Industrial strong brine treatment system with high recycling rate

Abstract

The utility model discloses a high-recycling-rate industrial strong brine treatment system which comprises a homogenizing unit, a coagulating sedimentation unit, a water regeneration unit, a salt separation crystallization unit, a carnallite crystallization unit, a harmless treatment unit and a regenerated salt metering unit which are connected in sequence, the regenerated salt metering unit is also respectively connected with inlets of the homogenizing unit, the coagulating sedimentation unit, the water regeneration unit, the salt separation crystallization unit and the carnallite crystallization unit. According to the treatment system, the generated mixed salt is distributed to each treatment unit, so that the emission amount of chemical waste salt is reduced, the environmental influence of the waste salt is reduced, the industrial strong brine treatment system can be thoroughly and circularly operated, zero emission in a real sense is realized, and the treatment cost and the operation cost of the chemical waste salt are reduced.

Description

Technical Field

[0001] The utility model belongs to the field of industrial wastewater resource utilization, and specifically relates to an industrial concentrated brine treatment system with a high resource utilization rate. Background Art

[0002] At present, the zero-discharge treatment process for high-salt wastewater has basically matured. The zero-discharge process for wastewater in general industry consists of four parts: pretreatment, nanofiltration (NF), reverse osmosis (RO) concentration, and evaporation crystallization. Zero-discharge treatment of high-salt wastewater can not only reduce wastewater pollution, but also play an important role in saving water and recycling water resources. However, there are still many problems in the operation of the zero-discharge process for wastewater, among which the treatment of waste salt produced by evaporation and crystallization is the most difficult. Nowadays, the waste salt disposal process is not yet mature, and there is a lack of complete relevant regulations for the disposal of waste salt to guide the industry to carry out harmless treatment of waste salt, let alone return to the front end of the water treatment system for recycling treatment, which leads to a significant increase in operating costs and waste salt disposal costs.

[0003] If an industrial brine treatment system could be provided to render waste salt harmless and reuse the resulting regenerated salt, true zero emissions could be achieved. Utility Model Content

[0004] In view of the defects of the prior art, the utility model provides an industrial brine treatment system and method with a high resource utilization rate, which can achieve the cyclic operation of the industrial brine treatment system and realize zero emission in the true sense.

[0005] An industrial brine treatment system with a high resource utilization rate comprises a homogenizing unit, a coagulation and sedimentation unit, a water regeneration unit, a salt separation crystallization unit, a mixed salt crystallization unit, a harmless treatment unit and a regenerated salt metering unit which are connected in sequence, wherein the regenerated salt metering unit is also respectively connected to the inlets of the homogenizing unit, the coagulation and sedimentation unit, the water regeneration unit, the salt separation crystallization unit and the mixed salt crystallization unit.

[0006] Preferably, the water regeneration unit comprises an ultrafiltration device and a reverse osmosis device connected in sequence, the inlet of the ultrafiltration device is respectively connected to the coagulation and sedimentation unit and the regeneration salt metering unit; the water production outlet of the reverse osmosis device is connected to a water production tank, and the concentrated water outlet of the reverse osmosis device is connected to the salt separation and crystallization unit.

[0007] Preferably, the salt separation crystallization unit includes a nanofiltration device, the inlet of the nanofiltration device is respectively connected to the concentrated water outlet of the reverse osmosis device and the regeneration salt metering unit; the water production outlet of the nanofiltration device is sequentially connected to a first multiple-effect evaporation concentration device and an evaporative crystallizer, and the concentrated water outlet of the nanofiltration device is sequentially connected to a second multiple-effect evaporation concentration device, a freezing crystallizer and a hot melt crystallizer.

[0008] Preferably, the impure salt crystallization unit is an impure salt crystallizer, and the evaporation crystallizer and the freezing crystallizer are both connected to the impure salt crystallization unit.

[0009] Preferably, the harmless treatment unit comprises a pyrolysis device, the pyrolysis device is connected to the regeneration salt metering unit, and the pyrolysis device is also connected to a tail gas treatment unit.

[0010] Preferably, the homogenizing unit is a homogenizing tank or a homogenizing pool.

[0011] Preferably, the coagulation sedimentation unit is a high-density sedimentation tank, and a reagent addition port is provided on the high-density sedimentation tank.

[0012] The regenerated salt metering unit realizes the redistribution of mixed salt, specifically as follows: firstly, the material balance diagram of the system is calculated, and the mixed salt produced by the pyrolysis device is distributed according to the calculation result. The regenerated salt metering unit distributes the mixed salt to the homogenization unit, the coagulation and sedimentation unit, the water regeneration unit, the salt separation crystallization unit, and the miscellaneous salt crystallization unit, respectively, thereby realizing the complete circulation operation of the industrial brine treatment system.

[0013] A method for treating industrial concentrated brine with a high resource utilization rate is carried out using the system of the utility model. The specific method is as follows:

[0014] (i) Industrial brine enters the homogenization unit for mixing, then enters the coagulation and sedimentation unit, where reagents are added to precipitate impurities, and the supernatant enters the water regeneration unit;

[0015] (ii) In the water regeneration unit, the supernatant is further filtered of impurities by an ultrafiltration device, and then enters a reverse osmosis device for concentration. The reverse osmosis produced water enters a water production tank for recycling, and the reverse osmosis concentrated water enters a nanofiltration device in a salt separation and crystallization unit;

[0016] (III) In the salt separation and crystallization unit, the salt is separated by the nanofiltration device, and the nanofiltration water first enters the first multiple-effect evaporation concentration device, and then enters the evaporation crystallizer, and after treatment, the product salt sodium chloride is produced; the nanofiltration concentrated water first enters the second multiple-effect evaporation concentration device, and then enters the freezing crystallizer and the hot melt crystallizer in sequence, and after treatment, the product salt sodium sulfate is produced, and the mother liquors produced by the evaporation crystallizer and the freezing crystallizer are all entered into the mixed salt crystallizer;

[0017] (iv) In the impurity salt crystallizer, impurity salt is produced through crystallization treatment, and the impurity salt enters the pyrolysis device for carbonization to remove impurities, thereby obtaining a mixed salt of sodium chloride and sodium sulfate, which enters the regeneration salt metering unit; the waste gas generated by the pyrolysis device enters the tail gas treatment unit for further treatment;

[0018] (V) In the regenerated salt metering unit, the mixed salt is distributed and enters the homogenization unit, the coagulation and sedimentation unit, the water regeneration unit, the salt separation crystallization unit, and the mixed salt crystallization unit respectively.

[0019] Advantages of the utility model:

[0020] The treatment system of the utility model reduces the discharge of chemical waste salt and the environmental impact of the waste salt by distributing the generated mixed salt to various treatment units, so that the industrial brine treatment system can be completely circulated and operated, achieving true zero emission and reducing the treatment cost and operation cost of chemical waste salt. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a schematic diagram of the structure of the industrial concentrated brine treatment system of the utility model;

[0022] Among them, 1-homogenization unit, 2-coagulation and sedimentation unit, 3-water regeneration unit, 4-salt separation and crystallization unit, 5-miscellaneous salt crystallization unit, 6-harmless treatment unit, 7-regeneration salt metering unit. DETAILED DESCRIPTION

[0023] Example 1

[0024] An industrial concentrated brine treatment system with a high resource utilization rate comprises a homogenizing unit 1, a coagulation and sedimentation unit 2, a water regeneration unit 3, a salt separation crystallization unit 4, a mixed salt crystallization unit 5, a harmless treatment unit 6 and a regeneration salt metering unit 7 which are connected in sequence, wherein the regeneration salt metering unit 7 is also connected to the inlets of the homogenizing unit 1, the coagulation and sedimentation unit 2, the water regeneration unit 3, the salt separation crystallization unit 4 and the mixed salt crystallization unit 5 respectively;

[0025] The method for treating industrial concentrated brine using the industrial concentrated brine treatment system is as follows:

[0026] (i) Industrial brine enters the homogenization unit 1 for mixing, then enters the coagulation and sedimentation unit 2, where reagents are added to precipitate impurities, and the supernatant enters the water regeneration unit 3;

[0027] (ii) In the water regeneration unit 3, the supernatant is further treated, the produced water is recycled, and the concentrated water enters the salt separation crystallization unit 4;

[0028] (iii) after being processed by the salt separation crystallization unit 4, sodium chloride and sodium sulfate are produced, and the mother liquor produced in the salt separation crystallization process enters the impurity salt crystallization unit 5;

[0029] (iv) generating impure salt through the impure salt crystallization unit 5, and the impure salt enters the harmless treatment unit 6 to obtain a mixed salt of sodium chloride and sodium sulfate, and enters the regeneration salt metering unit 7;

[0030] (V) In the regeneration salt metering unit 7, the mixed salt is distributed and enters the homogenization unit 1, the coagulation and sedimentation unit 2, the water regeneration unit 3, the salt separation crystallization unit 4, and the mixed salt crystallization unit 5 respectively.

[0031] Example 2

[0032] Based on Example 1, the water regeneration unit 3 includes an ultrafiltration device and a reverse osmosis device connected in sequence, and the inlet of the ultrafiltration device is respectively connected to the coagulation and sedimentation unit 2 and the regeneration salt metering unit 7; the water production outlet of the reverse osmosis device is connected to a water production tank, and the concentrated water outlet of the reverse osmosis device is connected to the salt separation crystallization unit 4.

[0033] Example 3

[0034] On the basis of Example 2, the salt separation crystallization unit 4 includes a nanofiltration device, the inlet of the nanofiltration device is respectively connected to the concentrated water outlet of the reverse osmosis device and the regeneration salt metering unit 7; the water production outlet of the nanofiltration device is sequentially connected to the first multiple-effect evaporation concentration device and the evaporation crystallizer, and the concentrated water outlet of the nanofiltration device is sequentially connected to the second multiple-effect evaporation concentration device, the freezing crystallizer and the hot melt crystallizer.

[0035] Example 4

[0036] On the basis of Example 3, the impure salt crystallization unit 5 is an impure salt crystallizer (the impure salt crystallizer can adopt the existing technology, such as the evaporation crystallizer in the existing technology), and the evaporation crystallizer and the freezing crystallizer are both connected to the impure salt crystallization unit 5.

[0037] The harmless treatment unit 6 includes a pyrolysis device (the pyrolysis device can adopt existing technology, such as a rotary kiln), the pyrolysis device is connected to the regeneration salt metering unit 7, and the pyrolysis device is also connected to a tail gas treatment unit.

[0038] The homogenizing unit 1 is a homogenizing tank or a homogenizing pool.

[0039] The coagulation sedimentation unit 2 is a high-density sedimentation tank, and a reagent addition port is arranged on the high-density sedimentation tank.

[0040] The regenerated salt metering unit 7 realizes the redistribution of mixed salt, specifically as follows: firstly, the material balance diagram of the system is calculated, and the mixed salt produced by the pyrolysis device is distributed according to the calculation result. The regenerated salt metering unit 7 distributes the mixed salt to the homogenization unit 1, the coagulation and sedimentation unit 2, the water regeneration unit 3, the salt separation crystallization unit 4, and the miscellaneous salt crystallization unit 5, respectively, thereby realizing the complete circulation operation of the industrial brine treatment system.

[0041] A method for treating industrial concentrated brine with a high resource utilization rate is carried out using the system, and the specific method is as follows:

[0042] (I) Industrial brine enters the homogenization unit 1 for mixing to ensure the stability of the system water quality, and then enters the coagulation and sedimentation unit 2, where reagents are added to precipitate impurities and remove SS and Ca 2+ Mg 2+ , Si, F and other impurities, and the supernatant enters the water regeneration unit 3;

[0043] (ii) In the water regeneration unit 3, the supernatant is further filtered of impurities by the ultrafiltration device, and then enters the reverse osmosis device for concentration, the reverse osmosis produced water enters the water production tank for recycling, and the reverse osmosis concentrated water enters the nanofiltration device in the salt separation crystallization unit 4;

[0044] (III) In the salt separation crystallization unit 4, salt is separated by the nanofiltration device, and the nanofiltration product water first enters the first multiple-effect evaporation concentration device, and then enters the evaporation crystallizer, and after treatment, the product salt sodium chloride is produced; the nanofiltration concentrated water first enters the second multiple-effect evaporation concentration device, and then enters the freezing crystallizer and the hot melt crystallizer in sequence, and after treatment, the product salt sodium sulfate is produced, and the mother liquors produced by the evaporation crystallizer and the freezing crystallizer are all entered into the mixed salt crystallizer;

[0045] (iv) In the impurity salt crystallizer, impurity salt is produced through crystallization treatment, and the impurity salt enters the pyrolysis device for carbonization to mainly remove impurities such as TOC, thereby obtaining a mixed salt of sodium chloride and sodium sulfate with a higher purity, which enters the regeneration salt metering unit 7; the waste gas generated by the pyrolysis device enters the tail gas treatment unit for further treatment;

[0046] (V) In the regeneration salt metering unit 7, the material balance diagram of the system is calculated, the mixed salt is distributed according to the calculation result, and the mixed salt is returned to the homogenization unit 1, the coagulation and sedimentation unit 2, the water regeneration unit 3, the salt separation crystallization unit 4, and the miscellaneous salt crystallization unit 5.

Claims

1. An industrial brine treatment system with high resource utilization rate, characterized by: The invention comprises a homogenizing unit (1), a coagulation and sedimentation unit (2), a water regeneration unit (3), a salt separation and crystallization unit (4), a mixed salt crystallization unit (5), a harmless treatment unit (6) and a regeneration salt metering unit (7) which are connected in sequence, wherein the regeneration salt metering unit (7) is also connected to the inlets of the homogenizing unit (1), the coagulation and sedimentation unit (2), the water regeneration unit (3), the salt separation and crystallization unit (4) and the mixed salt crystallization unit (5) respectively.

2. The industrial brine treatment system with high resource utilization rate according to claim 1 is characterized in that: The water regeneration unit (3) comprises an ultrafiltration device and a reverse osmosis device connected in sequence, wherein the inlet of the ultrafiltration device is connected to the coagulation and sedimentation unit (2) and the regeneration salt metering unit (7) respectively; the water production outlet of the reverse osmosis device is connected to a water production tank, and the concentrated water outlet of the reverse osmosis device is connected to the salt separation crystallization unit (4).

3. The industrial brine treatment system with high resource utilization rate according to claim 2 is characterized in that: The salt separation crystallization unit (4) comprises a nanofiltration device, the inlet of the nanofiltration device is respectively connected to the concentrated water outlet of the reverse osmosis device and the regeneration salt metering unit (7); the water output outlet of the nanofiltration device is sequentially connected to a first multiple-effect evaporation concentration device and an evaporation crystallizer, and the concentrated water outlet of the nanofiltration device is sequentially connected to a second multiple-effect evaporation concentration device, a freezing crystallizer and a hot melt crystallizer.

4. The industrial brine treatment system with high resource utilization rate according to claim 3 is characterized in that: The impure salt crystallization unit (5) is an impure salt crystallizer, and the evaporation crystallizer and the freezing crystallizer are both connected to the impure salt crystallization unit.

5. The industrial brine treatment system with high resource utilization rate according to claim 4 is characterized in that: The harmless treatment unit (6) comprises a pyrolysis device, the pyrolysis device is connected to the regeneration salt metering unit (7), and the pyrolysis device is also connected to a tail gas treatment unit.

6. The industrial brine treatment system with high resource utilization rate according to claim 1 is characterized in that: The homogenizing unit (1) is a homogenizing tank or a homogenizing pool.

7. The industrial brine treatment system with high resource utilization rate according to claim 1 is characterized in that: The coagulation sedimentation unit (2) is a high-density sedimentation tank, and a reagent addition port is provided on the high-density sedimentation tank.

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