A hazardous waste mixed salt treatment system

Abstract

The utility model relates to a kind of hazardous waste miscellaneous salt processing system, including incineration module, clarification dehydration module and salt separation crystallization module;Incineration module includes reaction furnace;Clarification dehydration module includes the solubilization pool, clarification removes miscellaneous pool and dehydration machine communicated sequentially;Salt separation crystallization module includes forced circulation evaporator, first crystallization piece and second crystallization piece, the liquid inlet end of forced circulation evaporator is connected with the water outlet end of dehydration machine, the exhaust end of forced circulation evaporator is connected with first crystallization piece, first crystallization piece is used to separate out sodium chloride crystallization, the liquid inlet end of second crystallization piece is communicated with the liquid outlet end of first crystallization piece, and second crystallization piece is used to separate out sodium sulfide crystallization;The system carries out secondary utilization to hazardous waste miscellaneous salt, reduces miscellaneous salt disposal cost, and output sodium chloride salt and sodium sulfide salt can be sold outside processing, improve the social and economic benefits of hazardous waste miscellaneous salt, meet the requirement of high-salt wastewater resource and low consumption energy saving.

Description

Technical Field

[0001] This utility model relates to the field of wastewater treatment technology, and in particular to a hazardous waste salt treatment system. Background Technology

[0002] Wastewater generated by steel and coking enterprises contains recalcitrant organic pollutants. These organic pollutants are soluble and can easily flow into soil, groundwater, and water bodies with rainwater, leading to soil salinization, water pollution, and ecosystem damage. This not only affects the sustainable development of industrial production but also directly impacts public health and ecological security.

[0003] Steel coking wastewater contains a large amount of suspended solids, COD, ammonia nitrogen, cyanide, thiocyanate, chloride ions, and sulfate ions. After treatment by a biological system to remove most of the COD and toxic polymers, the wastewater enters a reclaimed water treatment system to remove ionic impurities before reuse. The concentrated wastewater enters subsequent pretreatment, desalination, and evaporation systems, ultimately yielding reclaimed water, sodium chloride, sodium sulfate, and other salts.

[0004] Most of the aforementioned mixed salts are sent to professional hazardous waste treatment facilities for disposal. However, these mixed salts cannot be utilized as resources, and the treatment costs are high. Utility Model Content

[0005] In view of this, it is necessary to provide a hazardous waste salt treatment system to solve the problem that the salts in wastewater cannot be utilized as resources and that the cost of sending them for external treatment is high.

[0006] This utility model provides a hazardous waste salt treatment system, including an incineration module, a clarification and dehydration module, and a salt separation and crystallization module. The incineration module includes a reactor for incinerating mixed salts, crushed coke powder, and activated carbon sludge to generate a solid sinter containing sodium chloride, sodium sulfide, and impurities. The clarification and dehydration module includes a dissolving tank, a clarification and impurity removal tank, and a dehydrator connected in sequence, so that the solid sinter is sequentially dissolved, precipitated, and dehydrated to form a filtrate. The salt separation and crystallization module includes a forced circulation evaporator, a first crystallizer, and a second crystallizer. The inlet end of the forced circulation evaporator is connected to the outlet end of the dehydrator, and the exhaust end of the forced circulation evaporator is connected to the first crystallizer. The first crystallizer is used to separate sodium chloride crystals, and the outlet end of the first crystallizer is connected to the inlet end of the second crystallizer. The second crystallizer is used to separate sodium sulfide crystals.

[0007] Furthermore, the clarification and impurity removal tank includes a tank body, a mixer, and a first lift pump. The mixer is installed on the tank body, and the mixing end of the mixer extends into the tank body. The top of the tank body is connected to the bottom of the dissolving tank via the first lift pump.

[0008] Furthermore, the clarification and dewatering module also includes a sludge tank, a second lift pump, and a third lift pump. The top of the sludge tank is connected to the bottom of the impurity removal tank via the second lift pump, and the bottom of the sludge tank is connected to the feed end of the dewatering machine via the third lift pump.

[0009] Furthermore, the clarification and dehydration module also includes a dehydration filtrate collection tank and a fourth lift pump. The dehydration filtrate collection tank is connected to the outlet end of the dehydrator, and the dehydration filtrate collection tank is connected to the dissolving tank via the fourth lift pump.

[0010] Furthermore, the first crystallizing element includes a sodium chloride crystallizer, a sodium chloride thickening tank, and a sodium chloride centrifuge connected in sequence. The air inlet of the sodium chloride crystallizer is connected to the exhaust end of the forced circulation evaporator, and the liquid outlet of the sodium chloride centrifuge is connected to the liquid inlet of the second crystallizing element.

[0011] Furthermore, the second crystallizing element includes a sodium chloride mother liquor collection tank, a fifth lift pump, and a sodium sulfide refrigeration heat exchanger, a sodium sulfide refrigeration crystallizer, a sodium sulfide refrigeration thickening tank, and a sodium sulfide refrigeration centrifuge connected in sequence. The sodium chloride mother liquor collection tank is connected to the discharge end of the sodium chloride centrifuge, and the sodium chloride mother liquor collection tank is connected to the inlet end of the sodium sulfide refrigeration heat exchanger via the fifth lift pump.

[0012] Furthermore, the salt separation crystallization module also includes a residual liquid collection tank and a sixth lift pump. The residual liquid collection tank is connected to the discharge end of the sodium sulfide refrigerated centrifuge, and the residual liquid collection tank is connected to the inlet end of the salt separation crystallization module via the sixth lift pump.

[0013] Furthermore, it also includes a waste heat recovery module, which includes a waste heat boiler and a flue gas dust removal device. The exhaust end of the reactor is connected to the inlet end of the waste heat boiler, and the exhaust end of the waste heat boiler is connected to the inlet end of the flue gas dust removal device.

[0014] Furthermore, the waste heat recovery module also includes a demineralized water tank and a demineralized water pump, wherein the demineralized water tank is connected to the waste heat boiler via the demineralized water pump.

[0015] Furthermore, the incineration module also includes a miscellaneous salt warehouse, a crushed coke powder warehouse, and a coking wastewater activated carbon sludge warehouse, the discharge ends of which are all connected to the feed end of the reactor.

[0016] Compared with existing technologies, the incineration of mixed salts, coke powder, and activated carbon sludge in a reactor can effectively remove organic matter, high concentrations of phenols, heterocyclic substances, and other combustibles from the mixed salts. Simultaneously, the sodium sulfate in the mixed salts reacts with the carbon elements contained in the coke powder and activated carbon sludge to produce sodium sulfide and carbon dioxide. The sodium chloride contained in the mixed salts and the sodium sulfide produced by the reaction are discharged from the reactor and cooled to form a solid sintered material of sodium chloride, sodium sulfide, and impurities. The solid sintered material is added to a dissolving tank for dissolution, and the dissolved solution is introduced into a clarification and impurity removal tank. By adding flocculants and other agents, a precipitate is generated. The precipitate is introduced into a dewatering machine for dehydration to obtain sodium chloride solution and sodium sulfide solution. Sodium chloride crystals and sodium sulfide crystals can be obtained sequentially through a forced circulation evaporator, a first crystallizer, and a second crystallizer. This system enables the secondary utilization of hazardous waste salts, reducing disposal costs while producing sodium chloride and sodium sulfide salts that can be sold for further processing, thus improving the socio-economic benefits of hazardous waste salts. It meets the requirements for resource utilization and low-energy consumption of high-salt wastewater and is suitable for the green circular development needs of industries such as coal chemical, metallurgy, and steel. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the overall structure of the hazardous waste salt treatment system provided in this embodiment of the utility model; Figure 2 for Figure 1 Schematic diagram of the incineration module; Figure 3 for Figure 1 Schematic diagram of the clarification and dehydration module; Figure 4 for Figure 1 Schematic diagram of the structure of the salt crystallization module; Figure 5 for Figure 1 A schematic diagram of the waste heat recovery module equipped in the reactor. Detailed Implementation

[0018] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of this application and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not intended to limit the scope of the present invention.

[0019] First, it should be noted that the price of industrial-grade sodium chloride is 100 yuan / ton, and the price of industrial-grade sodium sulfate is 150 yuan / ton; as hazardous waste, the cost of external disposal of miscellaneous salts is 2,000 to 3,000 yuan / ton. Based on this, this application is used to recover sodium chloride and sodium sulfate from hazardous waste miscellaneous salts, thereby improving production efficiency and reducing the cost of miscellaneous salt disposal.

[0020] like Figure 1As shown in the figure, this utility model provides a hazardous waste salt treatment system, including an incineration module 100, a clarification and dehydration module 200, and a salt separation and crystallization module 300. The incineration module 100 includes a reactor 110 for incinerating mixed salts, coke powder, and activated carbon sludge to generate a solid sinter containing sodium chloride, sodium sulfide, and impurities. The clarification and dehydration module 200 includes a dissolving tank 210, a clarification and impurity removal tank 220, and a dewatering machine 230 connected in sequence, for the solid sinter to undergo dissolution, precipitation, and crystallization in sequence. After dehydration, a filtrate is formed; the salt separation and crystallization module 300 includes a forced circulation evaporator 310, a first crystallizer 320, and a second crystallizer 330. The liquid inlet of the forced circulation evaporator 310 is connected to the water outlet of the dehydrator 230, and the exhaust end of the forced circulation evaporator 310 is connected to the first crystallizer 320. The first crystallizer 320 is used to separate sodium chloride crystals, and the liquid outlet of the first crystallizer 320 is connected to the liquid inlet of the second crystallizer 330. The second crystallizer 330 is used to separate sodium sulfide crystals.

[0021] During implementation, miscellaneous salts, coke powder, and activated carbon sludge are introduced into reactor 110 for incineration, which can effectively remove organic matter, high concentrations of phenols, heterocyclic substances, and other combustible substances from the miscellaneous salts. At the same time, the sodium sulfate in the miscellaneous salts reacts with the carbon elements contained in the coke powder and activated carbon sludge to generate sodium sulfide and carbon dioxide. The sodium chloride contained in the miscellaneous salts and the sodium sulfide generated by the reaction are discharged from reactor 110 and cooled to form a solid sintered material of sodium chloride, sodium sulfide, and impurities. The solid sintered material is added to dissolving tank 210 for dissolution, and the dissolved solution is introduced into clarification and impurity removal tank 220. By adding flocculants and other agents, precipitates are generated. The precipitates are introduced into dewatering machine 230 for dehydration to obtain sodium chloride solution and sodium sulfide solution. Sodium chloride crystals and sodium sulfide crystals can be obtained sequentially through forced circulation evaporator 310, first crystallizer 320, and second crystallizer 330.

[0022] This system enables the secondary utilization of hazardous waste salts, reducing disposal costs while producing sodium chloride and sodium sulfide salts that can be sold for further processing, thus improving the socio-economic benefits of hazardous waste salts. It meets the requirements for resource utilization and low-energy consumption of high-salt wastewater and is suitable for the green circular development needs of industries such as coal chemical, metallurgy, and steel.

[0023] The incineration module 100 in this embodiment includes a reactor 110 for incinerating miscellaneous salts, crushed coke powder, and activated carbon sludge to generate a solid sinter containing sodium chloride, sodium sulfide, and impurities. The reactor 110 is a conventional structure that will be apparent to those skilled in the art, and will not be elaborated upon further here.

[0024] In this process, when the mixed salts, coke powder, and activated carbon sludge are incinerated in the incinerator, the organic matter, high concentrations of phenols, heterocyclic compounds, and other combustible substances in the mixed salts are first removed. Subsequently, the sodium sulfate in the mixed salts reacts with the carbon elements contained in the coke powder and activated carbon sludge to produce sodium sulfide and carbon dioxide. Finally, the sodium chloride contained in the mixed salts and the sodium sulfide produced in the reaction are discharged through reactor 110 and cooled.

[0025] It is understandable that the generated sodium sulfide will react with water vapor and carbon dioxide to produce sodium carbonate and hydrogen sulfide. In order to suppress the generation of the above side reactions, the temperature of the reactor 110 needs to be controlled between 1000℃ and 1100℃, and the mass ratio of sodium sulfate to carbon element needs to be controlled at 1:0.3 to reduce the generation of hydrogen sulfide.

[0026] like Figure 2 As shown, in order to facilitate the separate storage of miscellaneous salts, crushed coke powder, and activated carbon sludge, in one embodiment, the incineration module 100 further includes a miscellaneous salt storage room 120, a crushed coke powder storage room 130, and a coking wastewater activated carbon sludge storage room 140. The discharge ends of the miscellaneous salt storage room 120, the crushed coke powder storage room 130, and the coking wastewater activated carbon sludge storage room 140 are all connected to the feed end of the reactor 110.

[0027] Among them, the coke powder generated during the coking process and the activated carbon sludge generated from the biochemical treatment of coking wastewater can be rationally reused through the above treatment.

[0028] After the solid sinter is formed, in order to facilitate the storage and cooling of the solid sinter, in one embodiment, the incineration module 100 also includes a slag storage room 150 for storing the solid sinter.

[0029] It is understandable that materials can be transferred via screw conveyor M and / or material transfer trolley N.

[0030] like Figure 3 As shown, the clarification and dehydration module 200 in this embodiment includes a dissolving tank 210, a clarification and impurity removal tank 220 and a dehydrator 230 connected in sequence, so that the solid sintered material can be dissolved, precipitated and dehydrated in sequence to form filtrate.

[0031] In one embodiment, the clarification and impurity removal tank 220 includes a tank body, a stirrer, and a first lift pump 211. The stirrer is installed on the tank body, and the stirring end of the stirrer extends into the tank body. The top of the tank body is connected to the bottom of the dissolving tank 210 via the first lift pump 211.

[0032] The residue from reactor 110 (i.e., the solid sinter described above) can be transported to dissolving tank 210 via screw conveyor M and / or material transfer trolley N, where it is dissolved by stirring and adding chemicals. The dissolved wastewater is then pumped from dissolving tank 210 to clarification and impurity removal tank 220, where coagulants and flocculants are added to cause suspended impurities to settle.

[0033] In one embodiment, the clarification and dewatering module 200 further includes a sludge tank 221, a second lift pump 222 and a third lift pump 223. The top of the sludge tank 221 is connected to the bottom of the impurity removal tank via the second lift pump 222, and the bottom of the sludge tank 221 is connected to the feed end of the dewatering machine 230 via the third lift pump 223.

[0034] To facilitate the temporary storage of sludge and provide time for sludge concentration, in one embodiment, the clarification and dewatering module 200 further includes a dewatering filtrate collection tank 231 and a fourth lift pump 232. The dewatering filtrate collection tank 231 is connected to the outlet end of the dewatering machine 230, and the dewatering filtrate collection tank 231 is connected to the dissolving tank 210 via the fourth lift pump 232.

[0035] The precipitated impurities are temporarily stored in the sludge tank 221 via the second lift pump 222. After the sludge is concentrated, it is sent to the dewatering machine 230 via the third lift pump 223. The dewatering machine 230 presses the wastewater into mud cakes with a moisture content of about 65%. The mud cakes are sent to the ash and slag silo 240 for batching via the screw conveyor M and / or the material transfer trolley N. The filtrate produced by the dewatering machine 230 is discharged into the dewatering filtrate collection tank 231 and sent to the salt separation and crystallization module 300 for treatment via the fourth lift pump 232.

[0036] like Figure 4 As shown, the salt separation crystallization module 300 in this embodiment includes a forced circulation evaporator 310, a first crystallizer 320, and a second crystallizer 330. The liquid inlet of the forced circulation evaporator 310 is connected to the water outlet of the dehydrator 230, and the exhaust end of the forced circulation evaporator 310 is connected to the first crystallizer 320. The first crystallizer 320 is used to separate sodium chloride crystals, and the liquid outlet of the first crystallizer 320 is connected to the liquid inlet of the second crystallizer 330. The second crystallizer 330 is used to separate sodium sulfide crystals.

[0037] In one embodiment, the first crystallizer 320 includes a sodium chloride crystallizer 321, a sodium chloride thickening tank 322, and a sodium chloride centrifuge 323 connected in sequence. The air inlet of the sodium chloride crystallizer 321 is connected to the exhaust end of the forced circulation evaporator 310, and the liquid outlet of the sodium chloride centrifuge 323 is connected to the liquid inlet of the second crystallizer 330.

[0038] In one embodiment, the second crystallizer 330 includes a sodium chloride mother liquor collection tank 331, a fifth lift pump 332, and a sodium sulfide refrigeration heat exchanger 333, a sodium sulfide refrigeration crystallizer 334, a sodium sulfide refrigeration thickening tank 335, and a sodium sulfide refrigeration centrifuge 336 connected in sequence. The sodium chloride mother liquor collection tank 331 is connected to the discharge end of the sodium chloride centrifuge 323, and the sodium chloride mother liquor collection tank 331 is connected to the inlet end of the sodium sulfide refrigeration heat exchanger 333 via the fifth lift pump 332.

[0039] The salt separation and crystallization module 300 also includes a residual liquid collection tank 340 and a sixth lift pump 341. The residual liquid collection tank 340 is connected to the discharge end of the sodium sulfide refrigerated centrifuge 336, and the residual liquid collection tank 340 is connected to the inlet end of the salt separation and crystallization module 300 via the sixth lift pump 341. That is, the collected residual liquid can be returned to the dehydrated filtrate collection tank 231 through the sixth lift pump 341.

[0040] In one embodiment, the salt separation crystallization module 300 further includes a finished product storage warehouse 350 for storing sodium chloride and sodium sulfide.

[0041] like Figure 5 As shown, this embodiment also includes a waste heat recovery module 400, which includes a waste heat boiler 410 and a flue gas dust removal device 420. The exhaust end of the reactor 110 is connected to the air inlet end of the waste heat boiler 410, and the exhaust end of the waste heat boiler 410 is connected to the air inlet end of the flue gas dust removal device 420.

[0042] In one embodiment, the waste heat recovery module 400 further includes a demineralized water tank 430 and a demineralized water pump 440, with the demineralized water tank 430 connected to the waste heat boiler 410 via the demineralized water pump 440. Demineralized water from the plant area first enters the demineralized water tank 430, is pressurized by the demineralized water pump 440, and then enters the waste heat boiler 410. The low-pressure steam generated after being heated by flue gas can be sent to the salt separation and crystallization module 300 and other steam users in the plant area.

[0043] Workflow: Mixed salts, coke powder, and activated carbon sludge are introduced into reactor 110 for incineration, which can effectively remove organic matter, high concentrations of phenols, heterocyclic substances, and other combustible substances from the mixed salts. At the same time, the sodium sulfate in the mixed salts reacts with the carbon elements contained in the coke powder and activated carbon sludge to generate sodium sulfide and carbon dioxide. The sodium chloride contained in the mixed salts and the sodium sulfide generated by the reaction are discharged from reactor 110 and cooled to form a solid sintered material of sodium chloride, sodium sulfide, and impurities. The solid sintered material is added to dissolving tank 210 for dissolution, and the dissolved solution is introduced into clarification and impurity removal tank 220. By adding flocculants and other agents, precipitates are generated. The precipitates are introduced into dewatering machine 230 for dehydration to obtain sodium chloride solution and sodium sulfide solution. Sodium chloride crystals and sodium sulfide crystals can be obtained sequentially through forced circulation evaporator 310, first crystallizer 320, and second crystallizer 330.

[0044] Compared with existing technologies: This system enables the secondary utilization of hazardous waste salts, reducing disposal costs while producing sodium chloride and sodium sulfide salts that can be sold for further processing, thus improving the socio-economic benefits of hazardous waste salts. It meets the requirements for resource utilization and low-energy consumption of high-salt wastewater and is suitable for the green circular development needs of industries such as coal chemical, metallurgy, and steel.

[0045] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present utility model should be included within the protection scope of the present utility model.

Claims

1. A hazardous waste salt treatment system, characterized in that, include: The incineration module includes a reactor for incinerating miscellaneous salts, crushed coke powder, and activated carbon sludge to produce a solid sinter containing sodium chloride, sodium sulfide, and impurities. The clarification and dehydration module includes a dissolving tank, a clarification and impurity removal tank, and a dehydrator connected in sequence, so that the solid sintered material is dissolved, precipitated, and dehydrated in sequence to form a filtrate; The salt separation and crystallization module includes a forced circulation evaporator, a first crystallizer, and a second crystallizer. The liquid inlet of the forced circulation evaporator is connected to the water outlet of the dehydrator, and the exhaust outlet of the forced circulation evaporator is connected to the first crystallizer. The first crystallizer is used to separate sodium chloride crystals, and the liquid outlet of the first crystallizer is connected to the liquid inlet of the second crystallizer. The second crystallizer is used to separate sodium sulfide crystals.

2. The hazardous waste salt treatment system according to claim 1, characterized in that, The clarification and impurity removal tank includes a tank body, a mixer, and a first lift pump. The mixer is installed on the tank body, and the mixing end of the mixer extends into the tank body. The top of the tank body is connected to the bottom of the dissolving tank via the first lift pump.

3. The hazardous waste salt treatment system according to claim 1, characterized in that, The clarification and dewatering module also includes a sludge tank, a second lift pump, and a third lift pump. The top of the sludge tank is connected to the bottom of the impurity removal tank via the second lift pump, and the bottom of the sludge tank is connected to the feed end of the dewatering machine via the third lift pump.

4. The hazardous waste salt treatment system according to claim 1, characterized in that, The clarification and dehydration module also includes a dehydration filtrate collection tank and a fourth lift pump. The dehydration filtrate collection tank is connected to the outlet end of the dehydrator, and the dehydration filtrate collection tank is connected to the dissolving tank via the fourth lift pump.

5. The hazardous waste salt treatment system according to claim 1, characterized in that, The first crystallizing element includes a sodium chloride crystallizer, a sodium chloride thickening tank, and a sodium chloride centrifuge connected in sequence. The air inlet of the sodium chloride crystallizer is connected to the exhaust end of the forced circulation evaporator, and the liquid outlet of the sodium chloride centrifuge is connected to the liquid inlet of the second crystallizing element.

6. The hazardous waste salt treatment system according to claim 5, characterized in that, The second crystallizing unit includes a sodium chloride mother liquor collection tank, a fifth lift pump, and a sodium sulfide refrigeration heat exchanger, a sodium sulfide refrigeration crystallizer, a sodium sulfide refrigeration thickening tank, and a sodium sulfide refrigeration centrifuge connected in sequence. The sodium chloride mother liquor collection tank is connected to the discharge end of the sodium chloride centrifuge, and the sodium chloride mother liquor collection tank is connected to the inlet end of the sodium sulfide refrigeration heat exchanger via the fifth lift pump.

7. The hazardous waste salt treatment system according to claim 6, characterized in that, The salt separation crystallization module also includes a residual liquid collection tank and a sixth lift pump. The residual liquid collection tank is connected to the discharge end of the sodium sulfide refrigerated centrifuge, and the residual liquid collection tank is connected to the inlet end of the salt separation crystallization module via the sixth lift pump.

8. The hazardous waste salt treatment system according to claim 1, characterized in that, It also includes a waste heat recovery module, which includes a waste heat boiler and a flue gas dust removal device. The exhaust end of the reactor is connected to the inlet end of the waste heat boiler, and the exhaust end of the waste heat boiler is connected to the inlet end of the flue gas dust removal device.

9. The hazardous waste salt treatment system according to claim 8, characterized in that, The waste heat recovery module also includes a demineralized water tank and a demineralized water pump, wherein the demineralized water tank is connected to the waste heat boiler via the demineralized water pump.

10. The hazardous waste salt treatment system according to claim 1, characterized in that, The incineration module also includes a mixed salt warehouse, a crushed coke powder warehouse, and a coking wastewater activated carbon sludge warehouse. The discharge ends of the mixed salt warehouse, the crushed coke powder warehouse, and the coking wastewater activated carbon sludge warehouse are all connected to the feed end of the reactor.

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