Metallurgical wastewater pretreatment device

Abstract

The utility model discloses a metallurgical wastewater pretreatment device. Metallurgical wastewater comprises clean wastewater, polluted acid wastewater and acidic wastewater, the metallurgical wastewater pretreatment device comprises a vulcanization reaction tank, a neutralization reaction tank, a neutralization reaction water production tank and a softening reaction tank which are sequentially arranged along the treatment direction of waste acid wastewater, the reaction water production tank and the softening reaction tank are sequentially arranged along the treatment direction of the acid wastewater; the coagulative precipitation tank is arranged along the treatment direction of the clean wastewater; effluent of the softening reaction tank and the coagulative precipitation tank enters a subsequent advanced treatment system. The pretreatment device disclosed by the utility model is used for wastewater pretreatment of the whole plant in the non-ferrous metal smelting industry, clean sewage diversion and rain sewage diversion are adopted, water balance, energy conservation and consumption reduction of the whole plant are realized, and finally resource utilization of the whole plant is realized.

Description

Technical Field

[0001] The utility model relates to the technical field of wastewater treatment, in particular to a metallurgical wastewater pretreatment device, which can be applied to a pretreatment system of non-ferrous metal smelting industry. Background Art

[0002] At present, in the wastewater treatment system of the non-ferrous metal smelting industry, the sources of wastewater are usually divided into initial rainwater and production wastewater; production wastewater mainly includes polluted acid wastewater, acidic wastewater and general production wastewater. Polluted acid wastewater mainly comes from the purification process in the process of acid production from metal smelting flue gas. The wastewater is highly acidic and has a high content of heavy metals; the main sources of acidic wastewater are polluted acid post-treatment liquid, laboratory wastewater, acid mist purification drainage, etc. The wastewater is acidic and has a high content of heavy metals; general production wastewater refers to other wastewater discharged in the production process except polluted acid wastewater and acidic wastewater, mainly including concentrated brine from desalted water stations and softened water stations, indirect cooling drainage, road and ordinary ground washing water, etc. The pH of the wastewater is close to neutral and contains a small amount of heavy metals.

[0003] Conventional engineering design is to mix initial rainwater, general production wastewater, dirty acid wastewater and acidic wastewater for treatment. However, there are great disadvantages for smelters; the reason is that initial rainwater and general production wastewater (collectively referred to as clean wastewater) have low heavy metal content and pH close to neutral. Only a small amount of alkali is needed for neutralization and precipitation to meet the "Water Quality for Industrial Water Use in Urban Wastewater Recycling" (GB / T19923-2005) discharge standard, and the treatment cost is low. However, process wastewater (mainly dirty acid wastewater and acidic wastewater) has complex composition, high arsenic and heavy metal content, complex treatment process, large dosage of reagents, and high cost. Therefore, the key is to separate clean and dirty water, rainwater and sewage, strictly control the generation of heavy metal wastewater, and balance the generation and utilization of heavy metal water. Utility Model Content

[0004] In view of the deficiencies in the prior art, the utility model provides a metallurgical wastewater pretreatment device.

[0005] The utility model discloses a metallurgical wastewater pretreatment device, wherein the metallurgical wastewater includes clean wastewater (initial rainwater and general production wastewater), polluted acid wastewater and acidic wastewater; the metallurgical wastewater pretreatment device includes:

[0006] The sulfidation reaction tank, neutralization reaction tank, neutralization reaction water production tank and softening reaction tank are arranged in sequence along the treatment direction of the polluted acid wastewater;

[0007] The reaction water production tank and the softening reaction tank are sequentially arranged along the treatment direction of the acidic wastewater;

[0008] Coagulation and sedimentation tanks are set up along the treatment direction of clean wastewater;

[0009] The effluent from the softening reaction tank and the coagulation sedimentation tank enters the subsequent deep treatment system.

[0010] As a further improvement of the utility model, the dosing port of the sulfidation reaction tank is connected to a sulfiding agent dosing unit, and the sulfiding agent dosing unit is composed of a dissolving tank, an agitator and a dosing metering pump; the mud outlet of the sulfidation reaction tank is connected to a first sludge dewatering machine, and the filtrate of the first sludge dewatering machine enters the neutralization reaction tank.

[0011] As a further improvement of the utility model, the dosing port of the neutralization reaction tank is connected to a lime dosing unit, which is composed of a dissolving tank, an agitator and a dosing metering pump, and the water distribution of the lime dosing unit comes from the neutralization reaction water production tank; the mud outlet of the neutralization reaction tank is connected to a second sludge dewatering machine, and the filtrate of the second sludge dewatering machine enters the neutralization reaction water production tank.

[0012] As a further improvement of the utility model, aeration pipes are vertically arranged at the four corners of the sedimentation zone of the neutralization reaction tank, and the four aeration pipes are connected in parallel to the compressed air delivery pipe of the plant area; a mud level meter for monitoring the mud level is provided at the bottom of the sedimentation zone, and the mud outlet at the bottom of the sedimentation zone is connected to the second sludge dewatering machine through at least one sludge pump.

[0013] As a further improvement of the utility model, each aeration pipe is provided with a manual valve, and the delivery pipe of the plant area compressed air is provided with a manual valve and an automatic valve, and during normal operation, the manual valve is in an open state;

[0014] The mud level meter, sludge pump and automatic valve are linked together. When the mud level meter detects that the mud level in the sedimentation area reaches a preset height, the sludge pump starts to transport the sludge, and the automatic valve opens for aeration and purging.

[0015] As a further improvement of the utility model, the distance between the air outlet at the lower end of the aeration pipe and the pool bottom is 150-250 mm, preferably 200 mm; the number of sludge pumps is 2, and the two sludge pumps are arranged in parallel, one for backup and the other for use, or opened / closed at the same time.

[0016] As a further improvement of the utility model, the dosing port of the softening reaction tank is connected to a sodium hydroxide dosing unit and a sodium carbonate dosing unit, and the sodium hydroxide dosing unit and the sodium carbonate dosing unit are both composed of a dissolving tank, an agitator and a dosing metering pump; the mud outlet of the softening reaction tank is connected to a third sludge dewatering machine, and the filtrate of the third sludge dewatering machine enters a subsequent deep treatment system.

[0017] As a further improvement of the utility model, the mud outlet of the coagulation sedimentation tank is connected to the third sludge dewatering machine.

[0018] Compared with the prior art, the beneficial effects of the utility model are:

[0019] 1. The utility model is used for pretreatment of wastewater in the whole plant of non-ferrous metal smelting industry. It adopts clean and dirty water separation, rain and sewage separation, so as to achieve water balance in the whole plant, save energy and reduce consumption, and finally realize resource utilization of the whole plant.

[0020] 2. The water source of the lime dosing device of the neutralization reaction device of the utility model adopts the water produced by the neutralization reaction for dosing, thereby saving production water, optimizing operation costs, and saving energy and reducing consumption.

[0021] 3. The utility model adds an automatic aeration device at the bottom of the sedimentation zone of the neutralization reaction device, and sets a mud level meter in the sedimentation zone, which is interlocked with the sludge pump. The sludge is discharged regularly according to the height of the mud level meter, and aeration and purging are performed while the sludge is discharged. The problem of sludge compaction can be effectively solved, and the shutdown period for maintenance and the cost of cleaning sludge can be reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the metallurgical wastewater pretreatment device disclosed in the utility model;

[0023] Figure 2 for Figure 1 A schematic diagram of the structure of the precipitation zone of the neutralization reaction tank;

[0024] Figure 3 for Figure 1 The plan layout of the sedimentation area of ​​the neutralization reaction tank.

[0025] In the figure:

[0026] 10. Sulfidation reaction tank; 11. Sulfiding agent dosing unit; 12. First sludge dewatering machine; 20. Neutralization reaction tank; 21. Lime dosing unit; 22. Mud level meter; 23. Sludge pump; 24. Second sludge dewatering machine; 25. Aeration pipe; 26. Manual valve; 27. Automatic valve; 28. Sedimentation area; 30. Neutralization reaction water production tank; 40. Softening reaction tank; 41. Sodium hydroxide dosing unit; 42. Sodium carbonate dosing unit; 43. Third sludge dewatering machine; 50. Coagulation sedimentation tank. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all of the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0028] The utility model is further described in detail below in conjunction with the accompanying drawings:

[0029] In view of the characteristics of metallurgical wastewater, such as many types and large differences in components, the utility model specifically proposes a metallurgical wastewater pretreatment device. Among them, for clean wastewater: mainly initial rainwater and general wastewater, it is collected separately and directly treated by coagulation and sedimentation. For process wastewater: mainly dirty acid wastewater and acidic wastewater, it is treated separately in the early stage and combined in the later stage; that is, the dirty acid wastewater is first subjected to a sulfidation reaction to remove most of the heavy metals, fluoride ions and arsenides, and the harmful waste residues after dehydration are sent to the hazardous waste storage for treatment; the supernatant produces gypsum through a neutralization reaction. The dirty acid supernatant is combined with the acidic wastewater for softening treatment, and the softened clean water enters the deep treatment system.

[0030] Specific:

[0031] like Figure 1 As shown, the utility model provides a metallurgical wastewater pretreatment device, the metallurgical wastewater includes clean wastewater (initial rainwater and general production wastewater), polluted acid wastewater and acidic wastewater; the metallurgical wastewater pretreatment device includes: a sulfidation reaction tank 10, a neutralization reaction tank 20, a neutralization reaction water production tank 30, a softening reaction tank 40 and a coagulation sedimentation tank 50; the sulfidation reaction tank 10, the neutralization reaction tank 20, the neutralization reaction water production tank 30 and the softening reaction tank 40 are sequentially arranged along the treatment direction of the polluted acid wastewater, and the sulfidation reaction tank 10, the neutralization reaction tank 20, the neutralization reaction water production tank 30 and the softening reaction tank 40 are sequentially arranged along the treatment direction of the polluted acid wastewater. The reaction water production tank 30 and the softening reaction tank 40 are arranged in the treatment direction of the acidic wastewater, and the coagulation sedimentation tank 50 is arranged along the treatment direction of the clean wastewater. The effluent of the softening reaction tank 40 and the coagulation sedimentation tank 50 enters the subsequent deep treatment system; that is, the effluent of the acidic wastewater after the sulfidation reaction and the neutralization reaction is mixed with the acidic wastewater and softened together. After the softened effluent and the clean wastewater after coagulation and sedimentation complete the above pretreatment, they enter the subsequent deep treatment system for deep treatment. Furthermore, each of the above-mentioned reaction tanks is also equipped with accessories such as agitators and monitoring instruments, so they are not elaborated in detail here; adjacent and connected reaction tanks are connected by pipelines, and the power for transporting wastewater between the tanks comes from a delivery pump or self-flowing through a liquid level difference under the action of gravity. They are all existing conventional transportation methods, so they are not elaborated in detail here.

[0032] in,

[0033] The dosing port of the sulfidation reaction tank 10 of the utility model is connected with a sulfiding agent dosing unit 11, which is composed of a dissolving tank, an agitator and a dosing metering pump. The agitator is placed in a dissolving tank of the sulfiding agent (existing conventional agent), and the outlet of the dissolving tank is connected to the dosing port of the sulfidation reaction tank 10 through a pipeline, and a dosing metering pump is arranged on the pipeline. The mud outlet of the sulfidation reaction tank 10 is connected with a first sludge dewatering machine 12, and the first sludge dewatering machine 12 can adopt a plate and frame filter press, and the filtrate of the first sludge dewatering machine 12 enters the neutralization reaction tank 20; further, before the acid wastewater enters the sulfidation reaction tank 10, it can first enter a regulating tank (not shown in the figure) for homogenization regulation. The utility model performs sulfidation treatment on the acid wastewater through the sulfidation reaction tank 10. Most of the heavy metal ions can be removed by adding a sulfiding agent into the sulfidation reaction tank 10. The sulfidation reaction tank 10 is mainly used to treat wastewater with high concentrations of arsenic and copper ions. Putting the sulfidation reaction before the neutralization reaction can reduce the output of harmful sludge and increase the output of harmless sludge.

[0034] The dosing port of the neutralization reaction tank 20 of the utility model is connected to a lime dosing unit 21, which is composed of a dissolving tank, an agitator and a dosing metering pump. The agitator is placed in the lime dissolving tank, and the dissolving tank outlet is connected to the dosing port of the neutralization reaction tank 20 through a pipeline, and a dosing metering pump is arranged on the pipeline. The water required by the lime dissolving tank comes from the neutralization reaction water production tank 30, so as to save production water, optimize operation costs, and save energy and reduce consumption. The mud outlet of the neutralization reaction tank 20 is connected to a second sludge dewatering machine 24, and the second sludge dewatering machine 24 can adopt a plate and frame filter press, and the filtrate of the second sludge dewatering machine 24 enters the neutralization reaction water production tank 30.

[0035] Furthermore, the neutralization reaction tank 20 of the utility model may include a water collection area, a drug-dosing neutralization reaction area and a sedimentation area which are connected in sequence. The water collection area is used to receive the effluent from the sulfidation reaction tank 10, and the drug-dosing neutralization reaction area is used to perform a drug-dosing neutralization reaction on the wastewater collected in the water collection area, and then send it to the sedimentation area 28 for sedimentation treatment; that is, the neutralization reaction tank 20 treats the clean water of the sulfidation reaction, and adjusts the pH of the inlet water by adding lime. In this process, most of the heavy metals, fluoride ions and arsenides in the raw water are removed, and sulfate and calcium ions are also precipitated in the form of gypsum.

[0036] like Figure 2 , 3As shown, the utility model vertically arranges aeration pipes 25 at the four corners of the sedimentation area of ​​the neutralization reaction tank 20, and the four aeration pipes 25 are connected in parallel to the delivery pipe of the compressed air in the plant area, and the distance between the air outlet at the lower end of the aeration pipe 25 and the bottom of the tank is 150-250 mm, preferably 200 mm; each aeration pipe 25 is provided with a manual valve 26, and the delivery pipe of the compressed air in the plant area is provided with a manual valve 26 and an automatic valve 27. When working normally, the manual valve 26 is in an open state. A mud level meter 22 for monitoring mud level is provided at the bottom of the sedimentation area 28. The mud outlet at the bottom of the sedimentation area is connected to the second sludge dewatering machine 24 through at least one sludge pump 23. Preferably, two sludge pumps 23 are provided, and the two sludge pumps are provided in parallel, one for backup and the other for use, or opened / closed at the same time. The mud level meter 22, the sludge pump 23 and the automatic valve 27 are linked, or the mud level meter 22 is connected to the input end of the controller, and the sludge pump 23 and the automatic valve 27 are connected to the output end of the controller. When the mud level meter 22 detects that the mud level in the sedimentation area reaches a preset height, the sludge pump 23 is controlled to start the sludge transportation, and the automatic valve 27 is opened for aeration and purging. At the same time, the aeration pipe 25 can also be aerated separately according to demand.

[0037] The dosing port of the softening reaction tank 40 of the utility model is connected to a sodium hydroxide dosing unit 41 and a sodium carbonate dosing unit 42. Both the sodium hydroxide dosing unit 41 and the sodium carbonate dosing unit 42 are composed of a dissolving tank, an agitator and a dosing metering pump. The agitator is placed in the sodium hydroxide dissolving tank and the sodium carbonate dissolving tank. The drug outlets of the sodium hydroxide dissolving tank and the sodium carbonate dissolving tank are connected to the dosing port of the softening reaction tank 40 through a pipeline, and a dosing metering pump is provided on the pipeline. The mud outlet of the softening reaction tank 40 is connected to a third sludge dewatering machine 43. The third sludge dewatering machine 43 can adopt a plate and frame filter press. The filtrate of the third sludge dewatering machine 43 enters the subsequent deep treatment system. The utility model combines the two streams of water, the neutralization reaction effluent and the acidic wastewater, through the softening reaction tank 40, and adjusts the pH of the inlet water by adding sodium hydroxide, and adds a soda ash solution to generate calcium and magnesium ion precipitation. In this process, most of the Ca in the raw water is removed. 2+ Mg 2+ , CO2 and SiO2 are removed and the effluent water is softened.

[0038] The coagulation sedimentation tank 50 of the utility model may include a regulating tank, a coagulation tank, a flocculation tank and a sedimentation tank connected in sequence. The clean wastewater may be homogenized and regulated first in the regulating tank, and then coagulated, flocculated and precipitated through the coagulation tank, the flocculation tank and the sedimentation tank. The coagulation tank and the flocculation tank are connected with corresponding dosing units, and each dosing unit is composed of a dissolving tank, an agitator and a dosing metering pump, which is the same as the above structure, so it will not be elaborated in detail here. The mud outlet of the coagulation sedimentation tank 50 is connected with a third sludge dewatering machine 43, which can choose to share a sludge dewatering machine with the softening reaction tank 40. The utility model performs coagulation and sedimentation treatment on the clean wastewater through the coagulation sedimentation tank 50, and removes heavy metals, suspended matter, etc. in the water by adding PFS, PAM and other agents, so as to ensure the water quality of the deep treatment inlet and reduce the operating load of the deep treatment.

[0039] The advantages of the utility model are:

[0040] 1. The utility model is used for pretreatment of wastewater in the whole plant of non-ferrous metal smelting industry. It adopts clean and dirty water separation, rain and sewage separation, so as to achieve water balance in the whole plant, save energy and reduce consumption, and finally realize resource utilization of the whole plant.

[0041] 2. The water source of the lime dosing device of the neutralization reaction device of the utility model adopts the water produced by the neutralization reaction for dosing, thereby saving production water, optimizing operation costs, and saving energy and reducing consumption.

[0042] 3. The utility model adds an automatic aeration device at the bottom of the sedimentation zone of the neutralization reaction device, and sets a mud level meter in the sedimentation zone, which is interlocked with the sludge pump. The sludge is discharged regularly according to the height of the mud level meter, and aeration and purging are performed while the sludge is discharged. The sludge compaction problem can be effectively solved, the shutdown period for maintenance and the cost of cleaning sludge can be reduced, and energy saving and consumption reduction of the whole plant can be fully realized.

[0043] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may be subject to various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A pretreatment device for metallurgical wastewater, wherein the metallurgical wastewater includes clean wastewater, acid wastewater and acidic wastewater; characterized in that: The metallurgical wastewater pretreatment device comprises: The sulfidation reaction tank, neutralization reaction tank, neutralization reaction water production tank and softening reaction tank are arranged in sequence along the treatment direction of the polluted acid wastewater; The reaction water production tank and the softening reaction tank are sequentially arranged along the treatment direction of the acidic wastewater; Coagulation and sedimentation tanks are set up along the treatment direction of clean wastewater; The effluent from the softening reaction tank and the coagulation sedimentation tank enters the subsequent deep treatment system.

2. The metallurgical wastewater pretreatment device according to claim 1, characterized in that: The dosing port of the sulfidation reaction tank is connected with a sulfiding agent dosing unit, which is composed of a dissolving tank, an agitator and a dosing metering pump; the mud outlet of the sulfidation reaction tank is connected with a first sludge dewatering machine, and the filtrate of the first sludge dewatering machine enters the neutralization reaction tank.

3. The metallurgical wastewater pretreatment device according to claim 1, characterized in that: The dosing port of the neutralization reaction tank is connected to a lime dosing unit, which consists of a dissolving tank, an agitator and a dosing metering pump, and the water distribution of the lime dosing unit comes from the neutralization reaction water production tank; the mud outlet of the neutralization reaction tank is connected to a second sludge dewatering machine, and the filtrate of the second sludge dewatering machine enters the neutralization reaction water production tank.

4. The metallurgical wastewater pretreatment device according to claim 3, characterized in that: Aeration pipes are vertically arranged at the four corners of the sedimentation area of ​​the neutralization reaction tank, and the four aeration pipes are connected in parallel to the compressed air delivery pipe of the factory area; a mud level meter for monitoring the mud level is provided at the bottom of the sedimentation area, and the mud outlet at the bottom of the sedimentation area is connected to the second sludge dewatering machine through at least one sludge pump.

5. The metallurgical wastewater pretreatment device according to claim 4, characterized in that: Each aeration pipe is provided with a manual valve, and the delivery pipe of the plant area compressed air is provided with a manual valve and an automatic valve. During normal operation, the manual valve is in an open state; The mud level meter, sludge pump and automatic valve are linked together. When the mud level meter detects that the mud level in the sedimentation area reaches a preset height, the sludge pump starts to transport the sludge, and the automatic valve opens for aeration and purging.

6. The metallurgical wastewater pretreatment device according to claim 4, characterized in that: The distance between the air outlet at the lower end of the aeration pipe and the bottom of the pool is 150-250 mm; the number of sludge pumps is 2, and the two sludge pumps are arranged in parallel, one for backup and the other for use, or opened / closed at the same time.

7. The metallurgical wastewater pretreatment device according to claim 1, characterized in that: The dosing port of the softening reaction tank is connected to a sodium hydroxide dosing unit and a sodium carbonate dosing unit, and the sodium hydroxide dosing unit and the sodium carbonate dosing unit are both composed of a dissolving tank, an agitator and a dosing metering pump; the mud outlet of the softening reaction tank is connected to a third sludge dewatering machine, and the filtrate of the third sludge dewatering machine enters a subsequent deep treatment system.

8. The metallurgical wastewater pretreatment device according to claim 7, characterized in that: The mud outlet of the coagulation sedimentation tank is connected to the third sludge dewatering machine.

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