A method for treating waste incineration fly ash by plasma melting

Abstract

The present invention relates to the technical field of thermochemical treatment of solid waste, and provides a method for treating fly ash from garbage incineration by using plasma melting. After pretreatment, the fly ash enters a plasma furnace to generate a solid melt, and then passes through a slag cooler to be rapidly cooled into a glassy slag, while the high-temperature exhaust gas generated by the melting furnace enters the high-temperature exhaust gas pretreatment and gas treatment system to be purified into a gas that meets environmental protection standards. By adding an active carrier of organic particles prepared from silicone resin and silicon dioxide to the fly ash, the dioxin molecules and the heavy metals in the fly ash are respectively firmly wrapped in a three-dimensional network, thereby solving the problem of harmless reduction treatment of dioxins and solidified heavy metals, and at the same time solving the problem of too high melting glass transition temperature when plasma equipment treats fly ash from garbage incineration, and the problem of pipeline blockage caused by the diffusion of fly ash with tail gas during the feeding process.

Description

Technical Field

[0001] This invention relates to the field of thermochemical treatment technology for solid waste, and in particular to a method for plasma melting treatment of fly ash from waste incineration. Background Technology

[0002] Currently, the main methods for harmless disposal of waste in my country are landfill and incineration. Waste incineration technology is increasingly widely used due to its advantages in harmlessness, volume reduction, and high resource recovery. Toxic and harmful substances in incineration fly ash include dioxins and heavy metals such as Cd, Cr, Ni, Pb, Zn, and Cu. Dioxins are highly toxic and carcinogenic, difficult to degrade and eliminate in nature, and are persistent organic pollutants. Incineration is a significant source of dioxin production in nature, with concentrations in incineration fly ash reaching as high as 7.4 ng-TEQ / g. The heavy metal pollution caused by improper fly ash disposal also deserves attention. Fly ash particles are generally less than 200 μm in diameter, and the escaped particles are easily dispersed by wind, containing numerous heavy metal compounds. Heavy metal pollution not only harms the ecological environment but also threatens human health. Given the ecological and human threats posed by incineration fly ash, in 2008, my country, in accordance with the Solid Waste Prevention and Control Law, classified municipal solid waste incineration fly ash as HW18 hazardous waste in the National Hazardous Waste List. The state also clearly stipulates that fly ash must undergo stabilization treatment before being disposed of in landfills. Therefore, the harmless and resource-based treatment of waste incineration fly ash is urgently needed.

[0003] Currently, there are three main methods for treating fly ash from waste incineration at home and abroad: melting and sintering, separation and extraction, and solidification and stabilization. Among them, melting and sintering is the method with the highest reduction in fly ash volume and the best solidification effect. Plasma melting has the advantages of high melting temperature and good solidification effect of heavy metals in the melting products, and has attracted more and more attention.

[0004] Chinese patent CN107159678A discloses a dioxin control method in the co-processing of waste fly ash during iron ore sintering. The method involves mixing and granulating four components: waste fly ash, lime slurry, flammable solid fuel, and sludge, and then drying them to obtain small balls containing waste fly ash. After granulation, iron ore sintering raw materials are mixed with the small balls containing waste fly ash, and the mixture is then ignited and sintered. However, this method only solidifies the fly ash and does not address issues such as the difficulty in forming a glassy body, the high melting temperature, and the leaching of heavy metals from the solidified fly ash.

[0005] Because a large amount of lime slurry is injected into the flue gas treatment system of waste incineration plants, the fly ash has a high CaO content and a low SiO2 content in the glass network forging, making it difficult to form a glassy structure. The fly ash particle size is on the order of micrometers, and its large specific surface area makes it difficult to feed into the plasma furnace. Under negative pressure inside the furnace, directly feeding fly ash into the furnace will cause the fly ash particles to drift into the flue gas and diffuse into the flue gas treatment system, resulting in excessive secondary fly ash production and low treatment efficiency. It will also clog downstream pipes, increase the pressure of flue gas treatment, and prevent continuous processing. Furthermore, the small particle size and large specific surface area of ​​fly ash result in high inter-particle friction, causing "bridging" and wall adhesion phenomena during the feeding of fly ash into the plasma device, leading to problems such as discontinuous fly ash feeding.

[0006] Chinese patent CN106984633B discloses a method for resource-based treatment of waste incineration fly ash using a plasma torch. The method pre-treats the fly ash by adding incineration bottom ash, broken glass, construction waste, and other silicon-containing wastes, as well as high-calorific-value liquid hazardous waste, and then molding the mixture. The pre-treated material is fed into a transfer arc plasma torch melting furnace using oxygen as the working gas. The molten fly ash is then cooled by air to form a glassy substance. The exhaust gas generated in the furnace first passes through a salt collection and purification unit to remove chloride salts, and then enters an acid recovery unit to recover HCl and an SO2 recovery unit to recover SO2, thus achieving harmless treatment of the exhaust gas. This method reduces the entrainment or secondary fly ash phenomena in the subsequent melting furnace or sintering process, and addresses the issue of harmless exhaust gas treatment. However, plasma melting technology for treating fly ash has high melting temperatures and high energy consumption, and it does not consider the performance and resource utilization of the glassy substance produced after adding flux.

[0007] How to reduce the melting point of fly ash to decrease energy consumption, solve the problem of secondary pollution from fly ash, solve the problem of heavy metal leaching after fly ash solidification, and at the same time make the glass produced by melting suitable for resource utilization, will be the problems that must be solved in the process of widespread application of this technology. Summary of the Invention

[0008] In order to overcome the shortcomings and deficiencies of the existing technology, the primary objective of this invention is to provide a method for plasma melting treatment of waste incineration fly ash. This method utilizes plasma melting technology to completely decompose harmful substances such as dioxins in fly ash by adding active carriers of organic microparticles, solidifying heavy metals and converting them into non-toxic, stable, and inert byproducts. The gas generated in the melting furnace is then treated in a gas treatment system to produce gas that meets environmental emission standards, thereby achieving the harmlessness and resource utilization of fly ash.

[0009] One of the objectives of this invention is to provide an active carrier for organic microparticles that can adsorb dioxins, lower the melting temperature, and form a network structure in the system, thereby solidifying heavy metals in the melt.

[0010] First, a method for plasma melting treatment of waste incineration fly ash is provided. After pretreatment, the fly ash enters a plasma furnace where the organic matter is completely decomposed into smaller molecules. It then enters a slag cooler for rapid cooling, causing the solidified solids in the melting furnace to solidify into glassy slag. The exhaust gas generated in the melting furnace undergoes high-temperature pretreatment before entering a gas treatment system to ensure emissions meet environmental standards. The method specifically includes the following steps:

[0011] S001, Fly Ash Pretreatment: Fly ash is mixed with water, and soluble substances are dissolved in the water by physical or chemical methods. Solid particles in the fly ash are separated from liquid by filtration and centrifugation to obtain pretreated fly ash. The mixture of pretreated fly ash and active carrier of organic microparticles is thoroughly stirred at 180-200℃, and then crushed, granulated and screened to obtain granular material with a particle size of 10-20mm.

[0012] S002, Plasma Furnace: The above-mentioned granular material is fed into the plasma torch melting furnace. A combustion fan increases the furnace temperature and oxygen content, promoting the reaction. The plasma torch generates plasma, providing a high-temperature environment. Under the action of the high-temperature plasma, the organic matter in the fly ash is completely decomposed into small molecules, and the organic matrix in the granular material also generates small molecule gases, forming high-temperature exhaust gas together. Inorganic substances are melted into solid melts, achieving the solidification of heavy metals and the decomposition of dioxins.

[0013] The plasma melting furnace operates at a high temperature of 1000–1200℃, with a melting time of 20–40 minutes.

[0014] S003, Slag Cooler: After being processed by the plasma furnace, the high-temperature solid molten material enters the slag cooler through the lower pipe and is rapidly cooled by water. The solid molten material is quickly cooled and solidified into a glassy slag in the slag cooler.

[0015] Rapid cooling in a slag cooler is to prevent the molten material from releasing harmful substances during the cooling process and to reduce the risk of secondary pollution.

[0016] S004, High-temperature exhaust gas pretreatment: High-temperature exhaust gas pretreatment includes a gravity dust collector and a quench tower; high-temperature exhaust gas containing dust enters the gravity dust collector through a pipeline. Under the action of gravity, the heavier particles gradually settle to the bottom of the container and accumulate at the bottom. After collection, it re-enters the fly ash pretreatment stage, while the exhaust gas that has undergone preliminary purification is discharged from the top and enters the quench tower through a pipeline. The preliminarily purified exhaust gas enters the gas treatment system through the upper pipeline of the quench tower.

[0017] During the plasma melting process, some larger particles in the fly ash may not be completely melted or may re-aggregate during the cooling process. Gravity settling devices capture unmelted or re-aggregated large particles, reducing dust entrainment or secondary fly ash in the flue, as well as reducing blockage problems in the harmless treatment of exhaust gas.

[0018] S005, Gas Treatment System: The exhaust gas obtained after quenching passes through a jet scrubber and a packed bed scrubber. The exhaust gas first passes through the jet scrubber, where a scrubbing liquid (alkaline solution) is sprayed to absorb some of the harmful gases. Then it passes through the packed bed scrubber, where positively charged adsorption microspheres fill the space inside to further treat the gas. The gas then passes through an SCR system to convert NOx into harmless nitrogen and water. The treated gas then passes through a vaporizer to decompose the organic matter in the fly ash into clean combustible gas. Finally, the purified gas is discharged by an induced draft fan.

[0019] On the one hand, the exhaust gas after passing through the quench tower may still be at a high temperature. Entering the jet scrubber device further reduces the exhaust gas temperature, which is beneficial for subsequent treatment and emissions. On the other hand, in purifying the flue gas, the exhaust gas may contain incompletely melted fly ash particles. The jet scrubber captures these fine particles by spraying water. Acidic gases in the exhaust gas are absorbed by the scrubbing liquid. The packing material in the packed bed scrubber provides a large surface area, allowing for more contact between the exhaust gas and the scrubbing liquid, thus improving purification efficiency. Even after treatment by the jet scrubber, the exhaust gas may still contain trace amounts of harmful substances. Thanks to the structural characteristics of the packed bed scrubber, the exhaust gas and scrubbing liquid come into full contact through the packed bed, which can more effectively remove acidic gases (such as sulfur dioxide SO2 and nitrogen oxides NOx) and other harmful gases, especially showing excellent removal effects for difficult-to-treat aerosol particles and volatile organic compounds (VOCs).

[0020] The SCR system comprises a heat exchanger (No. 1), an SCR unit (No. 1), an SCR unit (No. 2), and another heat exchanger (No. 2). The core component of the SCR unit is its catalyst bed, which is composed of honeycomb or plate-shaped catalysts. Before the flue gas enters the catalyst bed, a reducing agent is injected into the flue gas. The reducing agent reacts with NOx under the action of the catalyst, thereby achieving efficient NOx removal. The catalyst promotes the chemical reaction between NOx and the reducing agent, converting NOx into harmless nitrogen and water. The catalyst can also further decompose dioxins escaping from the flue gas, ensuring that the final exhaust gas is completely free of dioxins. The SCR system also includes a monitoring and control system for real-time monitoring of NOx concentration and ammonia escape in the flue gas, and adjusting the injection volume of the reducing agent as needed to ensure that emission standards are met while avoiding excessive use of the reducing agent. The catalyst is nano-carbon dioxide, and the reducing agent is ammonia or urea solution.

[0021] The vaporizer described above can be used to dry flue gas if the flue gas contains a large amount of moisture. If subsequent treatment equipment requires dried flue gas or flue gas under specific conditions, the vaporizer can serve as a pretreatment step to prepare the flue gas for subsequent processing. It also includes the following two aspects: First, decomposing organic matter: The vaporizer decomposes the organic matter in fly ash into clean combustible gases, namely hydrogen, carbon monoxide, and methane, through a high-temperature environment. These gases can be recovered and reused as energy.

[0022] The primary function of the induced draft fan is to ensure deep purification of flue gas, but the induced draft fan at the end of the process has specific functions. First, maintaining negative pressure in the furnace: The induced draft fan helps maintain a negative pressure state within the furnace, which is crucial for ensuring a stable and safe combustion process. This negative pressure prevents flue gas from leaking into the environment and ensures smooth discharge through the flue. Second, overcoming pressure losses: The induced draft fan needs to overcome the pressure losses generated when the flue gas flows through the tail flue, gravity dust collector, jet scrubber, packed bed scrubber, SCR unit 1, vaporizer, SCR unit 2, and heat exchangers, ensuring smooth flue gas flow. Third, flue gas extraction and discharge: The induced draft fan is responsible for extracting the treated flue gas from the heat exchanger and sending it through the flue to the chimney for discharge. At this point, the flue gas has undergone multiple treatment stages, including dust removal, desulfurization, and denitrification, ensuring that emissions meet environmental standards. In addition to these, it also plays a role in energy saving optimization, flow regulation, and maintaining system balance.

[0023] The high-temperature exhaust gas pretreatment first removes dust from the exhaust gas and cools it down. The jet scrubber, packed bed scrubber, SCR system, vaporizer and induced draft mechanism form a complete exhaust gas treatment system. These two links together ensure the high efficiency and environmental protection of the plasma melting treatment of fly ash process.

[0024] From a microscopic perspective, this method utilizes an external electric field to cause the dielectric to discharge and generate a large number of energetic electrons. Molecules are ionized and excited by the intense bombardment of these electrons, accompanied by a series of physical and chemical reactions. This transforms complex, toxic, and harmful macromolecular waste into simple, non-toxic, and safe small-molecule substances, thus degrading and rendering the waste harmless. From a macroscopic perspective, the arc discharge generates plasma reaching temperatures as high as 7000°C, heating the fly ash to extremely high temperatures, thereby rapidly and effectively destroying the waste. Combustible organic components are fully decomposed and gasified, converting them into combustible gases such as carbon monoxide and hydrogen, which can be used for energy recovery. Non-combustible inorganic components are transformed into harmless slag after high-temperature plasma treatment, which can be used as building materials. The flue gas generated in the system is properly treated, achieving the harmlessness, volume reduction, and resource recovery of fly ash. It is an advanced solid waste treatment technology that not only solves the problems of excessive secondary fly ash production, low treatment efficiency, blockage of downstream pipelines, and increased pressure on exhaust gas treatment, but also effectively solves the problems of complete decomposition of dioxins and harmful substances in fly ash and complete solidification of heavy metals. Furthermore, it can transform fly ash into a stable glassy substance, making it less likely to leach heavy metals and reducing its impact on the environment.

[0025] Dioxins can be effectively decomposed within 5 seconds at temperatures above 850°C. The most challenging aspect of dioxin removal is the high-temperature combustion of already decomposed dioxins. Furthermore, at temperatures between 300 and 500°C, encountering sufficient amounts of heavy metals will cause dioxins to regenerate. Therefore, we provide an active carrier of organic microparticles. This carrier possesses a large specific surface area and abundant microporous structure, effectively adsorbing and immobilizing dioxin molecules on its surface, allowing for effective decomposition at high temperatures. Moreover, within the 300–500°C range, it effectively isolates heavy metals, preventing regeneration.

[0026] The active carrier of the organic microparticles is prepared from silicone resin and silicon dioxide, specifically:

[0027] S101, in a reaction vessel, methylphenyltriethoxysilane, methyltriethoxysilane and 3-aminopropylmethyldiethoxysilane are mixed with an appropriate amount of ethanol and stirred evenly. A certain mass of deionized water is added as a reaction solvent, and a certain proportion of dilute phosphoric acid is added dropwise. The mixture is stirred at room temperature for 2-3 hours until the solution is clear, and then heated to 50-60℃ for 8-10 hours. After the reaction is stopped, the acid-water layer is separated by standing for 60-80 minutes. After washing with water several times until neutral, the residual small molecules and other substances in the reaction system are removed to obtain a polymer matrix with a molecular weight of 100,000-120,000.

[0028] S102, silica microparticles, carboxymethyl cellulose and polymer matrix are mixed in an alcohol ether solution by high-speed stirring for 60 to 80 minutes, so that silica microparticles and carboxymethyl cellulose are fully cross-linked in the matrix and together form an active carrier of organic microparticles;

[0029] The matrix with a large molecular weight is chosen because at temperatures above 500°C, it creates numerous cavities, allowing small molecule gases to escape and resulting in weight loss, forming highly porous and strong microparticles. This also allows the silica microparticles to combine with silicon-oxygen at high temperatures. The introduction of silica microparticles introduces large particles into the matrix. When silica undergoes lattice transformation at high temperatures, it can fuse with heavy metals in the waste, turning this reversible process into an irreversible one. As the furnace temperature rises, the side chain groups of the matrix are oxidized and decomposed into small molecule gases such as CO2 and H2O. The continuous release of these gases causes the active carrier to expand in volume, resulting in a semi-inorganic, semi-organic polymer with -Si-O-Si- as the main chain. Under certain conditions, this polymer undergoes a cross-linking reaction, forming a three-dimensional network structure. This three-dimensional network structure cross-links the molten fly ash, forming a layered structure with a certain shape and strength. The generated dioxin molecules are firmly fixed within the layered structure by the polarity of carbonized carboxymethyl cellulose. The heavy metals in fly ash are also firmly encapsulated by the silica in the three-dimensional network structure. When dioxin molecules are decomposed and escape from the micropores at high temperatures, the heavy metals are firmly locked in, preventing the decomposed dioxin molecules from being regenerated.

[0030] The mass ratio of 3-aminopropylmethyldiethoxysilane, methylphenyltriethoxysilane and methyltriethoxysilane in the matrix is ​​1:2-3:4-6;

[0031] Among them, heat exchanger No. 1 is controlled at a temperature of 900–1000℃, and heat exchanger No. 2 is controlled at a temperature of 350–450℃.

[0032] The functions of a heat exchanger include the following two aspects: 1. Heat energy recovery and utilization: It recovers and utilizes the high-temperature heat energy in flue gas through heat exchange and transfers it to other media for heating, steam generation, or use in other industrial processes, thereby improving the energy utilization efficiency of the entire system. 2. Purification and cooling of waste gas: It treats waste gas containing pollutants and organic matter generated during industrial production through a thermal oxidation process, oxidizing the organic matter in the flue gas into harmless carbon dioxide and water vapor, thereby reducing the emission of air pollutants; it also cools the flue gas temperature of the previous unit, ensuring that the next unit's treatment system operates within the optimal temperature range.

[0033] Plasma melting has unique advantages compared to other fly ash disposal technologies. The high temperature of the plasma flame enables the organic matter in the fly ash to rapidly pyrolyze and vaporize, ultimately transforming it into simple, low-molecular-weight substances. Meanwhile, the inorganic matter and the active carriers of the organic particles in the fly ash are melted, and after a sufficiently long reaction time, rapid cooling yields a vitreous substance, effectively solidifying heavy metals. This vitreous substance can be applied in building materials and other fields, exhibiting a high degree of resource utilization and saving a significant amount of landfill space.

[0034] The addition of organic microparticles as an active carrier can effectively fix heavy metals and dioxin molecules firmly in the micropores, and also serve as the matrix for forming glassy slag. Adding an appropriate amount of organic microparticles as an active carrier to fly ash can reduce the melting temperature and promote the formation of glassy slag, thereby improving the density and stability of the glassy slag network structure. Furthermore, the proportion of organic microparticles as an active carrier directly affects the leaching concentration of heavy metals.

[0035] The aforementioned packed bed scrubber, wherein the positively charged adsorption microspheres filling the interior of the packed bed scrubber are positively charged calcium-based montmorillonite microspheres prepared from montmorillonite, specifically:

[0036] Calcium-based montmorillonite was selected and added to deionized water. Dilute hydrochloric acid was added and stirred until homogeneous, dispersing the calcium-based montmorillonite in the dilute hydrochloric acid solution. The temperature was raised to 60°C, sodium dodecyl sulfonate was added, and the mixture was stirred thoroughly for 1–2 hours to obtain a calcium-based montmorillonite suspension. The pH was adjusted to 3.2–3.5, glutamic acid was added, and the mixture was stirred thoroughly for 1–2 hours to obtain a calcium-based montmorillonite suspension. The suspension was then centrifuged at 3000 rpm, washed 2–3 times with deionized water to remove hydrochloric acid, and centrifuged again. The solid mixture at the bottom was collected, dried at 80°C, ground, and sieved to obtain calcium-based montmorillonite microspheres with a particle size of 30–50 mm and a positively charged outer surface. The mass ratio of sodium dodecyl sulfonate to calcium-based montmorillonite was 1:20, and the mass ratio of glutamic acid to calcium-based montmorillonite was 1:4–5.

[0037] Positively charged adsorption microspheres are more likely to adsorb acidic substances due to the effect of charge, and the microspheres provide a huge surface area, which allows for more contact between the exhaust gas and the washing liquid, thus improving the purification efficiency of the flue gas.

[0038] Compared with existing technologies, the complete process for plasma melting treatment of waste incineration fly ash provided by this invention has significant effects, achieving the harmlessness, volume reduction, and resource recovery of fly ash. It has significant effects in the following aspects:

[0039] 1) The plasma melting treatment of waste incineration fly ash provided by this invention is an advanced solid waste treatment technology. After pretreatment, the fly ash enters a plasma furnace, then a slag cooler, where the solid molten material produced in the furnace is cooled and solidified into a glassy slag. The exhaust gas generated in the furnace is purified into emissions that meet environmental standards through a high-temperature exhaust gas pretreatment system and a gas treatment system. This effectively solves the problems of excessively high melting and glass transition temperatures, the regeneration of dioxin molecules after high-temperature decomposition, pipe blockage caused by fly ash diffusion with the exhaust gas during feeding, and the need for harmless exhaust gas treatment. By sending pretreated waste incineration fly ash into the plasma melting furnace, the melt undergoes effective and continuous processing to obtain a completely harmless glassy substance. The system's exhaust gas is treated for acid removal, dust removal, and harmless treatment, ensuring continuous and stable system operation. This effectively solves the problem of heavy metals and harmful substances in fly ash and can transform fly ash into a stable glassy substance, reducing its environmental impact.

[0040] 2) This invention provides an active carrier for organic microparticles. The active carrier is added to fly ash to be melted to form granules, which are then melted to obtain a molten glass. This carrier has a large specific surface area and abundant microporous structure. On the one hand, it can effectively fix heavy metals and dioxin molecules firmly within the micropores. Specifically, dioxin molecules are firmly fixed in the network structure under the polar effect of carbonized carboxymethyl cellulose. The heavy metals in the fly ash are also firmly encapsulated by the silicon-oxygen bonds in the three-dimensional network structure. This allows for effective decomposition at high temperatures. Furthermore, when the reaction is completed and the rapid cooling stage reaches a temperature range of 300–500°C, the heavy metals are isolated and do not regenerate. This plasma melting technology has high energy efficiency, enables more thorough decomposition of organic matter, and completely disperses dioxin-producing organic molecules, eliminating dioxin generation at its source and preventing secondary pollution. Moreover, the high-temperature environment facilitates the complete melting of incineration fly ash, resulting in a more uniform distribution of heavy metals in the molten mixture. The heavy metals in the molten mixture are bonded to the network, thoroughly stabilizing the incineration fly ash. On the other hand, it also forms the matrix for glassy slag. Adding an appropriate amount of organic microparticles as an active carrier to fly ash can both lower the melting temperature and promote the formation of glassy slag, improving the density and stability of the glassy slag network structure and effectively inhibiting the leaching of heavy metals. Lowering the melting temperature from around 1500℃ to 1000-1200℃ expands the temperature range of the melting treatment, shortens the melting treatment time, saves energy, reduces operating costs, and yields glassy slag with good mechanical properties, with a flexural strength reaching 92MPa.

[0041] 3) High-temperature exhaust gas pretreatment first removes dust from the exhaust gas and cools it down. The jet scrubber, packed bed scrubber, SCR system, vaporizer, and induced draft mechanism form a complete exhaust gas treatment system. These two stages together ensure the high efficiency and environmental friendliness of the plasma melting treatment of fly ash, ensuring that flue gas emissions meet stringent environmental standards. The plasma melting treatment technology for fly ash provided by this invention represents a technological advancement in the field of solid waste treatment and helps promote the industry towards a more sustainable and environmentally friendly direction. Attached Figure Description

[0042] Figure 1 Figures showing the glass phase content in the glassy slag after the solid melts of Examples 1-2 and Comparative Examples 1-3 were melted at 1000℃, 1200℃ and 1500℃;

[0043] Figure 2 A system flow diagram for plasma melting treatment of waste incineration fly ash;

[0044] Figure 3 The graph of the molten liquid phase content as a function of temperature during the melting process of the solid melt in Example 1. Detailed Implementation

[0045] The present invention will be further described below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the description of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined by the appended claims.

[0046] Example 1

[0047] A method for plasma melting treatment of waste incineration fly ash firstly involves preparing an active carrier for organic microparticles, specifically:

[0048] In a reaction vessel, 20 parts of methylphenyltriethoxysilane, 60 parts of methyltriethoxysilane, and 10 parts of 3-aminopropylmethyldiethoxysilane were mixed with an appropriate amount of ethanol and stirred until homogeneous. A certain mass of deionized water was added as a reaction solvent, and then dilute phosphoric acid was added dropwise. The mixture was stirred at room temperature for 3 hours until the solution became clear, and then heated to 60°C and reacted for 10 hours. After the reaction was stopped, the acid-water layer was separated after standing for 80 minutes. The mixture was washed with water several times until neutral, and then residual small molecules and other substances in the reaction system were removed to obtain a polymer matrix with a molecular weight of 113825.

[0049] Ten parts of silica microparticles, ten parts of carboxymethyl cellulose, and 100 parts of polymer matrix were mixed in an alcohol ether solution and stirred at high speed for 60 minutes to ensure that the silica microparticles and carboxymethyl cellulose were fully cross-linked in the matrix and together formed an active carrier of organic microparticles.

[0050] Furthermore, positively charged adsorption microspheres were prepared. Specifically, positively charged calcium-based montmorillonite microspheres were prepared from montmorillonite, as follows:

[0051] 100 parts of calcium-based montmorillonite were selected and added to 100 parts of deionized water. Dilute hydrochloric acid was added and stirred until homogeneous, dispersing the calcium-based montmorillonite in the dilute hydrochloric acid solution. The temperature was raised to 60℃, and 5 parts of sodium dodecyl sulfonate were added. The mixture was stirred thoroughly and reacted for 2 hours to obtain a calcium-based montmorillonite suspension. The pH was adjusted to 3.2, and 25 parts of glutamic acid were added. The mixture was stirred thoroughly and reacted for 2 hours. The suspension was removed and centrifuged at 3000 rpm. The mixture was washed three times with deionized water to remove the hydrochloric acid, and then centrifuged again. The solid mixture at the bottom was removed, dried at 80℃, ground, and sieved to obtain calcium-based montmorillonite microspheres with a particle size of 30-50 mm and positively charged externally. The prepared positively charged calcium-based montmorillonite microspheres were then filled into the interior of a packed bed scrubber.

[0052] Finally, 200 parts of fly ash were mixed with water to remove soluble substances. After filtration, centrifugation, and drying, pretreated fly ash was obtained. The mixture of the pretreated fly ash and 100 parts of organic microparticle active carrier was thoroughly stirred at 180-200℃, and then crushed, granulated, and screened to obtain granular material with an average particle size of 12mm. The granular material was then fed into a plasma torch melting furnace. The furnace temperature was increased by a combustion fan to increase the oxygen content and promote the reaction. After melting at 1200℃ for 20 minutes, a solid melt and high-temperature exhaust gas were obtained. The high-temperature solid melt entered a slag cooler through a lower pipe, where it was rapidly cooled and solidified into a glassy slag. The high-temperature exhaust gas entered a gravity settling chamber through an upper pipe and then entered a quench tower. After rapid cooling, the exhaust gas is processed by a jet scrubber and a packed bed scrubber to remove acidic substances. Then, it passes through an SCR system to convert NOx into harmless nitrogen and water. The treated gas then passes through a vaporizer to decompose the organic matter in the fly ash into clean combustible gas. Finally, the purified gas is discharged through an induced draft fan.

[0053] Example 2

[0054] A method for plasma melting treatment of waste incineration fly ash firstly involves preparing an active carrier for organic microparticles, specifically:

[0055] In a reaction vessel, 30 parts of methylphenyltriethoxysilane, 40 parts of methyltriethoxysilane, and 10 parts of 3-aminopropylmethyldiethoxysilane were mixed with an appropriate amount of ethanol and stirred until homogeneous. A certain mass of deionized water was added as a reaction solvent, and then dilute phosphoric acid was added dropwise. The mixture was stirred at room temperature for 3 hours until the solution became clear, and then heated to 50°C and reacted for 10 hours. After the reaction was stopped, the acidic water layer was separated after standing for 80 minutes. The mixture was washed with water several times until neutral, and then residual small molecules and other substances in the reaction system were removed to obtain a polymer matrix with a molecular weight of 114,169.

[0056] Ten parts of silica microparticles, ten parts of carboxymethyl cellulose, and 100 parts of polymer matrix were mixed in an alcohol-ether solution and stirred at high speed for 80 minutes to ensure that the silica microparticles and carboxymethyl cellulose were fully cross-linked in the matrix, forming an active carrier for the organic microparticles. The mass ratio of silica microparticles, carboxymethyl cellulose, and polymer matrix was 1:1:10.

[0057] Furthermore, positively charged adsorption microspheres were prepared. Specifically, positively charged calcium-based montmorillonite microspheres were prepared from montmorillonite, as follows:

[0058] 100 parts of calcium-based montmorillonite were selected and added to 100 parts of deionized water. Dilute hydrochloric acid was added and stirred until homogeneous, dispersing the calcium-based montmorillonite in the dilute hydrochloric acid solution. The temperature was raised to 60℃, and 5 parts of sodium dodecyl sulfonate were added. The mixture was stirred thoroughly and reacted for 2 hours to obtain a calcium-based montmorillonite suspension. The pH was adjusted to 3.4, and 20 parts of glutamic acid were added. The mixture was stirred thoroughly and reacted for 2 hours. The suspension was removed and centrifuged at 3000 rpm. The mixture was washed three times with deionized water to remove the hydrochloric acid, and then centrifuged again. The solid mixture at the bottom was removed, dried at 80℃, ground, and sieved to obtain calcium-based montmorillonite microspheres with a particle size of 30-50 mm and positively charged externally. The prepared positively charged calcium-based montmorillonite microspheres were then filled into the interior of a packed bed scrubber.

[0059] 200 parts of fly ash were mixed with water to remove soluble substances. After filtration, centrifugation, and drying, pretreated fly ash was obtained. The pretreated fly ash was then mixed with 50 parts of an active carrier of organic microparticles and stirred thoroughly at 200°C. After crushing, granulation, and sieving, granular material was obtained with an average particle size of 12 mm. The granular material was then fed into a plasma torch melting furnace. The furnace temperature was increased by a combustion fan to increase the oxygen content and promote the reaction. After melting at 1200°C for 30 minutes, a solid melt and high-temperature exhaust gas were obtained. The high-temperature solid melt entered a slag cooler through a lower pipe, where it was rapidly cooled and solidified into a glassy slag. The high-temperature exhaust gas entered a gravity settling chamber through an upper pipe and then entered a quench tower. After rapid cooling, the exhaust gas is processed by a jet scrubber and a packed bed scrubber to remove acidic substances. Then, it passes through an SCR system to convert NOx into harmless nitrogen and water. The treated gas then passes through a vaporizer to decompose the organic matter in the fly ash into clean combustible gas. Finally, the purified gas is discharged through an induced draft fan.

[0060] Example 3

[0061] A method for plasma melting treatment of waste incineration fly ash firstly involves preparing an active carrier for organic microparticles, specifically:

[0062] In a reaction vessel, 20 parts of methylphenyltriethoxysilane, 60 parts of methyltriethoxysilane, and 10 parts of 3-aminopropylmethyldiethoxysilane were mixed with an appropriate amount of ethanol and stirred until homogeneous. A certain mass of deionized water was added as a reaction solvent, and then dilute phosphoric acid was added dropwise. The mixture was stirred at room temperature for 2 hours until the solution became clear, and then heated to 60°C and reacted for 8 hours. After the reaction was stopped, the acid-water layer was separated after standing for 80 minutes. The mixture was washed with water several times until neutral, and then residual small molecules and other substances in the reaction system were removed to obtain a polymer matrix with a molecular weight of 110713.

[0063] Ten parts of silica microparticles, ten parts of carboxymethyl cellulose, and 100 parts of polymer matrix were mixed in an alcohol ether solution and stirred at high speed for 80 minutes to ensure that the silica microparticles and carboxymethyl cellulose were fully cross-linked in the matrix, forming an active carrier of organic microparticles.

[0064] Furthermore, positively charged adsorption microspheres were prepared. Specifically, positively charged calcium-based montmorillonite microspheres were prepared from montmorillonite, as follows:

[0065] 100 parts of calcium-based montmorillonite were selected and added to 100 parts of deionized water. Dilute hydrochloric acid was added and stirred until homogeneous, dispersing the calcium-based montmorillonite in the dilute hydrochloric acid solution. The temperature was raised to 60℃, and 5 parts of sodium dodecyl sulfonate were added. The mixture was stirred thoroughly and reacted for 1-2 hours to obtain a calcium-based montmorillonite suspension. The pH was adjusted to 3.5, and 25 parts of glutamic acid were added. The mixture was stirred thoroughly and reacted for 2 hours. The suspension was removed and centrifuged at 3000 rpm. The mixture was washed three times with deionized water to remove the hydrochloric acid, and then centrifuged again. The solid mixture at the bottom was removed, dried at 80℃, ground, and sieved to obtain calcium-based montmorillonite microspheres with a particle size of 30-50 mm and positively charged externally. The prepared positively charged calcium-based montmorillonite microspheres were then filled into the interior of a packed bed scrubber.

[0066] 200 parts of fly ash were mixed with water to remove soluble substances. After filtration, centrifugation, and drying, pretreated fly ash was obtained. The pretreated fly ash was then mixed with 100 parts of an active carrier of organic microparticles and stirred thoroughly at 200°C. After crushing, granulation, and sieving, granular material was obtained with an average particle size of 18 mm. The granular material was then fed into a plasma torch melting furnace. The furnace temperature was increased by a combustion fan to increase the oxygen content and promote the reaction. After melting at 1200°C for 20 minutes, a solid melt and high-temperature exhaust gas were obtained. The high-temperature solid melt entered a slag cooler through a lower pipe, where it was rapidly cooled and solidified into a glassy slag. The high-temperature exhaust gas entered a gravity settling chamber through an upper pipe and then entered a quench tower. After rapid cooling, the exhaust gas is processed by a jet scrubber and a packed bed scrubber to remove acidic substances. Then, it passes through an SCR system to convert NOx into harmless nitrogen and water. The treated gas then passes through a vaporizer to decompose the organic matter in the fly ash into clean combustible gas. Finally, the purified gas is discharged through an induced draft fan.

[0067] Example 4

[0068] A method for plasma melting treatment of waste incineration fly ash firstly involves preparing an active carrier for organic microparticles, specifically:

[0069] In a reaction vessel, 30 parts of methylphenyltriethoxysilane, 50 parts of methyltriethoxysilane, and 10 parts of 3-aminopropylmethyldiethoxysilane were mixed with an appropriate amount of ethanol and stirred until homogeneous. A certain mass of deionized water was added as a reaction solvent, and then dilute phosphoric acid was added dropwise. The mixture was stirred at room temperature for 3 hours until the solution became clear. The temperature was then raised to 50-60°C and reacted for 10 hours. After the reaction was stopped, the acid-water layer was separated by standing for 60-80 minutes. The mixture was washed with water several times until neutral, and then residual small molecules and other substances in the reaction system were removed to obtain a polymer matrix with a molecular weight of 115231.

[0070] Ten parts of silica microparticles, ten parts of carboxymethyl cellulose, and 100 parts of polymer matrix were mixed in an alcohol ether solution and stirred at high speed for 80 minutes to ensure that the silica microparticles and carboxymethyl cellulose were fully cross-linked in the matrix, forming an active carrier of organic microparticles.

[0071] Furthermore, positively charged adsorption microspheres were prepared. Specifically, positively charged calcium-based montmorillonite microspheres were prepared from montmorillonite, as follows:

[0072] 100 parts of calcium-based montmorillonite were selected and added to 100 parts of deionized water. Dilute hydrochloric acid was added and stirred until homogeneous, dispersing the calcium-based montmorillonite in the dilute hydrochloric acid solution. The temperature was raised to 60℃, and 5 parts of sodium dodecyl sulfonate were added. The mixture was stirred thoroughly and reacted for 2 hours to obtain a calcium-based montmorillonite suspension. The pH was adjusted to 3.3, and 25 parts of glutamic acid were added. The mixture was stirred thoroughly and reacted for 2 hours. The suspension was removed and centrifuged at 3000 rpm. The mixture was washed three times with deionized water to remove the hydrochloric acid, and then centrifuged again. The solid mixture at the bottom was removed, dried at 80℃, ground, and sieved to obtain calcium-based montmorillonite microspheres with a particle size of 30-50 mm and positively charged externally. The prepared positively charged calcium-based montmorillonite microspheres were then filled into the interior of a packed bed scrubber.

[0073] 200 parts of fly ash were mixed with water to remove soluble substances. After filtration, centrifugation, and drying, pretreated fly ash was obtained. The pretreated fly ash was then mixed with 80 parts of an active carrier of organic microparticles and stirred thoroughly at 180°C. After crushing, granulation, and sieving, granular material was obtained with an average particle size of 15 mm. The granular material was then fed into a plasma torch melting furnace. The furnace temperature was increased by a combustion fan to increase the oxygen content and promote the reaction. After melting at 1200°C for 20 minutes, a solid melt and high-temperature exhaust gas were obtained. The high-temperature solid melt entered a slag cooler through a lower pipe, where it was rapidly cooled and solidified into a glassy slag. The high-temperature exhaust gas entered a gravity settling chamber through an upper pipe and then entered a quench tower. After rapid cooling, the exhaust gas is processed by a jet scrubber and a packed bed scrubber to remove acidic substances. Then, it passes through an SCR system to convert NOx into harmless nitrogen and water. The treated gas then passes through a vaporizer to decompose the organic matter in the fly ash into clean combustible gas. Finally, the purified gas is discharged through an induced draft fan.

[0074] Comparative Example 1: Quartz sand was used in place of an equal amount of the active carrier of organic microparticles, and the rest was the same as in Example 1.

[0075] Comparative Example 2: The active carrier of the organic microparticles did not contain silica microparticles or carboxymethyl cellulose, but otherwise it was the same as in Example 1;

[0076] Comparative Example 3 uses the vitrification additive from Example 1 of Chinese Patent Publication No. CN110043905B, at an addition amount of 20%, and adds fly ash; other aspects are the same as in Example 1.

[0077] Comparative Example 4: The gas treatment system's packed bed scrubber was filled with ordinary calcium-based montmorillonite. The SCR system did not have SCR unit 1 or SCR unit 2 catalytic devices. Otherwise, it was the same as in Example 1.

[0078] Test results

[0079] 1. Performance testing of the glass phase in solid melts

[0080] The melting points of the solid melts from Examples 1-4 and Comparative Examples 1-3 were measured and are shown in Table 1. Table 1 shows that the melting temperature of the solid melts from Examples 1-4, due to the addition of organic microparticles as an active carrier, was only around 1150°C. In contrast, the melting temperature of the melt from Comparative Example 1, after adding quartz sand, reached as high as 1485°C, and the melting temperature of the solid melt from Comparative Example 3 was 1330°C. Different raw materials have different chemical compositions, and during melting, they form eutectic compounds with different compositions. The different melting points of these eutectic compounds cause the different melting temperatures of the solid melts. The three monomers we selected—methylphenyltriethoxysilane, methyltriethoxysilane, and 3-aminopropylmethyldiethoxysilane—have different functional groups, and their synergistic effect lowers the melting temperature of the entire system. However, qualitative judgment alone regarding the formation of the glass body is not accurate enough. To evaluate whether a glassy phase forms after the incineration fly ash melts, the method in GB / T 18046-2017 was used to calculate the glass phase content in the slag, and slag with a glass phase content of 80% or more was defined as a glassy phase. The glass phase content in the slag of the solid melts from Examples 1-2 and Comparative Examples 1-3 after melting at 1000℃, 1200℃, and 1500℃ is as follows: Figure 1 As shown. From Figure 1 It is evident that the glass phase content increased in all formulation samples with increasing melting temperature, thus highlighting the crucial role of plasma melting temperature in glass formation. From... Figure 1 It can also be seen that the melting temperature of the solid melt in Examples 1-2, which have added organic microparticles as active carriers, is significantly reduced, and a large amount of glassy material has already formed at 1000°C.

[0081] Table 1. Performance Test Record of Glass Phase in Solid Molten Material

[0082]

[0083] To better study the melting state of the solid melt, we examined the curve of the molten liquid phase content as a function of temperature from the initial melting to complete melting of the solid melt of Example 1. The melting process can be summarized into three stages: the first stage is from 600℃ to 800℃, during which a molten liquid phase begins to form in the system. In this stage, the molten liquid phase content is very low and the growth rate is relatively slow. The second stage is from 950℃ to 1000℃, during which the molten liquid phase content significantly increases from 7.20% to 43.95%. This may be because the temperature in the second stage reaches the melting temperature of the low-melting-point eutectic compound in the sample, causing the eutectic compound to melt extensively and form a liquid phase. The third stage is from 1050℃ to 1150℃, where the molten liquid phase content continues to increase, the refractory mineral phase begins to melt, and the liquid phase content reaches 95% at 1110℃, after which the system rapidly reaches a complete melting state.

[0084] 2. Heavy metal curing effect test

[0085] To further analyze and compare the solidification effects of heavy metals before and after plasma melting treatment, it is necessary to detect the heavy metal content in the original fly ash sample and the vitreous body obtained after high-temperature melting treatment. This paper employs the US EPA 3050 soil digestion method, using nitric acid-hydrofluoric acid-perchloric acid to pre-treat the original fly ash sample and the rapidly cooled vitreous body, obtaining liquid samples for testing. These samples were then analyzed using inductively coupled plasma atomic emission spectrometry (ICP-AES).

[0086] The specific digestion steps are as follows: Fly ash and vitreous body were crushed and ground in an agate mortar to a particle size less than 100 mesh. Three portions each of fly ash and vitreous body samples obtained in Examples 1-2 and Comparative Examples 1-3 were weighed (1.0 ± 0.01 g) and placed in a polytetrafluoroethylene crucible. 10 mL of HNO3 was added, the crucible was covered, and after the reaction was complete, the crucible was transferred to a low-temperature heating plate and heated to dissolve for 1 hour. After cooling, 5 mL of HF was added, and heating continued for 1 hour. After cooling, 5 mL of HClO4 was added, and heating continued until the solution was almost dry, at which point the solution appeared milky white. After cooling again, 2 mL of HClO4 was added, and heating continued until the solution evaporated to a grayish-white solid. 20 mL of 2% HNO3 was added, and heating was continued until a gentle boil was reached. The solution was then removed, cooled, filtered, and diluted to volume in a 50 mL volumetric flask. Finally, the concentration of heavy metals in the digestion solution was analyzed using ICP-OES, and the results are shown in Table 2.

[0087] Table 2 Heavy Metal Content Monitoring Record (mg / L)

[0088]

[0089] Table 2 shows that Zn content was highest in waste incineration fly ash, followed by Cu, with a content of 620.86 mg / kg. Ni and Pb contents were similar; although the concentrations of Pb and Cd were relatively low, their hazards were significant. Table 2 also shows that after adding the active carrier of organic microparticles, heavy metals were firmly fixed in the silicon-oxygen bonds under high temperature, making them difficult to dissolve. Therefore, the heavy metal dissolution in Examples 1-4 was very low, almost nonexistent. Combining Table 2 with Table 1, it can be seen that increasing the melting temperature from 1200℃ to 1500℃ had little effect on the solidification rate of heavy metals Cd, Cr, and Ni, but a significant impact on the solidification rate of heavy metals Pb and Zn. With increasing melting temperature, the solidification rate of heavy metal Pb decreased. Simultaneously, the volatility of all chemical forms of heavy metal Zn increased, resulting in a significant decrease in the overall solidification rate. Therefore, the varying degrees of increase in the heavy metal dissolution ratio in Examples 1-3 were due to both the low degree of solidification of heavy metals by the solid melt and the reduced solidification rate of certain heavy metals caused by excessively high melting temperatures. The mechanical strength of the glass in Examples 1-4 and Comparative Examples 1-4 was tested. The flexural strength of the glass obtained in the examples can reach 92 MPa, which is higher than that of ordinary glass. It can be used safely and realize the resource utilization of fly ash.

[0090] 3. Detection records of the purified gas discharged from the induced draft fan.

[0091] The purified gases discharged from the induced draft fans of Examples 1-4 and Comparative Examples 3-4 were analyzed using gas chromatography, as shown in Table 3. Table 3 shows that the gases ultimately discharged from the induced draft fans in Examples 1-4 meet the requirements of the "Integrated Emission Standard of Air Pollutants" GB18918-2017. However, in Comparative Example 4, because the gas treatment system used ordinary calcium-based montmorillonite as filler in the packed bed scrubber, and the SCR system lacked SCR units 1 and 2, the total nitrogen content was higher, and a small amount of escaped dioxins were not degraded by the catalyst. The dioxins appearing in Comparative Example 3 are likely dioxins that decomposed at high temperatures; after the temperature dropped, due to the lack of proper separation between dioxins and heavy metals, a problem of regeneration occurred.

[0092] Plasma melting technology effectively reduces the melting temperature and increases the solidification rate of heavy metals by utilizing the synergistic effect of various elements and functional groups in the active carrier of organic microparticles. Simultaneously, it makes the resulting glassy structure more dense. Furthermore, the melting process significantly reduces the volume and weight of incineration fly ash, enabling the treatment of organic and inorganic pollutants with uncertain content, thus fully realizing the harmless treatment of incineration fly ash.

[0093] Table 3. Detection Records of the Purified Gas

[0094]

[0095] The above description is only used to illustrate the technical solution of the present invention and is not intended to limit it. Equal modifications and variations made by those skilled in the art to the technical solution of the present invention, as long as they do not depart from the overall concept of the present invention, shall still fall within the scope of the present invention.

Claims

1. A method for treating waste incineration fly ash by plasma melting, characterized in that: The method for treating waste incineration fly ash by plasma melting is to pre-treat the fly ash before entering a plasma furnace, and then enter a slag cooler for rapid cooling, so that the solid melt produced by the plasma furnace is cooled and solidified into a vitreous slag, and the waste gas produced by the plasma furnace is pre-treated with high-temperature waste gas, and then enters a gas treatment system for treatment into a gas that meets environmental protection standards. Specifically, the following steps are included: S001, fly ash pretreatment: mix fly ash with water, dissolve soluble substances in water by physical or chemical methods, separate solid particles from liquid in fly ash by filtering and centrifugal separation to obtain pretreated fly ash; fully stir the mixture of pretreated fly ash and active carrier of organic particles at 180-200°C, and then crush, granulate and screen to obtain granular material, the particle size of which is 10-20mm; S002, plasma furnace treatment: the above-mentioned granular materials are introduced into a plasma furnace, and the temperature in the furnace is increased by a combustion-supporting fan, the oxygen content in the furnace is increased, and the reaction is promoted; the plasma torch generates plasma, so that the plasma furnace is in a high-temperature environment. Under the action of the high-temperature plasma, the organic matter in the fly ash is completely decomposed into small molecular substances, generating high-temperature exhaust gas, and the inorganic matter is melted into a solid melt; S003, slag cooler treatment: After being treated by the plasma furnace, the high-temperature solid melt enters the slag cooler through the lower pipeline and is rapidly cooled by water. The solid melt is quickly cooled and solidified into vitreous slag in the slag cooler; S004, high-temperature exhaust gas pretreatment: high-temperature exhaust gas containing dust enters the gravity dust collector through the pipeline. Under the action of gravity, heavier particles gradually settle to the bottom of the dust collector and gather at the bottom. After collection, they re-enter the fly ash pretreatment link, while the preliminarily purified exhaust gas is discharged from the top and enters the quenching tower through the pipeline. The preliminarily purified exhaust gas enters the gas treatment system through the upper pipeline of the quenching tower; S005, gas treatment system treatment: the waste gas obtained after rapid cooling first passes through a jet scrubber, which sprays a scrubbing liquid to absorb part of the harmful gas, and the spray scrubbing liquid is an alkaline solution; then passes through a packed bed scrubber, and the positively charged adsorption microspheres filled inside the packed bed scrubber further treat the gas, and then passes through an SCR system to convert NOx in the gas into harmless nitrogen and water, and completely decompose the residual dioxins in the gas; the treated gas then passes through a vaporizer to decompose the organic matter in the fly ash into clean combustible gas, and finally the purified gas is discharged through an induced draft fan; The active carrier of the organic particles is prepared from silicone resin and silicon dioxide, specifically: S101, in a reaction kettle, methylphenyltriethoxysilane, methyltriethoxysilane and 3-aminopropylmethyldiethoxysilane, add an appropriate amount of ethanol, mix and stir evenly, add a certain amount of deionized water as a reaction solvent, then drop dilute phosphoric acid, stir at room temperature for 2 to 3 hours until the solution is clear, heat to 50 to 60°C and react for 8 to 10 hours; after the reaction stops, stand for 60 to 80 minutes to separate the acid and water layers, wash with water several times until neutral, and then remove the small molecular substances remaining in the reaction system to obtain a polymer matrix with a molecular weight of 100,000 to 120,000; the mass ratio of 3-aminopropylmethyldiethoxysilane, methylphenyltriethoxysilane and methyltriethoxysilane is 1:2 to 3:4 to 6; S102, mixing silica particles, carboxymethyl cellulose and a polymer matrix in an alcohol ether solution, and stirring at high speed for 60 to 80 minutes, so that the silica particles and carboxymethyl cellulose are fully cross-linked in the polymer matrix to form an active carrier of the organic particles; The positively charged adsorption microspheres filled in the packed bed scrubber are calcium-based montmorillonite microspheres prepared from montmorillonite and having positive charges on the outside.

2. The method for treating waste incineration fly ash by plasma melting according to claim 1, characterized in that: The gas treatment system comprises a jet scrubber, a packed bed scrubber, an SCR system, a vaporizer and an induced draft fan, and is a complete exhaust gas treatment system.

3. The method for treating waste incineration fly ash by plasma melting according to claim 1, characterized in that: The SCR system is composed of a No. 1 heat exchanger, a No. 1 SCR device, a No. 2 SCR device and a No. 2 heat exchanger. The core component of the SCR device is its catalyst bed, which is composed of a honeycomb or plate-shaped catalyst. Before the exhaust gas enters the catalyst bed, a reducing agent is sprayed into the exhaust gas. The reducing agent reacts with NOx under the action of the catalyst to convert NOx into harmless nitrogen and water. The catalyst further completely decomposes dioxins escaping at high temperatures. The SCR system also includes a monitoring and control system to monitor the NOx concentration and ammonia escape amount in the exhaust gas in real time. The catalyst is nano titanium dioxide, and the reducing agent is ammonia or urea solution.

4. The method for treating waste incineration fly ash by plasma melting according to claim 1, characterized in that: The positively charged adsorption microspheres are calcium-based montmorillonite microspheres with external positive charges prepared from montmorillonite, specifically: Calcium-based montmorillonite is selected, and deionized water is added to the calcium-based montmorillonite, and diluted hydrochloric acid is added and stirred evenly to disperse the calcium-based montmorillonite in the diluted hydrochloric acid solution, and the temperature is raised to 60°C, sodium dodecyl sulfate is added, and the mixture is fully stirred and reacted for 1 to 2 hours to obtain a suspension of calcium-based montmorillonite, and the pH value is adjusted to 3.2 to 3.5, glutamic acid is added, and the mixture is fully stirred and reacted for 1 to 2 hours, and the suspension is taken out and centrifuged at a speed of 3000 rpm, and the suspension is washed with deionized water for 2 to 3 times to remove the hydrochloric acid, and then centrifuged again, and the solid mixture at the bottom is taken out, dried and ground at 80°C, and then sieved to obtain calcium-based montmorillonite microspheres with a particle size of 30 to 50 mm and external positive charges; wherein the mass ratio of sodium dodecyl sulfate to calcium-based montmorillonite is 1:20; and the mass ratio of glutamic acid to calcium-based montmorillonite is 1:4 to 5.

5. The method for treating waste incineration fly ash by plasma melting according to claim 1, characterized in that: The mass ratio of the active carrier of organic particles to the pretreated fly ash is 1 to 2:

4.

6. The method for treating waste incineration fly ash by plasma melting according to claim 3, characterized in that: The temperature of heat exchanger No. 1 is controlled at 900~1000℃, and the temperature of heat exchanger No. 2 is controlled at 350~450℃.

7. The method for treating waste incineration fly ash by plasma melting according to claim 1, characterized in that: The high temperature environment of the plasma furnace is 1000-1200°C, and the melting treatment time is 20-40 minutes.

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