Sodium chloride evaporation mother liquor treatment device

Abstract

The utility model relates to the technical field of sodium chloride evaporation mother liquor treatment, in particular to a sodium chloride evaporation mother liquor treatment device which comprises pretreatment equipment, nanofiltration treatment equipment, evaporation crystallization equipment, organic matter and biochemical treatment equipment, a circulating reflux system and carnallite treatment equipment which are arranged in sequence, the pretreatment equipment comprises a reaction sedimentation tank and a filtering device, the reaction sedimentation tank and the filtering device are used for removing suspended solids in mother liquor wastewater and adjusting the pH value, the pretreatment equipment is connected with a sodium chloride evaporation mother liquor outlet, and an outlet of the pretreatment equipment is connected with the nanofiltration treatment equipment; according to the sodium chloride evaporation mother liquor treatment device, through tight connection and efficient treatment of all links, the recovery rate and the utilization rate of resources are increased, environmental pollution is remarkably reduced, and the sodium chloride evaporation mother liquor treatment device has important environmental protection significance and economic value.

Description

Technical Field

[0001] This utility model relates to the field of sodium chloride evaporation mother liquor treatment technology, specifically a sodium chloride evaporation mother liquor treatment device. Background Technology

[0002] In recent years, with the worsening water shortage and increasingly stringent national environmental protection policies, more and more enterprises are gradually implementing zero wastewater discharge with evaporation and crystallization as the final process.

[0003] In the process of seawater salt production, seawater is first introduced into evaporation ponds and evaporated by sunlight. Once the water content has decreased to a certain level, the concentrated seawater is poured into crystallization ponds for further evaporation. During this process, the salt (mainly sodium chloride) in the seawater gradually crystallizes out, forming crude salt. The remaining liquid, which no longer contains enough salt to continue crystallizing, is called the mother liquor.

[0004] Currently, some companies use a process where nanofiltration concentrate is mixed with sodium chloride evaporation mother liquor and then fed into another mixed salt evaporation system for the treatment of mixed salts. Instead of directly treating the sodium chloride evaporation mother liquor, this results in a large volume of wastewater requiring treatment of the sodium chloride evaporation mother liquor, leading to high investment and operating costs for the evaporation crystallization system and a heavy workload for daily maintenance. Utility Model Content

[0005] The purpose of this invention is to provide a sodium chloride evaporation mother liquor treatment device to solve the problems mentioned in the background art.

[0006] To achieve the above objectives, this utility model provides the following technical solution:

[0007] A sodium chloride evaporation mother liquor treatment device includes a pretreatment device, a nanofiltration device, an evaporation crystallization device, an organic matter and biochemical treatment device, a circulation reflux system, and a miscellaneous salt treatment device arranged in sequence. The pretreatment device includes a reaction sedimentation tank and a filtration device, which are used to remove suspended solids from the mother liquor wastewater and adjust the pH value. The pretreatment device is connected to the outlet of the sodium chloride evaporation mother liquor, and the outlet of the pretreatment device is connected to the nanofiltration device.

[0008] As a preferred embodiment of this utility model, the nanofiltration treatment equipment includes a nanofiltration feed pump, a nanofiltration high-pressure pump, a nanofiltration membrane, and a nanofiltration permeate tank and a nanofiltration concentrate tank respectively connected to the nanofiltration membrane. The inlet of the nanofiltration feed pump is connected to the outlet of the pretreatment equipment, the inlet of the nanofiltration high-pressure pump is connected to the outlet of the nanofiltration feed pump, and the outlet of the nanofiltration high-pressure pump is connected to the nanofiltration membrane through a pipeline. The nanofiltration membrane is provided with a clear liquid outlet and a concentrate outlet. The clear liquid outlet is connected to the nanofiltration permeate tank through a clear liquid outlet pipe, and the concentrate outlet is connected to the nanofiltration concentrate tank through a concentrate outlet pipe. The concentrate is sodium chloride.

[0009] As a preferred embodiment of this utility model, the evaporation crystallization equipment includes an evaporator and a crystallizer. The evaporator is used to further process the concentrate inside the nanofiltration concentrate tank to precipitate sodium chloride product salt and obtain sodium chloride evaporation mother liquor. At the same time, the obtained nanofiltration concentrate is subjected to freeze crystallization treatment through the crystallizer to precipitate sodium sulfate freeze mother liquor, which is then further subjected to evaporation crystallization treatment through the evaporator and crystallizer to precipitate a mixed salt of sodium sulfate and sodium chloride.

[0010] As a preferred embodiment of this utility model, the organic matter and biochemical treatment equipment includes an ozone generator, an electrolysis treatment device, a Fenton treatment device, an electrocatalytic treatment device, and a nitrification-denitrification treatment device. The organic matter and biochemical treatment equipment is used to sequentially treat and dilute the sodium chloride evaporation mother liquor and the sodium sulfate evaporation mother liquor obtained in the claims, thereby removing nitrate and COD from the mother liquor. The ozone generator contacts the liquid to be treated through a pipeline to perform an oxidation reaction and remove organic matter. The outlet of the ozone generator is connected to the inlet of the electrolysis treatment device through a pipeline. The outlet of the electrolysis treatment device is connected to the inlet of the Fenton treatment device through a pipeline. The outlet pipeline of the Fenton treatment device is connected to the inlet of the electrocatalytic treatment device. The outlet of the electrocatalytic treatment device is connected to the inlet of the nitrification-denitrification treatment device.

[0011] As a preferred embodiment of this utility model, the recirculation system includes a connecting pipe and a delivery pump, which are used to transport the treated liquid back to the pretreatment system to form a closed loop, so as to minimize waste discharge and improve resource utilization. The outlet of the nitrification-denitrification treatment device is connected to the inlet of the recirculation system through a pipeline.

[0012] As a preferred embodiment of this utility model, the miscellaneous salt treatment equipment includes a dryer, which is used to treat the miscellaneous salts generated during the evaporation and crystallization process in order to realize resource utilization.

[0013] Compared with the prior art, the beneficial effects of this utility model are:

[0014] In response to the problems raised in the background art, the sodium chloride evaporation mother liquor treatment device of this application, through the close connection and efficient treatment of each link, not only improves the resource recovery rate and utilization rate, but also significantly reduces environmental pollution, which has important environmental protection significance and economic value.

[0015] By reducing the throughput and removing suspended solids and adjusting the pH value through pretreatment equipment, the burden on subsequent processing steps is reduced.

[0016] Resource recovery: Nanofiltration equipment can effectively separate and concentrate sodium chloride, thus improving the resource recovery rate.

[0017] To reduce operating costs, the design of the evaporation crystallization equipment allows for the separate recovery of sodium chloride and sodium sulfate, thus reducing energy consumption and operating costs.

[0018] Environmental protection: The application of organic matter and biochemical treatment equipment helps remove harmful substances and protect the environment;

[0019] The design of the closed-loop, circulating system minimizes waste emissions and improves resource utilization.

[0020] Resource utilization: The application of miscellaneous salt treatment equipment has enabled the resource utilization of miscellaneous salts generated during the evaporation and crystallization process.

[0021] The present invention will be explained in detail below with reference to the accompanying drawings and specific embodiments. Attached Figure Description

[0022] Figure 1 This is a block diagram of the processing equipment of this utility model;

[0023] Figure 2 This is a flowchart of the processing method of this utility model.

[0024] In the diagram: 1. Pretreatment equipment; 2. Nanofiltration equipment; 3. Evaporation and crystallization equipment; 4. Organic matter and biochemical treatment equipment; 5. Circulation reflux system; 6. Miscellaneous salt treatment equipment. Detailed Implementation

[0025] To facilitate understanding of this utility model, a more comprehensive description of the utility model will be given below with reference to the accompanying drawings, which show several embodiments of the utility model. However, the utility model can be implemented in different forms and is not limited to the embodiments described in the text. On the contrary, these embodiments are provided to make the disclosure of the utility model more thorough and comprehensive. Example

[0026] Please see Figure 1-2This utility model provides a technical solution: a sodium chloride evaporation mother liquor treatment device, comprising a pretreatment device 1, a nanofiltration device 2, an evaporation crystallization device 3, an organic matter and biochemical treatment device 4, a circulation reflux system 5, and a miscellaneous salt treatment device 6 arranged sequentially. The pretreatment device 1 includes a reaction sedimentation tank and a filtration device, which are used to remove suspended solids from the mother liquor wastewater and adjust the pH value. The pretreatment device 1 is connected to the outlet of the sodium chloride evaporation mother liquor, and the outlet of the pretreatment device 1 is connected to the nanofiltration device 2. The nanofiltration device 2 includes a nanofiltration inlet pump, a nanofiltration high-pressure pump, a nanofiltration membrane, and a nanofiltration permeate tank and a nanofiltration concentrate tank respectively connected to the nanofiltration membrane. The inlet of the nanofiltration inlet pump is connected to the outlet of the pretreatment device 1. The inlet of the nanofiltration high-pressure pump is connected to the outlet of the nanofiltration feed pump. The outlet of the nanofiltration high-pressure pump is connected to the nanofiltration membrane through a pipeline. The nanofiltration membrane is equipped with a clear liquid outlet and a concentrated liquid outlet. The clear liquid outlet is connected to the nanofiltration product water tank through a clear liquid outlet pipe, and the concentrated liquid outlet is connected to the nanofiltration concentrate tank through a concentrated liquid outlet pipe. The concentrate is sodium chloride. The evaporation crystallization equipment 3 includes an evaporator and a crystallizer. The evaporator is used to further process the concentrate inside the nanofiltration concentrate tank to precipitate sodium chloride product salt and obtain sodium chloride evaporation mother liquor. At the same time, the obtained nanofiltration concentrate is subjected to freeze crystallization treatment through the crystallizer to precipitate sodium sulfate and obtain sodium sulfate freeze mother liquor. It is then further subjected to evaporation crystallization treatment through the evaporator and crystallizer to precipitate a mixed salt of sodium sulfate and sodium chloride.

[0027] As a preferred embodiment of this utility model, the organic matter and biochemical treatment equipment 4 includes an ozone generator, an electrolysis treatment device, a Fenton treatment device, an electrocatalytic treatment device, and a nitration-denitrification treatment device. The organic matter and biochemical treatment equipment 4 is used to sequentially treat and dilute the sodium chloride evaporation mother liquor and the sodium sulfate evaporation mother liquor obtained from the evaporation crystallization device 3, thereby removing nitrate and COD from the mother liquor. The ozone generator contacts the liquid to be treated through a pipe to carry out an oxidation reaction and remove organic matter. The outlet of the ozone generator is connected to the inlet of the electrolysis treatment device through a pipeline, and the outlet of the electrolysis treatment device is connected to the inlet of the electrolysis treatment device through a pipeline. The pipeline is connected to the inlet of the Fenton treatment unit, and the outlet pipeline of the Fenton treatment unit is connected to the inlet of the electrocatalytic treatment unit. The outlet of the electrocatalytic treatment unit is connected to the inlet of the nitration-denitrification treatment unit. The circulation reflux system 5 includes a connecting pipe and a transfer pump, which are used to transport the treated liquid back to the pretreatment system to form a closed loop, so as to minimize waste discharge and improve resource utilization. The outlet of the nitration-denitrification treatment unit is connected to the inlet of the circulation reflux system 5 through a pipeline. The miscellaneous salt treatment equipment 6 includes a dryer, which is used to treat the miscellaneous salts generated during the evaporation and crystallization process to achieve resource utilization.

[0028] It should be noted that in this embodiment, the pretreatment device 1 removes suspended solids from the mother liquor wastewater and adjusts the pH value through a reaction sedimentation tank and a filtration device, and then the treated water is transported to the nanofiltration treatment device 2. This connection ensures that the water entering the nanofiltration system is cleaner, reduces the pollution and clogging of the nanofiltration membrane, and improves the treatment efficiency and lifespan of the entire system.

[0029] Furthermore, the nanofiltration feed pump sends the pretreated water to the nanofiltration high-pressure pump, which then pressurizes the water and sends it to the nanofiltration membrane. The clear liquid separated by the nanofiltration membrane enters the nanofiltration product tank, while the concentrate flows into the nanofiltration concentrate tank. This design can effectively separate sodium chloride and other dissolved solids from the water, providing high-quality raw materials for the subsequent evaporation and crystallization process.

[0030] Furthermore, the evaporator further processes the concentrate in the nanofiltration concentrate tank to precipitate sodium chloride product salt and sodium sulfate crystals. At the same time, the crystallizer freezes the nanofiltration concentrate to obtain sodium sulfate frozen mother liquor. This connection not only realizes the recycling of resources, but also reduces energy consumption and operating costs.

[0031] Furthermore, by combining ozone generators, electrolysis treatment devices, Fenton treatment devices, electrocatalytic treatment devices, and nitrification-denitrification treatment devices, harmful substances such as nitrate and COD in sodium chloride evaporation mother liquor and sodium sulfate evaporation mother liquor are effectively removed, protecting the environment and improving product quality.

[0032] Furthermore, the recirculation system 5 returns the treated liquid to the pretreatment system, forming a closed loop. Finally, the clean liquid is discharged from the system, achieving the goals of resource recycling and environmental protection. This design minimizes waste emissions, improves resource utilization, and also reduces environmental pressure.

[0033] Dryers are used to treat the mixed salts generated during the evaporation and crystallization process, enabling resource utilization. This not only solves the waste disposal problem but also brings additional economic benefits to enterprises.

[0034] This sodium chloride evaporation mother liquor treatment device, through the close connection and efficient processing of each link, not only improves the recovery and utilization rate of resources, but also significantly reduces environmental pollution, which has important environmental protection significance and economic value.

[0035] Workflow: Pretreatment equipment 1 removes suspended solids and adjusts the pH value of high-salinity wastewater. Nanofiltration equipment 2 separates sodium chloride and sodium sulfate. The nanofiltration permeate undergoes evaporation and crystallization to precipitate sodium chloride product salt, yielding sodium chloride evaporation mother liquor. For nanofiltration concentrate, freezing crystallization precipitates sodium sulfate (sodium sulfate), yielding sodium sulfate freezing mother liquor. Further evaporation and crystallization precipitates a mixed salt of sodium sulfate and sodium chloride. The sodium chloride and sodium sulfate evaporation mother liquors are sequentially subjected to organic matter treatment, dilution, and biochemical treatment to remove nitrate and COD. The treated liquid is then returned to the pretreatment system or nanofiltration system via a circulation reflux system 5, forming a closed loop. Finally, the clean liquid is discharged from the system. Impurities generated during evaporation and crystallization are treated via a dissolving tank and drying equipment.

[0036] The working process of this utility model:

[0037] In operation, the pretreatment equipment 1 removes suspended solids and adjusts the pH value of the high-salinity wastewater. The nanofiltration equipment 2 separates sodium chloride and sodium sulfate. The nanofiltration permeate is then subjected to evaporation and crystallization treatment to precipitate sodium chloride product salt, resulting in sodium chloride evaporation mother liquor. For the nanofiltration concentrate, the sodium sulfate precipitate is obtained through freeze crystallization treatment. Further evaporation and crystallization treatment precipitates a mixed salt of sodium sulfate and sodium chloride. The sodium chloride evaporation mother liquor and sodium sulfate evaporation mother liquor are then subjected to organic matter treatment, dilution, and biochemical treatment to remove nitrate and COD from the mother liquor. The treated liquid is then transported back to the pretreatment system or nanofiltration system through the circulation reflux system 5, forming a closed loop. Finally, the clean liquid is discharged from the system. The impurities generated during the evaporation and crystallization process are treated through dissolving tanks, drying equipment, etc.

[0038] The present invention has been described above by way of example in conjunction with the accompanying drawings. Obviously, the specific implementation of the present invention is not limited to the above-described manner. Any non-substantial improvement made by adopting the inventive concept and technical solution of the present invention, or the direct application of the inventive concept and technical solution of the present invention to other occasions without modification, shall be within the protection scope of the present invention.

Claims

1. A device for treating sodium chloride evaporation mother liquor, characterized in that: The equipment includes a pretreatment device (1), a nanofiltration device (2), an evaporation crystallization device (3), an organic matter and biochemical treatment device (4), a circulation reflux system (5), and a miscellaneous salt treatment device (6) arranged in sequence. The pretreatment device (1) includes a reaction sedimentation tank and a filtration device. The reaction sedimentation tank and the filtration device are used to remove suspended solids in the mother liquor wastewater and adjust the pH value. The pretreatment device (1) is connected to the outlet of the sodium chloride evaporation mother liquor, and the outlet of the pretreatment device (1) is connected to the nanofiltration device (2).

2. The sodium chloride evaporation mother liquor treatment device according to claim 1, characterized in that: The nanofiltration treatment equipment (2) includes a nanofiltration inlet pump, a nanofiltration high-pressure pump, a nanofiltration membrane, and a nanofiltration product tank and a nanofiltration concentrate tank respectively connected to the nanofiltration membrane. The inlet of the nanofiltration inlet pump is connected to the outlet of the pretreatment equipment (1), the inlet of the nanofiltration high-pressure pump is connected to the outlet of the nanofiltration inlet pump, and the outlet of the nanofiltration high-pressure pump is connected to the nanofiltration membrane through a pipeline. The nanofiltration membrane is provided with a clear liquid outlet and a concentrate outlet. The clear liquid outlet is connected to the nanofiltration product tank through a clear liquid outlet pipe, and the concentrate outlet is connected to the nanofiltration concentrate tank through a concentrate outlet pipe. The concentrate is sodium chloride.

3. The sodium chloride evaporation mother liquor treatment device according to claim 2, characterized in that: The evaporation crystallization equipment (3) includes an evaporator and a crystallizer. The evaporator is used to further process the concentrate inside the nanofiltration concentrate tank to precipitate sodium chloride product salt and obtain sodium chloride evaporation mother liquor. At the same time, the obtained nanofiltration concentrate is subjected to freeze crystallization treatment through the crystallizer to precipitate sodium sulfate freeze mother liquor, and then further subjected to evaporation crystallization treatment through the evaporator and crystallizer to precipitate sodium sulfate and sodium chloride mixed salt.

4. The sodium chloride evaporation mother liquor treatment device according to claim 1, characterized in that: The organic matter and biochemical treatment equipment (4) includes an ozone generator, an electrolysis treatment device, a Fenton treatment device, an electrocatalytic treatment device, and a nitrification-denitrification treatment device. The organic matter and biochemical treatment equipment (4) is used to sequentially treat and dilute the sodium chloride evaporation mother liquor and the sodium sulfate evaporation mother liquor obtained in claim 3 to remove nitrate and COD from the mother liquor. The ozone generator contacts the liquid to be treated through a pipeline to carry out an oxidation reaction and remove organic matter. The outlet of the ozone generator is connected to the inlet of the electrolysis treatment device through a pipeline. The outlet of the electrolysis treatment device is connected to the inlet of the Fenton treatment device through a pipeline. The outlet pipeline of the Fenton treatment device is connected to the inlet of the electrocatalytic treatment device. The outlet of the electrocatalytic treatment device is connected to the inlet of the nitrification-denitrification treatment device.

5. The sodium chloride evaporation mother liquor treatment device according to claim 4, characterized in that: The recirculation system (5) includes a connecting pipe and a delivery pump, which are used to transport the treated liquid back to the pretreatment system to form a closed loop, so as to minimize waste discharge and improve resource utilization. The outlet of the nitrification-denitrification treatment device is connected to the inlet of the recirculation system (5) through a pipeline.

6. The sodium chloride evaporation mother liquor treatment device according to claim 1, characterized in that: The mixed salt treatment equipment (6) includes a dryer for treating the mixed salts generated during the evaporation and crystallization process, so as to realize resource utilization.

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