A method for detoxifying dioxins from waste incineration fly ash

Abstract

The present invention provides a method for detoxifying dioxins from waste incineration fly ash. The method involves grinding waste incineration fly ash to obtain fine fly ash, producing a mixed inert gas, and then suspending and heating the fine fly ash with the mixed inert gas at a predetermined gas-to-solid ratio to achieve pre-degradation of dioxins, producing a first gas-solid mixture. The first gas-solid mixture is then treated to produce dioxin-detoxified fly ash and a first qualified gas. The dioxin-detoxified fly ash is a finished product obtained by complete degradation. This method achieves pre-degradation of dioxins without the use of a catalyst, thus avoiding the high cost and need for regular catalyst replacement. The dioxin degradation efficiency exceeds 99.7%.

Description

Technical Field

[0001] The invention belongs to the technical field of solid waste treatment and disposal, and particularly relates to a method for detoxifying dioxins in fly ash from garbage incineration. Background Art

[0002] With the acceleration of industrialization, waste incineration has become a widely used method of waste disposal. However, the fly ash produced during waste incineration contains large amounts of highly toxic dioxins, posing a serious threat to the ecological environment and human health. Therefore, the effective treatment of dioxins in fly ash has become a critical issue that needs to be addressed.

[0003] Traditional dioxin treatment methods include high-temperature incineration, but this often consumes significant amounts of energy and places stringent demands on equipment. In contrast, low-temperature pyrolysis technology has attracted attention due to its relatively low energy consumption. However, in practice, low-temperature pyrolysis of dioxins in fly ash faces numerous challenges.

[0004] From the perspective of pyrolysis efficiency, dioxin molecules have extremely stable chemical structures, especially polychlorinated dioxins, which have high energy barriers to overcome for chemical bond breaking and recombination under low-temperature conditions. Based on the principles of chemical reaction kinetics, low-temperature environments cause the reaction rate constant to be significantly reduced. Compared with high-temperature pyrolysis, the reaction rate constant may differ by several orders of magnitude. This directly leads to the difficulty of completely decomposing dioxins during low-temperature pyrolysis, and the chlorine atoms in some dioxin molecules cannot be effectively removed, remaining in the fly ash. At the same time, the fly ash itself has a complex composition, and inorganic components such as metal oxides are easily adsorbed or reacted with dioxins to form relatively stable forms, which further hinders the decomposition process of dioxins during low-temperature pyrolysis, greatly reducing the overall pyrolysis efficiency. It often takes a long processing time to achieve a relatively ideal removal effect.

[0005] In order to improve the efficiency of low-temperature pyrolysis of dioxins, auxiliary measures such as the addition of catalysts are often required. Among the many types of catalysts, precious metal catalysts have a certain effect on improving the decomposition rate of dioxins. However, the precious metal catalysts themselves are expensive, which greatly increases the operating costs of the equipment. In addition, various impurities present in fly ash, such as heavy metals and other organic and inorganic compounds, may react with precious metal catalysts during the pyrolysis process, causing their active sites to be occupied or changing their chemical environment, making the catalyst easily deactivated. Once the catalyst is deactivated, in order to maintain the effective treatment effect of dioxins, the catalyst must be replaced regularly, which undoubtedly further increases the burden of treatment costs and becomes one of the important factors limiting the large-scale application of low-temperature pyrolysis of dioxins technology.

[0006] Therefore, developing a detoxification method that can efficiently degrade dioxins in waste incineration fly ash without using a catalyst has become a key issue that needs to be tackled in the current field of solid waste treatment. Summary of the Invention

[0007] In view of the above-mentioned defects or deficiencies in the prior art, the present application aims to provide a method for detoxifying dioxins in waste incineration fly ash, comprising the following steps:

[0008] Grinding waste incineration fly ash to obtain fine fly ash;

[0009] obtaining a mixed inert gas, the mixed inert gas comprising at least carbon dioxide, water, and nitrogen;

[0010] According to a set gas-solid ratio, the fine fly ash is suspended and heated by a mixed inert gas to achieve pre-degradation of dioxins to obtain a first gas-solid mixture;

[0011] Treating the first gas-solid mixture to obtain dioxin detoxification fly ash and a first qualified gas, wherein the dioxin detoxification fly ash is a finished product obtained by complete degradation;

[0012] The first qualified gas is discharged.

[0013] Preferably, processing the first gas-solid mixture to obtain dioxin-detoxified fly ash and the first qualified gas comprises the following steps:

[0014] Gas-solid separation of the first gas-solid mixture to obtain first fly ash and second qualified gas;

[0015] In the second qualified gas atmosphere, the first fly ash is efficiently degraded according to the set time to obtain the highly degraded fly ash;

[0016] The fly ash is efficiently degraded to obtain dioxin-detoxified fly ash and the first gas that meets the standards.

[0017] Preferably, processing the highly efficient degraded fly ash to obtain the dioxin detoxified fly ash and the first qualified gas comprises the following steps:

[0018] Separate air to obtain inert gas;

[0019] The fly ash is efficiently degraded by inert gas suspension cooling to form a second gas-solid mixture;

[0020] The second gas-solid mixture is separated by gas-solid separation to obtain dioxin detoxification fly ash and the first qualified gas.

[0021] Preferably, gas-solid separation of the first gas-solid mixture to obtain the first fly ash and the second qualified gas comprises the following steps:

[0022] cyclone separation of the first gas-solid mixture to obtain first fly ash and second exhaust gas;

[0023] The second exhaust gas is treated by dust collection to obtain a second gas that meets the standards.

[0024] Preferably, the dust collection and treatment of the second exhaust gas to obtain second fly ash; gas-solid separation of the first gas-solid mixture to obtain first fly ash and second qualified gas, and the treatment of the high-efficiency degradation fly ash to obtain dioxin detoxification fly ash and first qualified gas further include the following steps:

[0025] In the second qualified gas atmosphere, the second fly ash is degraded according to the set time to obtain highly efficiently degraded fly ash.

[0026] Preferably, collecting and treating the second exhaust gas to obtain the second qualified gas comprises the following steps:

[0027] The ceramic dust collector collects the second waste gas to obtain the third waste gas;

[0028] Detect the third exhaust gas and determine whether it is qualified:

[0029] If qualified, the third exhaust gas is converted into the second qualified gas;

[0030] If it fails to meet the standards, the third exhaust gas is purified by plasma to obtain the second qualified gas.

[0031] Preferably, in the second qualified gas atmosphere, the first fly ash is degraded according to the set time to obtain the first waste gas, and in the second qualified gas atmosphere, the second fly ash is degraded according to the set time to obtain the first waste gas, and the detoxification method further includes the following steps:

[0032] The ceramic dust collector collects the first exhaust gas to obtain the third exhaust gas;

[0033] Detect the third exhaust gas and determine whether it is qualified:

[0034] If qualified, the third exhaust gas is converted into the second qualified gas;

[0035] If it fails to meet the standards, the third exhaust gas is purified by plasma to obtain the second qualified gas.

[0036] Preferably, obtaining the mixed inert gas comprises the following steps:

[0037] Separating air also yields oxygen;

[0038] Burning fuel in the oxygen environment to obtain high-temperature flue gas, wherein the high-temperature flue gas includes at least carbon dioxide and water;

[0039] High-temperature flue gas and qualified gas are mixed to obtain a mixed inert gas; the mixed inert gas includes at least carbon dioxide, water, and nitrogen; the qualified gas does not include organic small molecule gas, and includes at least carbon dioxide, water, and nitrogen; the qualified gas includes a first qualified gas and a second qualified gas.

[0040] Preferably, gas-solid separation of the second gas-solid mixture to obtain dioxin-detoxified fly ash and the first qualified gas comprises the following steps:

[0041] cyclone separation of the second gas-solid mixture to obtain third fly ash and fourth exhaust gas;

[0042] collecting and treating the fourth exhaust gas to obtain fourth fly ash and the first qualified gas;

[0043] The third fly ash and the fourth fly ash are both dioxin detoxification fly ashes.

[0044] Preferably, the dust collection and treatment of the fourth exhaust gas to obtain the fourth fly ash and the first qualified gas comprises the following steps:

[0045] The fourth exhaust gas is collected by bag dust collector to obtain the fourth fly ash and the fifth exhaust gas;

[0046] Detect the fifth exhaust gas and determine whether it is qualified:

[0047] If qualified, the fifth exhaust gas is converted into the first qualified gas;

[0048] If it fails to meet the standards, the fifth exhaust gas is purified by plasma to obtain the first qualified gas.

[0049] In summary, the present invention provides a method for detoxifying dioxins from waste incineration fly ash. The method comprises grinding waste incineration fly ash to obtain fine fly ash, obtaining a mixed inert gas, and suspending and heating the fine fly ash with the mixed inert gas according to a set gas-to-solid ratio to achieve dioxin pre-degradation and obtain a first gas-solid mixture. The first gas-solid mixture is then treated to obtain dioxin-detoxified fly ash and a first qualified gas. The dioxin-detoxified fly ash is a finished product obtained by complete degradation. The present invention achieves dioxin pre-degradation without the use of a catalyst by suspending and heating the fine fly ash with a mixed inert gas, thereby avoiding the high cost of catalysts and the need for periodic replacement. Furthermore, the present invention suspends and heats the waste incineration fly ash before storage, which can enhance the activity and reactivity of dioxin molecules and disrupt the stable binding of dioxins with fly ash components. This method can efficiently degrade dioxins without the use of a catalyst, with a degradation efficiency exceeding 99.7%. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 A schematic flow chart of a method for detoxifying dioxins from waste incineration fly ash provided in an embodiment of the present application;

[0051] Figure 2 Schematic diagram of the detoxification process of dioxins in waste incineration fly ash provided in an embodiment of the present application;

[0052] The text labels shown in the figure represent:

[0053] 1. Oxygen and inert gas preparation system; 11. Air oxygen generator; 12. Inert gas storage tank; 13. Oxygen storage tank; 2. Inert gas heat source preparation system; 21. Combustion chamber; 22. Mixing chamber; 3. Fly ash fine grinding system; 4. Suspension heating system; 5. Gas-solid separation system; 51. Cyclone separation; 52. Ceramic dust collector; 53. Gas monitoring; 54. Plasma generator; 6. Temperature and atmosphere control system; 7. Suspension cooling system; 8. Finished product collection system; 81. Cyclone separation; 82. Bag dust collector. DETAILED DESCRIPTION

[0054] The present application will be further described in detail below with reference to the accompanying drawings and examples. It should be understood that the specific embodiments described herein are intended only to illustrate the relevant invention and are not intended to limit the invention. It should also be noted that, for ease of description, only portions relevant to the invention are shown in the accompanying drawings.

[0055] It should be noted that, in the absence of conflict, the embodiments and features of the embodiments in this application can be combined with each other. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0056] Example 1

[0057] As the technical problem mentioned in the background technology, this application proposes a detoxification system for dioxins in waste incineration fly ash, such as Figure 2 Shown, including:

[0058] The oxygen and inert gas preparation system 1 is used to process air to prepare oxygen and inert gas; the oxygen and inert gas preparation system 1 includes an air oxygen generator 11, an inert gas storage tank 12 and an oxygen storage tank 13;

[0059] The inert gas heat source preparation system 2 is used to prepare mixed inert gas; the inert gas heat source preparation system 2 includes a combustion chamber 21 and a mixing chamber 22;

[0060] The outlet of the oxygen storage tank 13 is connected to the combustion chamber 21, and the outlet of the combustion chamber 21 is connected to the inlet of the mixing chamber 22; the combustion chamber 21 is used to burn natural gas fuel in an oxygen environment to obtain high-temperature flue gas; the mixing chamber 22 is used to mix the high-temperature flue gas, the first qualified gas and the second qualified gas to obtain a mixed inert gas.

[0061] The outlet of the mixing chamber 22 is connected to the inlet of the suspension heating system 4; the outlet of the inert gas storage tank 12 is connected to the inlet of the suspension cooling system 7;

[0062] Fly ash fine grinding system 3, used for grinding waste incineration fly ash to obtain fine fly ash;

[0063] The suspension heating system 4 is used to suspend and heat the fine fly ash by mixing inert gas to achieve dioxin pre-degradation and obtain a first gas-solid mixture; the outlet of the fly ash fine grinding system 3 is connected to the inlet of the suspension heating system 4; the outlet of the suspension heating system 4 is connected to the inlet of the gas-solid separation system 5;

[0064] A gas-solid separation system 5 is used to separate the first gas-solid mixture to obtain first fly ash and second qualified gas; the gas-solid separation system 5 includes a cyclone separator 51 and a ceramic dust collector 52;

[0065] The outlet of the suspension heating system 4 is connected to the inlet of the cyclone separator 51, and the cyclone separator 51 is used to separate the first gas-solid mixture to obtain the second exhaust gas and the first fly ash;

[0066] The outlet of the cyclone separation 51 is respectively connected to the inlet of the temperature atmosphere control system 6 and the inlet of the ceramic dust collector 52. The temperature atmosphere control system 6 is used to efficiently degrade the first fly ash and the second fly ash to obtain efficiently degraded fly ash and the first exhaust gas; the ceramic dust collector 52 is used to process the second exhaust gas and the first exhaust gas to obtain the third exhaust gas and the second fly ash.

[0067] a temperature and atmosphere control system 6 for efficiently degrading the first fly ash to obtain efficiently degraded fly ash and first exhaust gas; an outlet of the temperature and atmosphere control system 6 is connected to an inlet of a suspension cooling system 7;

[0068] The suspension cooling system 7 is used to quickly cool the fly ash for efficient degradation to prevent dioxin resynthesis and obtain a second gas-solid mixture; the outlet of the suspension cooling system 7 is connected to the inlet of the finished product collection system 8;

[0069] The finished product collection system 8 is used to separate the second gas-solid mixture to obtain dioxin-detoxified fly ash and the first qualified gas; the finished product collection system 8 includes a cyclone separator 81 and a bag dust collector 82;

[0070] The outlet of the suspension cooling system 7 is connected to the inlet of the cyclone separator 81; the cyclone separator 81 is used to separate the second gas-solid mixture to obtain the third fly ash and the fourth exhaust gas;

[0071] The cyclone separator 81 has two outlets, namely outlet 811 and outlet 812. One outlet is connected to the inlet of the bag dust collector 82, and the other outlet discharges the third fly ash, i.e., dioxin detoxification fly ash.

[0072] The bag dust collector 82 is used to treat the fourth exhaust gas to obtain fourth fly ash and the first qualified gas;

[0073] The bag dust collector 82 has three outlets, namely outlet 821, outlet 822 and outlet 823. The outlet 821 is connected to the inlet of the mixing chamber 22. The outlet 822 discharges the exhaust gas that meets the standards. The outlet 823 discharges the fourth fly ash, which is also the dioxin detoxification fly ash.

[0074] In a preferred embodiment of the present invention, the finished product collection system further includes a gas monitor 83 and a plasma generator 84 ; the outlet 822 of the bag dust collector 82 is connected to the inlet of the gas monitor 83 , and the outlet of the gas monitor 83 is connected to the inlet of the plasma generator 84 .

[0075] The bag dust collector 82 is used to process the fourth exhaust gas to obtain fourth fly ash and fifth exhaust gas;

[0076] Gas monitoring 83 is used to detect the fifth exhaust gas and determine whether the fifth exhaust gas is qualified:

[0077] If qualified, the fifth exhaust gas is converted into the first qualified gas;

[0078] If it fails to meet the standards, the plasma generator 84 purifies the fifth exhaust gas with plasma to obtain the first qualified gas.

[0079] In a preferred embodiment of the present invention, the gas-solid separation system 5 further includes a gas monitor 53 and a plasma generator 54;

[0080] The outlet of the ceramic dust collector 52 is connected to the inlet of the gas monitoring 53; the outlet of the gas monitoring 53 is respectively connected to the inlet of the plasma generator 54, the inlet of the mixing chamber 22 and the inlet of the temperature atmosphere control system 6;

[0081] The gas monitoring device 53 is used to detect whether the third exhaust gas is qualified. If qualified, the third exhaust gas is converted into the second qualified gas; if unqualified, the third exhaust gas is purified by plasma to obtain the second qualified gas.

[0082] The outlet of the plasma generator 54 is connected to the inlet of the mixing chamber 22 and the inlet of the temperature and atmosphere control system 6;

[0083] In a preferred embodiment of the present invention, the outlet of the temperature and atmosphere control system 6 is connected to the inlet of the ceramic dust collector 52, and the ceramic dust collector 52 is used to process the first exhaust gas and the second exhaust gas to obtain the third exhaust gas and the second fly ash;

[0084] In a preferred embodiment of the present invention, the outlet of the ceramic dust collector 52 is connected to the inlet of the temperature atmosphere control system 6; the temperature atmosphere control system 6 is used to efficiently degrade the first fly ash and the second fly ash in the second qualified gas atmosphere.

[0085] In such Figure 2 In the schematic diagram of the detoxification process of dioxins in waste incineration fly ash shown, the dotted arrows represent the gas flow path, and the solid arrows represent the gas-solid mixture or solid flow path.

[0086] Example 2

[0087] Based on Example 1, this application proposes a method for detoxifying dioxins in waste incineration fly ash, such as Figure 1 As shown, the following steps are included:

[0088] S1. Grinding waste incineration fly ash to obtain fine fly ash;

[0089] Optionally, the toxic equivalent concentration of dioxins in waste incineration fly ash is 993.75 ng-TEQ / kg;

[0090] Optionally, the grinding equipment in the fly ash fine grinding system is a ball mill or a vibration mill;

[0091] Among them, fine fly ash includes 5% fly ash with a fineness of 400~600 mesh, 10% fly ash with a fineness of 600~800 mesh, and 85% fly ash with a fineness of 800~2000 mesh.

[0092] Grinding fly ash into fine particles can increase the specific surface area, making dioxin molecules more susceptible to reaction with heat and improving decomposition efficiency. Small particles are conducive to heat and mass transfer, allowing heat to be transferred to the interior of the particles faster, and the reaction gases to diffuse better, promoting the reaction. It can also increase the reactivity of fly ash, change its crystal structure and surface chemical properties, and enhance catalytic effects. Small particles also help to suspend and disperse fly ash in the airflow, ensuring sufficient mixing with the heating medium, allowing each particle to react under optimal conditions, avoiding agglomeration and sedimentation, and ensuring a uniform and complete reaction, thereby achieving efficient dioxin removal.

[0093] S2. Obtaining a mixed inert gas, the mixed inert gas comprising at least carbon dioxide, water, and nitrogen; this step specifically comprises:

[0094] S21. Separate air to obtain oxygen;

[0095] S22. Burning fuel in an oxygen environment to obtain high-temperature flue gas, which includes at least carbon dioxide and water;

[0096] S23. Mixing high-temperature flue gas and qualified gas to obtain the mixed inert gas;

[0097] The mixed inert gas includes at least carbon dioxide, water, and nitrogen;

[0098] The qualified gas does not include organic small molecule gas, and at least includes carbon dioxide, water, and nitrogen; the qualified gas includes a first qualified gas and a second qualified gas.

[0099] Combusting the fuel in an oxygen environment avoids the formation of nitrogen oxides, eliminating the need for denitrification, and improving production efficiency. The high-temperature flue gas generated by the fuel combustion is then mixed with the first and second qualified gases to adjust the temperature of the mixed inert gas to 1200-1250°C.

[0100] S3 according to the set gas-solid ratio, by mixing the inert gas suspension heating fine fly ash, to achieve dioxin pre-degradation, to obtain a first gas-solid mixture;

[0101] Specifically, the mixed inert gas has an oxygen content of 0-0.3%. Its chemically stable properties provide an oxygen-free environment at high temperatures, preventing unnecessary oxidation reactions of dioxins and fly ash components, avoiding the production of difficult-to-treat oxidation products. It also prevents oxidation of certain fly ash components, which could affect degradation and subsequent treatment. It also dilutes the atmosphere surrounding dioxins and fly ash, reducing the concentration of harmful substances, facilitating the dispersion and decomposition of dioxin molecules, improving degradation efficiency, and reducing the potential for resynthesis. Furthermore, the mixed inert gas exhibits excellent heat transfer properties, ensuring sufficient heating of the fly ash and uniform dioxin degradation. Its high safety profile reduces the risk of explosions, fires, and other safety incidents during high-temperature treatment, ensuring a safe and stable degradation process.

[0102] Suspending and heating finely ground fly ash in an inert atmosphere effectively reduces the energy barrier for chemical bond breakage and recombination in dioxin molecules, increasing the reaction rate constant. This also provides more uniform heating of the fly ash, improving degradation efficiency. Furthermore, it disrupts adsorption or complex structures formed between dioxins and inorganic components in the fly ash, such as metal oxides, making them more susceptible to thermal decomposition. In an inert gas suspension environment, fly ash particles are fully dispersed and suspended, providing more uniform and sufficient contact with the heat source. These favorable heat transfer conditions enable the fly ash to heat rapidly during the pre-degradation process. Despite being at a relatively low temperature, this provides more energy to dioxin molecules, intensifying their molecular vibrations and making it easier for chemical bonds to reach the energy state required for breakage. Compared to traditional static low-temperature pyrolysis, under the same low-temperature conditions, suspension heating effectively reduces the energy barrier for chemical bond breakage and recombination in dioxin molecules, increasing the reaction rate constant. This facilitates the removal of chlorine atoms from dioxin molecules, reducing residual residues. Experimental comparisons have shown that inert gas suspension heating can increase the dioxin decomposition rate by approximately 30% at 360°C compared to traditional static low-temperature pyrolysis at the same temperature.

[0103] When fly ash is suspended, dioxin molecules within it are more easily exposed to the heating environment. This reduces uneven heating caused by fly ash agglomeration or localized accumulation, avoids the ineffective decomposition of some dioxins due to being trapped in "cold zones," and overall improves the efficiency of dioxin pre-degradation, laying a good foundation for subsequent treatment. During the suspension heating process, the vigorous movement and mutual collisions of fly ash particles, as well as the friction with the inert gas, can disrupt the adsorption or complex structures formed between dioxins and inorganic components such as metal oxides in the fly ash. Once these stable structures are destroyed, dioxin molecules are released, making them more susceptible to decomposition reactions during the subsequent thermal decomposition process. For example, microscopic observations show that after a period of suspension heating, dioxin particles originally attached to the metal oxide surface gradually detach, and their molecular structure becomes loose, making them more susceptible to thermal decomposition.

[0104] Specifically, according to 0.2~0.3Nm 3 / kg gas-solid ratio, the mixed inert gas at 1200~1250℃ can quickly heat the fine fly ash to 350~380℃; the dioxin pre-degradation rate accounts for 20~30% of the overall degradation rate.

[0105] The temperature range of 350-380°C achieves an ideal decomposition rate and degree, breaking down dioxins into harmless small molecules. This temperature range also inhibits dioxin resynthesis, disrupting the conditions for resynthesis. It also facilitates the treatment of other harmful substances in fly ash, such as heavy metals, by causing them to volatilize and solidify, thereby reducing environmental risks. From an economic and feasibility perspective, this temperature range balances energy consumption, equipment costs, and operational complexity, achieving optimal overall benefits while ensuring degradation results.

[0106] S4. Treat the first gas-solid mixture to obtain dioxin-detoxified fly ash and the first qualified gas. The dioxin-detoxified fly ash is a finished product obtained by complete degradation. This step specifically includes:

[0107] S41. Gas-solid separation of the first gas-solid mixture to obtain first fly ash and second qualified gas; specifically comprising:

[0108] S411. Cyclone separation of the first gas-solid mixture to obtain first fly ash and second exhaust gas;

[0109] Optionally, the dioxin toxicity equivalent concentration in the first fly ash is 400.09 ng-TEQ / kg;

[0110] S412. Collect dust and process the second waste gas to obtain a second gas that meets the standards.

[0111] Specifically, the second gas meeting the standards does not include small organic molecule gases, that is, small organic molecule gases in the second exhaust gas are removed to obtain the second gas meeting the standards.

[0112] S42. In the second qualified gas atmosphere, the first fly ash is efficiently degraded according to the set time to obtain efficiently degraded fly ash;

[0113] Specifically, the time for efficient degradation of the first fly ash is 45-60 minutes and the temperature is 350-380°C.

[0114] S43. Processing the fly ash for efficient degradation to obtain dioxin-detoxified fly ash and first-standard gas; specifically including:

[0115] S431. Separating air to obtain inert gas;

[0116] S432. Efficiently degrading fly ash by inert gas suspension cooling to form a second gas-solid mixture;

[0117] Specifically, the temperature of the second gas-solid mixture is below 30°C;

[0118] S433. Gas-solid separation of the second gas-solid mixture to obtain a third fly ash and a fourth exhaust gas;

[0119] S434. The fourth waste gas is treated by dust collection to obtain the fourth fly ash and the first qualified gas; the third fly ash and the fourth fly ash are both dioxin detoxification fly ashes.

[0120] In a preferred embodiment of the present invention, after the second exhaust gas is processed by dust collection to obtain second fly ash; after the gas-solid separation of the first gas-solid mixture to obtain first fly ash and second qualified gas, the following steps are further included before the highly efficient degradation fly ash is processed to obtain the dioxin detoxification fly ash and the first qualified gas:

[0121] Degrading the second fly ash in the second qualified gas atmosphere according to a set time to obtain the highly efficient degraded fly ash;

[0122] Among them, the second fly ash is used as ceramic dust collection recyclable material and is efficiently degraded together with the first fly ash, eliminating the operational procedures of separate treatment of recyclable materials, reducing energy consumption, and the efficient degradation of the first fly ash and the second fly ash further improves the degradation efficiency.

[0123] In a preferred embodiment of the present invention, in the second qualified gas atmosphere, the first fly ash is degraded according to a set time to obtain a first waste gas, and in the second qualified gas atmosphere, the second fly ash is degraded according to a set time to obtain a first waste gas, and the detoxification method further includes the following steps:

[0124] The ceramic dust collector collects the first waste gas to obtain the third waste gas;

[0125] Detecting the third exhaust gas and determining whether the third exhaust gas is qualified:

[0126] If qualified, the third exhaust gas is converted into the second qualified gas;

[0127] If it fails to meet the standards, the third exhaust gas is purified by plasma to obtain the second qualified gas.

[0128] The ceramic dust collector for the first exhaust gas, which produces the third exhaust gas, uses the same equipment as the ceramic dust collector for the second exhaust gas, and the resulting third exhaust gases are identical. This operation enables centralized waste gas treatment and simplifies the operational process. Dioxin degradation also produces small amounts of gaseous products such as carbon dioxide, water, sulfur dioxide, or nitrogen oxides. Incomplete decomposition may also produce small organic molecule gaseous products. When these gaseous products reach a certain level, they can affect the rate and efficiency of dioxin degradation. Plasma purification removes these gaseous products from unqualified exhaust gas, ensuring rapid and positive dioxin decomposition.

[0129] In a preferred embodiment of the present invention, the dust collection and treatment of the fourth exhaust gas to obtain the fourth fly ash and the first qualified gas includes the following steps:

[0130] The fourth exhaust gas obtains fourth fly ash and fifth exhaust gas;

[0131] Detect the fifth exhaust gas and determine whether it is qualified:

[0132] If qualified, the fifth exhaust gas is converted into the first qualified gas;

[0133] If it fails to meet the standards, the fifth exhaust gas is purified by plasma to obtain the first qualified gas.

[0134] The efficient dioxin degradation process also produces small amounts of gaseous products such as carbon dioxide, water, sulfur dioxide, or nitrogen oxides. Incomplete decomposition may also produce small organic gaseous products. When these gaseous products reach a certain level, they can affect the rate and efficiency of dioxin degradation. Plasma purification can remove these gaseous products from unqualified waste gas, ensuring a rapid and positive dioxin decomposition reaction.

[0135] The present invention achieves dioxin pre-degradation without the use of a catalyst by mixing inert gas to suspend and heat fine fly ash, thereby avoiding the problem of high catalyst cost and the need for regular replacement. In addition, the present invention first suspends and heats the waste incineration fly ash for pre-degradation before storing it for efficient dioxin degradation. This can enhance the activity and reactivity of dioxin molecules and destroy the stable combination of dioxin and fly ash components. It can still efficiently degrade dioxins without the use of a catalyst, with a degradation efficiency of more than 99.7%. At the same time, the dioxin detoxification process provided by the present invention realizes inert gas circulation and heat recovery.

[0136] The above description is merely a preferred embodiment of the present application and an illustration of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to the technical solutions formed by the specific combination of the above-mentioned technical features, but also encompasses other technical solutions formed by any combination of the above-mentioned technical features or their equivalents without departing from the inventive concept. For example, a technical solution formed by replacing the above-mentioned features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A method for detoxifying dioxins from waste incineration fly ash, characterized in that: The method comprises the following steps: Grinding waste incineration fly ash to obtain fine fly ash; Obtaining a mixed inert gas, wherein the mixed inert gas includes at least carbon dioxide, water, and nitrogen; According to a set gas-solid ratio, the fine fly ash is suspended and heated by the mixed inert gas to achieve dioxin pre-degradation to obtain a first gas-solid mixture; gas-solid separation of the first gas-solid mixture to obtain first fly ash and second qualified gas; In the second qualified gas atmosphere, degrading the first fly ash according to a set time to obtain highly efficiently degraded fly ash; The highly efficient degradation fly ash is processed to obtain dioxin detoxification fly ash and first qualified gas.

2. The method for detoxifying dioxins from waste incineration fly ash according to claim 1, characterized in that: The processing of the highly efficient degradation fly ash to obtain the dioxin detoxification fly ash and the first qualified gas comprises the following steps: Separate air to obtain inert gas; Suspending and cooling the highly efficient degraded fly ash through the inert gas to form a second gas-solid mixture; The second gas-solid mixture is separated into gas-solid mixture to obtain the dioxin detoxification fly ash and the first qualified gas.

3. The method for detoxifying dioxins from waste incineration fly ash according to claim 1, characterized in that: The gas-solid separation of the first gas-solid mixture to obtain first fly ash and second qualified gas comprises the following steps: Cyclone separation of the first gas-solid mixture to obtain the first fly ash and the second exhaust gas; The second exhaust gas is processed by dust collection to obtain the second qualified gas.

4. The method for detoxifying dioxins from waste incineration fly ash according to claim 3, characterized in that: The second exhaust gas is treated by dust collection to obtain second fly ash; after the first gas-solid mixture is separated by gas-solid separation to obtain first fly ash and second qualified gas, the following steps are further included before the high-efficiency degradation fly ash is treated to obtain the dioxin detoxification fly ash and the first qualified gas: In the second qualified gas atmosphere, the second fly ash is degraded according to a set time to obtain the highly efficient degraded fly ash.

5. The method for detoxifying dioxins from waste incineration fly ash according to claim 4, characterized in that: The dust collection and treatment of the second exhaust gas to obtain the second standard-compliant gas comprises the following steps: The ceramic dust collector collects the second waste gas to obtain the third waste gas; Detecting the third exhaust gas and determining whether the third exhaust gas is qualified: If qualified, the third exhaust gas is converted into the second qualified gas; If it fails to meet the standards, the third exhaust gas is purified by plasma to obtain the second qualified gas.

6. The method for detoxifying dioxins from waste incineration fly ash according to claim 5, characterized in that: In the second qualified gas atmosphere, the first fly ash is degraded according to a set time to obtain a first waste gas. In the second qualified gas atmosphere, the second fly ash is degraded according to a set time to obtain a first waste gas. The detoxification method further includes the following steps: The ceramic dust collector collects the first waste gas to obtain the third waste gas; Detecting the third exhaust gas and determining whether the third exhaust gas is qualified: If qualified, the third exhaust gas is converted into the second qualified gas; If it fails to meet the standards, the third exhaust gas is purified by plasma to obtain the second qualified gas.

7. The method for detoxifying dioxins from waste incineration fly ash according to claim 5, characterized in that: The method of obtaining the mixed inert gas comprises the following steps: Separating air also yields oxygen; Burning fuel in the oxygen environment to obtain high-temperature flue gas, wherein the high-temperature flue gas includes at least carbon dioxide and water; The high-temperature flue gas and the qualified gas are mixed to obtain the mixed inert gas; the mixed inert gas includes at least carbon dioxide, water, and nitrogen; the qualified gas does not include organic small molecule gas, and includes at least carbon dioxide, water, and nitrogen; the qualified gas includes a first qualified gas and a second qualified gas.

8. The method for detoxifying dioxins from waste incineration fly ash according to claim 2, characterized in that: The gas-solid separation of the second gas-solid mixture to obtain the dioxin detoxification fly ash and the first qualified gas comprises the following steps: cyclone separation of the second gas-solid mixture to obtain third fly ash and fourth exhaust gas; collecting and treating the fourth exhaust gas to obtain fourth fly ash and the first qualified gas; The third fly ash and the fourth fly ash are both dioxin detoxification fly ashes.

9. The method for detoxifying dioxins from waste incineration fly ash according to claim 8, characterized in that: The dust collection and treatment of the fourth exhaust gas to obtain the fourth fly ash and the first qualified gas comprises the following steps: The fourth exhaust gas is collected by bag dust collector to obtain the fourth fly ash and the fifth exhaust gas; Detect the fifth exhaust gas and determine whether it is qualified: If qualified, the fifth exhaust gas is converted into the first qualified gas; If it fails to meet the standards, the fifth exhaust gas is purified by plasma to obtain the first qualified gas.

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