System and method for reducing the amount of fly ash from household waste incineration and detoxifying heavy metals

Abstract

The present application provides a kind of life garbage incineration fly ash reduction-heavy metal detoxification system and method to solve the problem of poor resource utilization of fly ash in the prior art, the system includes pulping unit, electrolysis / heavy metal detoxification unit, hydrochloric acid preparation unit and low temperature pyrolysis unit, water washing, electrolysis, solid-liquid separation are integrated, reduce the loss caused by fly ash in the process of transfer, by using the synthesized hydrochloric acid and lye in the process, the precipitation of heavy metals is realized, the mixing of additional ions is reduced, the economic benefit is improved, the present application aims at waste control waste, utilizes a large amount of chloride ions in fly ash, synthesizes hydrochloric acid by chlorine and hydrogen produced by electrolysis, and the heavy metals in ash are acid leaching detoxification, and the reduction of fly ash is also realized, and the subsequent processing cost of fly ash is reduced.

Description

Technical Field

[0001] This invention relates to the field of waste incineration fly ash treatment technology, and in particular to a system and method for reducing fly ash from municipal solid waste incineration and detoxifying heavy metals. Background Technology

[0002] Incineration, as an efficient means of harmless, reduced-volume, and resource-based disposal of municipal solid waste, has become a key technology and mainstream method for municipal solid waste treatment at present. The fly ash produced during waste incineration contains high concentrations of heavy metals that leach out. Fly ash also contains a large amount of soluble salts, mainly in the form of chloride salts, which increase the risk of heavy metal leaching. Therefore, chloride in fly ash is a major challenge in the limited resource utilization of fly ash.

[0003] Fly ash dechlorination typically involves transferring chloride ions and soluble salts from fly ash to water to achieve dechlorination. The chloride ions in the washing solution are then evaporated as salts for industrial use. However, the salts obtained from fly ash washing contain potassium chloride, calcium chloride, and sodium chloride. The step-by-step evaporation and recovery process is complex, and the purity is not very high.

[0004] Fly ash contains a large amount of heavy metals, and ordinary water washing cannot remove heavy metal ions. The heavy metals remain in the bottom ash residue and are easily precipitated in an acidic environment, causing secondary pollution.

[0005] To address the above problems, Chinese invention patent CN112391534A proposes a method for reducing and recycling fly ash from municipal solid waste incineration. The method includes: Step 1, adding fly ash, acid, and oxidant to an acid washing tank and mixing to produce an acid washing slurry; Step 2, performing solid-liquid separation on the acid washing slurry to obtain an acid washing solution and acid washing waste residue; Step 3, washing the acid washing waste residue with water to obtain ash residue that can be recycled. This invention optimizes the acid leaching process by adding an oxidant. The addition of the oxidant maintains oxidation conditions throughout the leaching period, keeping the oxidation-reduction potential constant at greater than 300mV, thereby preventing the oxidation of metal components in the slurry and leading to the formation of a PbCuO alloy during the reduction cementation process, significantly improving the leaching rate of Pb, Cu, Cd, and Zn ions.

[0006] This method for reducing and recycling fly ash from municipal solid waste incineration has the following drawbacks:

[0007] Pickling fly ash requires the purchase of acid and oxidizing agents, which is costly. Summary of the Invention

[0008] This invention primarily addresses the problem of poor utilization of fly ash resources in existing technologies, and provides a system and method for reducing fly ash volume and detoxifying heavy metals from municipal solid waste incineration.

[0009] The above-mentioned technical problems of the present invention are mainly solved by the following technical solutions:

[0010] A system for reducing fly ash and detoxifying heavy metals from municipal solid waste incineration is characterized by comprising a pulping unit, an electrolysis / heavy metal detoxification unit, a hydrochloric acid preparation unit, and a low-temperature pyrolysis unit. The pulping unit includes an ash silo and a three-way pipe, with a shut-off valve between the ash silo and the three-way pipe. The electrolysis / heavy metal detoxification unit includes an electrolysis chamber, an alkali storage tank, and a solid-liquid separation chamber with its outlet connected to the alkali storage tank. The electrolysis chamber has a slurry inlet connected to the three-way pipe, and a booster pump is installed between the slurry inlet and the three-way pipe. A shut-off valve is installed between the solid-liquid separation chamber and the alkali storage tank. The solid-liquid separation chamber includes a centrifugal drum, a baffle cone, a drum head, a motor, and a belt connected to the discharge port. This system integrates washing, electrolysis, and solid-liquid separation, reducing fly ash losses during transport, shortening transport time, and improving work efficiency.

[0011] As a preferred embodiment, the electrolysis chamber includes a metal cylinder, a lifting cylinder assembly, a sliding assembly, and an electrolysis assembly. The metal cylinder is formed by stacking three cylinders that decrease in size from top to bottom, with the weight of the metal cylinders increasing from top to bottom. The metal cylinders are allowed to fall freely under gravity to form the electrolysis chamber. A strong magnet is installed on the metal cylinder, with the magnetic field direction being N-S. Under the combined action of the electric and magnetic fields, the electrolyte generates forced convection. The bubbles generated by electrolysis quickly leave the electrode surface and move upward, increasing the current density on the electrode surface and accelerating the electrolysis efficiency.

[0012] As a preferred embodiment, the sliding assembly includes a sliding groove disposed inside a metal cylinder, a slide rail mounted on the sliding groove, and a pulley assembly inside the slide rail, which can drive the metal cylinder to slide up and down.

[0013] As a preferred embodiment, the lifting cylinder assembly is located above the metal cylinder. The lifting cylinder assembly includes a pneumatic cylinder body and a pneumatic top cap. The pneumatic top cap is located below the pneumatic cylinder body. The pneumatic top cap is connected to a sliding pulley assembly on the metal cylinder via a tension spring. The pneumatic top cap and the pneumatic cylinder body are connected via a piston rod.

[0014] As a preferred embodiment, the electrolysis assembly includes an insulating rod inserted horizontally above the electrolysis chamber, on which electrolysis rods are mounted. Springs are installed at both ends of the electrolysis rods, which can move left and right under the force of the springs to change the electrode spacing, thereby accelerating the electrolysis efficiency.

[0015] As a preferred option, the tee pipe includes a main pipe and branch pipes with a diameter of 100-1500mm. The main pipe is connected to the washing liquid, and the branch pipe is connected to the ash silo. The main pipe is equipped with a flow rate controller to ensure that the ratio of fly ash to water for slurry preparation is 0.5 to 5:1.

[0016] As a preferred option, the electrolysis chamber is also equipped with chlorine and hydrogen collection pipelines that connect to the hydrochloric acid preparation unit to synthesize hydrochloric acid. The generated hydrochloric acid is transported to the electrolysis chamber through pipelines, making use of the large amount of chloride ions in fly ash. Hydrochloric acid is synthesized through chlorine and hydrogen generated by electrolysis, which reduces the treatment cost of fly ash.

[0017] A method for reducing fly ash and detoxifying heavy metals from municipal solid waste incineration, characterized by the following steps:

[0018] S1: By controlling the flow rate of the washing liquid, the washing liquid and fly ash are mixed in the three-way pipe to achieve fly ash slurry preparation. The fly ash slurry is then pumped into the electrolysis / heavy metal detoxification unit for washing.

[0019] S2: The metal cylinder falls to form an electrolysis chamber. After the fly ash is washed with water, electricity is turned on. Chlorine gas is generated at the positive electrode and hydrogen gas is generated at the negative electrode. The generated gas is transported to the hydrochloric acid preparation unit through the gas collection pipeline to prepare hydrochloric acid.

[0020] S3: The electrolyzed slurry enters the solid-liquid separation chamber. The transmission device drives the drum head to perform centrifugal motion, realizing the separation of slag and electrolyzed alkaline solution. The alkaline solution is then transported to the alkaline solution storage tank.

[0021] S4: Hydrochloric acid is transported to the electrolysis chamber through the hydrochloric acid conveying pipeline to acid leach the ash residue. The acid-leached slurry enters the solid-liquid separation chamber, and the transmission device drives the drum head to perform centrifugal motion to achieve the separation of ash residue and acid leaching liquid.

[0022] S5: The acid leaching solution and the alkaline solution are returned to the electrolysis chamber through the reflux pipe to fully react and form heavy metal precipitates.

[0023] This invention reduces the purchase of reagents and utilizes self-synthesized hydrochloric acid and alkali solution to precipitate heavy metals, thereby reducing the introduction of additional ions and improving economic efficiency.

[0024] As a preferred embodiment, in step S4, the ash residue is conveyed from the discharge port to the low-temperature pyrolysis unit via a belt for dioxin removal.

[0025] As a preferred embodiment, in step S5, heavy metals are collected through the discharge port and treated as hazardous waste, while the mixed liquid is reused at the washing liquid inlet to prepare mortar.

[0026] Therefore, the advantages of the present invention are:

[0027] 1. This invention aims to treat waste with waste, utilizing the large amount of chloride ions in fly ash. The chlorine and hydrogen generated by electrolysis are used to synthesize hydrochloric acid, which is used to detoxify the heavy metals in the ash residue through acid leaching. This also reduces the volume of fly ash and lowers the subsequent treatment costs.

[0028] 2. This invention reduces the purchase of reagents, utilizes self-synthesized hydrochloric acid and alkaline solution to precipitate heavy metals, reduces the introduction of additional ions, and improves economic efficiency.

[0029] 3. This invention integrates water washing, electrolysis, and solid-liquid separation, reducing the amount of fly ash lost during transportation and shortening the transportation time, thereby improving work efficiency.

[0030] 4. The electrolytic rod of the present invention can be moved left and right as needed, thereby improving the electrolysis efficiency by changing the electrode spacing.

[0031] 5. The present invention has a metal cylinder equipped with a magnet, which can accelerate the escape of bubbles generated by electrolysis by changing the direction of movement of the electrolyte, thereby improving the electrolysis efficiency. Attached Figure Description

[0032] Figure 1 This is a structural diagram of the system of the present invention;

[0033] Figure 2 This is a cross-sectional view of the electrolysis / heavy metal detoxification unit of the present invention;

[0034] Figure 3 This is a cross-sectional view of the electrolysis chamber of the present invention;

[0035] Figure 4 This is a top view of the electrolysis chamber of the present invention;

[0036] Figure 5 This is a schematic diagram of the lifting cylinder assembly of the present invention.

[0037] In the diagram: 1. Washing liquid inlet; 2. Ash silo; 3. T-junction pipe; 4. Electrolysis chamber; 5. Solid-liquid separation chamber; 6. Alkali storage tank; 7. Hydrochloric acid preparation unit; 8. Low-temperature pyrolysis unit; 31. Main pipe; 32. Branch pipe; 41. Metal cylinder; 42. Electrolysis assembly; 43. Lifting cylinder assembly; 44. Tension spring; 51. Motor; 52. Drum head; 53. Centrifugal drum; 55. Liquid outlet; 56. Material discharge. 57. Acid leaching reflux pipe; 71. Hydrochloric acid delivery pipe; 411. Sliding groove; 412. Roller pulley block; 413. Bolt; 421. Positioning spring; 422. Insulating rod; 423. Electrolytic rod; 431. Pneumatic cylinder body; 432. Pneumatic switching valve; 433. Pneumatic top cap; 434. Exhaust pipe; 435. Intake pipe; 511. Belt; 521. Rotating spindle; 4311. Piston rod. Detailed Implementation

[0038] The technical solution of the present invention will be further described in detail below through embodiments and in conjunction with the accompanying drawings.

[0039] Example 1:

[0040] like Figure 1 As shown, a system for reducing fly ash and detoxifying heavy metals from municipal solid waste incineration includes a pulping unit, an electrolysis / heavy metal detoxification unit, a hydrochloric acid preparation unit, and a low-temperature pyrolysis unit.

[0041] The pulping system includes an ash silo 2 and a three-way pipe 3. The washing liquid inlet 1, ash silo 2, and electrolysis chamber 4 are connected via the three-way pipe 3. The main pipe 31 is equipped with a flow rate controller, and the branch pipe 32 is equipped with a shut-off valve. The fly ash and washing liquid are pulped at a flow rate of 0.2-3 m / s, and then transported to the electrolysis / heavy metal detoxification unit by a booster pump.

[0042] The electrolysis / heavy metal detoxification unit consists of an electrolysis chamber 4, a solid-liquid separation chamber 5, and an alkaline solution storage tank 6. The alkaline solution storage tank 6 is connected to the solid-liquid separation chamber 5 through a pipeline. The alkaline solution separated in the solid-liquid separation chamber 5 is transported to the alkaline solution storage tank 6 through a pipeline via a lift pump. The acid leaching solution separated in the solid-liquid separation chamber is returned to the electrolysis chamber 4 through a pipeline via a lift pump.

[0043] like Figure 2 As shown, the electrolysis chamber 4 is composed of a metal cylinder 41, a tension spring 44, an electrolysis assembly 42, and a lifting cylinder assembly 43. The metal cylinder 41 is composed of three metal cylinders 41 whose size decreases from top to bottom, and the weight of the metal cylinders 41 increases from top to bottom, so that the metal cylinders 41 can fall by gravity to form the electrolysis chamber 4. A sliding groove 411 is provided on the metal cylinder 41, and a pulley assembly 412 is built into the sliding groove. The pulley assembly 412 is connected to the next metal cylinder 41 by bolts 413. One end of the tension spring 44 is connected to the pulley assembly 412, and the other end is connected to the pneumatic top cap 433. The piston rod 4311 inside the pneumatic cylinder 431 can drive the pneumatic top cap 433 to move upward, thereby driving the pulley assembly 412 to move upward, causing the metal cylinder 41 to retract upward, and the slurry in the electrolysis chamber 4 enters the solid-liquid separation chamber 5.

[0044] Electrolysis assembly 42 is located above electrolysis chamber 4 and consists of insulating rod 422, electrolysis rod 423, and positioning spring 421. Insulating rod 422 passes horizontally through metal cylinder 41. Electrolysis rod 423 is mounted on insulating rod 422. The positive electrode of electrolysis rod 423 is made of graphite, and the negative electrode is made of low-carbon steel. Positioning spring 421 is wound around both sides of insulating rod 422. The other end of positioning spring 421 is mounted on electrolysis rod 423. The elastic force of positioning spring 421 drives electrolysis rod 423 to move, thereby changing the electrode spacing and accelerating electrolysis efficiency. A magnet is installed on the outside of metal cylinder 41 with the magnetic field direction N-S. When energized, the electrolyte moves upward under the action of magnetic field and electric field force. The bubbles generated on electrolysis rod 423 will accelerate upward, thereby increasing current density and accelerating electrolysis efficiency. Electrolysis rod 423 is equipped with absorption pipes for hydrogen and chlorine. The gas pipes lead to hydrochloric acid preparation unit 7 to synthesize hydrochloric acid.

[0045] The lifting cylinder assembly 43 is located above the electrolysis chamber 4. The lifting cylinder assembly 43 includes a pneumatic top cap 433 and a pneumatic cylinder body 431. The pneumatic cylinder body 431 is located above the pneumatic top cap 433. The pneumatic top cap 433 is connected to the pulley block 412 through a tension spring 44. The pneumatic top cap 433 and the pneumatic cylinder body 431 are connected through a piston rod 4311. The piston rod 4311 extends into the pneumatic cylinder body 431. A pneumatic switching valve 432 is provided on the pneumatic cylinder body 431. An air inlet pipe 435 and an exhaust pipe 434 are provided on one side of the pneumatic switching valve. Gas is introduced through the air inlet pipe 435. The piston rod 4311 drives the pneumatic top cap 433 to move downward. The tension spring 44 applies a downward force to the metal cylinder 41. The metal cylinder 41 is subjected to force and its own weight, and falls to form the electrolysis chamber 4.

[0046] The solid-liquid separation chamber 5 is located outside the electrolysis chamber 4 and consists of a centrifugal drum 53, a baffle cone 51, a drum head 52, a motor 51, and a belt 511. The baffle cone 51 is used to throw the slurry out of the drum 53 under centrifugal force. The centrifugal drum 53 is evenly provided with 2mm small holes for solid-liquid separation. The bottom of the centrifugal drum 53 is provided with a groove into which a metal cylinder 41 is inserted to prevent the slurry from escaping during the washing process. The bottom of the centrifugal drum 53 is provided with a drum head 52, which contains a rotating main shaft 521. The belt 511 connects the rotating main shaft 521 and the motor 51. When the motor 51 starts, it drives the rotating main shaft 341 to rotate through the belt 511, thereby realizing the solid-liquid separation of the material.

[0047] like Figure 1 As shown, the hydrochloric acid prepared by the hydrochloric acid preparation unit 7 is transported to the electrolysis chamber 4 through the hydrochloric acid delivery pipeline 71. The hydrochloric acid delivery pipeline 71 is equipped with a shut-off valve and is made of polytetrafluoroethylene.

[0048] like Figure 1 As shown, the ash residue after acid leaching is discharged from the discharge port 56 and conveyed by belt to the low-temperature pyrolysis unit 8 to remove dioxins.

[0049] Example 2:

[0050] A method for reducing fly ash and detoxifying heavy metals from municipal solid waste incineration, the specific steps of which are as follows:

[0051] Step S1: The washing liquid is introduced into the three-way pipe 3 through the washing liquid inlet 1. The fly ash enters the main pipe 31 through the branch pipe 32 and mixes with the washing liquid. The fly ash and washing liquid are pulped at a flow rate of 0.2-3m / s and then enter the electrolysis chamber 4 through the booster pump.

[0052] Step S2: Gas is introduced through the inlet pipe 435. The piston rod 4311 drives the pneumatic cap 433 to move downward. The tension spring 44 applies a downward force to the metal cylinder 41. The metal cylinder 41 is subjected to force and its own gravity, and falls to form the electrolysis chamber 4. The fly ash falls into the electrolysis chamber 4. The electrode 51 drives the drum head 52 to rotate left and right at a speed of 500-1000 r / min. The time interval between left and right rotations is 2 min. Through continuous forward and reverse rotation, the ash slurry in the metal cylinder 41 rubs against each other for a duration of 20-40 min, thereby achieving a thorough water washing reaction of the fly ash and washing out all the soluble chloride salts in the fly ash.

[0053] Step S3: After the fly ash is washed with water, the electrolytic rod 432 is energized. Every 20 minutes, the electrolytic rod 423 is moved by the positioning spring 421. By changing the electrode spacing, the electrolysis efficiency is accelerated. The electrolysis time is 2-6 hours. The chlorine and hydrogen generated on the positive and negative electrodes are introduced into the hydrochloric acid preparation unit 7 through the gas absorption pipe to prepare hydrochloric acid.

[0054] Step S4: Open the pneumatic switching valve 432 to absorb gas from the exhaust pipe 434. The piston rod 4311 in the pneumatic cylinder 431 moves upward, driving the pneumatic top cap 433 to move upward. The tension spring 44 is subjected to an upward pulling force, which pulls the pulley assembly 412 to slide upward, thereby recovering the metal cylinder 41. The electrolyzed slurry is transferred into the solid-liquid separation chamber 5, where the motor 51 drives the drum head 52 to rotate at a speed of 3000-6000 r / min, realizing the solid-liquid separation of the slurry. The separated alkaline solution flows out from the outlet 55 and enters the alkaline solution storage tank 6 through the pipeline.

[0055] Step S5: Gas is introduced through the inlet pipe 435. The piston rod 4311 drives the pneumatic cap 433 to move downward. The tension spring 44 applies a downward force to the metal cylinder 41. The metal cylinder 41, under the action of force and its own gravity, falls to form the electrolysis chamber 4. The hydrochloric acid prepared by the hydrochloric acid preparation unit 7 is transported to the electrolysis chamber 4 through the hydrochloric acid delivery pipe 71 to perform acid leaching on the fly ash. The pH of the acid leaching solution is 1.5-3.5. The electrode 51 drives the drum head 52 to rotate left and right at a speed of 500-1000 r / min. The time interval between left and right rotations is 2 min. Through continuous forward and reverse rotation, the ash slurry inside the metal cylinder 41 rubs against each other for a duration of 20-40 min, thereby extracting the heavy metals in the fly ash and achieving the purpose of detoxifying the fly ash heavy metals.

[0056] Step S6: Open the pneumatic switching valve 432 to absorb gas from the exhaust pipe 434. The piston rod 4311 in the pneumatic cylinder 431 moves upward, driving the pneumatic top cap 433 to move upward. The tension spring 44 is subjected to an upward pulling force, which pulls the pulley assembly 412 to slide upward, thereby recovering the metal cylinder 41. The acid-leached slurry enters the solid-liquid separation chamber 5. The motor 51 drives the drum head 52 to rotate at a speed of 3000-6000 r / min, realizing the solid-liquid separation of the acid-leached slurry. The treated ash residue is discharged from the discharge port 56 and conveyed to the low-temperature pyrolysis unit 8 via the belt 511 to remove dioxins.

[0057] Step S7: The separated acid leaching solution is returned to the electrolysis chamber 4 through the acid leaching return pipe 57, and the alkaline solution is introduced into the electrolysis chamber 4 through the alkaline solution storage tank 6. The motor 51 drives the drum head 52 to rotate left and right at a speed of 500-1000 r / min, with a time interval of 2 min between left and right rotations. The acid leaching solution and the alkaline solution are fully mixed to form a heavy metal precipitate. As in the previous steps, the metal cylinder 41 retracts, and the heavy metal precipitate and the mixture are separated through the solid-liquid separation chamber 5. The heavy metal precipitate is discharged from the discharge port 56 as hazardous waste, and the mixture is reused to the washing liquid inlet 1 for fly ash pulping.

[0058] The specific embodiments described herein are merely illustrative of the spirit of the invention. Those skilled in the art to which this invention pertains may make various modifications or additions to the described specific embodiments or use similar methods to substitute them, without departing from the spirit of the invention or exceeding the scope defined by the appended claims.

Claims

1. A system for reducing fly ash and detoxifying heavy metals from municipal solid waste incineration, characterized in that, The system includes a pulping unit, an electrolysis / heavy metal detoxification unit, a hydrochloric acid preparation unit, and a low-temperature pyrolysis unit. The pulping unit includes an ash silo and a three-way pipe, with a shut-off valve between the ash silo and the three-way pipe. The electrolysis / heavy metal detoxification unit includes an electrolysis chamber, an alkali storage tank, and a solid-liquid separation chamber with its outlet connected to the alkali storage tank. The electrolysis chamber has a slurry inlet connected to the three-way pipe, and a booster pump is installed between the slurry inlet and the three-way pipe. A shut-off valve is installed between the solid-liquid separation chamber and the alkali storage tank. The solid-liquid separation chamber includes a centrifugal drum, a baffle cone, a drum head, a motor, and a belt connected to the discharge port. The electrolysis chamber also has chlorine and hydrogen collection pipes connected to the hydrochloric acid preparation unit to synthesize hydrochloric acid. The generated hydrochloric acid is transported to the electrolysis chamber through pipes. The solid-liquid separation chamber is located outside the electrolysis chamber. A groove is provided at the bottom of the centrifugal drum, and the metal cylinder of the electrolysis chamber is inserted into the groove.

2. The system for reducing fly ash and detoxifying heavy metals from municipal solid waste incineration according to claim 1, characterized in that, The electrolysis chamber includes a metal cylinder, a lifting cylinder assembly, a sliding assembly, and an electrolysis assembly. The metal cylinder is composed of three cylinders stacked from top to bottom, with the weight of the metal cylinders increasing from top to bottom. A strong magnet is installed on the metal cylinder, and the magnetic field direction is N-S.

3. A system for reducing fly ash and detoxifying heavy metals from municipal solid waste incineration according to claim 2, characterized in that, The sliding assembly includes a sliding groove inside a metal cylinder, a slide rail mounted on the sliding groove, and a pulley system inside the slide rail.

4. A system for reducing fly ash and detoxifying heavy metals from municipal solid waste incineration according to claim 1, 2, or 3, characterized in that, The lifting cylinder assembly is located above the metal cylinder. The lifting cylinder assembly includes a pneumatic cylinder body and a pneumatic top cap. The pneumatic top cap is located below the pneumatic cylinder body. The pneumatic top cap is connected to the pulley group on the metal cylinder through a tension spring. The pneumatic top cap and the pneumatic cylinder body are connected through a piston rod.

5. A system for reducing fly ash and detoxifying heavy metals from municipal solid waste incineration according to claim 2, characterized in that, The electrolysis assembly includes an insulating rod inserted horizontally above the electrolysis chamber, on which electrolysis rods are mounted, and springs are installed at both ends of the electrolysis rods.

6. A system for reducing fly ash and detoxifying heavy metals from municipal solid waste incineration according to claim 1, characterized in that, The tee pipe consists of a main pipe and branch pipes, with a diameter of 100-1500mm. The main pipe is connected to the washing liquid, and the branch pipe is connected to the ash silo. The main pipe is equipped with a flow rate controller.

7. A method for reducing fly ash and detoxifying heavy metals from municipal solid waste incineration, comprising the system for reducing fly ash and detoxifying heavy metals from municipal solid waste incineration as described in any one of claims 1 to 6, characterized in that, Includes the following steps: S1: By controlling the flow rate of the washing liquid, the washing liquid and fly ash are mixed in the three-way pipe to achieve fly ash slurry preparation. The fly ash slurry is then pumped into the electrolysis / heavy metal detoxification unit for washing. S2: The metal cylinder falls to form an electrolysis chamber. After the fly ash is washed with water, electricity is turned on. Chlorine gas is generated at the positive electrode and hydrogen gas is generated at the negative electrode. The generated gas is transported to the hydrochloric acid preparation unit through the gas collection pipeline to prepare hydrochloric acid. S3: The electrolyzed slurry enters the solid-liquid separation chamber. The transmission device drives the drum head to perform centrifugal motion, realizing the separation of slag and electrolyzed alkaline solution. The alkaline solution is then transported to the alkaline solution storage tank. S4: Hydrochloric acid is transported to the electrolysis chamber through the hydrochloric acid conveying pipeline to acid leach the ash residue. The acid-leached slurry enters the solid-liquid separation chamber, and the transmission device drives the drum head to perform centrifugal motion to achieve the separation of ash residue and acid leaching liquid. S5: The acid leaching solution and alkali solution are returned to the electrolysis chamber through the reflux pipe to fully react and form heavy metal precipitates.

8. A method for reducing fly ash and detoxifying heavy metals from municipal solid waste incineration according to claim 7, characterized in that, In step S4, the ash residue is conveyed from the discharge port to the low-temperature pyrolysis unit via belt for dioxin removal.

9. A method for reducing fly ash and detoxifying heavy metals from municipal solid waste incineration according to claim 7, characterized in that, In step S5, the heavy metal precipitate is collected through the outlet and treated as hazardous waste, while the mixed liquid is reused at the washing liquid inlet to prepare slurry.

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