enters the secondary suspended matter pretreatment device 7 to further remove suspended matter in the water;

[0047] S4, the water treated by the secondary suspended matter pretreatment device 7 is pressurized by the second high-pressure pump 8 and enters the secondary membrane concentration device 10, where the water is concentrated again to further increase the salt concentration in the water and recover more fresh water;

[0048] S5, the energy generated during the operation of the secondary membrane concentration device 10 is recovered by the secondary energy recovery device 9, and the water after the recovery process enters the tertiary suspended matter pretreatment device 11 to further remove suspended matter in the water;

[0049] S6, the water treated by the three-stage suspended matter pretreatment device 11 is pressurized by the third high-pressure pump 12 and then enters the three-stage membrane concentration device 14 for final concentration treatment;

[0050] S7. The energy generated during the operation of the three-stage membrane concentration device 14 is recovered through the three-stage energy recovery device 13, and the water after the recovery process is evaporated and crystallized. Specific embodiment:

[0052] The designed water volume of the selected coal mine is 2400m 3 / h, TDS is about 7000mg / L, of which Ca, Mg and Si are 400mg / L, 80mg / L and 20mg / L respectively. The original scheme adopted traditional coagulation sedimentation to remove hardness + three-stage membrane concentration + MVR evaporation crystallization, and the cost of mine water treatment was 16.2 yuan / m 3 .

[0053] (1) Induced crystallization to remove hardness and silicon in steps

[0054] The process of the present invention is adopted. The hardness removal adopts step-by-step induced crystallization. The pH value of the first-stage hardness removal is controlled at 9.5-10, which is much lower than the conventional pH value of 11-11.5. It saves 120 mg / L of sodium hydroxide and 150 mg / L of concentrated sulfuric acid. This link saves 0.6 yuan / m3 of reagent costs. 3 , reducing the salt content in the water by about 200mg / L. The induced crystallization hardness removal process removes 85% of calcium and 30% of magnesium. The hardness is moderate, and it is not easy to form scale after entering the reverse osmosis. At the same time, more than 70% of the magnesium in the water is retained, which reserves the conditions for the next step of silicon removal.

[0055] After the first-level membrane concentration device 6 performs the first-level membrane concentration, the calcium content of the reverse osmosis concentrated water is 200 mg / L, the magnesium content is 186 mg / L, and the silicon content is 66 mg / L. At this time, if entering the next level of membrane concentration, it is necessary to remove hardness and silicon at the same time. According to the conventional treatment process, magnesium agent needs to be added to remove silicon. After adopting the process of the present invention, there is no need to add magnesium agent in this link. Reduce the dosage of magnesium chloride by 300 mg / L (equivalent to 100 mg / L of raw water), and reduce the dosage of sodium hydroxide by 250 mg / L (equivalent to 75 mg / L of raw water). This link saves 0.4 yuan / m 3 This step reduces the salt content in the water by about 100 mg / L (equivalent to raw water).

[0056] After inducing crystallization to remove hardness, solid particles are formed, with a solid content of more than 10%. After simple water control, the solid content reaches 90% and can be directly transported without dehydration. The particles can also be used as building materials without special landfill treatment. Reduce the amount of chemical sludge by 128t / d (solid content 40%) and reduce the cost of sludge treatment by 0.8 yuan / m2 per ton of water. 3 .

[0057] By inducing crystallization to remove hardness and silicon in steps, the cost of reagents is reduced by 1.0 yuan / m 3 (reducing reagents by 16%); salt content is reduced by 300 mg / L (reducing salt content by 4.3%), reducing the pressure of the first, second and third stage membrane concentration pumps by about 4%, saving 3% of high-salt reverse osmosis power consumption, reducing the amount of evaporation and crystallization concentrated brine by 4.3%, and reducing the system energy consumption by about 3%.

[0058] (2) Adjustable energy recovery throughout the reverse osmosis process

[0059] The recovery rate of the primary energy recovery device 5 and the secondary energy recovery device 9 is 68%. The energy consumption of the high-pressure pump is reduced by 30% by using an adjustable energy recovery system. The recovery rate of the tertiary energy recovery device 13 is 47%. The energy consumption of the high-pressure pump is reduced by 50% by using an adjustable energy recovery system. The use of full-process adjustable energy recovery can save 8.8 million kWh / year and reduce system power consumption by 9%.

[0060] Compared with conventional processes, the process route of this invention can reduce drug consumption by 16%, power consumption by 12%, concentrated brine volume by 4.3%, and chemical sludge by 60%. The operating cost of this project has been reduced from 16.2 yuan / m 3 , reduced to 13.9 yuan / m 3 , total operating costs were reduced by 14.2%, and annual operating costs were reduced by more than 40 million yuan.

[0061] Using the present invention:

[0062] (1) Save 15%-20% of pharmaceutical costs.

[0063] (2) Reduce evaporation of concentrated brine by 3%-5%.

[0064] (3) Reduce system power consumption by 10%-15%.

[0065] (4) The energy recovery system operates stably within 30% variation of TDS and flow rate.

[0066] (5) Chemical sludge is reduced by 40%-60%.

[0067] (6) Total operating costs are reduced by 10%-15%.

[0068] The low-cost high-salt mine water treatment method and system of the present invention, when used specifically, the present invention uses an induction fine crystal nucleus small particle of about 0.05-0.1mm, and allows calcium ions in the water to form calcium carbonate adsorbed on the induction particle ions to crystallize into small particles (about 1-2mm) at pH 9.5-10.5, and magnesium ions rarely participate in the reaction, thereby removing most of the calcium ions in the water and retaining most of the magnesium ions in the water. The first-level membrane concentration device 6 then uses a double alkali method to adjust the pH value to above 11-11.5 to generate CaCO3 and Mg(OH)2 from calcium and magnesium in the water, and at the same time, the magnesium remaining in the water reacts with silicon, and there is no need to specifically add magnesium agent or sodium aluminate for silicon removal.

[0069] The small particles formed by induced crystallization have high density and do not require a special sludge dewatering system. After simple solid-liquid separation by the solid-liquid separator 15, the solid content can reach more than 90%, and its water content is much lower than that after ordinary chemical sludge plate and frame dehydration. The formed particles have a certain strength and can be used as building materials such as sand and gravel.

[0070] The present invention breaks the traditional system design of energy recovery only for desalinated seawater or water close to seawater quality. The three-stage membrane concentration of high-salinity mine water adopts energy recovery design from low-pressure reverse osmosis to high-pressure reverse osmosis. In order to cope with the changing characteristics of mine water quality and quantity, on the basis of traditional seawater desalination energy recovery technology, a water quality and flow linkage control system is added to ensure the stability of the system.

[0071] This solves the technical problem in the prior art that the cost of mine water treatment is extremely high, which causes a heavy burden on coal mining enterprises.

[0072] What is disclosed above is only a preferred embodiment of the present invention, and it certainly cannot be used to limit the scope of rights of the present invention. Ordinary technicians in this field can understand that all or part of the processes of the above embodiment and equivalent changes made according to the claims of the present invention still fall within the scope of the invention.

Claims

1. A low-cost high-salt mine water treatment system, characterized in that: It includes a regulating pre-sedimentation tank, an induced crystallization device, a primary suspended matter pretreatment device, a first high-pressure pump, a primary energy recovery device, a primary membrane concentration device, a secondary suspended matter pretreatment device, a second high-pressure pump, a secondary energy recovery device, a secondary membrane concentration device, a tertiary suspended matter pretreatment device, a third high-pressure pump, a tertiary energy recovery device and a tertiary membrane concentration device; The induced crystallization devices are connected to the regulating pre-sedimentation tank and the first-level suspended pretreatment device, the first high-pressure pump is arranged between the first-level suspended matter pretreatment device and the first-level membrane concentrating device, the first-level energy recovery device is connected to the first-level membrane concentrating device, the second-level suspended matter pretreatment device is connected to the first-level energy recovery device, the second high-pressure pump is arranged between the second-level suspended matter pretreatment device and the second-level membrane concentrating device, the second-level energy recovery device is connected to the second-level membrane concentrating device, the third-level suspended matter pretreatment device is connected to the second-level energy recovery device, the third high-pressure pump is arranged between the third-level suspended matter pretreatment device and the third-level membrane concentrating device, and the third-level energy recovery device is connected to the third-level membrane concentrating device.

2. The low-cost high-salt mine water treatment system according to claim 1, characterized in that: The low-cost high-salt mine water treatment system also includes a solid-liquid separator, which is used to separate solids in the induced crystallization device.

3. The low-cost high-salt mine water treatment system according to claim 2, characterized in that: The first-stage energy recovery device, the second-stage energy recovery device and the third-stage energy recovery device all include a water inlet assembly, a fourth high-pressure pump, a control module, a boost flow meter, a boost regulating valve, an energy recovery device, a concentrated water flow meter and a concentrated water regulating valve; The plurality of water inlet components are respectively connected to the first high-pressure pump, the second high-pressure pump and the third high-pressure pump, the fourth high-pressure pump and the energy recovery device are both connected to the corresponding water inlet components, the plurality of fourth high-pressure pumps are also respectively connected to the first-stage membrane concentrating device, the second-stage membrane concentrating device and the third-stage membrane concentrating device, the plurality of energy recovery devices are also respectively connected to the first-stage membrane concentrating device, the second-stage membrane concentrating device and the third-stage membrane concentrating device, the boost regulating valve is connected to the corresponding energy recovery device, the boost flowmeter is connected to the corresponding boost regulating valve, the plurality of boost flowmeters are respectively connected to the first-stage membrane concentrating device, the second-stage membrane concentrating device and the third-stage membrane concentrating device, the concentrated water flowmeter is connected to the corresponding energy recovery device, the concentrated water regulating valve is connected to the corresponding concentrated water flowmeter, and the concentrated water regulating valves in the first-stage energy recovery device and the second-stage energy recovery device are respectively connected to the second-stage suspended matter pretreatment device and the third-stage suspended matter pretreatment device.

4. The low-cost high-salt mine water treatment system according to claim 3, characterized in that: The water inlet assembly includes a booster pump and a water inlet flow meter. The multiple booster pumps are respectively connected to the first high-pressure pump, the second high-pressure pump and the third high-pressure pump. The water inlet flow meter is connected to the corresponding booster pump.

5. The low-cost high-salt mine water treatment system according to claim 4, characterized in that: The water inlet component also includes a water quality monitoring instrument, which is used to monitor water quality.

6. A low-cost high-salt mine water treatment method, applied to the low-cost high-salt mine water treatment system as claimed in claim 5, characterized in that: The steps include: The high-salt mine water is introduced into the regulating pre-sedimentation tank for preliminary precipitation to remove large particle impurities, and then enters the induced crystallization device to remove part of the calcium ions in the water and retain part of the magnesium ions; The water after the crystallization treatment enters the first-stage suspension pretreatment device to remove suspended solids in the water, and then is pressurized by the first high-pressure pump and enters the first-stage membrane concentration device, where the water is concentrated using membrane separation technology to increase the salt concentration in the water, while the fresh water generated during the concentration process is discharged; The energy generated by the primary membrane concentration device during operation is recovered by the primary energy recovery device, and the water after the recovery process enters the secondary suspended matter pretreatment device to further remove suspended matter in the water; The water treated by the secondary suspended matter pretreatment device enters the secondary membrane concentration device after being pressurized by the second high-pressure pump, and the water is concentrated again to further increase the salt concentration in the water and recover more fresh water; The energy generated during the operation of the secondary membrane concentration device is recovered by the secondary energy recovery device, and the water after the recovery process enters the tertiary suspended matter pretreatment device to further remove suspended matter in the water; The water treated by the three-stage suspended matter pretreatment device enters the three-stage membrane concentration device after being pressurized by the third high-pressure pump for final concentration treatment; The energy generated during the operation of the three-stage membrane concentration device is recovered by the three-stage energy recovery device, and the water after the recovery process is evaporated and crystallized.

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