Method for crystallization, quality improvement and salt separation of high-salt water

Abstract

The invention relates to a method for crystallizing, upgrading and separating salt in high-salt water, which comprises a plurality of evaporating crystallizers arranged in sequence, and each evaporating crystallizer is provided with an online salinity monitor, an automatic regulating valve, a gas-liquid separator, a dryer and the like; high-temperature flue gas is injected into the heavy salt water through a flue gas inlet pipe of the evaporation crystallizer to form tiny bubbles, so that water is efficiently taken away, and a gas-liquid mixture is generated; the gas-liquid mixture is discharged from the flue gas outlet and enters the gas-liquid separator; the flow rate of high-salt water flowing into the next evaporation crystallizer is controlled through an automatic regulating valve at a high-salt water outlet of the evaporation crystallizer, so that the salinity value of the evaporation crystallizer is kept in a set range, and specific salt is crystallized and separated out in the evaporation crystallizer; and discharging the separated crystal salt from the bottom of the evaporation crystallizer, feeding the crystal salt into a drying machine, and drying the wet salt by using the flue gas residual heat separated by the gas-liquid separator to finally obtain the dry salt. Therefore, crystallization, quality improvement and salt separation are realized through a plurality of evaporation crystallizers according to the salinity difference of separated salts in the high salt water.

Description

Technical Field

[0001] This invention belongs to the field of high-salinity wastewater treatment technology, specifically relating to a high-salinity water crystallization, quality improvement, and salt separation method. Background Technology

[0002] The treatment of high-salinity wastewater has become a significant challenge in modern industrial environmental protection. With increasingly stringent national wastewater discharge standards, industrial enterprises must adopt effective measures to comply. Simultaneously, with the acceleration of industrialization, particularly in industries such as chemical, metallurgical, coal mining, and salt production, the generation of high-salinity wastewater has increased significantly. This type of wastewater not only severely pollutes water resources but also poses a potential threat to the ecological environment and human health. Therefore, developing efficient and economical high-salinity wastewater treatment technologies is of paramount importance. Furthermore, the recovery and reuse of salts can not only reduce negative environmental impacts but also achieve effective resource regeneration, promoting the development of a circular economy.

[0003] Currently, mainstream high-salinity water treatment technologies include evaporation crystallization, membrane separation, and chemical precipitation. Evaporation crystallization concentrates and crystallizes salts by heating the high-salinity water and utilizing the evaporation process. While this method effectively removes salts, it is energy-intensive, and its efficiency in separating multiple salts remains limited. Membrane separation, although highly efficient, suffers from membrane tolerance and fouling issues, leading to high long-term operating costs that severely restrict its application in high-salinity water treatment. Chemical precipitation involves adding chemical reagents to precipitate salts, but this method may introduce secondary pollution and increase treatment costs.

[0004] To address this issue, this invention proposes a novel method for graded treatment of high-salinity wastewater using multiple evaporators and crystallizers. This method not only effectively achieves efficient salt separation and resource utilization but also reduces solid waste treatment costs. By incorporating online salinity monitoring technology, the system can automatically adjust valve openings to ensure continuous and stable operation under various conditions. Furthermore, the waste heat recovery system in the evaporators and crystallizers effectively reduces energy consumption and improves overall treatment efficiency. This method demonstrates significant advantages in the field of high-salinity wastewater treatment, providing a new approach to solving this environmental challenge. Summary of the Invention

[0005] In view of the above-mentioned shortcomings of the existing technology, the purpose of this invention is to provide a high-salt water crystallization method for salt extraction and separation.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a high-salt water crystallization and salt separation method, comprising high-temperature flue gas, which is introduced into multiple sequentially arranged evaporators and crystallizers, each equipped with an online salinity monitor, an automatic regulating valve, a gas-liquid separator, and a dryer. The method includes the following steps:

[0007] (1) High-salt water enters the first evaporator crystallizer. High-temperature flue gas is injected into the high-salt water in the form of tiny bubbles through the flue gas inlet of the first evaporator crystallizer. It efficiently removes water and generates a gas-liquid mixture. The gas-liquid mixture is discharged through the flue gas outlet of the first evaporator crystallizer and enters the gas-liquid separator.

[0008] (2) The flow rate of high brine entering the next evaporator crystallizer is controlled by the automatic regulating valve connected to the high brine outlet of the first evaporator crystallizer, so that the salinity value of the first evaporator crystallizer is kept within the set range, ensuring that salt 1 crystallizes and precipitates in the first evaporator crystallizer.

[0009] (3) The crystalline salt precipitated in the first evaporator crystallizer is discharged through the bottom and enters the dryer. The residual heat of the flue gas separated by the gas-liquid separator is used to dry the wet salt to obtain salt 1.

[0010] (4) The high-salt water after being concentrated by the first evaporator crystallizer enters the next evaporator crystallizer. The high-temperature flue gas is injected into the high-salt water in the form of tiny bubbles through the flue gas inlet of the next evaporator crystallizer, which efficiently removes water and generates a gas-liquid mixture. The gas-liquid mixture is discharged through the flue gas outlet of the next evaporator crystallizer and enters the gas-liquid separator.

[0011] (5) The flow rate of high brine into the next evaporator crystallizer is controlled by the automatic regulating valve connected to the high brine outlet of the next evaporator crystallizer, so that the salinity value on the next evaporator crystallizer is kept within the set range, and salt 2 is crystallized and precipitated in the next evaporator crystallizer.

[0012] (6) The crystallized salt precipitated in the next evaporator crystallizer is discharged through the bottom and enters the dryer. The residual heat of the flue gas separated by the gas-liquid separator is used to dry the wet salt to obtain salt 2.

[0013] (7) Follow the above steps until all the salt is obtained.

[0014] Furthermore, the method for obtaining the high-temperature flue gas includes a reduction furnace, an oxidation furnace, and an oxygen carrier. The reduction furnace uses the energy in the fuel gas (including natural gas from coalbed methane wells or purchased fuel gas) to reduce the oxygen carrier to generate metal monomers and produce high-temperature flue gas. The metal monomers are transported from the reduction furnace to the oxidation furnace, where they react with air to regenerate the oxygen carrier and simultaneously generate high-temperature flue gas. The regenerated oxygen carrier is recycled back to the reduction furnace to participate in the next cycle reaction.

[0015] Furthermore, the flue gas discharged from the evaporator crystallizer enters the gas-liquid separator, the separated fresh water is discharged from the bottom, and the flue gas is discharged from the top and sequentially enters each dryer to dry the wet salt.

[0016] Furthermore, the salts in each evaporator crystallizer precipitate out sequentially from low to high according to their crystallization supersaturation.

[0017] Furthermore, the method for controlling the salinity of the evaporator crystallizer:

[0018] (1) Monitor the salinity in the evaporator crystallizer in real time using an online salinity monitor;

[0019] (2) Based on the known minimum salinity value X for all salt i to precipitate. i The opening of valve i is automatically adjusted based on the real-time salinity value feedback, thereby controlling the salinity of evaporator crystallizer i within the range of X. i ~ηX i Between, where ηX i = (0.05~0.5)×(X) i+1 -X i )+X i ;

[0020] (3) For the last evaporation crystallization n, since there is no subsequent salt precipitation, the salinity value X is... n+1 Control the salinity of the evaporator crystallizer to be greater than X. n .

[0021] Furthermore, the method for maintaining a constant evaporation rate in an evaporator crystallizer:

[0022] (1) The flue gas inlet pipe of the evaporator crystallizer is equipped with an automatically adjustable telescopic device, and the evaporator crystallizer is equipped with an online liquid level gauge;

[0023] (2) Salinity value X in the evaporator crystallizer i Fluctuations within a set range lead to a high saline solution level h. i The temperature fluctuates accordingly. To maintain a constant depth of the flue gas inlet pipe inserted into the high saline solution, the liquid level value fed back by the online level gauge is used to control the automatic adjustment telescopic device to adjust the telescopic length of the flue gas inlet pipe.

[0024] (3) The online level gauge of the evaporator crystallizer is set to alarm the level. When the level exceeds or falls below the preset value, an alarm signal is issued to prompt the operator to make necessary adjustments.

[0025] Compared with the prior art, the present invention has the following beneficial effects:

[0026] 1. This invention effectively improves the evaporation efficiency of water by injecting high-temperature flue gas into a high-salt water environment to form microbubbles. This design can significantly accelerate the removal of water, thereby improving the overall treatment efficiency.

[0027] 2. This invention integrates an online salinity monitor, enabling real-time monitoring of salinity in the evaporator crystallizer and automatically adjusting the valve opening based on the detection results. This automated control method ensures the stability and accuracy of the concentration process.

[0028] 3. This invention employs a multi-stage evaporator crystallizer design, processing salts according to their different precipitation sequences. Each evaporator crystallizer is a standalone system. This design not only enables the separation and recovery of high-purity salts but also provides high flexibility and scalability for various high-salt water conditions.

[0029] 4. After gas-liquid separation, the residual heat of the flue gas discharged from the evaporator crystallizer is used to dry the precipitated crystalline salt, significantly reducing energy consumption. This waste heat utilization design improves the system's energy efficiency and meets the requirements of sustainable development.

[0030] 5. In this invention, the flue gas inlet pipe of the evaporator crystallizer is immersed in high-salt water, and its immersion depth is automatically adjusted according to changes in the liquid level. This dynamic adjustment mechanism ensures a constant evaporation rate, thereby improving the operational stability and reliability of the system.

[0031] 6. The evaporator crystallizer of this invention has a wide range of energy sources, utilizing high-temperature flue gas as well as renewable energy sources such as electricity and solar energy. This flexible energy utilization method allows the system to operate efficiently under different conditions. Furthermore, this method is not only applicable to the chemical, metallurgical, coal mining, and salt-making industries, but can also be extended to other fields that generate high-salinity wastewater. This broad applicability provides an effective solution for high-salinity wastewater treatment in various industries. Attached Figure Description

[0032] Figure 1 This is a schematic diagram of a high-salt water crystallization, upgrading, and salt separation method according to the present invention;

[0033] Figure 2 This is a flowchart of one embodiment of the present invention;

[0034] Figure 3 This is a schematic diagram of the first evaporator crystallizer in one embodiment of the present invention.

[0035] The markings in the diagram mean: 1-First evaporator crystallizer, 1-1 First evaporator chamber flue gas inlet, 1-2 First evaporator chamber flue gas outlet, 1-3 Second evaporator chamber flue gas inlet, 1-4 Second evaporator chamber flue gas outlet, 2-Second evaporator crystallizer, 3-Third evaporator crystallizer, 4-Fourth evaporator crystallizer, 5-Fifth evaporator crystallizer, 6-Gas-liquid separator, 6-1 Gas-liquid separator A, 6-2 Gas-liquid separator B, (7-1, 7-2, 7-3, 7-4, 7-5)- Dryer, (8-1, 8-2, 8-3, 8-4, 8-5) - Online salinity monitor, (9-1, 9-2, 9-3, 9-4, 9-5) - Automatic adjustment and expansion device for flue gas inlet pipe, (10-1, 10-2, 10-3, 10-4, 10-5) - Automatic regulating valve, 11 - Heat exchanger A, 12 - Heat exchanger B, 13 - Filter tank, 14 - Sludge pyrolysis furnace, 15 - Freshwater tank, 16 - Reduction furnace, 17 - Oxidation furnace, 18 - High-salinity water tank, X i - The minimum salinity value at which all salt i precipitates out, h i - Liquid level value. Detailed Implementation

[0036] To better understand the technical essence and beneficial effects of the present invention, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0037] Example 1

[0038] Combination Figure 1 A method for high-salt water crystallization, quality improvement, and salt separation includes high-temperature flue gas, which is introduced into multiple sequentially arranged evaporators and crystallizers. Each evaporator and crystallizer is equipped with an online salinity monitor, an automatic regulating valve, a gas-liquid separator, and a dryer. The method includes the following steps:

[0039] (1) High-salt water enters the first evaporator crystallizer. High-temperature flue gas is injected into the high-salt water in the form of tiny bubbles through the flue gas inlet of the first evaporator crystallizer. It efficiently removes water and generates a gas-liquid mixture. The gas-liquid mixture is discharged through the flue gas outlet of the first evaporator crystallizer and enters the gas-liquid separator.

[0040] (2) The flow rate of high brine entering the next evaporator crystallizer is controlled by the automatic regulating valve connected to the high brine outlet of the first evaporator crystallizer, so that the salinity value of the first evaporator crystallizer is kept within the set range, ensuring that salt 1 crystallizes and precipitates in the first evaporator crystallizer.

[0041] (3) The crystalline salt precipitated in the first evaporator crystallizer is discharged through the bottom and enters the dryer. The residual heat of the flue gas separated by the gas-liquid separator is used to dry the wet salt to obtain salt 1.

[0042] (4) The high-salt water after being concentrated by the first evaporator crystallizer enters the next evaporator crystallizer. The high-temperature flue gas is injected into the high-salt water in the form of tiny bubbles through the flue gas inlet of the next evaporator crystallizer, which efficiently removes water and generates a gas-liquid mixture. The gas-liquid mixture is discharged through the flue gas outlet of the next evaporator crystallizer and enters the gas-liquid separator.

[0043] (5) The flow rate of high brine into the next evaporator crystallizer is controlled by the automatic regulating valve connected to the high brine outlet of the next evaporator crystallizer, so that the salinity value on the next evaporator crystallizer is kept within the set range, and salt 2 is crystallized and precipitated in the next evaporator crystallizer.

[0044] (6) The crystallized salt precipitated in the next evaporator crystallizer is discharged through the bottom and enters the dryer. The residual heat of the flue gas separated by the gas-liquid separator is used to dry the wet salt to obtain salt 2.

[0045] (7) Follow the above steps until all the salt is obtained.

[0046] The embodiments are combined with Figure 2 The method for obtaining the high-temperature flue gas includes a reduction furnace, an oxidation furnace, and an oxygen carrier. The reduction furnace uses the energy in the fuel gas (including natural gas from coalbed methane wells or purchased fuel gas) to reduce the oxygen carrier to generate metal monomers and produce high-temperature flue gas. The metal monomers are transported from the reduction furnace to the oxidation furnace, where they react with air to regenerate the oxygen carrier and simultaneously generate high-temperature flue gas. The regenerated oxygen carrier is recycled back to the reduction furnace to participate in the next cycle reaction.

[0047] In this embodiment, the flue gas discharged from the evaporator crystallizer enters the gas-liquid separator, the separated fresh water is discharged from the bottom, and the flue gas is discharged from the top and sequentially enters each dryer to dry the wet salt.

[0048] In this embodiment, each evaporator crystallizer precipitates salts sequentially from low to high based on the degree of supersaturation of the salt crystallization.

[0049] In the embodiment, the method for controlling the salinity of an evaporator crystallizer is as follows:

[0050] (1) Monitor the salinity in the evaporator crystallizer in real time using an online salinity monitor;

[0051] (2) Based on the known minimum salinity value X for all salt i to precipitate. i The opening of valve i is automatically adjusted based on the real-time salinity value feedback, thereby controlling the salinity of evaporator crystallizer i within the range of X. i ~ηX i Between, where ηX i = (0.05~0.5)×(X) i+1 -X i )+X i ;

[0052] (3) For the last evaporation crystallization n, since there is no subsequent salt precipitation, the salinity value X is... n+1 Control the salinity of the evaporator crystallizer to be greater than X. n .

[0053] In the embodiment, the method for maintaining a constant evaporation rate in an evaporator crystallizer is as follows:

[0054] (1) The flue gas inlet pipe of the evaporator crystallizer is equipped with an automatically adjustable telescopic device, and the evaporator crystallizer is equipped with an online liquid level gauge;

[0055] (2) Salinity value X in the evaporator crystallizer i Fluctuations within a set range lead to a high saline solution level h. i The temperature fluctuates accordingly. To maintain a constant depth of the flue gas inlet pipe inserted into the high saline solution, the liquid level value fed back by the online level gauge is used to control the automatic adjustment telescopic device to adjust the telescopic length of the flue gas inlet pipe.

[0056] (3) The online level gauge of the evaporator crystallizer is set to alarm the level. When the level exceeds or falls below the preset value, an alarm signal is issued to prompt the operator to make necessary adjustments.

[0057] In this embodiment, the evaporator crystallizer has a wide range of energy sources, including high-temperature flue gas, electricity, solar energy, and other renewable energy sources. This flexible energy utilization method enables the system to operate efficiently under different conditions. Furthermore, this method is not only applicable to the chemical, metallurgical, coal mining, and salt-making industries, but can also be extended to other fields that generate high-salinity wastewater.

[0058] Example 2

[0059] This embodiment takes the high-salinity water produced from a coalbed methane well as an example, combined with... Figure 2 This paper describes a high-salt water crystallization upgrading and salt separation method, including high-salt water pretreatment and high-temperature flue gas acquisition, high-salt water crystallization upgrading and salt separation, and flue gas waste heat recovery and treatment.

[0060] Steps for high-salinity pretreatment and obtaining high-temperature flue gas:

[0061] (1) The high-salt water produced from the coalbed methane well enters the high-salt water pool (18), and is then pumped (17) to the filter pool (13) for solid-liquid separation;

[0062] (2) The separated filter residue is sent to the sludge pyrolysis furnace (14) for pyrolysis. The generated pyrolysis gas is used as fuel gas for the reduction furnace (16). The remaining dry sludge can be used for road repair.

[0063] (3) The natural gas produced by the coalbed methane well and the pyrolysis gas produced by the sludge pyrolysis furnace (14) are used as fuel for the reduction furnace (16) to reduce Fe2O3 oxygen carrier into elemental iron and produce high-temperature flue gas (CO2 and H2O). The high-temperature flue gas is divided into two paths: one path serves as the heat source for the sludge pyrolysis furnace (14), and the other path enters the first evaporator crystallizer (1) to provide a heat source for high brine concentration.

[0064] (4) The reduced elemental iron is sent to the oxidation furnace (17) to react with air to generate Fe2O3 oxygen carrier and high-temperature flue gas (N2 and O2). The regenerated Fe2O3 oxygen carrier is returned to the reduction furnace (16) for recycling. The generated high-temperature flue gas provides a heat source for the evaporator crystallizer and dryer.

[0065] High-salt water crystallization, upgrading, and salt separation steps:

[0066] Given X1 = 486.30 g / L, X2 = 528.05 g / L, X3 = 689.41 g / L, X4 = 917.32 g / L, and X5 = 1050.20 g / L.

[0067] (1) The high brine after heat exchange in heat exchanger A and heat exchanger B enters the first evaporator crystallizer (1) for evaporation and concentration. The opening of the automatic regulating valve (10-1) is controlled by the real-time feedback of the salinity value from the online salinity monitor (8-1) to control the salinity value of the evaporator crystallizer at 486.30~490.48g / L. The salt precipitated in the first evaporator crystallizer (1) is discharged from the bottom and enters the dryer (7-1) for drying to obtain salt 1.

[0068] (2) The high brine concentrated by the first evaporator crystallizer (1) is controlled by the automatic regulating valve (10-1) to enter the second evaporator crystallizer (2) for evaporation and concentration. The opening of the automatic regulating valve (10-2) is controlled by the salinity value fed back in real time by the online salinity monitor (8-2) to control the salinity value of the evaporator crystallizer at 528.05~544.19g / L. The salt precipitated in the second evaporator crystallizer (2) is discharged from the bottom and enters the dryer (7-2) for drying to obtain salt 2.

[0069] (3) The high brine concentrated by the second evaporator crystallizer (2) is controlled by the automatic regulating valve (10-2) to enter the third evaporator crystallizer (3) for evaporation and concentration. The opening of the automatic regulating valve (10-3) is controlled by the salinity value fed back in real time by the online salinity monitor (8-3) to control the salinity value of the evaporator crystallizer at 689.41~712.20g / L. The salt precipitated in the third evaporator crystallizer (3) is discharged from the bottom and enters the dryer (7-3) for drying to obtain salt 3.

[0070] (4) The high brine concentrated by the third evaporator crystallizer (3) is controlled by the automatic regulating valve (10-3) to enter the fourth evaporator crystallizer (4) for evaporation and concentration. The opening of the automatic regulating valve (10-4) is controlled by the salinity value fed back in real time by the online salinity monitor (8-4) to control the salinity value of the evaporator crystallizer at 917.32~930.61g / L. The salt precipitated in the fourth evaporator crystallizer (4) is discharged from the bottom and enters the dryer (7-4) for drying to obtain salt 4.

[0071] (5) The high brine concentrated by the fourth evaporator crystallizer (4) is controlled by the automatic regulating valve (10-4) to enter the fifth evaporator crystallizer (5) for evaporation and concentration. The opening of the automatic regulating valve (10-5) is controlled by the salinity value fed back in real time by the online salinity monitor (8-5) so that the salinity value of the evaporator crystallizer is kept greater than 1050.20 g / L. The salt precipitated in the fifth evaporator crystallizer (5) is discharged from the bottom and enters the dryer (7-5) for drying to obtain salt 5.

[0072] (6) To ensure the continuous and stable operation of each evaporator crystallizer, the flue gas inlet pipe of each evaporator crystallizer is equipped with an automatically adjustable telescopic device and an online level gauge. Since the salinity value Xi in the evaporator crystallizer fluctuates within the set range, the high saline liquid level hi changes accordingly. In order to keep the insertion depth of the flue gas inlet pipe in the high saline liquid constant, the level value fed back by the online level gauge is used to control the telescopic device and adjust the telescopic length of the flue gas inlet pipe. This ensures that each evaporator crystallizer maintains a constant evaporation rate.

[0073] Waste heat recovery and treatment of flue gas.

[0074] (1) The first evaporator crystallizer (1) is equipped with two evaporation chambers, namely the first evaporation chamber and the second evaporation chamber. Each evaporation chamber is equipped with an independent flue gas inlet and outlet, and the two flue gases are not interconnected.

[0075] (2) The high-temperature flue gas generated by the reduction furnace (16) enters the first evaporator crystallizer (1) through the flue gas inlet (1-1). In the evaporator crystallizer, the flue gas is dispersed into tiny bubbles, which fully contact the high brine and promote the efficient evaporation of water. The evaporated flue gas carries water vapor and is discharged through the flue gas outlet (1-2) and enters the gas-liquid separator (6-1) for gas-liquid separation. The separated fresh water is discharged into the fresh water pool (15) for reuse, while the flue gas (mainly CO2) enters the heat exchanger A (11) to exchange heat with the filtered high brine. The generated CO2 can be sold externally (achieving zero CO2 emission). The high brine after heat exchange enters the first evaporator crystallizer (1) through valve 1.

[0076] (3) The high-temperature flue gas generated by the oxidation furnace is divided into three paths. The first path of high-temperature flue gas enters the first evaporator crystallizer (1) through the flue gas inlet (1-3). In the evaporator crystallizer, the flue gas is dispersed into tiny bubbles and fully contacts the high-salt water. The evaporated flue gas carries water vapor and is discharged through the flue gas outlet (1-4). It enters the gas-liquid separator (6-2) together with the flue gas discharged from the second to fifth evaporators crystallizers for gas-liquid separation. The separated fresh water is discharged into the fresh water pool (15) for reuse, while the flue gas enters the heat exchanger B (12) to exchange heat with the filtered high-salt water. The high-salt water after heat exchange enters the first evaporator crystallizer (1) through valve 2. The flue gas (composed of O2 and N2) can be directly discharged into the atmosphere. The second path of high-temperature flue gas serves as the heat source for the evaporation and crystallization process of the second evaporator crystallizer (2), the third evaporator crystallizer (3), the fourth evaporator crystallizer (4), and the fifth evaporator crystallizer (5). The third path of high-temperature flue gas is used in the dryer (7) for drying wet salt, providing the necessary heat energy to ensure the effective drying of wet salt.

[0077] Of course, the above description is not intended to limit the present invention, and the present invention is not limited to the examples given above. Any changes made by those skilled in the art within the scope of the present invention are also within the protection scope of the present invention.

Claims

1. A method for high-salt water crystallization, quality improvement, and salt separation, comprising high-temperature flue gas, wherein the high-temperature flue gas is introduced into multiple sequentially arranged evaporators and crystallizers, characterized in that, The method, comprising multiple sequentially arranged evaporators / crystallizers, each equipped with an online salinity monitor, an automatic regulating valve, a gas-liquid separator, and a dryer, includes the following steps: (1) High-salt water enters the first evaporator crystallizer. High-temperature flue gas is injected into the high-salt water in the form of tiny bubbles through the flue gas inlet of the first evaporator crystallizer. It efficiently removes water and generates a gas-liquid mixture. The gas-liquid mixture is discharged through the flue gas outlet of the first evaporator crystallizer and enters the gas-liquid separator. (2) The flow rate of high brine entering the next evaporator crystallizer is controlled by the automatic regulating valve connected to the high brine outlet of the first evaporator crystallizer, so that the salinity value of the first evaporator crystallizer is kept within the set range, ensuring that salt 1 crystallizes and precipitates in the first evaporator crystallizer. (3) The crystalline salt precipitated in the first evaporator crystallizer is discharged through the bottom and enters the dryer. The residual heat of the flue gas separated by the gas-liquid separator is used to dry the wet salt to obtain salt 1. (4) The high-salt water after being concentrated by the first evaporator crystallizer enters the next evaporator crystallizer. The high-temperature flue gas is injected into the high-salt water in the form of tiny bubbles through the flue gas inlet of the next evaporator crystallizer, which efficiently removes water and generates a gas-liquid mixture. The gas-liquid mixture is discharged through the flue gas outlet of the next evaporator crystallizer and enters the gas-liquid separator. (5) The flow rate of high brine into the next evaporator crystallizer is controlled by the automatic regulating valve connected to the high brine outlet of the next evaporator crystallizer, so that the salinity value on the next evaporator crystallizer is kept within the set range, and salt 2 is crystallized and precipitated in the next evaporator crystallizer. (6) The crystallized salt precipitated in the next evaporator crystallizer is discharged through the bottom and enters the dryer. The residual heat of the flue gas separated by the gas-liquid separator is used to dry the wet salt to obtain salt 2. (7) Follow the above steps until all the salt is obtained.

2. The high-salt water crystallization, upgrading, and salt separation method according to claim 1, characterized in that, The method for obtaining high-temperature flue gas includes a reduction furnace, an oxidation furnace, and an oxygen carrier. The reduction furnace uses the energy in the fuel gas (including natural gas from coalbed methane wells or purchased fuel gas) to reduce the oxygen carrier to generate metal monomers and produce high-temperature flue gas. The metal monomers are transported from the reduction furnace to the oxidation furnace, where they react with air to regenerate the oxygen carrier and simultaneously generate high-temperature flue gas. The regenerated oxygen carrier is recycled back to the reduction furnace to participate in the next cycle reaction.

3. The high-salt water crystallization, upgrading, and salt separation method according to claim 1, characterized in that, The flue gas discharged from the evaporator crystallizer enters the gas-liquid separator. The separated fresh water is discharged from the bottom, and the flue gas is discharged from the top and enters each dryer in sequence to dry the wet salt.

4. The high-salt water crystallization, upgrading, and salt separation method according to claim 1, characterized in that, The salts in each evaporator crystallizer precipitate out sequentially from low to high supersaturation.

5. The high-salt water crystallization, upgrading, and salt separation method according to claim 1, characterized in that, The method for controlling the salinity of an evaporator crystallizer: (1) Monitor the salinity in the evaporator crystallizer in real time using an online salinity monitor; (2) Based on the known minimum salinity value X for all salt i to precipitate. i The opening of valve i is automatically adjusted based on the real-time salinity value feedback, thereby controlling the salinity of evaporator crystallizer i within the range of X. i ~ηX i Between, where ηX i = (0.05~0.5)×(X) i+1 -X i )+X i ; (3) For the last evaporation crystallization n, since there is no subsequent salt precipitation, the salinity value X is... n+1 Control the salinity of the evaporator crystallizer to be greater than X. n .

6. The high-salt water crystallization, upgrading, and salt separation method according to claim 1, characterized in that, The method for maintaining a constant evaporation rate in an evaporator crystallizer: (1) The flue gas inlet pipe of the evaporator crystallizer is equipped with an automatically adjustable telescopic device, and the evaporator crystallizer is equipped with an online liquid level gauge; (2) Salinity value X in the evaporator crystallizer i Fluctuations within a set range lead to a high saline solution level h. i The temperature fluctuates accordingly. To maintain a constant depth of the flue gas inlet pipe inserted into the high saline solution, the liquid level value fed back by the online level gauge is used to control the automatic adjustment telescopic device to adjust the telescopic length of the flue gas inlet pipe. (3) The online level gauge of the evaporator crystallizer is set to alarm the level. When the level exceeds or falls below the preset value, an alarm signal is issued to prompt the operator to make necessary adjustments.

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