Resourceful treatment system for waste incineration fly ash washing liquid
The waste incineration fly ash water washing solution is treated through heavy metal removal systems and anti-solvent crystallization systems, which solves the problems of long processes, complex equipment and high costs in the existing technology, and achieves efficient and low-cost resource processing.
Patent Information
- Application Number
- CN202422043550.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-22
- Publication Date
- 2025-07-29
- Estimated Expiration
- 2034-08-22
AI Technical Summary
The existing waste incineration fly ash water washing liquid treatment process is long, covers a large area, is complex in equipment, has high operating and maintenance and chemical consumption costs, and is relatively high in energy consumption.
The heavy metal removal system and anti-solvent crystallization system are used to remove heavy metal ions first, then remove impurities, and recycle the heavy metal trapping agent and organic anti-solvent, simplify the process flow and reduce the consumption of agents and the number of equipment.
It has achieved simplified process flow, reduced equipment investment and operation and maintenance costs, improved processing efficiency, and reduced chemical consumption and energy consumption.
Smart Images
Figure CN223163303U_ABST
Abstract
Description
Technical Field
[0001] The present application relates to the technical field of sewage treatment, and specifically provides a resource treatment system for the washing liquid of municipal solid waste incineration fly ash. Background Art
[0002] The washing liquid of municipal solid waste incineration fly ash contains heavy metals, calcium, sodium, potassium, chlorine, etc. The commonly used treatment technology at present is to remove heavy metals by adding chemical agents, then remove calcium by adding agents, filter and neutralize, and then evaporate and crystallize after meeting the water inlet requirements of the MVR evaporation equipment. First, the sodium salt with a high content in the fly ash washing liquid is separated, and then the mother liquor is refluxed to enrich the potassium salt until the potassium salt is saturated and precipitated. To save the energy consumption of MVR and improve the purity of the crystalline salt, some processes perform membrane concentration before entering MVR. The membrane has higher requirements for the influent water, so it is necessary to further filter to remove hardness and suspended solids, generally a combination of two or more stages of multi-stage sand filtration, resin, ultrafiltration, nanofiltration, and reverse osmosis.
[0003] The commonly used equipment for recovering sodium salt and potassium salt by evaporation crystallization technology is a triple-effect evaporator or a multi-effect evaporator, as well as a supporting condensate collection system, non-condensable gas treatment system, mechanical vapor recompression system, etc. Removing calcium before evaporation crystallization is to avoid calcium scaling in the multi-effect evaporator and affect the normal operation of the evaporator.
[0004] The common problems existing in the existing fly ash washing liquid treatment process are: 1) The process is long, and the water tanks and equipment used are numerous, occupying a large area and having a high investment cost; 2) The structure is complex, and it is easy to scale during long-term operation, with a high operation and maintenance cost; 3) The consumption of chemical agents is large, and a large amount of heavy metal removal agents and hardness removal agents need to be additionally invested, with a high input cost; 4) The efficiency is low, and the energy consumption for salt production by evaporation is relatively high. Summary of the Invention
[0005] In view of this, the present application provides a resource treatment system for the washing liquid of municipal solid waste incineration fly ash.
[0006] The present application provides a resource treatment system for the washing liquid of municipal solid waste incineration fly ash. The resource treatment system includes a heavy metal removal system for removing heavy metal ions in the washing liquid of municipal solid waste incineration fly ash and an anti-solvent crystallization system for removing miscellaneous salts in the washing liquid of municipal solid waste incineration fly ash, and the washing liquid of municipal solid waste incineration fly ash sequentially passes through the heavy metal removal system and the anti-solvent crystallization system;
[0007] The anti-solvent crystallization system includes an anti-solvent crystallization unit, a second solid-liquid separation unit, and an anti-solvent regeneration unit;
[0008] Wherein, the first solid-liquid separation unit and the anti-solvent crystallization unit are connected through a third pipeline, and the third pipeline is provided with a third delivery pump that limits the delivery from the first solid-liquid separation unit to the anti-solvent crystallization unit; the anti-solvent crystallization unit and the second solid-liquid separation unit are connected through a fourth pipeline, and the fourth pipeline is provided with a fourth delivery pump that limits the delivery from the anti-solvent crystallization unit to the second solid-liquid separation unit; the second solid-liquid separation unit and the anti-solvent regeneration unit are connected through a sixth pipeline, and the sixth pipeline is provided with a sixth delivery pump that limits the delivery from the second solid-liquid separation unit to the anti-solvent regeneration unit; the anti-solvent regeneration unit and the anti-solvent crystallization unit are connected through a seventh pipeline, and the seventh pipeline is provided with a seventh delivery pump that limits the delivery from the anti-solvent regeneration unit to the anti-solvent crystallization unit.
[0009] In some optional embodiments of the present application, the anti-solvent crystallization system further includes a distillation unit; the anti-solvent regeneration unit and the distillation unit are connected via an eighth pipeline, and the eighth pipeline is provided with an eighth delivery pump that limits delivery from the anti-solvent regeneration unit to the distillation unit.
[0010] In some optional embodiments of the present application, the anti-solvent crystallization system further includes a miscellaneous salt drying unit; wherein, the miscellaneous salt drying unit is located below the second solid-liquid separation unit, and the second solid-liquid separation unit and the miscellaneous salt drying unit are connected through a fifth pipeline, and the fifth pipeline is provided with a fifth on-off valve.
[0011] In some optional embodiments of the present application, the fifth pipe is arranged vertically.
[0012] In some optional embodiments of the present application, the heavy metal removal system includes a heavy metal capture unit and a first solid-liquid separation unit; wherein, the heavy metal capture unit and the first solid-liquid separation unit are connected by a first pipeline, and the first pipeline is provided with a first delivery pump that limits the delivery from the heavy metal capture unit to the first solid-liquid separation unit.
[0013] In some optional embodiments of the present application, the heavy metal capture unit is connected to a waste incineration fly ash water washing liquid flow pump and a heavy metal capture agent addition pump.
[0014] In some optional embodiments of the present application, the heavy metal capture unit is further connected to a flocculant addition pump.
[0015] In some alternative embodiments of the present application, the heavy metal removal system further includes a sludge drying unit; wherein, the sludge drying unit is located below the first solid-liquid separation unit, and the first solid-liquid separation unit and the sludge drying unit are connected through a second pipeline, and a second on-off valve for restricting the transportation direction from the first solid-liquid separation unit to the sludge drying unit is provided on the second pipeline.
[0016] In some alternative embodiments of the present application, the second pipeline is vertically arranged.
[0017] The present application has the following beneficial effects:
[0018] In the present application, the washing liquid of the waste incineration fly ash first removes heavy metal ions (such as cadmium, chromium, lead, copper, mercury, etc.) through the heavy metal removal system, and then removes the miscellaneous salts (such as sodium chloride, potassium chloride, etc.) through the anti-solvent crystallization system to obtain recycled clear water. Therefore, the advantages of the present application mainly include: 1) The process flow is simple, there is no problem of system scaling, so there is no need to remove hardness step by step to precipitate sodium salts and potassium salts. Through two-stage processes, the heavy metals and salts in the fly ash can be precipitated; 2) The consumption of chemicals is small. A large amount of calcium, sodium, and potassium salts are removed through the recycled organic anti-solvent, and the input cost of chemicals is low; 3) The equipment is simple, the floor area is small, and the investment cost is low; 4) The system operation is simple, the operation and maintenance cost is low, and the treatment efficiency is high and the operation cost is low. Description of the Drawings
[0019] Figure 1 is a schematic structural diagram of a resource treatment system for the washing liquid of waste incineration fly ash in an embodiment.
[0020] In the figure, 1. Heavy metal capture unit; 11. Flow pump for the washing liquid of waste incineration fly ash; 12. Sampling pump for heavy metal capture agent; 13. Sampling pump for flocculant; 2. First solid-liquid separation unit; 3. Sludge drying unit; 4. Anti-solvent crystallization unit; 5. Second solid-liquid separation unit; 6. Miscellaneous salt drying unit; 7. Anti-solvent regeneration unit; 8. Distillation unit; 121. First pipeline; 122. First transfer pump; 231. Second pipeline; 232. Second on-off valve; 241. Third pipeline; 242. Third transfer pump; 451. Fourth pipeline; 452. Fourth transfer pump; 561. Fifth pipeline; 562. Fifth on-off valve; 571. Sixth pipeline; 572. Sixth transfer pump; 741. Seventh pipeline; 742. Seventh transfer pump; 781. Eighth pipeline; 782. Eighth transfer pump. Detailed Embodiments
[0021] The present application will be further described in detail below with reference to the drawings and embodiments. Through these descriptions, the features and advantages of the present application will become more clearly defined.
[0022] As used herein, the term "exemplary" means "serving as an example, embodiment, or illustration". Any embodiment described as "exemplary" herein need not be construed as superior to or better than other embodiments. Although various aspects of the embodiments are shown in the drawings, the drawings are not necessarily drawn to scale unless otherwise specified.
[0023] In addition, the technical features involved in different embodiments of the present application described below can be combined with each other as long as they do not conflict with each other.
[0024] An embodiment of the present application discloses a resource treatment system for the washing liquid of municipal solid waste incineration fly ash.
[0025] Refer to Figure 1 , a resource treatment system for the washing liquid of municipal solid waste incineration fly ash includes a heavy metal removal system and an anti-solvent crystallization system. Among them, the washing liquid of municipal solid waste incineration fly ash first removes heavy metal ions (such as cadmium, chromium, lead, copper, mercury, etc.) through the heavy metal removal system, and then removes miscellaneous salts (such as sodium chloride, potassium chloride, etc.) through the anti-solvent crystallization system to obtain recycled clear water. Among them, the recycled clear water can be used for the washing treatment of fly ash in the washing stage of municipal solid waste incineration fly ash.
[0026] The working principle of the heavy metal removal system is as follows: using the chelation effect of a heavy metal capturer and heavy metal ions to capture the heavy metal ions in the washing liquid of municipal solid waste incineration fly ash and generate flocculent precipitates; then using a flocculant to change the charge property on the surface of the flocculent precipitates, increasing the interaction between the flocculent precipitates, so as to promote the sedimentation and aggregation of the flocculent precipitates, and separating the flocculent precipitates in the washing liquid of municipal solid waste incineration fly ash by a solid-liquid separation method.
[0027] The heavy metal removal system includes a heavy metal capture unit 1, a first solid-liquid separation unit 2, and a sludge drying unit 3.
[0028] Among them, the heavy metal capture unit 1 is connected with a flow pump 11 for the washing liquid of municipal solid waste incineration fly ash, a heavy metal capturer dosing pump 12, and a flocculant dosing pump 13. The heavy metal capture unit 1 and the first solid-liquid separation unit 2 are connected through a first pipeline 121; a first delivery pump 122 for limiting the delivery direction from the heavy metal capture unit 1 to the first solid-liquid separation unit 2 is provided on the first pipeline 121.
[0029] The sludge drying unit 3 is located below the first solid-liquid separation unit 2, and the first solid-liquid separation unit 2 and the sludge drying unit 3 are connected through a second pipeline 231. The second pipeline 231 is vertically arranged; a second on-off valve 232 is provided on the second pipeline 231. Among them, when the second on-off valve 232 is opened, the flocculent precipitate separated by the first solid-liquid separation unit 2 flows by gravity to the sludge drying unit 3, and then the heavy metal ions in the flocculent precipitate are stabilized by the sludge drying unit 3 to reduce the migration of metal ions.
[0030] The working principle of the antisolvent crystallization system is as follows: First, water and an organic antisolvent (such as an organic antisolvent composed of 20 wt% of propyl ether and 80 wt% of triethylamine, etc.) are mutually soluble at a first temperature (such as 30 °C, etc.), and the miscellaneous salts in the washed liquid of the fly ash from waste incineration crystallize out and are separated from the washed liquid of the fly ash from waste incineration by a solid-liquid separation method; then, water and the organic antisolvent are immiscible at a second temperature (such as 70 °C, etc.), so that water and the organic solvent are separated into water and oil layers; finally, the water layer is further purified through the distillation unit 8 to obtain recycled clean water.
[0031] The antisolvent crystallization system includes an antisolvent crystallization unit 4, a second solid-liquid separation unit 5, a miscellaneous salt drying unit 6, an antisolvent regeneration unit 7, and a distillation unit 8.
[0032] The first solid-liquid separation unit 2 and the antisolvent crystallization unit 4 are connected through a third pipeline 241. A third delivery pump 242 for limiting the conveyance direction from the first solid-liquid separation unit 2 to the antisolvent crystallization unit 4 is provided on the third pipeline 241. The antisolvent crystallization unit 4 and the second solid-liquid separation unit 5 are connected through a fourth pipeline 451. A fourth delivery pump 452 for limiting the conveyance direction from the antisolvent crystallization unit 4 to the second solid-liquid separation unit 5 is provided on the fourth pipeline 451. Among them, the washed liquid of the fly ash from waste incineration separated by the first solid-liquid separation unit 2 is conveyed to the antisolvent crystallization unit 4 through the third delivery pump 242; in the antisolvent crystallization unit 4, water and the organic antisolvent in the washed liquid of the fly ash from waste incineration are mutually soluble at the first temperature, and at the same time, the miscellaneous salts in the washed liquid of the fly ash from waste incineration crystallize out; then, in the second solid-liquid separation unit 5, the mutual solution of water and the organic antisolvent and the crystallized miscellaneous salts are separated.
[0033] The miscellaneous salt drying unit 6 is located below the second solid-liquid separation unit 5. The second solid-liquid separation unit 5 and the miscellaneous salt drying unit 6 are connected through a fifth pipeline 561. The fifth pipeline 561 is vertically arranged; a fifth on-off valve 562 is provided on the fifth pipeline 561. Among them, when the fifth on-off valve 562 is opened, the crystallized miscellaneous salts separated by the second solid-liquid separation unit 5 flow by gravity to the miscellaneous salt drying unit 6, and then the crystallized miscellaneous salts are dried by the miscellaneous salt drying unit 6.
[0034] The second solid-liquid separation unit 5 and the anti-solvent regeneration unit 7 are connected via a sixth pipeline 571. The sixth pipeline 571 is provided with a sixth delivery pump 572 that is limited to delivering water from the second solid-liquid separation unit 5 to the anti-solvent regeneration unit 7. The miscible mixture of water and organic anti-solvent separated by the second solid-liquid separation unit 5 is delivered to the anti-solvent regeneration unit 7 via the sixth delivery pump 572. In the anti-solvent regeneration unit 7, the miscible mixture of water and organic anti-solvent is separated into water and oil at the second temperature.
[0035] The anti-solvent regeneration unit 7 and the anti-solvent crystallization unit 4 are connected via a seventh pipeline 741. The seventh pipeline 741 is provided with a seventh delivery pump 742 that is configured to deliver oil from the anti-solvent regeneration unit 7 to the anti-solvent crystallization unit 4. The oil phase (organic anti-solvent) separated by the anti-solvent regeneration unit 7 is delivered to the anti-solvent crystallization unit 4 via the seventh delivery pump 742, thereby recycling the organic anti-solvent.
[0036] The anti-solvent regeneration unit 7 and the distillation unit 8 are connected via an eighth pipeline 781, which is equipped with an eighth delivery pump 782 for conveying water from the anti-solvent regeneration unit 7 to the distillation unit 8. The aqueous phase separated by the anti-solvent regeneration unit 7 is delivered to the distillation unit 8 via the eighth delivery pump 782. In the distillation unit 8, the aqueous phase is further purified to produce recycled water. This recycled water can be used to wash the fly ash during the waste incineration fly ash washing process, thereby achieving recycling of the recycled water.
[0037] In the description of the present application, it should be noted that the terms "upper", "lower", "inside", "outside", "front", "back", "left", "right", etc. indicate directions or positional relationships based on the directions or positional relationships in the working state of the present application. They are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they should not be understood as limitations on the present application.
[0038] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "install", "connect" and "connect" should be understood in a broad sense. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.
Claims
1. A resource treatment system for the washing liquid of municipal solid waste incineration fly ash, characterized in that, The resource treatment system includes a heavy metal removal system for removing heavy metal ions from the washing liquid of waste incineration fly ash and an anti-solvent crystallization system for removing miscellaneous salts from the washing liquid of waste incineration fly ash, and the washing liquid of waste incineration fly ash sequentially passes through the heavy metal removal system and the anti-solvent crystallization system; The heavy metal removal system includes a heavy metal capture unit (1) and a first solid-liquid separation unit (2); wherein, the heavy metal capture unit (1) and the first solid-liquid separation unit (2) are connected through a first pipeline (121), and a first delivery pump (122) for restricting the delivery direction from the heavy metal capture unit (1) to the first solid-liquid separation unit (2) is provided on the first pipeline (121); The anti-solvent crystallization system includes an anti-solvent crystallization unit (4), a second solid-liquid separation unit (5) and an anti-solvent regeneration unit (7); Wherein, the first solid-liquid separation unit (2) and the anti-solvent crystallization unit (4) are connected through a third pipeline (241), and a third delivery pump (242) for restricting the delivery direction from the first solid-liquid separation unit (2) to the anti-solvent crystallization unit (4) is provided on the third pipeline (241); the anti-solvent crystallization unit (4) and the second solid-liquid separation unit (5) are connected through a fourth pipeline (451), and a fourth delivery pump (452) for restricting the delivery direction from the anti-solvent crystallization unit (4) to the second solid-liquid separation unit (5) is provided on the fourth pipeline (451); the second solid-liquid separation unit (5) and the anti-solvent regeneration unit (7) are connected through a sixth pipeline (571), and a sixth delivery pump (572) for restricting the delivery direction from the second solid-liquid separation unit (5) to the anti-solvent regeneration unit (7) is provided on the sixth pipeline (571); the anti-solvent regeneration unit (7) and the anti-solvent crystallization unit (4) are connected through a seventh pipeline (741), and a seventh delivery pump (742) for restricting the delivery direction from the anti-solvent regeneration unit (7) to the anti-solvent crystallization unit (4) is provided on the seventh pipeline (741).
2. The resource treatment system according to claim 1, characterized in that, The anti-solvent crystallization system further includes a distillation unit (8); wherein, the anti-solvent regeneration unit (7) and the distillation unit (8) are connected through an eighth pipeline (781), and an eighth delivery pump (782) for restricting the delivery direction from the anti-solvent regeneration unit (7) to the distillation unit (8) is provided on the eighth pipeline (781).
3. The resource recovery processing system according to claim 1 or 2, characterized in that: The anti-solvent crystallization system further includes a miscellaneous salt drying unit (6); wherein, the miscellaneous salt drying unit (6) is located below the second solid-liquid separation unit (5), and the second solid-liquid separation unit (5) and the miscellaneous salt drying unit (6) are connected through a fifth pipeline (561), and a fifth on-off valve (562) is provided on the fifth pipeline (561).
4. The resource treatment system according to claim 3, characterized in that The fifth pipeline (561) is vertically arranged.
5. The resource treatment system according to claim 1, characterized in that The heavy metal capture unit (1) is connected with a waste incineration fly ash washing liquid flow pump (11) and a heavy metal capture agent sampling pump (12).
6. The resource treatment system according to claim 5, characterized in that, The heavy metal capture unit (1) is also connected with a flocculant dosing pump (13).
7. The resource recovery processing system according to claim 1, 5 or 6, characterized in that: The heavy metal removal system further includes a sludge drying unit (3); wherein, the sludge drying unit (3) is located below the first solid-liquid separation unit (2), and the first solid-liquid separation unit (2) and the sludge drying unit (3) are connected and communicated through a second pipeline (231), and a second on-off valve (232) is arranged on the second pipeline (231).
8. The resource treatment system according to claim 7, wherein The second pipeline (231) is vertically arranged.