Detoxification method for dioxin in waste incineration fly ash

Abstract

The invention provides a detoxification method for dioxin in waste incineration fly ash, which comprises the following steps: grinding the waste incineration fly ash to obtain fine fly ash, obtaining mixed inert gas, and heating the fine fly ash in a suspension manner through the mixed inert gas according to a set gas-solid ratio to realize pre-degradation of the dioxin to obtain a first gas-solid mixture; the first gas-solid mixture is treated, dioxin detoxification fly ash and first standard gas are obtained, and the dioxin detoxification fly ash is a finished product obtained through complete degradation. The predegradation of the dioxin is realized under the condition that a catalyst is not used, so that the problems that the catalyst is high in cost and needs to be replaced regularly are avoided, and the degradation efficiency of the dioxin reaches 99.7% or above.

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 been widely used as a common waste disposal method. However, the fly ash produced during waste incineration contains a large amount of highly toxic dioxins, which pose a serious threat to the ecological environment and human health. Therefore, the effective treatment of dioxins in fly ash has become a key issue that needs to be solved urgently.

[0003] Traditional dioxin treatment methods include high-temperature incineration, but high-temperature incineration often consumes a lot of energy and has strict requirements on equipment. In contrast, low-temperature pyrolysis technology has attracted attention due to its relatively low energy consumption. However, in practical applications, low-temperature pyrolysis of dioxins in fly ash faces many difficulties.

[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 principle of chemical reaction kinetics, the low temperature environment causes the reaction rate constant to be greatly 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 and remain 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 a relatively stable form, 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 more ideal removal effect.

[0005] In order to improve the efficiency of low-temperature pyrolysis of dioxins, some auxiliary measures are often needed, such as adding catalysts. 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 cost of the equipment. In addition, various impurities present in fly ash, such as heavy metals, other organic and inorganic compounds, etc., 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 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: Grinding waste incineration fly ash to obtain fine fly ash; Obtaining a mixed inert gas, the mixed inert gas comprising at least carbon dioxide, water, and nitrogen; 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; 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; The first qualified gas is discharged.

[0008] Preferably, treating the first gas-solid mixture to obtain dioxin-detoxified fly ash and the first qualified gas comprises the following steps: Gas-solid separation of a first gas-solid mixture to obtain first fly ash and second qualified gas; In the second qualified gas atmosphere, the first fly ash is efficiently degraded according to the set time to obtain the highly efficient degraded fly ash; The fly ash is efficiently degraded to obtain dioxin detoxified fly ash and the first qualified gas.

[0009] Preferably, treating the highly efficient degradation fly ash to obtain the dioxin detoxification fly ash and the first qualified gas comprises the following steps: Separating air to obtain inert gas; The fly ash is efficiently degraded by inert gas suspension cooling to form a second gas-solid mixture; The second gas-solid mixture is separated by gas-solid separation to obtain dioxin detoxification fly ash and the first qualified gas.

[0010] 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: Cyclone separation of the first gas-solid mixture to obtain first fly ash and second exhaust gas; The second exhaust gas is treated by dust collection to obtain a second gas that meets the standards.

[0011] Preferably, the second waste 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 the first fly ash and the second qualified gas, the highly efficient degradation fly ash is treated to obtain the dioxin detoxification fly ash and the first qualified gas, and the following steps are also included before the gas-solid separation to obtain the first fly ash and the second qualified gas: In the second qualified gas atmosphere, the second fly ash is degraded according to the set time to obtain highly efficient degraded fly ash.

[0012] Preferably, the dust collection and treatment of the second exhaust gas to obtain the second qualified gas comprises the following steps: The ceramic dust collector collects the second waste gas to obtain the third waste gas; Detect the third exhaust gas and determine 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.

[0013] 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 comprises the following steps: The ceramic dust collector collects the first waste gas to obtain the third waste gas; Detect the third exhaust gas and determine 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.

[0014] Preferably, 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; 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.

[0015] Preferably, gas-solid separation of the second gas-solid mixture to obtain 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.

[0016] 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: The fourth waste gas is collected by bag dust collector to obtain the fourth fly ash and the fifth waste 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.

[0017] In summary, the present invention provides a method for detoxifying dioxins in waste incineration fly ash, which is obtained by grinding waste incineration fly ash to obtain fine fly ash, obtain mixed inert gas, and suspend and heat the fine fly ash by the mixed inert gas according to the set gas-solid ratio, so as to achieve pre-degradation of dioxins and obtain a first gas-solid mixture; treat the first gas-solid mixture to obtain dioxin detoxification fly ash and a first qualified gas, and the dioxin detoxification fly ash is a finished product obtained by complete degradation; the present invention achieves pre-degradation of dioxins without using a catalyst by suspending and heating the fine fly ash with a mixed inert gas, 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 before storing it, which can enhance the activity and reactivity of dioxin molecules, destroy the stable combination of dioxins and fly ash components, and can still efficiently degrade dioxins without using a catalyst, with a degradation efficiency of more than 99.7%. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A schematic diagram of a process for detoxifying dioxins from waste incineration fly ash provided in an embodiment of the present application; Figure 2 A schematic diagram of the detoxification process of dioxins in waste incineration fly ash provided in an embodiment of the present application; The text labels shown in the figure represent: 1. Oxygen and inert gas preparation system; 11. Air oxygen production equipment; 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 collection; 53. Gas monitoring; 54. Plasma generator; 6. Temperature atmosphere control system; 7. Suspension cooling system; 8. Finished product collection system; 81. Cyclone separation; 82. Bag dust collection. DETAILED DESCRIPTION

[0019] The present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the relevant invention, rather than to limit the invention. It is also necessary to explain that, for ease of description, only the parts related to the invention are shown in the accompanying drawings.

[0020] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present 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.

[0021] Example 1 As mentioned in the background technology, the present application proposes a detoxification system for dioxins in fly ash from garbage incineration, such as Figure 2 As shown, including: 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; 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; 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.

[0022] 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; The fly ash fine grinding system 3 is used for grinding waste incineration fly ash to obtain fine fly ash; 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; 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 separation 51 and a ceramic dust collector 52; The outlet of the suspension heating system 4 is connected to the inlet of the cyclone separation 51, and the cyclone separation 51 is used to separate the first gas-solid mixture to obtain the second exhaust gas and the first fly ash; 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 the efficiently degraded fly ash and the first exhaust gas; the ceramic dust collector 52 is used to treat the second exhaust gas and the first exhaust gas to obtain the third exhaust gas and the second fly ash; The temperature atmosphere control system 6 is used to efficiently degrade the first fly ash to obtain the efficiently degraded fly ash and the first exhaust gas; the outlet of the temperature atmosphere control system 6 is connected to the inlet of the suspension cooling system 7; The suspension cooling system 7 is used to quickly cool the fly ash with high efficiency degradation to prevent dioxin from being resynthesized 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; The finished product collection system 8 is used to separate the second gas-solid mixture to obtain dioxin detoxification fly ash and the first qualified gas; the finished product collection system 8 includes a cyclone separation 81 and a bag dust collector 82; The outlet of the suspension cooling system 7 is connected to the inlet of the cyclone separation 81; the cyclone separation 81 is used to separate the second gas-solid mixture to obtain the third fly ash and the fourth exhaust gas; The cyclone separator 81 has two outlets, namely, outlet 811 and outlet 812, one of which is connected to the inlet of the bag dust collector 82, and the other outlet discharges the third fly ash, i.e., the dioxin detoxification fly ash; The bag dust collector 82 is used to treat the fourth exhaust gas to obtain fourth fly ash and the first qualified gas; 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.

[0023] In a preferred embodiment of the present invention, the finished product collection system also 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.

[0024] The bag dust collector 82 is used to process the fourth exhaust gas to obtain fourth fly ash and fifth exhaust gas; Gas monitoring 83 is used to detect the fifth exhaust gas and determine whether the fifth exhaust gas is qualified: If qualified, the fifth exhaust gas is converted into the first qualified gas; If it is unqualified, the plasma generator 84 purifies the fifth exhaust gas with plasma to obtain the first qualified gas.

[0025] 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; The outlet of the ceramic dust collector 52 is connected to the inlet of the gas monitor 53; the outlet of the gas monitor 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; The gas monitoring 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; The outlet of the plasma generator 54 is connected to the inlet of the mixing chamber 22 and the inlet of the temperature atmosphere control system 6; In a preferred embodiment of the present invention, the outlet of the temperature 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; 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.

[0026] In such Figure 2 In the schematic diagram of the detoxification process of dioxins in waste incineration fly ash shown in the figure, the dotted arrows represent the gas flow path, and the solid arrows represent the gas-solid mixture or solid flow path.

[0027] Example 2 Based on Example 1, the present application proposes a method for detoxifying dioxins in fly ash from garbage incineration, such as Figure 1 As shown, the following steps are included: S1. Grinding waste incineration fly ash to obtain fine fly ash; Optionally, the toxic equivalent concentration of dioxins in waste incineration fly ash is 993.75 ng-TEQ / kg; Optionally, the grinding equipment in the fly ash fine grinding system is a ball mill or a vibration mill; 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.

[0028] 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, so heat can be transferred to the interior of the particles faster, and the reaction gas can also diffuse better, promoting the reaction. It can increase the reaction activity 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 full 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 removal of dioxins.

[0029] S2. Obtaining a mixed inert gas, the mixed inert gas comprising at least carbon dioxide, water, and nitrogen; this step specifically comprises: S21. Separate air to obtain oxygen; S22. Combustion of fuel in an oxygen environment to obtain high-temperature flue gas, the high-temperature flue gas includes at least carbon dioxide and water; S23. Mixing the high-temperature flue gas and the qualified gas 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 at least includes carbon dioxide, water, and nitrogen; the qualified gas includes a first qualified gas and a second qualified gas.

[0030] Among them, burning fuel in an oxygen environment avoids the generation of nitrogen oxides, and the gas does not need to be denitrated, which improves production efficiency. The high-temperature flue gas obtained by fuel combustion has a high temperature. By mixing with the first qualified gas and the second qualified gas, the temperature of the mixed inert gas is adjusted to 1200~1250℃.

[0031] S3. According to the set gas-solid ratio, the fine fly ash is heated by mixing the inert gas suspension to achieve pre-degradation of dioxins to obtain a first gas-solid mixture; Specifically, the oxygen content of the mixed inert gas is 0-0.3%. The mixed inert gas has stable chemical properties and can 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, and preventing certain components in the fly ash from being oxidized and affecting the degradation effect and subsequent treatment; it can dilute the atmosphere around dioxins and fly ash, reduce the concentration of harmful substances, facilitate the dispersion and decomposition of dioxin molecules, improve degradation efficiency and reduce the possibility of resynthesis. In addition, the mixed inert gas has good heat transfer performance, can fully heat the fly ash, ensure uniform degradation of dioxins, and has high safety, which can reduce the risk of safety accidents such as explosions and fires during high-temperature treatment, and ensure safe and stable operation of the degradation process.

[0032] Among them, the suspended heating of fine fly ash after grinding in an inert atmosphere can effectively reduce the energy barrier of chemical bond breaking and recombination of dioxin molecules and increase the reaction rate constant; the fly ash is heated more evenly, which improves the degradation efficiency; the adsorption or composite structure formed by dioxin and inorganic components such as metal oxides in the fly ash is destroyed, making dioxin more susceptible to thermal decomposition. In an inert gas suspension environment, fly ash particles can be fully dispersed and suspended, and have more uniform and sufficient contact with the heating source. This good heat transfer condition enables the fly ash to heat up quickly during the pre-degradation process. Although it is in a relatively low temperature range, it can provide more energy for dioxin molecules, promote its molecular vibration to intensify, and chemical bonds are more likely to reach the energy state required for breaking. Compared with traditional static low-temperature pyrolysis, under the same low-temperature conditions, suspended heating can effectively reduce the energy barrier of chemical bond breaking and recombination of dioxin molecules, increase the reaction rate constant, and thus make it easier to remove chlorine atoms in dioxin molecules and reduce residues. Through experimental comparison, it was found that the decomposition rate of dioxin at 360°C can be increased by about 30% compared with traditional static low-temperature pyrolysis at the same temperature by using inert gas suspension heating.

[0033] When fly ash is in suspension, the dioxin molecules inside it are more easily exposed to the heating environment, reducing the problem of uneven heating caused by fly ash agglomeration or local accumulation, avoiding the situation where some dioxins cannot be effectively decomposed due to being in the "cold zone", and improving the overall pre-degradation efficiency of dioxins, laying a good foundation for subsequent further treatment. During the suspension heating process, the violent movement and mutual collision of fly ash particles, as well as the friction with inert gas, can destroy the adsorption or composite structure formed by dioxins and inorganic components such as metal oxides in fly ash. When these stable forms are destroyed, dioxin molecules are released and are more likely to undergo decomposition reactions in the subsequent pyrolysis process. For example, in microscopic observations, it can be seen that after a certain period of suspension heating, the dioxin particles originally attached to the surface of the metal oxide gradually detach, and their molecular structure becomes loose, making them more susceptible to thermal decomposition.

[0034] Specifically, according to 0.2~0.3Nm 3 / kg gas-to-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.

[0035] Among them, in the temperature range of 350~380℃, the decomposition rate and degree are ideal, and dioxins can be decomposed into small molecular harmless substances. This temperature range can also inhibit the resynthesis of dioxins and destroy the resynthesis reaction conditions. At the same time, this temperature is conducive to the treatment of other harmful substances such as heavy metals in fly ash, causing them to volatilize, solidify, and reduce environmental risks. From the perspective of economy and feasibility, this temperature range can take into account energy consumption, equipment cost and operation difficulty, and has good comprehensive benefits while ensuring the degradation effect.

[0036] S4. Treat the first gas-solid mixture to obtain dioxin detoxification fly ash and the first qualified gas, wherein the dioxin detoxification fly ash is a finished product obtained by complete degradation. This step specifically includes: S41. Gas-solid separation of the first gas-solid mixture to obtain first fly ash and second qualified gas; specifically comprising: S411. Cyclone separation of the first gas-solid mixture to obtain first fly ash and second exhaust gas; Optionally, the dioxin toxicity equivalent concentration in the first fly ash is 400.09 ng-TEQ / kg; S412. Collect dust and process the second waste gas to obtain a second gas that meets the standards.

[0037] Specifically, the second gas that meets the standards does not include small organic molecules, that is, the small organic molecules in the second exhaust gas are removed to obtain the second gas that meets the standards.

[0038] 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; Specifically, the time for efficient degradation of the first fly ash is 45-60 minutes and the temperature is 350-380°C.

[0039] S43. Treating the fly ash with high efficiency degradation to obtain dioxin detoxification fly ash and the first qualified gas; specifically including: S431. Separating air to obtain inert gas; S432. Efficiently degrading fly ash by inert gas suspension cooling to form a second gas-solid mixture; Specifically, the temperature of the second gas-solid mixture is below 30°C; S433. gas-solid separation of the second gas-solid mixture to obtain a third fly ash and a fourth exhaust gas; 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.

[0040] In a preferred embodiment of the present invention, the second waste gas is treated 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 highly efficient degradation fly ash is treated to obtain the dioxin detoxification fly ash and the first qualified gas, and the following steps are also included before the 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 second fly ash according to a set time to obtain the highly efficient degraded fly ash; Among them, the second fly ash, as a ceramic dust collection recyclate, is efficiently degraded together with the first fly ash, eliminating the operational procedures of separate treatment of recyclables, reducing energy consumption, and the efficient degradation of the first fly ash and the second fly ash further improves the degradation efficiency.

[0041] In a preferred embodiment of the present invention, in the second standard gas atmosphere, the first fly ash is degraded according to the set time to obtain the first waste gas, and in the second standard 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: 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 is unqualified, the third exhaust gas is purified by plasma to obtain the second qualified gas.

[0042] Among them, the same set of equipment is used to obtain the third waste gas by ceramic dust collection of the first waste gas and the third waste gas by ceramic dust collection of the second waste gas, and the third waste gas obtained by the two is the same. This operation realizes centralized waste gas treatment and simplifies the operation process. At the same time, dioxin degradation will produce a small amount of gas products such as carbon dioxide, water, sulfur dioxide or nitrogen oxides. At the same time, organic small molecule gas products may also be produced due to incomplete decomposition. When the content of these gas products reaches a certain level, it will affect the degradation rate and efficiency of dioxins. Unqualified waste gas can remove these gas products through plasma purification to ensure that the dioxin decomposition reaction proceeds rapidly and positively.

[0043] In a preferred embodiment of the present invention, dust collection and treatment of the fourth exhaust gas to obtain fourth fly ash and first qualified gas comprises the following steps: The fourth exhaust gas obtains fourth fly ash and 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.

[0044] Among them, the efficient degradation process of dioxins will also produce a small amount of gas products such as carbon dioxide, water, sulfur dioxide or nitrogen oxides. At the same time, organic small molecule gas products may be produced due to incomplete decomposition. When the content of these gas products reaches a certain level, it will affect the degradation rate and efficiency of dioxins. Unqualified waste gas can be purified by plasma to remove these gas products, ensuring that the dioxin decomposition reaction proceeds rapidly and positively.

[0045] The present invention achieves dioxin pre-degradation without using 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, which 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 using 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, The above description is only a preferred embodiment of the present application and an explanation of the technical principles used. Those skilled in the art should understand that the scope of the invention involved in the present application is not limited to the technical solution formed by a specific combination of the above technical features, but should also cover other technical solutions formed by any combination of the above technical features or their equivalent features without departing from the inventive concept. For example, the above features are replaced with the technical features with similar functions disclosed in this application (but not limited to) by each other.

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; The first gas-solid mixture is treated to obtain dioxin detoxification fly ash and a first gas that meets the standards, wherein the dioxin detoxification fly ash is a finished product obtained by complete degradation.

2. The method for detoxifying dioxins from waste incineration fly ash according to claim 1, characterized in that: The processing of the first gas-solid mixture to obtain dioxin detoxification fly ash and the first qualified gas comprises the following steps: 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 efficient degraded fly ash; The highly efficient degradation fly ash is processed 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 2, 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: Separating 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 and solid to obtain the dioxin detoxification fly ash and the first qualified gas.

4. The method for detoxifying dioxins from waste incineration fly ash according to claim 2, characterized in that: The gas-solid separation of the first gas-solid mixture to obtain the first fly ash and the 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 treated by dust collection to obtain the second qualified gas.

5. The method for detoxifying dioxins from waste incineration fly ash according to claim 4, characterized in that: The second exhaust gas is treated by dust collection to obtain second fly ash; after the gas-solid separation of the first gas-solid mixture to obtain the first fly ash and the second qualified gas, the highly efficient degradation fly ash is treated to obtain the dioxin detoxification fly ash and the first qualified gas, and the following steps are also included before the gas-solid separation of the first gas-solid mixture to obtain the first fly ash and the second 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.

6. The method for detoxifying dioxins from waste incineration fly ash according to claim 5, characterized in that: The dust collection and treatment of the second exhaust gas to obtain the second qualified 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 is unqualified, 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 6, characterized in that: In the second standard gas atmosphere, the first fly ash is degraded according to the set time to obtain the first waste gas, and in the second standard 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: 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 is unqualified, the third exhaust gas is purified by plasma to obtain the second qualified gas.

8. The method for detoxifying dioxins from waste incineration fly ash according to claim 6, characterized in that: The step 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.

9. The method for detoxifying dioxins from waste incineration fly ash according to claim 3, 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.

10. The method for detoxifying dioxins from waste incineration fly ash according to claim 9, 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 waste gas is collected by bag dust collector to obtain the fourth fly ash and the fifth waste 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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