Waste incineration fly ash electrolysis co-processing and zero-emission recycling method
Through the electrolysis synergistic treatment method, the problem of treating chloride salts and heavy metals in waste incineration fly ash was solved, the zero landfill resource utilization and efficient detoxification of fly ash were achieved, and the environmental risks and operating costs were reduced.
Patent Information
- Application Number
- CN202510946165.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-09
- Publication Date
- 2025-10-10
- Estimated Expiration
- Not applicable · inactive patent
AI Technical Summary
The treatment of chloride salts and heavy metals in waste incineration fly ash is difficult to meet the reuse requirements. Traditional treatment methods pose environmental risks and waste resources. In addition, the existing technology has low desalination efficiency and cannot effectively solve the problem of heavy metal leaching.
An electrolytic synergistic treatment method is adopted, through a mixing mechanism and electrolytic cell combined with a plate and frame filter press, to mix the fly ash and water, electrolyze and separate the solid and liquid. Titanium-based coated electrodes and stainless steel 316L electrode plates are used for electrolysis to achieve the separation and recovery of chloride ions and heavy metals. Multi-effect evaporation, concentration, crystallization and chemical precipitation are combined to recover salt and heavy metals.
The fly ash is recycled without landfill, with a chloride ion removal rate of ≥98% and a heavy metal removal rate of ≥70%, thus reducing operating costs, avoiding environmental pollution risks, and enabling efficient recycling of resources.
Smart Images
Figure CN120755162A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of waste incineration fly ash treatment, and in particular to a method for electrolytically co-processing and zero-emission resource utilization of waste incineration fly ash. Background Art
[0002] Waste incineration fly ash is classified as hazardous waste because it is rich in chloride salts and heavy metals (HW18). The traditional treatment method is solidification and stabilization followed by landfill, which not only occupies land resources but also poses long-term environmental risks.
[0003] Existing technologies (such as water washing and acid washing) have low desalination efficiency (<80%) and cannot effectively solve the problem of heavy metal leaching, making it difficult to meet the requirements for fly ash reuse. Among them, the water washing method: high water consumption, difficult to handle the salt concentrate, and heavy metals may be dissolved again; solidification landfill: fly ash volume increases, landfill costs are high, and resource recovery cannot be achieved; direct back-incineration: chloride salts corrode the furnace, and heavy metal enrichment leads to excessive flue gas emissions. Therefore, we propose a method for electrolytic co-treatment and zero-emission resource recovery of waste incineration fly ash. Summary of the Invention
[0004] The purpose of the present invention is to solve the problems mentioned in the above background technology, and to provide a method for the electrolytic coordinated treatment and zero-emission resource utilization of waste incineration fly ash.
[0005] In order to achieve the above-mentioned purpose, the present invention specifically adopts the following technical solutions:
[0006] A method for electrolytic coordinated treatment and zero-emission resource utilization of waste incineration fly ash, the method comprising: a mixing mechanism, an electrolytic cell arranged below the mixing mechanism, and a plate and frame filter press connected to the electrolytic cell via a connecting pipe, the mixing mechanism comprising a mixing barrel, a barrel cover being detachably mounted on the upper end of the mixing barrel, a motor 1 being mounted inside the barrel cover, a motor shaft of the motor 1 being evenly axially provided with multiple groups of connecting seats, a mixing plate being provided on the outer side of each connecting seat, a discharging barrel being mounted on the lower end of the mixing barrel, fixed seats being provided on both sides of the mixing barrel, and a fixed frame being provided on the outer side of the fixed seat; the electrolytic cell being equipped with a stirring mechanism, and multiple groups of electrode plates being mounted inside the electrolytic cell.
[0007] Furthermore, the inner wall of the lower end of the cylinder cover is provided with an internal thread, the circumferential outer wall of the upper end of the mixing cylinder is provided with an external thread, the mixing cylinder and the cylinder cover are connected by threads, and two feed ports are opened inside the cylinder cover.
[0008] Furthermore, a clamping block is installed at the lower end of each fixing frame, and a clamping groove is provided at the upper end of the electrolytic cell, and the clamping block is clamped in the clamping groove.
[0009] Furthermore, the stirring mechanism includes a second motor, the inner end of the motor shaft of the second motor is drivingly connected to a rotating shaft, and a plurality of stirring plates are evenly arranged on the circumferential surface of the rotating shaft along the axial direction.
[0010] Furthermore, the rotation speed of the second motor is 50-100 rpm.
[0011] Furthermore, the anode of the electrode plate is made of titanium-based coated electrode or carbon steel, the cathode is made of stainless steel 316L, and the electrolysis parameters of the electrode plate are voltage 5-12V, current density 10-50mA / cm 2 , reaction time 30 to 60 minutes.
[0012] Furthermore, the input end of the connecting pipe is plugged into the right side of the electrolytic cell, the output side of the connecting pipe is plugged into the output side of the plate and frame filter press, and a slurry pump is installed on the input side of the connecting pipe.
[0013] Furthermore, the plate and frame filter press is equipped with a built-in pressure sensor and a moisture content sensor.
[0014] Further, the following steps are included:
[0015] Step 1: preparing fly ash slurry by mixing fly ash and water in a mass ratio of 1:5 to form a uniform slurry;
[0016] Step 2: electrolysis treatment, introducing the prepared uniform slurry into an electrolytic cell for electrolysis;
[0017] Step 3: solid-liquid separation: the slurry after electrolysis is separated into fly ash cake and filtrate through a plate and frame filter press, and the moisture content of the fly ash cake is less than 25%;
[0018] Step 4: fly ash recycling, testing the chloride ion content in the ash cake to be less than 0.1% and the heavy metal leaching concentration Pb to be less than 0.25mg / kg. After meeting the standards, the ash is dried and sprayed back into the incinerator;
[0019] Step 5: filtrate treatment and resource recovery: salt recovery and heavy metal recovery are performed on the filtrate.
[0020] Furthermore, in the salt recovery, the filtrate is concentrated and crystallized by multi-effect evaporation to recover industrial-grade NaCl / KCl; in the heavy metal recovery, the evaporated residual liquid is chemically precipitated or electrodeposited to recover heavy metals.
[0021] The beneficial effects of the present invention are as follows:
[0022] 1. Zero landfill of fly ash: 100% of the fly ash is sprayed back into the incinerator and eventually converted into slag, which completely solves the landfill problem. The slag can be used as a building material (such as aggregate or roadbed material) for resource utilization.
[0023] 2. High efficiency detoxification: Soluble salt removal rate ≥98% (such as Cl - From 3% to <0.05%), the total heavy metal removal rate is ≥70% (such as Pb+Zn from 3000mg / kg to <800mg / kg).
[0024] 3. Resource recovery: The purity of the recovered salts (NaCl / KCl) is ≥95% and can be directly used for industrial purposes. Heavy metals (such as Pb and Cd) are recovered in a high-purity form, reducing resource waste.
[0025] 4. Environmentally friendly: Avoid the potential pollution risk of fly ash landfill to soil and groundwater, reduce the incineration plant's dependence on external landfills, and reduce operating costs. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Figure 1 It is a three-dimensional schematic diagram of the present invention;
[0027] Figure 2 It is a process flow chart of the present invention.
[0028] Figure numerals: 1. Mixing mechanism; 11. Mixing cylinder; 12. Cylinder cover; 13. Motor 1; 14. Connecting seat; 15. Mixing plate; 16. Discharge cylinder; 17. Fixed seat; 18. Fixed frame; 2. Electrolytic cell; 3. Stirring mechanism; 31. Motor 2; 32. Rotating shaft; 33. Stirring plate; 4. Electrode plate; 5. Connecting pipe; 6. Slurry pump; 7. Plate and frame filter press. DETAILED DESCRIPTION
[0029] To make the objectives, technical solutions and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.
[0030] See also Figure 1 The present invention provides a method for electrolytic coordinated treatment and zero-emission resource utilization of waste incineration fly ash, which includes: a mixing mechanism 1, an electrolytic cell 2 arranged below the mixing mechanism 1, and a plate and frame filter press 7 connected to the electrolytic cell 2 through a connecting pipe 5. The mixing mechanism 1 includes a mixing barrel 11, and a barrel cover 12 is detachably installed on the upper end of the mixing barrel 11. A motor 13 is installed inside the barrel cover 12. The motor shaft of the motor 13 is evenly provided with multiple groups of connecting seats 14 along the axial direction, and a mixing plate 15 is provided on the outside of each connecting seat 14. A discharge barrel 16 is installed at the lower end of the mixing barrel 11, and fixed seats 17 are provided on both sides of the mixing barrel 11. A fixing frame 18 is provided on the outside of the fixed seat 17; the electrolytic cell 2 is equipped with a stirring mechanism 3, and multiple groups of electrode plates 4 are installed inside the electrolytic cell 2.
[0031] Under the action of the mixing drum 11, the purpose of storing fly ash and water can be achieved. The fly ash is tested in the laboratory after the pre-processing to ensure the safety of returning to the garbage storage bin. Under the action of the drum cover 12, the purpose of sealing the mixing drum 11 can be achieved to prevent the slurry from splashing out. Under the action of the motor 13, the purpose of rotating the connecting seat 14 and the mixing plate 15 can be achieved. Under the action of the discharge drum 16, the slurry inside the mixing drum 11 can be discharged. Under the action of the electrolytic cell 2, the purpose of supporting the fixed frame 18 can be achieved. Under the action of the fixed frame 18, the purpose of supporting the fixed seat 17 can be achieved. Under the action of the fixed seat 17, the purpose of supporting the mixing drum 11 can be achieved; under the coordinated action of the electrolytic cell 2 and the electrode plate 4, the purpose of electrolysis of the slurry can be achieved, and by setting the stirring mechanism 3, it can be ensured that the fly ash particles are fully dispersed, the anode oxidation in the electrode plate 4 degrades organic matter, and at the same time promotes chloride ions (Cl - ) migrate to the solution phase, and the cathode reduces and precipitates heavy metals (such as Pb 2+ →Pb 0 ), reduce the heavy metal content in fly ash, separate it into fly ash cake and filtrate through plate and frame filter press 7, and the moisture content of fly ash cake is controlled at <25%, which is convenient for subsequent back-injection into incinerator. 100% of fly ash is back-injected into incinerator and finally converted into slag, which completely solves the landfill problem. The slag can be used as a building material (such as aggregate or roadbed material) for resource utilization, realizing zero landfill of fly ash. Through dual treatment of electrolysis and filter press, the chloride and heavy metal content in fly ash is ensured to be extremely low, and the soluble salt removal rate is ≥98% (such as Cl - From 3% to <0.05%), the total heavy metal removal rate is ≥70% (such as Pb+Zn from 3000mg / kg to <800mg / kg), achieving efficient detoxification while avoiding the potential pollution risk of fly ash landfill to soil and groundwater, reducing the incineration plant's dependence on external landfills, and reducing operating costs.
[0032] In this embodiment, preferably, the inner wall of the lower end of the barrel cover 12 is provided with an internal thread, and the circumferential outer wall of the upper end of the mixing barrel 11 is provided with an external thread. The mixing barrel 11 and the barrel cover 12 are connected by threads, and two feed ports are opened inside the barrel cover 12. The threaded connection can ensure the connection stability between the barrel cover 12 and the mixing barrel 11 and facilitate disassembly. Fly ash and water can be injected into the interior of the mixing barrel 11 through the feed port.
[0033] In this embodiment, preferably, a snap-in block is installed at the lower end of each fixing bracket 18, and a snap-in groove is provided at the upper end of the electrolytic cell 2, in which the snap-in block is snapped; the installation stability of the snap-in block can be guaranteed under the action of the snap-in groove, that is, the support purpose of the fixing bracket 18 can be achieved under the action of the electrolytic cell 2.
[0034] In this embodiment, preferably, the stirring mechanism 3 includes a second motor 31, the inner end of the motor shaft of the second motor 31 is connected to the rotating shaft 32, and the circumferential surface of the rotating shaft 32 is evenly provided with multiple stirring plates 33 along the axial direction; under the action of the second motor 31, the purpose of rotation of the rotating shaft 32 and the stirring plates 33 on the circumferential surface can be achieved, and under the action of the stirring mechanism 3, it can be ensured that the fly ash particles are fully dispersed.
[0035] In this embodiment, preferably, the rotation speed of the second motor 31 is 50-100 rpm.
[0036] In this embodiment, preferably, the anode of the electrode plate 4 is made of titanium-based coated electrode or carbon steel, the cathode is made of stainless steel 316L, and the electrolysis parameters of the electrode plate 4 are voltage 5-12V, current density 10-50mA / cm 2 , reaction time 30 to 60 minutes. The precious metal coating (such as ruthenium, iridium, tantalum, etc.) on the surface of the titanium-based coated electrode significantly improves the electrocatalytic activity. The electrode shape is not easily deformed during the electrolysis process, ensuring stable cell pressure and improving operational safety. The titanium alloy substrate and precious metal coating have excellent corrosion resistance, can work stably for a long time, and reduce maintenance costs. The cost of carbon steel is relatively low. In this embodiment, the titanium-based coated electrode is preferably selected as the anode. Stainless steel 316L has excellent corrosion resistance and electrochemical stability. Under the action of the electrode plate 4, the purpose of electrolysis synergy can be achieved.
[0037] In this embodiment, preferably, the input end of the connecting pipe 5 is plugged into the right side of the electrolytic cell 2, the output side of the connecting pipe 5 is plugged into the output side of the plate and frame filter press 7, and a slurry pump 6 is installed on the input side of the connecting pipe 5; with the cooperation of the connecting pipe 5 and the slurry pump 6, the slurry inside the electrolytic cell 2 can be pumped into the plate and frame filter press 7, and filtered by the plate and frame filter press 7.
[0038] In this embodiment, preferably, the plate and frame filter press 7 is equipped with a pressure sensor and a moisture content sensor; the real-time pressure inside the plate and frame filter press 7 is monitored by the pressure sensor, and the water content inside the plate and frame filter press 7 is monitored in real time by the moisture content sensor.
[0039] See also Figure 2 The present invention provides a method for electrolytically co-processing and zero-emission resource utilization of waste incineration fly ash, comprising the following steps:
[0040] Step 1: preparing fly ash slurry by mixing fly ash and water in a mass ratio of 1:5 to form a uniform slurry to improve fluidity;
[0041] Step 2: electrolysis treatment, introducing the prepared uniform slurry into the interior of the electrolytic cell for electrolysis. The electrolytic cell is a long strip reaction cell with a built-in stirring device (rotation speed 50-100 rpm) to ensure that the fly ash particles are fully dispersed, and a built-in electrode sheet. The anode in the electrode plate 4 degrades organic matter by oxidation, while promoting the migration of chloride ions (Cl-) to the solution phase, and the cathode reduces and precipitates heavy metals (such as Pb2+→Pb0), thereby reducing the heavy metal content in the fly ash;
[0042] Step 3: solid-liquid separation: the slurry after electrolysis is separated into fly ash cake and filtrate through a plate and frame filter press, and the moisture content of the fly ash cake is less than 25%, which is convenient for subsequent back-injection into the incinerator;
[0043] Step 4: fly ash recycling. The chloride ion content in the ash cake is tested to be less than 0.1% and the heavy metal leaching concentration Pb is less than 0.25mg / kg. After meeting the standards, it is dried and sprayed back into the incinerator. The sprayed fly ash melts at high temperature (≥850℃) in the furnace and is eventually converted into harmless slag, which completely solves the landfill problem. The slag can be used as a resource for building materials (such as aggregates or roadbed materials), avoiding the potential pollution risk of fly ash landfill to soil and groundwater, reducing the incineration plant's dependence on external landfills, and reducing operating costs.
[0044] Step 5: filtrate treatment and resource recovery: the filtrate is subjected to salt recovery and heavy metal recovery; wherein, in salt recovery, the filtrate is concentrated and crystallized by multi-effect evaporation to recover industrial-grade NaCl / KCl, and the recovered NaCl / KCl has a purity of ≥95% and can be directly used for industrial purposes; in heavy metal recovery, the evaporated residual liquid is subjected to chemical precipitation or electrodeposition to recover heavy metals, and heavy metals (such as Pb and Cd) are recovered in a high-purity form, reducing resource waste. Through dual treatment of electrolysis and filter press, the chloride and heavy metal contents in the fly ash are ensured to be extremely low, and the soluble salt removal rate is ≥98% (such as Cl - From 3% to <0.05%), the total heavy metal removal rate is ≥70% (such as Pb+Zn from 3000mg / kg to <800mg / kg), achieving efficient detoxification.
[0045] The above description of the disclosed embodiments is intended to enable one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not limited to the embodiments shown herein but is intended to conform to the widest scope consistent with the principles and novel features disclosed herein.
Claims
1. A method for the electrolytic coordinated treatment and zero-emission resource utilization of waste incineration fly ash, comprising: A mixing mechanism (1), an electrolytic cell (2) arranged below the mixing mechanism (1), and a plate-frame filter press (7) connected to the electrolytic cell (2) via a connecting pipe (5), characterized in that the mixing mechanism (1) includes a mixing barrel (11), a barrel cover (12) is detachably mounted on the upper end of the mixing barrel (11), a motor (13) is mounted inside the barrel cover (12), a motor (13) is evenly arranged on the motor shaft of the motor (13) along the axial direction with multiple groups of connecting seats (14), a mixing plate (15) is arranged on the outer side of each connecting seat (14), a discharge barrel (16) is mounted on the lower end of the mixing barrel (11), a fixing seat (17) is arranged on both sides of the mixing barrel (11), and a fixing frame (18) is arranged on the outer side of the fixing seat (17); the electrolytic cell (2) is equipped with a stirring mechanism (3), and multiple groups of electrode plates (4) are mounted inside the electrolytic cell (2).
2. The method for electrolytic coordinated treatment and zero-emission resource utilization of waste incineration fly ash according to claim 1, characterized in that: The inner wall of the lower end of the cylinder cover (12) is provided with an internal thread, and the circumferential outer wall of the upper end of the mixing cylinder (11) is provided with an external thread. The mixing cylinder (11) and the cylinder cover (12) are connected by threads, and two feed ports are opened inside the cylinder cover (12).
3. The method for electrolytic coordinated treatment and zero-emission resource utilization of waste incineration fly ash according to claim 1, characterized in that: A clamping block is installed at the lower end of each fixing frame (18), and a clamping groove is provided at the upper end of the electrolytic cell (2), in which the clamping block is clamped.
4. The method for electrolytic coordinated treatment and zero-emission resource utilization of waste incineration fly ash according to claim 1, characterized in that: The stirring mechanism (3) comprises a second motor (31), the inner end of the motor shaft of the second motor (31) is connected to a rotating shaft (32) in a transmission manner, and a plurality of stirring plates (33) are evenly arranged on the circumferential surface of the rotating shaft (32) along the axial direction.
5. The method for electrolytic coordinated treatment and zero-emission resource utilization of waste incineration fly ash according to claim 1, characterized in that: The rotation speed of the motor 2 (31) is 50-100 rpm.
6. The method for electrolytic coordinated treatment and zero-emission resource utilization of waste incineration fly ash according to claim 1, characterized in that: The anode of the electrode plate (4) is a titanium-based coating electrode or carbon steel, and the cathode is 316L stainless steel. The electrolysis parameters of the electrode plate (4) are a voltage of 5 to 12 V and a current density of 10 to 50 mA / cm 2 , reaction time 30 to 60 minutes.
7. The method for electrolytic coordinated treatment and zero-emission resource utilization of waste incineration fly ash according to claim 1, characterized in that: The input end of the connecting pipe (5) is plugged into the right side of the electrolytic cell (2), the output side of the connecting pipe (5) is plugged into the output side of the plate and frame filter press (7), and a slurry pump (6) is installed on the input side of the connecting pipe (5).
8. The method for electrolytic coordinated treatment and zero-emission resource utilization of waste incineration fly ash according to claim 1, characterized in that: The plate and frame filter press (7) is equipped with a pressure sensor and a moisture content sensor.
9. The method for electrolytic coordinated treatment and zero-emission resource utilization of waste incineration fly ash according to claim 1, characterized in that: The following steps are also included: Step 1: preparing fly ash slurry by mixing fly ash and water in a mass ratio of 1:5 to form a uniform slurry; Step 2: electrolysis treatment, introducing the prepared uniform slurry into an electrolytic cell for electrolysis; Step 3: solid-liquid separation: the slurry after electrolysis is separated into fly ash cake and filtrate through a plate and frame filter press, and the moisture content of the fly ash cake is less than 25%; Step 4: fly ash recycling, testing the chloride ion content in the ash cake to be less than 0.1% and the heavy metal leaching concentration Pb to be less than 0.25mg / kg. After meeting the standards, the ash is dried and sprayed back into the incinerator; Step 5: filtrate treatment and resource recovery: salt recovery and heavy metal recovery are performed on the filtrate.
10. The method for electrolytic coordinated treatment and zero-emission resource utilization of waste incineration fly ash according to claim 9, characterized in that: The filtrate in the salt recovery is concentrated and crystallized by multi-effect evaporation to recover industrial grade NaCl / KCl; In the heavy metal recovery process, the evaporated residual liquid is used to recover the heavy metals through chemical precipitation or electrodeposition.