A fly ash valuable component step-by-step recovery system and process for a waste incineration power plant

Abstract

The application discloses a valuable component gradient recovery system and process for fly ash of waste incineration power plant, which comprises a flotation pretreatment unit, a potassium-sodium gradient recovery unit, a calcium gradient leaching recovery unit and a circulating water unit; the flotation pretreatment unit is used for slurry preparation of fly ash raw materials of waste incineration, and adsorption and flotation removal of dioxin for fly ash raw materials with over-standard dioxin are completed, carbon fuel is output, and the solid material after detoxification is output to the potassium-sodium gradient recovery unit; for fly ash raw materials with standard dioxin, the slurry-prepared material is directly output to the potassium-sodium gradient recovery unit; through the gradient recovery process of dioxin flotation removal, potassium-sodium elution and calcium leaching recovery, the application realizes the early removal of organic hazardous waste represented by dioxin in raw materials, effective recovery of potassium-sodium-calcium valuable components, effectively reduces the harmfulness of fly ash and improves the overall economic benefit of the technology.

Description

Technical Field

[0001] This invention relates to the field of solid waste treatment technology, specifically to a cascade recovery system and process for valuable components of fly ash from waste incineration power plants. Background Technology

[0002] With the rapid development of my country's economy and the steady upgrading of its industry, the amount of urban waste and its annual increase are growing daily, making waste disposal a major environmental issue nationwide and even globally. Waste-to-energy incineration is an effective means of solving urban waste problems, effectively alleviating urban waste issues, and can also bring certain economic benefits through thermal power generation. It is worth noting that while waste-to-energy incineration technology effectively solves urban waste problems, it also brings challenges to the treatment of fly ash from power plants. As a byproduct of waste-to-energy incineration, fly ash contains harmful components such as heavy metals and dioxins. Inadequate fly ash treatment can lead to serious environmental pollution problems.

[0003] As a highly hazardous solid waste, fly ash typically consists mainly of silicon and aluminum, containing some heavy metals and soluble salts. Furthermore, some power plants operate at low temperatures, resulting in significantly excessive dioxin levels in certain fly ash samples. Using traditional landfill techniques poses a risk of secondary pollution to soil and groundwater. Among newer technologies, physical methods are less effective, while chemical and thermal treatment methods are too costly. Biological methods face numerous limitations, and much of the fly ash is used for building materials, leading to low economic efficiency.

[0004] For fly ash from waste incineration, soluble alkali metal salts, mainly potassium and sodium, have the potential to be used as industrial salts, while the high content of calcium ions can effectively improve economic benefits after recycling.

[0005] Therefore, designing a tiered recycling process for valuable components of fly ash from waste-to-energy plants, which can effectively remove harmful substances such as dioxins from fly ash while simultaneously recovering valuable elements such as potassium, sodium, and calcium, is of great significance for the low-consumption and high-efficiency resource utilization of fly ash from waste-to-energy plants and similar solid wastes.

[0006] To address this, a cascaded recovery system and process for valuable components of fly ash from waste-to-energy plants is proposed. Summary of the Invention

[0007] The purpose of this invention is to provide a cascade recovery system and process for valuable components of fly ash from waste incineration power plants, in order to solve the problems mentioned in the background art.

[0008] To achieve the above objectives, the present invention provides the following technical solution: a cascade recovery system for valuable components of fly ash from a waste incineration power plant, comprising a flotation pretreatment unit, a potassium-sodium cascade recovery unit, a calcium cascade leaching recovery unit, and a circulating water unit;

[0009] The flotation pretreatment unit is used to adjust the fly ash raw material from waste incineration, and to perform dioxin adsorption and flotation removal on fly ash raw material with dioxin exceeding the standard, producing carbon fuel. At the same time, the detoxified material is output to the potassium and sodium cascade recovery unit. For fly ash raw material with dioxin meeting the standard, the adjusted material is directly output to the potassium and sodium cascade recovery unit.

[0010] The potassium and sodium graded recovery unit adopts a three-stage leaching and solid-liquid separation architecture. Its feed end receives the material output from the flotation pretreatment unit, and its discharge end is connected to the feed end of the calcium graded leaching and recovery unit. It is used to perform graded elution and mineralization crystallization of soluble potassium and sodium components in the material to produce potassium carbonate and sodium carbonate products. At the same time, the solid phase material after potassium and sodium removal is output to the calcium graded leaching and recovery unit.

[0011] The calcium cascade leaching and recovery unit adopts a grinding and dissociation, three-stage leaching and mineralization precipitation structure. Its feed end receives the material output from the potassium and sodium cascade recovery unit, which is used to target the leaching, mineralization and purification of the calcium component in the material to produce calcium carbonate product, while outputting harmless residue.

[0012] The circulating water unit adopts a circulating water tank, whose inlet end is connected to the liquid phase outlet of the flotation pretreatment unit, the potassium-sodium graded recovery unit, and the calcium graded leaching recovery unit, respectively, and the outlet end is connected to the water replenishment outlet of the slurry preparation and leaching process of each unit, forming a circulation system of process water throughout the entire process.

[0013] Preferably, the flotation pretreatment unit includes a raw material forced slurry conditioner, a flotation machine, an activated carbon plate and frame filter press, and a solenoid valve switching assembly;

[0014] The feed inlet of the forced raw material mixing machine is connected to the fly ash raw material and the replenishment water of the circulating water tank, and the discharge outlet is connected to the feed inlet of the flotation machine and the feed inlet of the potassium-sodium cascade recovery unit respectively through the solenoid valve switching component.

[0015] The flotation outlet of the flotation machine is connected to the feed inlet of the activated carbon plate and frame filter press. The filter solids outlet of the activated carbon plate and frame filter press produces carbon fuel. The filtrate outlet and the underflow outlet of the flotation machine are connected to the feed inlet of the potassium-sodium graded recovery unit.

[0016] Preferably, the potassium-sodium cascade recovery unit includes a potassium-sodium primary leaching module, a potassium-sodium secondary leaching module, a potassium-sodium tertiary leaching module arranged sequentially, as well as a potassium-sodium mineralization tower and a concentration crystallization kettle;

[0017] The potassium-sodium first-stage leaching module includes a potassium-sodium multi-field coupled leaching unit I and a potassium-sodium plate and frame filter press I. The inlet of the potassium-sodium multi-field coupled leaching unit I receives the material output from the flotation pretreatment unit, and the outlet is connected to the inlet of the potassium-sodium plate and frame filter press I. The filtrate outlet of the potassium-sodium plate and frame filter press I is connected to the inlet of the potassium-sodium mineralization tower, and the filter solids outlet is connected to the inlet of the potassium-sodium second-stage leaching module.

[0018] The outlet of the potassium-sodium mineralization tower is connected to the inlet of the concentration crystallization kettle. The solid phase outlet of the concentration crystallization kettle produces potassium carbonate and sodium carbonate products, and the condensate outlet outputs water vapor condensate to the circulating water tank.

[0019] The potassium-sodium two-stage leaching module includes a potassium-sodium slurry conditioner I, a potassium-sodium multi-field coupled extractor II, and a potassium-sodium plate and frame filter press II. The inlet of the potassium-sodium slurry conditioner I receives the filter solids output from the potassium-sodium plate and frame filter press I, and the outlet is connected to the inlet of the potassium-sodium plate and frame filter press II through the potassium-sodium multi-field coupled extractor II. The filtrate outlet of the potassium-sodium plate and frame filter press II outputs the potassium-sodium two-stage filtration filtrate and returns it to the flotation pretreatment unit. The filter solids outlet is connected to the inlet of the potassium-sodium three-stage leaching module.

[0020] The potassium-sodium three-stage leaching module includes a potassium-sodium slurry conditioner II, a potassium-sodium multi-field coupled extractor III, and a potassium-sodium plate and frame filter press III. The inlet of the potassium-sodium slurry conditioner II receives the filter solids output from the potassium-sodium plate and frame filter press II, and the outlet is connected to the inlet of the potassium-sodium plate and frame filter press III through the potassium-sodium multi-field coupled extractor III. The filtrate outlet of the potassium-sodium plate and frame filter press III outputs the potassium-sodium three-stage filtration filtrate back to the potassium-sodium slurry conditioner I, and the filter solids outlet outputs the potassium-sodium three-stage filtration filter solids to the inlet of the calcium cascade leaching and recovery unit.

[0021] Preferably, the calcium cascade leaching and recovery unit includes a grinding and classification module, a first-stage calcium leaching module, a second-stage calcium leaching module, a third-stage calcium leaching module, a calcium mineralization tower, a sedimentation tank, and a calcium product plate and frame filter press.

[0022] The grinding and classification module includes a ball mill and a hydrocyclone. The feed inlet of the ball mill receives the filtered solids output from the potassium-sodium graded recovery unit, and the discharge outlet is connected to the feed inlet of the hydrocyclone. The underflow discharge outlet of the hydrocyclone outputs the underflow of the hydrocyclone back to the feed inlet of the ball mill, and the overflow discharge outlet outputs the overflow of the hydrocyclone to the feed inlet of the calcium stage leaching module.

[0023] The calcium stage leaching module includes a calcium multi-field coupled extractor I and a calcium plate and frame filter press I. The feed inlet of the calcium multi-field coupled extractor I receives the overflow from the hydrocyclone. The discharge outlet of the calcium multi-field coupled extractor I is connected to the feed inlet of the calcium plate and frame filter press I. The filtrate outlet of the calcium plate and frame filter press I outputs the calcium stage filtration filtrate to the feed inlet of the calcium mineralization tower, and the filter solids outlet outputs the calcium stage filtration solids to the feed inlet of the calcium stage leaching module.

[0024] The outlet of the calcium mineralization tower is connected to the inlet of the sedimentation tank. The overflow outlet of the sedimentation tank outputs the sedimentation tank overflow to the circulating water tank, and the underflow outlet outputs the sedimentation tank underflow to the inlet of the calcium product plate and frame filter press. The filtrate outlet of the calcium product plate and frame filter press outputs the calcium product filter filtrate to the circulating water tank, and the filter solids outlet produces calcium carbonate product.

[0025] The calcium two-stage extraction module includes a calcium slurry conditioner I, a calcium multi-field coupled extractor II, and a calcium plate and frame filter press II. The feed inlet of the calcium slurry conditioner I receives the filter solids output from the calcium plate and frame filter press I, and the discharge outlet is connected to the feed inlet of the calcium plate and frame filter press II through the calcium multi-field coupled extractor II. The filtrate outlet of the calcium plate and frame filter press II outputs the calcium two-stage filter filtrate back to the feed inlet of the ball mill, and the filter solids outlet outputs the calcium two-stage filter solids to the feed inlet of the calcium three-stage extraction module.

[0026] The calcium three-stage extraction module includes a calcium slurry conditioner II, a calcium multi-field coupled extractor III, and a calcium plate and frame filter press III. The feed inlet of the calcium slurry conditioner II receives the filter solids output from the calcium plate and frame filter press II, and the discharge outlet is connected to the feed inlet of the calcium plate and frame filter press III through the calcium multi-field coupled extractor III. The filtrate outlet of the calcium plate and frame filter press III outputs the calcium three-stage filter filtrate, which is returned to the calcium slurry conditioner I. The filter solids outlet produces harmless residue.

[0027] Preferably, the equipment used for extraction in the potassium-sodium graded recovery unit and the calcium graded extraction and recovery unit are both multi-field coupled extractors;

[0028] The multi-field coupled extractor includes a tank with an insulation layer. Inside the tank, there is a stirring assembly with a stirring shaft, an ultrasonic irradiation assembly with an ultrasonic probe, and an air inlet aeration assembly with an air injection pipe. The tank is equipped with a dosing pipe, a feed pipe, and a discharge pipe. An exhaust pipe is installed at the top of the tank. The heat source of the multi-field coupled extractor is connected to the superheated waste gas of the waste incineration power plant to realize the cascade utilization of waste heat.

[0029] A cascade recovery process for valuable components of fly ash from waste-to-energy plants, implemented using any of the above-described recovery systems, includes the following steps:

[0030] S1. Raw material pretreatment: The dioxin content of the waste incineration fly ash raw material is detected. The material path is switched by the solenoid valve switching component. If the dioxin content exceeds the standard, the raw material enters the flotation pretreatment unit to complete the dioxin adsorption and flotation removal, and produce carbon fuel. The detoxified solid material enters step S2. If the dioxin content meets the standard, the raw material directly enters step S2 after slurry preparation.

[0031] S2, Potassium and Sodium Cascade Recovery: A three-stage leaching process is adopted to elute the soluble potassium and sodium components in the material output from step S2. The rich elution solution is mineralized, concentrated and crystallized to produce potassium carbonate and sodium carbonate products. The solid material after potassium and sodium removal enters step S3. The filtrate generated in the leaching process is recycled and reused in a countercurrent path, and the process condensate enters the circulating water tank.

[0032] S3, Calcium cascade leaching and recovery: The solid material output from step S2 is ground, dissociated, and classified. Then, the calcium component in the material is targeted for leaching through a three-stage leaching process. The rich leaching solution is mineralized, precipitated, and filtered to produce calcium carbonate. The solid phase after leaching is the harmless residue. The filtrate generated in the leaching process is recycled and reused through a countercurrent path. The process wastewater enters the circulating water tank for closed-loop circulation.

[0033] Preferably, in step S1, for fly ash raw materials exceeding dioxin standards, the pretreatment step specifically includes:

[0034] S11. Slurry preparation and adsorption: The fly ash raw material is fed into the raw material forced slurry preparation machine. Potassium and sodium slurry preparation water from the circulating water tank is added to adjust the slurry concentration. At the same time, activated carbon particles are added. Through stirring, the activated carbon fully adsorbs the dioxin components in the slurry to obtain the slurry to be floated.

[0035] S12, Flotation Separation: The slurry to be floated is fed into the flotation machine, and flotation reagents are added. The flotation reagents include frothers and collectors. The frothers reduce the surface tension of the liquid phase and increase the bubble density, while the collectors enhance the hydrophobicity of the activated carbon particles that adsorb dioxins. This causes the hydrophobic activated carbon particles to float to the froth layer of the flotation machine with the bubbles and enter the activated carbon plate and frame filter press for dewatering along with the flotation concentrate. The remaining components become flotation tailings.

[0036] S13, Filtration and Dewatering: The activated carbon plate and frame filter press is used for filtration. The filtered solids are carbon fuel products. The flotation concentrate filtrate after the filtration operation is discharged with the flotation tailings and sent to step S2.

[0037] Preferably, step S2 specifically includes:

[0038] S21, First stage leaching: The material output from step S1 is fed into the potassium-sodium multi-field coupled leaching extractor I. Under the action of multi-energy field coupling, the potassium and sodium components are initially eluted to obtain potassium-sodium first stage leaching slurry. After the potassium-sodium first stage leaching slurry is filtered by potassium-sodium plate and frame filter press I, the filtrate is potassium-sodium first stage filter filtrate and is sent to the potassium-sodium mineralization tower. The filter solid is potassium-sodium first stage filter solid and enters the second stage leaching process.

[0039] S22, mineralization and crystallization: mineralization gas I is introduced into the potassium-sodium mineralization tower, so that the potassium and sodium ions in the first-stage pressure filter filtrate combine with carbonate ions to form potassium-sodium mineralization slurry. The potassium-sodium mineralization slurry is sent to the concentration and crystallization kettle for evaporation, concentration and crystallization. The solid products are potassium carbonate and sodium carbonate products. The water vapor generated by evaporation is condensed and sent to the circulating water tank.

[0040] S23, Second-stage extraction: The potassium-sodium first-stage filter press filtrate is fed into the potassium-sodium slurry conditioner I. After adding potassium-sodium second-stage slurry conditioner makeup water from the circulating water tank to adjust the slurry concentration, the potassium-sodium second-stage slurry is obtained and fed into the potassium-sodium multi-field coupled extractor II for secondary elution to obtain the potassium-sodium second-stage extraction slurry. After the potassium-sodium second-stage extraction slurry is filtered by the potassium-sodium plate and frame filter press II, the filtrate is the potassium-sodium second-stage filter press filtrate, which is returned to the raw material forced slurry conditioner for reuse. The filter solid is the potassium-sodium second-stage filter press filtrate, which enters the third-stage extraction process.

[0041] S24. Three-stage extraction: The potassium-sodium two-stage pressure filtration solid is sent to the potassium-sodium slurry conditioning machine II. After adding potassium-sodium three-stage conditioning makeup water from the circulating water tank to adjust the slurry concentration, the potassium-sodium three-stage conditioning slurry is obtained. It is then sent to the potassium-sodium multi-field coupled extractor III to complete deep elution, resulting in a potassium-sodium three-stage extraction slurry. After the potassium-sodium three-stage extraction slurry is filtered by the potassium-sodium plate and frame filter press III, the filtrate is the potassium-sodium three-stage pressure filtration filtrate, which is returned to the potassium-sodium slurry conditioning machine I for reuse. The filtration solid is the potassium-sodium three-stage pressure filtration solid, which is sent to step S3.

[0042] Preferably, step S3 specifically includes:

[0043] S31. Grinding, dissociation, and classification: The potassium and sodium three-stage pressure filter output from step S2 is fed into a ball mill. Grinding makeup water from the circulating water tank and calcium leaching agent I are added to adjust the grinding concentration. The calcium component in the material is fully dissociated through grinding to obtain a dissociated slurry. The dissociated slurry is sent to a hydrocyclone for classification. The classification particle size is 50μm. The coarse particles in the slurry are returned to the ball mill for re-grinding with the hydrocyclone underflow, while the fine particles overflow with the hydrocyclone overflow into the first-stage leaching process.

[0044] S32, First stage leaching: The overflow from the hydrocyclone is fed into the calcium multi-field coupling leaching tank I. Under the action of multi-energy field coupling and calcium leaching agent I, the calcium ions in the raw material are transferred to the liquid phase to obtain the first stage calcium leaching slurry. After the first stage calcium leaching slurry is filtered by the calcium plate and frame filter press I, the filtrate is the first stage calcium filter filtrate and is sent to the calcium mineralization tower. The filter solid is the first stage calcium filter solid and enters the second stage leaching process.

[0045] S33, Mineralization Precipitation: Mineralizing gas II is introduced into the calcium mineralization tower, causing calcium ions in the first-stage calcium filter press filtrate to combine with carbonate ions to form calcium carbonate solid, resulting in calcium mineralization slurry. The calcium mineralization slurry is sent to the sedimentation tank for solid-liquid pre-separation. The liquid phase overflows from the sedimentation tank and returns to the circulating water tank, while the calcium carbonate solid settles and flows into the calcium product plate and frame filter press for dewatering with the bottom flow of the sedimentation tank. The filtered solid is the calcium carbonate product, and the filtrate is the calcium product filter press filtrate, which is sent to the circulating water tank.

[0046] S34. Second-stage extraction: The calcium first-stage filter press filtrate is fed into the calcium slurry conditioning machine I. After adding the calcium first-stage conditioning water from the circulating water tank to adjust the slurry concentration, the calcium first-stage conditioning slurry is obtained and fed into the calcium multi-field coupling extractor II. At the same time, calcium extraction agent II is added to complete the second extraction, resulting in the calcium second-stage extraction slurry. After the calcium second-stage extraction slurry is filtered by the calcium plate and frame filter press II, the filtrate is the calcium second-stage filter press filtrate, which is returned to the ball mill for reuse. The filter solid is the calcium second-stage filter press filtrate, which enters the third-stage extraction process.

[0047] S35. Three-stage extraction: The calcium two-stage filter press solids are sent to the calcium slurry conditioning machine II. After adding calcium two-stage conditioning makeup water from the circulating water tank to adjust the slurry concentration, the calcium two-stage conditioning slurry is obtained and sent to the calcium multi-field coupling extractor III. At the same time, calcium extraction agent III is added to complete the deep extraction, resulting in the calcium three-stage extraction slurry. After the calcium three-stage extraction slurry is filtered by the calcium plate and frame filter press III, the filtrate is the calcium three-stage filter press filtrate and is returned to the calcium slurry conditioning machine I for reuse. The filter solids are the harmless residue.

[0048] Compared with the prior art, the beneficial effects of the present invention are:

[0049] 1. This invention achieves the early removal of organic hazardous waste, represented by dioxins, from raw materials and the effective recovery of valuable components such as potassium, sodium, and calcium through a tiered recovery process of dioxin flotation removal, potassium and sodium washing, and calcium leaching and recovery. This effectively reduces the hazards of fly ash while improving the overall economic benefits of the technology.

[0050] 2. This invention can produce four products: carbon fuel, potassium carbonate and sodium carbonate, calcium carbonate and residue. The first three have significant economic value, while the tailings can be used as raw materials for building materials or gel materials. Overall, it avoids the generation of secondary solid waste and realizes the full resource utilization of solid waste.

[0051] 3. The present invention, through the design of the discharge pipe of the forced raw material mixing machine, can adapt the process to fly ash raw materials with different dioxin contents. For fly ash raw materials with dioxin content lower than the national standard, they can directly enter the subsequent washing and leaching process. For fly ash raw materials with high dioxin content, they can be decarbonized by activated carbon adsorption, flotation, and carbon fuel products. This effectively removes dioxins from fly ash and also generates certain economic benefits.

[0052] 4. By adding a potassium-sodium elution process before the calcium leaching process, this invention effectively avoids the interference of excessive alkali metal ions on the recovery effect in the subsequent calcium leaching and recovery process. At the same time, potassium-sodium recovery can also improve the overall economic benefits of the process.

[0053] 5. In the potassium and sodium desiccation process, this invention utilizes a multi-field coupled extraction device to efficiently desiccate potassium and sodium components from the sample. At the same time, it draws on the scavenging process in mineral flotation to achieve the reuse of desiccation water, effectively reducing water consumption in the potassium and sodium desiccation process.

[0054] 6. This invention sets up a grinding and dissociation and multi-stage leaching process. By dissociating and grinding, the calcium ion adsorption surface in the sample is fully released. At the same time, by using a multi-stage circulating leaching process based on a multi-field coupling leaching device, calcium ions are efficiently recovered, and the process water consumption cost is also effectively reduced.

[0055] 7. This invention can use superheated waste gas, which is widely present in waste incineration power plants, as a heat source, becoming the source of heat energy input in the multi-field coupled extraction device. It maximizes the use of useless by-products of thermal power generation, greatly reduces production costs, and significantly improves the overall environmental friendliness of the process. Attached Figure Description

[0056] Figure 1 This is a schematic diagram of the recycling system of the present invention;

[0057] Figure 2 This is a flowchart of the recycling process of the present invention;

[0058] Figure 3 This is a schematic diagram of the structure of the multi-energy field coupled extraction device of the present invention.

[0059] In the diagram: A. Forced raw material conditioning machine; B. Flotation machine; C. Activated carbon plate and frame filter press; D. Potassium-sodium multi-field coupled leaching unit I; E. Potassium-sodium plate and frame filter press I; F. Potassium-sodium mineralization tower; G. Concentration and crystallization kettle; H. Potassium-sodium conditioning machine I; I. Potassium-sodium multi-field coupled leaching unit II; J. Potassium-sodium plate and frame filter press II; K. Potassium-sodium conditioning machine II; L. Potassium-sodium multi-field coupled leaching unit III; M. Potassium-sodium plate and frame filter press... Filter press III; N, Ball mill; O, Hydrocyclone; P, Calcium multi-field coupled extractor I; Q, Calcium plate and frame filter press I; R, Calcium mineralization tower; S, Sedimentation tank; T, Calcium product plate and frame filter press; U, Calcium slurry conditioner I; V, Calcium multi-field coupled extractor II; W, Calcium plate and frame filter press II; X, Calcium slurry conditioner II; Y, Calcium multi-field coupled extractor III; Z, Calcium plate and frame filter press III; AA, Circulating water tank;

[0060] 1. Fly ash; 2. Activated carbon; 3. Pulp to be floated; 4. Flotation reagents; 5. Flotation concentrate; 6. Flotation tailings; 7. Flotation concentrate filtrate; 8. Carbon fuel; 9. Potassium-sodium stage slurry after conditioning; 10. Potassium-sodium stage leaching slurry; 11. Potassium-sodium stage pressure filtration filtrate; 12. Potassium-sodium stage pressure filtration solids; 13. Potassium-sodium mineralization slurry; 14. Mineralization gas I; 15. Water vapor condensate; 16. Carbon 17. Potassium carbonate and sodium carbonate slurry after two-stage potassium-sodium conditioning; 18. Potassium-sodium leaching slurry after two-stage potassium-sodium extraction; 19. Potassium-sodium filtrate after two-stage pressure filtration; 20. Potassium-sodium filtrate after two-stage pressure filtration; 21. Potassium-sodium slurry after three-stage potassium-sodium conditioning; 22. Potassium-sodium leaching slurry after three-stage potassium-sodium extraction; 23. Potassium-sodium filtrate after three-stage pressure filtration; 24. Potassium-sodium filtrate after three-stage pressure filtration; 25. Calcium extractant I; 26. Slurry after dissociation; 27. Hydrocyclone underflow; 28. 1. Hydrocyclone overflow; 29. ​​Calcium stage leaching slurry; 30. Calcium stage pressure filtration solids; 31. Calcium stage pressure filtration filtrate; 32. Mineralizing gas II; 33. Calcium mineralization slurry; 34. Sedimentation tank overflow; 35. Sedimentation tank underflow; 36. Calcium product pressure filtration filtrate; 37. Calcium carbonate; 38. Calcium stage slurry after conditioning; 39. Calcium extractant II; 40. Calcium stage leaching slurry; 41. Calcium stage pressure filtration filtrate. 42. Filtrate from two-stage calcium filtration; 43. Slurry after two-stage calcium filtration; 44. Calcium leaching agent III; 45. Calcium leaching slurry after three-stage calcium leaching; 46. Filtrate from three-stage calcium filtration; 47. Residue; 48. Make-up water for one-stage potassium-sodium slurry conditioning; 49. Make-up water for two-stage potassium-sodium slurry conditioning; 50. Make-up water for three-stage potassium-sodium slurry conditioning; 51. Grinding water; 52. Make-up water for one-stage calcium slurry conditioning; 53. Make-up water for two-stage calcium slurry conditioning.

[0061] D1, stirring shaft; D2, air injection pipe; D3, insulation layer; D4, exhaust pipe; D5, ultrasonic probe; D6, dosing pipe; D7, feed pipe; D8, discharge pipe. Detailed Implementation

[0062] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only for explaining the present invention and are not intended to limit the scope of protection of the present invention. The scope of protection of the present invention is defined by the claims.

[0063] The valuable component cascade recovery system of fly ash from waste incineration power plants disclosed in this invention comprises four core modules: a flotation pretreatment unit, a potassium and sodium cascade recovery unit, a calcium cascade leaching recovery unit, and a circulating water unit.

[0064] The present invention also discloses a tiered recovery process for valuable components of fly ash from waste incineration power plants based on the above-mentioned recovery system. This process is adaptable to the treatment of fly ash raw materials with different dioxin contents, and achieves efficient tiered recovery of fly ash disposal and valuable components.

[0065] Please see Figure 1 and Figure 3 The present invention provides a technical solution: a cascade recovery system for valuable components of fly ash from a waste incineration power plant, comprising a flotation pretreatment unit, a potassium-sodium cascade recovery unit, a calcium cascade leaching recovery unit, and a circulating water unit.

[0066] The flotation pretreatment unit is used to adsorb and remove dioxins from the raw materials to obtain carbon fuel 8, flotation tailings 6, and flotation concentrate filtrate 7.

[0067] The potassium-sodium cascade recovery unit is used to recover easily soluble metal ions, mainly potassium and sodium, from the raw materials to obtain potassium carbonate and sodium carbonate 16 products, steam condensate 15, potassium-sodium three-stage pressure filtration filtrate 23 and potassium-sodium three-stage pressure filtration solids 24.

[0068] The calcium cascade leaching and recovery unit is used to leach and recover valuable metals from calcium in the raw material, and obtain calcium carbonate 37 product, sedimentation tank overflow 34, calcium product pressure filtration filtrate 36, residue 47 and calcium three-stage pressure filtration filtrate 46.

[0069] The circulating water unit uses a circulating water tank. Its inlet is connected to the liquid phase outlet of the flotation pretreatment unit, the potassium-sodium graded recovery unit, and the calcium graded leaching recovery unit, respectively. Its outlet is connected to the water replenishment outlet of the slurry preparation and leaching processes of each unit, forming a closed-loop circulation system for the entire process water.

[0070] Furthermore, the flotation pretreatment unit includes a forced raw material slurry conditioner A, a flotation machine B, and an activated carbon plate and frame filter press C, arranged in the order of material flow. The discharge port of the forced raw material slurry conditioner A is connected to the inlet of the flotation machine B and the inlet of the potassium-sodium multi-field coupled extractor IDE, respectively. A solenoid valve controls the forced output of all material into the inlet of either the flotation machine B or the potassium-sodium multi-field coupled extractor IDE. The discharge port of the flotation machine B is connected to the inlet of the activated carbon plate and frame filter press C, and the activated carbon plate and frame filter press C outputs carbon fuel 8 product from the filter solids end.

[0071] Furthermore, the potassium and sodium recovery unit includes a potassium and sodium multi-field coupled extractor IDE, a potassium and sodium plate and frame filter press IE, a potassium and sodium mineralization tower F, a concentration crystallization kettle G, a potassium and sodium slurry conditioner HIH, a potassium and sodium multi-field coupled extractor III, a potassium and sodium plate and frame filter press IIJ, a potassium and sodium slurry conditioner IIK, a potassium and sodium multi-field coupled extractor IIIL, and a potassium and sodium plate and frame filter press IIIM, arranged in the order of material flow.

[0072] The outlet of the potassium-sodium multi-field coupled extractor IDE is connected to the inlet of the potassium-sodium plate and frame filter press IE. The filtrate outlet of the potassium-sodium plate and frame filter press IE is connected to the inlet of the potassium-sodium mineralization tower F. The filter solids outlet is connected to the inlet of the potassium-sodium slurry conditioner HIH. The outlet of the potassium-sodium mineralization tower F is connected to the inlet of the concentration crystallization kettle G. The product outlet of the concentration crystallization kettle G outputs potassium carbonate and sodium carbonate 16 products. The by-product outlet is connected to the inlet of the circulating water tank AA.

[0073] The outlet of the potassium-sodium slurry conditioner ⅠH is connected to the inlet of the potassium-sodium multi-field coupled extractor ⅡI. The outlet of the potassium-sodium multi-field coupled extractor ⅡI is connected to the inlet of the potassium-sodium plate and frame filter press ⅡJ. The filtrate outlet of the potassium-sodium plate and frame filter press ⅡJ is connected to the inlet of the raw material forced slurry conditioner A. The filter solids outlet is connected to the inlet of the potassium-sodium slurry conditioner ⅡK. The outlet of the potassium-sodium slurry conditioner ⅡK is connected to the inlet of the potassium-sodium multi-field coupled extractor ⅢL. The outlet of the potassium-sodium multi-field coupled extractor ⅢL is connected to the inlet of the potassium-sodium plate and frame filter press ⅢM. The filtrate outlet of the potassium-sodium plate and frame filter press ⅢM is connected to the inlet of the potassium-sodium slurry conditioner ⅠH. The filter solids outlet is connected to the inlet of the ball mill N.

[0074] Ideally, the CO2 content in the input potassium-sodium mineralization tower F should be no less than 50%, and the content of strongly acidic gases such as SO2 and NOx should be no more than 10%.

[0075] Furthermore, the calcium extraction unit includes a ball mill N, a hydrocyclone O, a calcium multi-field coupled extractor IP, a calcium plate and frame filter press ⅠQ, a calcium mineralization tower R, a sedimentation tank S, a calcium product plate and frame filter press T, a calcium slurry conditioner ⅠU, a calcium multi-field coupled extractor IIV, a calcium plate and frame filter press ⅡW, a calcium slurry conditioner IIX, a calcium multi-field coupled extractor ⅢY, and a calcium plate and frame filter press ⅢZ, arranged in the order of material flow.

[0076] The discharge port of ball mill N is connected to the inlet of hydrocyclone O. The underflow discharge port of hydrocyclone O is connected to the inlet of ball mill N. The overflow discharge port of hydrocyclone O is connected to the inlet of calcium multi-field coupled extractor IP. The discharge port of calcium multi-field coupled extractor IP is connected to the inlet of calcium plate and frame filter press ⅠQ. The filter solid discharge port of calcium plate and frame filter press ⅠQ is connected to the inlet of calcium slurry conditioner ⅠU. The filtrate discharge port is connected to the inlet of calcium mineralization tower R.

[0077] The outlet of the calcium mineralization tower R is connected to the inlet of the sedimentation tank S. The overflow outlet of the sedimentation tank S is connected to the inlet of the circulating water tank AA. The underflow outlet of the sedimentation tank S is connected to the inlet of the calcium product plate and frame filter press T. The filtrate outlet of the calcium product plate and frame filter press T is connected to the inlet of the circulating water tank AA. The filter solids outlet of the calcium product plate and frame filter press T produces calcium carbonate 37 product.

[0078] The outlet of the calcium slurry conditioner ⅠU is connected to the inlet of the calcium multi-field coupled extractor ⅡV. The outlet of the calcium multi-field coupled extractor ⅡV is connected to the inlet of the calcium plate and frame filter press ⅡW. The filtrate outlet of the calcium plate and frame filter press ⅡW is connected to the inlet of the ball mill N. The filter solids outlet of the calcium plate and frame filter press ⅡW is connected to the inlet of the calcium slurry conditioner ⅡX. The outlet of the calcium slurry conditioner ⅡX is connected to the inlet of the calcium multi-field coupled extractor ⅢY. The outlet of the calcium multi-field coupled extractor ⅢY is connected to the inlet of the calcium plate and frame filter press ⅢZ. The filtrate outlet of the calcium plate and frame filter press ⅢZ is connected to the inlet of the calcium slurry conditioner ⅠU. The filter solids outlet of the calcium plate and frame filter press ⅢZ produces residue 47.

[0079] Ideally, the hydrocyclone O is set to a classification particle size of 50 μm. The CO2 content in the input calcium mineralization tower R is not less than 50%, and the content of strongly acidic gases such as SO2 and NOx is not higher than 10%.

[0080] Furthermore, the discharge port of the circulating water tank AA is connected to the feed ports of the forced raw material mixing machine A, the potassium-sodium mixing machine ⅠH, the potassium-sodium mixing machine ⅡK, the ball mill N, the calcium mixing machine ⅠU, and the calcium mixing machine ⅡX, respectively.

[0081] Example 1

[0082] A tiered recycling process for valuable components of fly ash from waste-to-energy incineration plants. For example... Figure 2 As shown, using the above-mentioned cascade recovery system for valuable components of fly ash from waste-to-energy incineration plants, for raw materials with dioxin content exceeding national standards, the steps include:

[0083] Step S1: The solenoid valve at the discharge port of the forced raw material slurry conditioner A selects all the material to enter the flotation machine B. The forced raw material slurry conditioner A is used to slurry and disperse fly ash raw materials from waste-to-energy incineration plants. Potassium and sodium supplement water 48 is fed into the circulating water tank AA to adjust the slurry concentration. At the same time, a certain amount of activated carbon 2 particles are added. The hydrophobic and porous surface of the activated carbon 2 particles will effectively adsorb dioxin components in the raw material. After slurry conditioning, the slurry 3 to be floated enters the flotation machine B for flotation.

[0084] During the flotation process, flotation reagent 4 is added to flotation machine B. While a frother is added to reduce the surface tension of the liquid phase and increase the bubble concentration in the flotation environment, the collector further enhances the hydrophobicity of the activated carbon 2 particles that have adsorbed dioxins. The activated carbon 2 particles adhere to the bubble surface and float to the froth layer of flotation machine B, and are discharged with the flotation concentrate 5, entering the activated carbon plate and frame filter press C for dewatering. The remaining components become flotation tailings 6, which are discharged with the underflow and enter the potassium-sodium multi-field coupled leaching extractor IDE.

[0085] After the activated carbon plate and frame filter press C performs the filter operation, the flotation concentrate filtrate 7 is discharged with the underflow into the potassium-sodium multi-field coupled leaching extractor IDE, while the filter solids from the activated carbon plate and frame filter press C become carbon fuel 8, which can be sold as fuel for higher temperature power plants.

[0086] Step S2: The potassium-sodium multi-field coupled leaching unit IDE is used for preliminary washing of soluble alkali metals, mainly potassium and sodium, in the raw material. Potassium and sodium ions in the raw material particles dissolve and enter the liquid phase. After treatment, the potassium-sodium first-stage leaching slurry 10 enters the potassium-sodium plate and frame filter press IE for filtration and dewatering. After dewatering, the potassium-sodium first-stage filter press filtrate 11 enters the potassium-sodium mineralization tower F for mineralization. Mineralization gas I 14 is introduced into the potassium-sodium mineralization tower F to become carbonate ions, which combine with the ions in the potassium-sodium mineralization tower F slurry. The potassium-sodium mineralization slurry 13 enters the concentration crystallization kettle G for concentration and crystallization. After treatment, the solid crystals become potassium carbonate and sodium carbonate 16 products. The water vapor condensate 15 generated by the concentration crystallization kettle G is returned to the circulating water tank AA.

[0087] The potassium-sodium plate and frame filter press IE produces potassium-sodium primary filter solid 12, which enters the potassium-sodium slurry conditioner HIH for secondary slurry conditioning. The circulating water tank AA provides potassium-sodium secondary slurry conditioning makeup water 49 to adjust the slurry concentration. After the slurry conditioning, the potassium-sodium secondary slurry 17 enters the potassium-sodium multi-field coupled leaching unit III for secondary washing of soluble alkali metals, mainly potassium and sodium, in the raw material. After treatment, the potassium-sodium secondary leaching slurry 18 enters the potassium-sodium plate and frame filter press IIJ for filtration and dewatering. After dewatering, the potassium-sodium secondary filter filtrate 19 is returned to the raw material forced slurry conditioner A.

[0088] The potassium-sodium plate and frame filter press IIJ produces potassium-sodium second-stage filter solid 20, which is then fed into the potassium-sodium slurry conditioner IIK for third-stage slurry conditioning. The circulating water tank AA provides 50 ml of supplemental water for the third-stage slurry conditioning to adjust the slurry concentration. After the slurry conditioning, the potassium-sodium slurry 21 is fed into the potassium-sodium multi-field coupled extractor IIIL for three-stage washing of soluble alkali metals, mainly potassium and sodium, in the raw material. The potassium-sodium slurry 22 after treatment is fed into the potassium-sodium plate and frame filter press IIIM for filtration and dewatering. The potassium-sodium third-stage filter filtrate 23 after dewatering is returned to the potassium-sodium slurry conditioner IH. The potassium-sodium third-stage filter solid 24 produced during the dewatering process is fed into the ball mill N.

[0089] Step S3: Ball mill N is used to dissociate and release raw material particles. Grinding makeup water 51 is added to circulating water tank AA to adjust the grinding concentration. At the same time, calcium leaching agent I25 is added during the grinding operation to capture calcium ions in the raw material. After grinding, the dissociated slurry 26 enters hydrocyclone O for classification. The classification particle size is 50μm. The coarse particles in the slurry are returned to ball mill N with the hydrocyclone underflow 27 for re-dissociation. The fine particles are carried by the hydrocyclone overflow 28 into calcium multi-field coupled leaching tank IP for calcium primary leaching. Under the combined operation of multi-fields in the equipment and the capture effect of calcium leaching agent I25, the calcium ions in the raw material are transferred to the liquid phase. The calcium primary leaching slurry 29 enters calcium plate and frame filter press 1Q for filter dewatering. The calcium primary filter solid 30 enters calcium slurry conditioner 1U. The calcium primary filter filtrate 31 enters calcium mineralization tower R.

[0090] The calcium mineralization tower R performs mineralization on the calcium filtrate 31 from the first stage of the pressure filtration operation. Mineralization gas II 32 enters the calcium mineralization tower R. In the liquid phase, carbonate ions combine with calcium ions to form calcium carbonate solid. The calcium mineralization slurry 33 enters the sedimentation tank S for preliminary pre-dehydration. The liquid phase returns to the circulating water tank AA with the sedimentation tank overflow 34, while the calcium carbonate solid settles and enters the calcium product plate and frame filter press T with the sedimentation tank bottom flow 35 for pressure filtration and dehydration. The calcium product filtrate 36 returns to the circulating water tank AA with the sedimentation tank overflow 34, and the filtered solid is calcium carbonate product 37.

[0091] The calcium slurry conditioner ⅠU is used to condition the calcium first-stage filter press filtrate 30. The circulating water tank AA feeds in the calcium first-stage slurry conditioner supplement water 52 to adjust the slurry concentration. After the calcium first-stage slurry conditioner 38, it enters the calcium multi-field coupling extractor ⅡV for the calcium second-stage extraction. At the same time, calcium extractant Ⅱ39 is added to the calcium multi-field coupling extractor ⅡV to enhance the extraction. After the calcium ion phase is transferred to the liquid phase, the calcium second-stage extraction slurry 40 enters the calcium plate and frame filter press ⅡW for filter dewatering. The calcium second-stage filter press filtrate 42 enters the calcium slurry conditioner ⅡX, and the calcium second-stage filter press filtrate 41 is returned to the ball mill N.

[0092] The calcium slurry conditioner IIX is used to condition the calcium second-stage filter press filtrate 42. The circulating water tank AA feeds in the calcium second-stage slurry conditioner supplement water 53 to adjust the slurry concentration. After the calcium second-stage slurry conditioner, the slurry 43 enters the calcium multi-field coupling extractor ⅢY for calcium second-stage extraction. At the same time, calcium extractant Ⅲ44 is added to the calcium multi-field coupling extractor ⅢY to enhance the extraction process. After the calcium ion phase is transferred to the liquid phase, the calcium third-stage extraction slurry 45 enters the calcium plate and frame filter press ⅢZ for filter dewatering. The calcium third-stage filter press filtrate is the residue 47 product, and the calcium third-stage filter press filtrate 46 is returned to the calcium slurry conditioner IU.

[0093] Example 2

[0094] A tiered recycling process for valuable components of fly ash from waste-to-energy incineration plants. For example... Figure 2 As shown, for raw materials whose dioxin content in the sample meets national standards, the steps include:

[0095] Step S1: Switch the material path by using a solenoid valve so that the outlet of the forced raw material mixing machine A is directly connected to the potassium and sodium multi-field coupling extractor IDE of the potassium and sodium cascade recovery unit. The fly ash 1 raw material is fed into the forced raw material mixing machine A, and after adding water to the circulating water tank AA for mixing, it is directly fed into step S2.

[0096] Step S2: The specific process of this step is completely consistent with step S2 in Example 1. The soluble potassium and sodium components in the material are subjected to stepwise elution, mineralization and concentration crystallization to produce potassium carbonate and sodium carbonate 16 products. The solid material after potassium and sodium removal is sent to step S3.

[0097] Step S3: The specific procedures in this step are completely consistent with Step S3 in Example 1. The calcium component in the material is subjected to grinding and dissociation, targeted leaching, mineralization precipitation and purification to produce calcium carbonate 37 product. The solid phase after leaching is the harmless final residue 47.

[0098] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A cascade recovery system for valuable components of fly ash from waste-to-energy incineration plants, characterized in that: It includes a flotation pretreatment unit, a potassium and sodium graded recovery unit, a calcium graded leaching and recovery unit, and a circulating water unit; The flotation pretreatment unit is used to adjust the slurry of fly ash (1) raw material from waste incineration, and to perform dioxin adsorption and flotation removal on fly ash (1) raw material that meets dioxin standards, producing carbon fuel (8), and outputting the detoxified material to the potassium-sodium cascade recovery unit. For fly ash (1) raw material that meets dioxin standards, the slurry-adjusted material is directly output to the potassium-sodium cascade recovery unit. The potassium and sodium graded recovery unit adopts a three-stage leaching and solid-liquid separation structure. Its feed end receives the material output from the flotation pretreatment unit, and its discharge end is connected to the feed end of the calcium graded leaching and recovery unit. It is used to perform graded elution and mineralization crystallization of soluble potassium and sodium components in the material to produce potassium carbonate and sodium carbonate (16) products. At the same time, it outputs the solid phase material from which potassium and sodium have been removed to the calcium graded leaching and recovery unit. The calcium cascade leaching and recovery unit adopts a grinding and dissociation, three-stage leaching and mineralization precipitation structure. Its feed end receives the material output from the potassium and sodium cascade recovery unit, which is used to target the calcium component in the material for leaching, mineralization and purification, producing calcium carbonate (37) product, while outputting harmless residue (47). The circulating water unit adopts a circulating water tank (AA), whose inlet end is connected to the liquid phase outlet of the flotation pretreatment unit, the potassium-sodium graded recovery unit, and the calcium graded leaching recovery unit, respectively, and whose outlet end is connected to the water replenishment outlet of the slurry preparation and leaching process of each unit, forming a circulation system of process water throughout the entire process.

2. The cascade recovery system for valuable components of fly ash from a waste-to-energy plant according to claim 1, characterized in that: The flotation pretreatment unit includes a raw material forced slurry conditioner (A), a flotation machine (B), an activated carbon plate and frame filter press (C), and a solenoid valve switching assembly; The feed inlet of the forced slurry preparation machine (A) is connected to the fly ash (1) raw material and the replenishment water of the circulating water tank (AA), and the discharge outlet is connected to the feed inlet of the flotation machine (B) and the feed inlet of the potassium sodium cascade recovery unit respectively through the solenoid valve switching component. The flotation outlet of the flotation machine (B) is connected to the feed inlet of the activated carbon plate and frame filter press (C). The filter solids outlet of the activated carbon plate and frame filter press (C) produces carbon fuel (8). The filtrate outlet and the underflow outlet of the flotation machine (B) are connected to the feed inlet of the potassium sodium cascade recovery unit.

3. A cascade recovery system for valuable components of fly ash from a waste-to-energy plant according to claim 1, characterized in that: The potassium and sodium cascade recovery unit includes a potassium and sodium primary leaching module, a potassium and sodium secondary leaching module, a potassium and sodium tertiary leaching module arranged in sequence, as well as a potassium and sodium mineralization tower (F) and a concentration crystallization kettle (G). The potassium-sodium first-stage leaching module includes a potassium-sodium multi-field coupled leaching unit I (D) and a potassium-sodium plate and frame filter press I (E). The inlet of the potassium-sodium multi-field coupled leaching unit I (D) receives the material output from the flotation pretreatment unit, and the outlet is connected to the inlet of the potassium-sodium plate and frame filter press I (E). The filtrate outlet of the potassium-sodium plate and frame filter press I (E) is connected to the inlet of the potassium-sodium mineralization tower (F), and the filter solids outlet is connected to the inlet of the potassium-sodium second-stage leaching module. The outlet of the potassium-sodium mineralization tower (F) is connected to the inlet of the concentration crystallization vessel (G). The solid phase outlet of the concentration crystallization vessel (G) produces potassium carbonate and sodium carbonate (16) products, and the condensate outlet outputs steam condensate (15) to the circulating water tank (AA). The potassium-sodium two-stage leaching module includes a potassium-sodium slurry conditioner I (H), a potassium-sodium multi-field coupled extractor II (I), and a potassium-sodium plate and frame filter press II (J). The inlet of the potassium-sodium slurry conditioner I (H) receives the filter solid output from the potassium-sodium plate and frame filter press I (E), and the outlet is connected to the inlet of the potassium-sodium plate and frame filter press II (J) through the potassium-sodium multi-field coupled extractor II (I). The filtrate outlet of the potassium-sodium plate and frame filter press II (J) outputs the potassium-sodium two-stage filtration filtrate (19) and returns it to the flotation pretreatment unit. The filter solid outlet is connected to the inlet of the potassium-sodium three-stage leaching module. The potassium-sodium three-stage leaching module includes a potassium-sodium slurry conditioner II (K), a potassium-sodium multi-field coupled extractor III (L), and a potassium-sodium plate and frame filter press III (M). The inlet of the potassium-sodium slurry conditioner II (K) receives the filter solid output from the potassium-sodium plate and frame filter press II (J), and the outlet is connected to the inlet of the potassium-sodium plate and frame filter press III (M) through the potassium-sodium multi-field coupled extractor III (L). The filtrate outlet of the potassium-sodium plate and frame filter press III (M) outputs the potassium-sodium three-stage filtration filtrate (23) back to the potassium-sodium slurry conditioner I (H), and the filter solid outlet outputs the potassium-sodium three-stage filtration filter solid (24) to the inlet of the calcium cascade leaching and recovery unit.

4. A cascade recovery system for valuable components of fly ash from a waste-to-energy plant according to claim 1, characterized in that: The calcium cascade leaching and recovery unit includes a grinding and classification module, a first-stage calcium leaching module, a second-stage calcium leaching module, a third-stage calcium leaching module, a calcium mineralization tower (R), a sedimentation tank (S), and a calcium product plate and frame filter press (T). The grinding and classification module includes a ball mill (N) and a hydrocyclone (O). The feed inlet of the ball mill (N) receives the filtered solids output from the potassium-sodium graded recovery unit, and the discharge outlet is connected to the feed inlet of the hydrocyclone (O). The underflow outlet of the hydrocyclone (O) outputs the hydrocyclone underflow (27) back to the feed inlet of the ball mill (N), and the overflow outlet outputs the hydrocyclone overflow (28) to the feed inlet of the calcium stage leaching module. The calcium extraction module includes a calcium multi-field coupled extractor I (P) and a calcium plate and frame filter press I (Q). The feed inlet of the calcium multi-field coupled extractor I (P) receives the overflow of the hydrocyclone (O). The discharge outlet of the calcium multi-field coupled extractor I (P) is connected to the feed inlet of the calcium plate and frame filter press I (Q). The filtrate outlet of the calcium plate and frame filter press I (Q) outputs the calcium first-stage filter filtrate (31) to the feed inlet of the calcium mineralization tower (R). The filter solid outlet outputs the calcium first-stage filter solid (30) to the feed inlet of the calcium second-stage extraction module. The outlet of the calcium mineralization tower (R) is connected to the inlet of the sedimentation tank (S). The overflow outlet of the sedimentation tank (S) outputs the sedimentation tank overflow (34) to the circulating water tank (AA), and the underflow outlet outputs the sedimentation tank underflow (35) to the inlet of the calcium product plate and frame filter press (T). The filtrate outlet of the calcium product plate and frame filter press (T) outputs the calcium product filter filtrate (36) to the circulating water tank (AA). The filter solids outlet produces calcium carbonate (37) product. The calcium two-stage extraction module includes a calcium slurry preparation machine I (U), a calcium multi-field coupling extractor II (V), and a calcium plate and frame filter press II (W). The feed inlet of the calcium slurry preparation machine I (U) receives the filter solid output from the calcium plate and frame filter press I (Q), and the discharge outlet is connected to the feed inlet of the calcium plate and frame filter press II (W) through the calcium multi-field coupling extractor II (V). The filtrate outlet of the calcium plate and frame filter press II (W) outputs the calcium two-stage filter filtrate (41) back to the feed inlet of the ball mill (N), and the filter solid outlet outputs the calcium two-stage filter solid (42) to the feed inlet of the calcium three-stage extraction module. The calcium three-stage extraction module includes a calcium slurry conditioner II (X), a calcium multi-field coupling extractor III (Y), and a calcium plate and frame filter press III (Z). The feed inlet of the calcium slurry conditioner II (X) receives the filter solids output by the calcium plate and frame filter press II (W), and the discharge outlet is connected to the feed inlet of the calcium plate and frame filter press III (Z) through the calcium multi-field coupling extractor III (Y). The filtrate outlet of the calcium plate and frame filter press III (Z) outputs the calcium three-stage filter filtrate (46) and returns it to the calcium slurry conditioner I (U). The filter solids outlet produces harmless residue (47).

5. A cascade recovery system for valuable components of fly ash from a waste-to-energy plant according to claim 1, characterized in that: The equipment used for extraction in the potassium-sodium graded recovery unit and the calcium graded extraction and recovery unit are both multi-field coupled extractors. The multi-field coupled extractor includes a tank with an insulation layer (D3). Inside the tank, there is a stirring assembly with a stirring shaft (D1), an ultrasonic irradiation assembly with an ultrasonic probe (D5), and an air inlet aeration assembly with an air injection pipe (D2). The tank is equipped with a dosing pipe (D6), a feed pipe (D7), and a discharge pipe (D8). An exhaust pipe (D4) is installed at the top of the tank. The heat source of the multi-field coupled extractor is connected to the superheated waste gas of the waste incineration power plant to realize the cascade utilization of waste heat.

6. A cascade recovery process for valuable components of fly ash from waste-to-energy incineration plants, implemented using the recovery system described in any one of claims 1-5, characterized in that, Includes the following steps: S1. Raw material pretreatment: Detect the dioxin content of the fly ash (1) raw material from waste incineration, and switch the material path through the solenoid valve switching component. If the dioxin content exceeds the standard, the raw material enters the flotation pretreatment unit to complete dioxin adsorption and flotation removal, and produces carbon fuel (8). The detoxified solid material enters step S2. If the dioxin content meets the standard, the raw material directly enters step S2 after slurry preparation. S2, Potassium and Sodium Cascade Recovery: A three-stage leaching process is adopted to elute the soluble potassium and sodium components in the material output from step S1. The rich elution solution is mineralized, concentrated and crystallized to produce potassium carbonate and sodium carbonate (16) products. The solid material after potassium and sodium removal enters step S3. The filtrate generated in the leaching process is recycled and reused in a countercurrent path. The process condensate enters the circulating water tank (AA). S3, Calcium cascade leaching and recovery: The solid material output from step S2 is ground, dissociated and classified, and then the calcium component in the material is targeted for leaching through a three-stage leaching process. The leaching solution is mineralized, precipitated and filtered to produce calcium carbonate (37) product. The solid phase after leaching is the harmless residue (47). The filtrate generated in the leaching process is recycled and reused in a countercurrent path, and the process wastewater enters the circulating water tank (AA) for closed-loop circulation.

7. The cascade recovery process for valuable components of fly ash from waste incineration power plants according to claim 6, characterized in that: In step S1, the pretreatment step for fly ash raw materials exceeding dioxin standards specifically includes: S11, Slurry preparation and adsorption: The fly ash (1) raw material is fed into the raw material forced slurry preparation machine (A), and potassium sodium slurry preparation water (48) from the circulating water tank (AA) is added to adjust the slurry concentration. At the same time, activated carbon (2) particles are added. By stirring, the activated carbon (2) fully adsorbs the dioxin components in the slurry to obtain the slurry to be floated (3). S12, Flotation Separation: The slurry (3) to be floated is fed into the flotation machine (B), and flotation reagents (4) are added. The flotation reagents (4) include frothers and collectors. The frothers reduce the surface tension of the liquid phase and increase the bubble density. The collectors enhance the hydrophobicity of the activated carbon (2) particles that adsorb dioxins, so that the hydrophobic activated carbon (2) particles float to the foam layer of the flotation machine (B) with the bubbles, and enter the activated carbon plate and frame filter press (C) with the flotation concentrate (5) for filter dewatering. The remaining components become flotation tailings (6). S13, Filtration and dewatering: The activated carbon plate and frame filter press (C) is used for filtration. The filtered solid is carbon fuel (8) product. The flotation concentrate filtrate (7) after the filtration operation is discharged with the flotation tailings (6) and sent to step S2.

8. The cascade recovery process for valuable components of fly ash from waste incineration power plants according to claim 6, characterized in that: Step S2 specifically includes: S21, First stage leaching: The material output from step S1 is fed into the potassium-sodium multi-field coupled leaching machine I (D). Under the action of multi-energy field coupling, the potassium and sodium components are initially eluted to obtain potassium-sodium first stage leaching slurry (10). After the potassium-sodium first stage leaching slurry (10) is filtered by the potassium-sodium plate and frame filter press I (E), the filtrate is potassium-sodium first stage filter filtrate (11) and is sent to the potassium-sodium mineralization tower (F). The filter solid is potassium-sodium first stage filter solid (12) and enters the second stage leaching process. S22, mineralization and crystallization: mineralization gas I (14) is introduced into the potassium-sodium mineralization tower (F) to combine potassium and sodium ions with carbonate ions in the potassium-sodium first-stage pressure filter filtrate (11) to generate potassium-sodium mineralization slurry (13). The potassium-sodium mineralization slurry (13) is sent to the concentration and crystallization kettle (G) for evaporation, concentration and crystallization. The solid products are potassium carbonate and sodium carbonate (16). The water vapor condensate (15) generated by evaporation is sent to the circulating water tank (AA). S23, Second stage extraction: The potassium-sodium first stage filter press (12) is sent to the potassium-sodium slurry conditioner I (H), and potassium-sodium second stage slurry conditioner supplement water (49) from the circulating water tank (AA) is added to adjust the slurry concentration, and the potassium-sodium second stage slurry conditioner slurry (17) is obtained. It is sent to the potassium-sodium multi-field coupling extractor II (I) to complete the second washing and obtain the potassium-sodium second stage extraction slurry (18). The potassium-sodium second stage extraction slurry (18) is filtered by the potassium-sodium plate and frame filter press II (J), and the filtrate is the potassium-sodium second stage filter press filtrate (19), which is returned to the raw material forced slurry conditioner (A) for reuse. The filter solid is the potassium-sodium second stage filter press filtrate (20), which enters the third stage extraction process. S24, Three-stage extraction: The potassium-sodium two-stage pressure filter solid (20) is sent to the potassium-sodium slurry conditioner II (K), and potassium-sodium three-stage slurry conditioner makeup water (50) from the circulating water tank (AA) is added to adjust the slurry concentration, resulting in potassium-sodium three-stage slurry conditioner slurry (21), which is then sent to potassium-sodium multi-field coupling extractor III (L) for deep elution, resulting in potassium-sodium three-stage extraction slurry (22). After the potassium-sodium three-stage extraction slurry (22) is filtered by potassium-sodium plate and frame filter press III (M), the filtrate is potassium-sodium three-stage pressure filter filtrate (23), which is returned to potassium-sodium slurry conditioner I (H) for reuse, and the filter solid is potassium-sodium three-stage pressure filter solid (24), which is sent to step S3.

9. The cascade recovery process for valuable components of fly ash from waste incineration power plants according to claim 6, characterized in that: Step S3 specifically includes: S31, Grinding, dissociation and classification: The potassium and sodium three-stage pressure filter solid (24) output from step S2 is sent to the ball mill (N), and grinding makeup water (51) from the circulating water tank (AA) and calcium leaching agent I (25) are added to adjust the grinding concentration. The calcium component in the material is fully dissociated through grinding to obtain the dissociated slurry (26). The dissociated slurry (26) is sent to the hydrocyclone (O) for classification. The classification particle size is 50μm. The coarse particles in the slurry are returned to the ball mill (N) for re-grinding with the hydrocyclone underflow (27), and the fine particles are entered into the first stage of leaching process with the hydrocyclone overflow (28). S32, First stage leaching: The overflow (28) of the hydrocyclone is sent into the calcium multi-field coupling leaching machine I (P). Under the action of multi-energy field coupling and calcium leaching agent I (25), the calcium ion phase in the raw material is transferred to the liquid phase to obtain calcium first stage leaching slurry (29). After the calcium first stage leaching slurry (29) is filtered by calcium plate and frame filter press I (Q), the filtrate is calcium first stage filter filtrate (31) and sent to the calcium mineralization tower (R). The filter solid is calcium first stage filter solid (30) and enters the second stage leaching process. S33, mineralization precipitation: mineralization gas II (32) is introduced into the calcium mineralization tower (R) to combine calcium ions with carbonate ions in the first-stage calcium filter press filtrate (31) to form calcium carbonate solid, and obtain calcium mineralization slurry (33). The calcium mineralization slurry (33) is sent to the sedimentation tank (S) for solid-liquid pre-separation. The liquid phase is returned to the circulating water tank (AA) with the overflow (34) of the sedimentation tank, while the calcium carbonate solid settles and enters the calcium product plate and frame filter press (T) with the bottom flow (35) of the sedimentation tank for filter dewatering. The filtered solid is calcium carbonate (37) product, and the filtrate is calcium product filter press filtrate (36) sent to the circulating water tank (AA). S34, Second stage extraction: The calcium first stage filter press (30) is sent to the calcium slurry conditioning machine I (U), and calcium first stage slurry conditioning makeup water (52) from the circulating water tank (AA) is added to adjust the slurry concentration, and the calcium first stage slurry conditioning slurry (38) is obtained. It is sent to the calcium multi-field coupling extractor II (V), and calcium extraction agent II (39) is added at the same time to complete the second extraction, and the calcium second stage extraction slurry (40) is obtained. The calcium second stage extraction slurry (40) is filtered by the calcium plate and frame filter press II (W), and the filtrate is the calcium second stage filter press filtrate (41), which is returned to the ball mill (N) for reuse. The filter solid is the calcium second stage filter press filtrate (42), which enters the third stage extraction process. S35, Three-stage extraction: The calcium two-stage filter press (42) is sent to the calcium slurry conditioner II (X). After adding the calcium two-stage slurry conditioner makeup water (53) from the circulating water tank (AA) to adjust the slurry concentration, the calcium two-stage slurry (43) is obtained and sent to the calcium multi-field coupling extractor III (Y). At the same time, calcium extractant III (44) is added to complete the deep extraction and obtain the calcium three-stage extraction slurry (45). After the calcium three-stage extraction slurry (45) is filtered by the calcium plate and frame filter press III (Z), the filtrate is the calcium three-stage filter press filtrate (46) which is returned to the calcium slurry conditioner I (U) for reuse. The filter solid is the harmless residue (47).

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