A method for resource recycling and processing of waste incineration fly ash

Abstract

The application discloses a waste incineration fly ash resource recycling treatment method, which comprises the following steps: firstly, steam dewatering is performed on waste incineration fly ash to obtain dewatered powdery fly ash; then, the dewatered powdery fly ash is mixed with siliceous accessories and NaCl to perform high-temperature melting, so as to obtain molten salt, molten slag and flue gas; after that, the molten salt, the molten slag and the flue gas are subjected to post-treatment such as impurity removal; finally, the metal sodium+potassium chloride+calcium chloride dihydrate product is obtained in the molten salt system, the slag wool product is prepared in the molten slag system, and the sodium chloride and potassium chloride products are prepared in the flue gas purification system. The method can realize harmless treatment and complete resource utilization of the waste incineration fly ash, achieves the requirement of 'zero landfill', and has high environmental value and economic value.

Description

Technical Field

[0001] This invention belongs to the field of waste incineration fly ash treatment technology. Specifically, this invention relates to a method for the resource-based recycling and treatment of waste incineration fly ash. Background Technology

[0002] Fly ash from waste incineration is a secondary pollutant produced during the incineration of municipal solid waste for power generation. It is rich in heavy metals, dioxins, and chloride salts (such as NaCl, KCl, CaCl2, etc.), classifying it as hazardous waste. If left untreated and improperly stockpiled, it will cause irreversible pollution to soil and water environments. High chloride content is a typical characteristic of fly ash from waste incineration in my country, increasing the difficulty of its treatment. Current fly ash treatment methods mainly include high-temperature melting, co-processing in cement kilns, low-temperature pyrolysis, water washing, chelation treatment, and combinations of these methods. These methods primarily aim to address the high levels of dioxins, chloride salts, and heavy metals in fly ash, ultimately achieving the goal of harmless disposal of the fly ash.

[0003] The high-temperature melting method involves feeding fly ash into a high-temperature melting furnace. In this high-temperature environment, dioxins rapidly decompose, chlorides volatilize into secondary flue gas, and most heavy metals volatilize into the flue gas, with a small portion remaining in the molten slag. After water quenching, the heavy metals are solidified, and the resulting slag is general solid waste that can be used as a building material raw material. While high-temperature melting can achieve relatively thorough harmlessness, the large amount of chlorides in the flue gas easily condenses and clogs the pipes, causing significant problems for the flue gas treatment system. Furthermore, existing technologies require high temperatures, long volatilization times, and high energy consumption to achieve complete chloride volatilization. They also suffer from low resource utilization rates, poor product quality, and immature slag / molten salt separation technology. While fly ash washing can remove most chlorides, the resulting filter residue is still hazardous waste and requires a corresponding wastewater treatment system. The process is complex, costly, and lacks effective harmless disposal, making it difficult to promote and apply. Furthermore, in the existing technologies, only a few solutions propose slag / molten salt separation, but none of them involve the conditioning, homogenization, and resource utilization processes of the separated slag and molten salt.

[0004] In view of this, the present invention is hereby proposed. Summary of the Invention

[0005] This invention aims to at least partially solve one of the technical problems in related technologies. To this end, embodiments of this invention propose a method for the resource recovery and treatment of fly ash from waste incineration.

[0006] The waste incineration fly ash resource recovery and treatment method of this invention includes the following steps:

[0007] (1) Steam dehydration of waste incineration fly ash to obtain dehydrated powdered fly ash;

[0008] (2) The dehydrated powdered fly ash is mixed with siliceous additives and NaCl and then melted at high temperature to obtain molten salt, slag and flue gas;

[0009] (3) The molten salt obtained in step (2) is subjected to a first electrolytic depurification treatment to obtain ternary molten salt and impurity products; then the ternary molten salt is subjected to a second electrolytic depurification treatment to obtain binary molten salt and metallic sodium; the binary molten salt is cooled by air to obtain binary salt particles, and then the binary salt particles are placed in water to obtain binary saturated brine; then the binary saturated brine is evaporated, crystallized and filtered to obtain KCl product and filtrate, and the filtrate is cooled, crystallized and centrifuged to obtain CaCl2·2H2O product;

[0010] (4) Add silicon auxiliary material to the slag obtained in step (2) for conditioning treatment to obtain conditioned slag; then clarify and homogenize the conditioned slag and spin it to obtain glass fiber; then collect the fiber, lay it and add adhesive, heat preservation and molding to obtain mineral wool product.

[0011] (5) The flue gas obtained in step (2) is purified and impurities are removed for the first time using NaOH solution and Na2CO3 solution to obtain raw high-salt wastewater; then NaOH solution and Na2CO3 solution are added to the raw high-salt wastewater again for the second purification and impurity removal, and the mixture is filtered to obtain sludge product and primary high-salt water; then BaCl2 is added to the primary high-salt water for the third purification and impurity removal to obtain BaSO4 precipitate and secondary high-salt water; then the secondary high-salt water is filtered through a nanofiltration membrane to obtain refined brine; finally, the refined brine is evaporated, centrifuged and filtered to obtain NaCl crystals, and the residual filtrate is cooled and centrifuged and filtered to obtain KCl crystals.

[0012] In some embodiments, in step (1), the moisture content of the dehydrated powdered fly ash is ≤1%.

[0013] In some embodiments, in step (2), the siliceous auxiliary material includes at least one of quartz sand, fly ash, and siliceous tailings;

[0014] And / or, the high-temperature melting temperature is 800~1300℃.

[0015] In some embodiments, in step (2), the discharge temperature of the molten salt is 800~1300℃, and the mass fraction of NaCl+KCl+CaCl2 in the molten salt is ≥80%;

[0016] And / or, the discharge temperature of the slag is 800~1300℃, the mass ratio of SiO2 to CaO in the slag is (0.8~1.2):1, and the mass fraction of chlorine-containing substances is 10~20%.

[0017] In some embodiments, in step (3), the first electrolytic depurification treatment is performed in a depurifying electrolytic cell with a cell voltage of 1.5~3.5V and a cell current density of 20~200mA / cm². 2 The mass fraction of NaCl+KCl+CaCl2 in the ternary molten salt is ≥98%.

[0018] And / or, the second electrolytic purification treatment is carried out in a sodium electrolytic cell with a cell voltage of 6~7V and a current density of 0.5~2A / cm. 2 The binary molten salt is mainly composed of KCl and CaCl2, and the mass fraction of NaCl in the binary molten salt is ≤5%.

[0019] In some embodiments, during the second electrolytic purification process in step (3), the product obtained further includes chlorine gas released at the anode, which is absorbed by NaOH solution;

[0020] And / or, the sodium metal is liquid sodium metal, and is stored in a kerosene-sealed tank by siphoning.

[0021] In some embodiments, in step (3), the temperature of the binary molten salt is 650~750℃, the temperature of the binary saturated brine is 60~100℃, the temperature of the evaporation crystallization is 80~100℃, and the temperature of the cooling crystallization is 0~20℃.

[0022] In some embodiments, in step (4), the slag temperature in the tempered slag is 1400~1600℃, the mass ratio of SiO2 / CaO is ≥1.6, and the mass fraction of chlorine is ≤1.0%.

[0023] In some embodiments, in step (5), the Na+ of the original high-salinity wastewater + K + Ca 2+ SO4 2- The sum of their mass fractions is 10-15%, and the temperature of the original high-salinity wastewater is 40-100℃;

[0024] And / or, the sum of the mass fractions of Ca and Mg in the primary high-salt water is ≤100 mg / L, and the sum of the mass fractions of the remaining metal elements is ≤50 mg / L;

[0025] And / or, the SO4 in the secondary high-salinity water2- The mass fraction is ≤10mg / L;

[0026] And / or, the sum of the mass fractions of divalent elements in the purified brine is ≤10 mg / L.

[0027] In some embodiments, in step (5), the evaporation process is performed using multi-effect evaporation or mechanical vapor recompression technology;

[0028] And / or, the temperature of the evaporation treatment is 95~100℃;

[0029] And / or, the temperature of the filtrate is reduced to 20~50℃ before centrifugation.

[0030] The advantages and beneficial effects of the embodiments of the present invention are as follows:

[0031] The waste incineration fly ash resource recovery and treatment method of this invention achieves preliminary separation of molten slag and molten salt (also known as primary slag-salt separation) during the fly ash melting process. Then, the separated molten slag and molten salt are selectively subjected to fine slag-salt separation (also known as secondary slag-salt separation) based on the impurity content. This further removes molten salt from the molten slag system and further removes molten slag from the molten salt system to meet the requirements of separate resource utilization processes for molten slag and molten salt. Finally, a product of metallic sodium + potassium chloride + calcium chloride dihydrate is obtained in the molten salt system, a slag wool product is prepared in the molten slag system, and volatile dust is captured in the flue gas purification system to prepare sodium chloride and potassium chloride products, thus realizing the resource recovery and treatment of waste incineration fly ash. Attached Figure Description

[0032] Figure 1 This is a process flow diagram of the waste incineration fly ash resource recovery and treatment method according to an embodiment of the present invention. Detailed Implementation

[0033] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the protection scope of the present invention.

[0034] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.

[0035] In this invention, when a value is described as a range, it should be understood that such disclosure includes disclosure of all possible subranges within that range, as well as specific numerical values ​​falling within that range, regardless of whether specific numerical values ​​or specific subranges are explicitly specified.

[0036] In this invention, the terms “comprising” and “including” and their various variations mean that other elements or wholes may be included but are not specifically described.

[0037] In this invention, the term "and / or" is merely a description of the relationship between related objects, indicating that there can be three relationships. For example, A and / or B can represent three situations: A exists alone, A and B exist simultaneously, and B exists alone.

[0038] The following is in conjunction with the appendix Figure 1 This invention provides a detailed description of the waste incineration fly ash resource recovery and treatment method according to embodiments of the present invention.

[0039] The waste incineration fly ash resource recovery and treatment method of this invention includes the following steps:

[0040] (1) Steam dehydration of waste incineration fly ash to obtain dehydrated powdered fly ash;

[0041] (2) The dehydrated powdered fly ash is mixed with siliceous additives and NaCl and then melted at high temperature to obtain molten salt, slag and flue gas;

[0042] (3) The molten salt obtained in step (2) is subjected to a first electrolytic depurification treatment to obtain ternary molten salt and impurity products (which will eventually form a metal alloy on the cathode plate or the bottom of the electrolytic cell); then the ternary molten salt is subjected to a second electrolytic depurification treatment to obtain binary molten salt and metallic sodium; the binary molten salt is cooled by air to obtain binary salt particles, and then the binary salt particles are placed in water to obtain binary saturated brine; then the binary saturated brine is evaporated, crystallized, and filtered to obtain KCl product and filtrate, and the filtrate is cooled, crystallized, centrifuged, and filtered to obtain CaCl2·2H2O product;

[0043] (4) Add silicon auxiliary material to the slag obtained in step (2) for conditioning treatment to obtain conditioned slag; then clarify and homogenize the conditioned slag and spin it to obtain glass fiber; then collect the fiber, lay it and add adhesive, heat preservation and molding to obtain mineral wool product.

[0044] (5) The flue gas obtained in step (2) is purified and impurities are removed for the first time using NaOH solution and Na2CO3 solution to obtain raw high-salt wastewater; then NaOH solution and Na2CO3 solution are added to the raw high-salt wastewater again for the second purification and impurity removal, and the mixture is filtered to obtain sludge product and primary high-salt water; then BaCl2 is added to the primary high-salt water for the third purification and impurity removal to obtain BaSO4 precipitate and secondary high-salt water; then the secondary high-salt water is filtered through a nanofiltration membrane to obtain refined brine; finally, the refined brine is evaporated, centrifuged and filtered to obtain NaCl crystals, and the residual filtrate is cooled and centrifuged and filtered to obtain KCl crystals.

[0045] In some embodiments, in step (1), the moisture content of the dehydrated powdered fly ash is ≤1%.

[0046] In some embodiments, in step (2), the siliceous auxiliary material includes at least one of quartz sand, fly ash, and siliceous tailings; the NaCl is derived from NaCl industrial salt or waste salt mainly composed of NaCl.

[0047] And / or, the high-temperature melting temperature is 800~1300℃, preferably 800~1000℃.

[0048] In some embodiments, in step (2), the discharge temperature of the molten salt is 800~1300℃, preferably 700~1000℃; the mass fraction of NaCl+KCl+CaCl2 in the molten salt is ≥80%;

[0049] And / or, the discharge temperature of the slag is 800~1300℃, the mass ratio of SiO2 to CaO in the slag is (0.8~1.2):1, and the mass fraction of chlorine-containing substances is 10~20%.

[0050] In step (2), after high-temperature melting, the molten salt and slag obtained will separate into layers due to their different densities, thus achieving the separation of molten salt and slag.

[0051] In some embodiments, in step (3), the first electrolytic depurification treatment is performed in a depurifying electrolytic cell with a cell voltage of 1.5~3.5V and a cell current density of 20~200mA / cm². 2 The mass fraction of NaCl+KCl+CaCl2 in the ternary molten salt is ≥98%.

[0052] And / or, the second electrolytic purification treatment is carried out in a sodium electrolytic cell with a cell voltage of 6~7V and a current density of 0.5~2A / cm. 2The binary molten salt is mainly composed of KCl and CaCl2, and the mass fraction of NaCl in the binary molten salt is ≤5%.

[0053] In some embodiments, during the second electrolytic purification process in step (3), the product obtained further includes chlorine gas released at the anode, which is absorbed by NaOH solution;

[0054] And / or, the sodium metal is liquid sodium metal, and is stored in a kerosene-sealed tank by siphoning.

[0055] In some embodiments, in step (3), the temperature of the binary molten salt is 650~750℃, the temperature of the binary saturated brine is 60~100℃, the temperature of the evaporation crystallization is 80~100℃, and the temperature of the cooling crystallization is 0~20℃.

[0056] The principle of step (3) electrolytic depurification in the waste incineration fly ash resource recovery and treatment method of this invention embodiment is as follows:

[0057] In a molten salt system, applying a DC voltage between two electrodes will result in an electrochemical process. At the cathode, cations gain electrons and are reduced to metal atoms, while at the anode, halide anions release electrons and are oxidized to gaseous molecules—this is the electrode process. Specifically, the mechanism of the reduction reaction at the cathode is as follows: the more positive the deposition potential of a metal, the more preferentially it can be deposited at the cathode, and vice versa. The discharge order of cations at the cathode is Ag... + >Hg 2+ >Fe 3+ >Cu 2+ (>H) + >Pb 2+ >Sn 2+ >Fe 2+ >Zn 2+ >Al 3+ >Mg 2+ >Na + >K + Electrolytic oxidation involves discharging high-valence metal cations to obtain low-valence metal cations or elemental metals. Therefore, during electrolytic depurification, at the cathode, after the most oxidizing ions have reacted, the remaining, most oxidizing ions in the solution continue to discharge, eventually resulting in the collection of various heavy metal alloys at the bottom of the molten pool. Simultaneously, the mechanism of oxidation at the anode (loss of electrons) is as follows: the electrode potential is higher than that of Cl... - More negative anions SO4 2- PO4 3- Will precede Cl - The impurities such as S and P are deposited on the anode, thereby achieving the purpose of removing impurities such as S and P from the molten salt.

[0058] In some embodiments, in step (4), the slag temperature in the tempered slag is 1400~1600℃, the mass ratio of SiO2 / CaO is ≥1.6, and the mass fraction of chlorine is ≤1.0%.

[0059] It should be noted that the type of adhesive mentioned in step (4) is not particularly limited. Those skilled in the art can choose according to actual needs. For example, in normal or low temperature environments (-20℃~80℃), water-based emulsion adhesives are preferred; in medium and high temperature environments (81℃~300℃), solvent-based polyurethane / epoxy resin adhesives can be selected; while in high temperature environments (>300℃), inorganic silicate or phosphate adhesives must be used.

[0060] In some embodiments, in step (5), the Na+ of the original high-salinity wastewater... + K + Ca 2+ SO4 2- The sum of their mass fractions is 10-15%, and the temperature of the original high-salt wastewater is 40-100℃;

[0061] And / or, the sum of the mass fractions of Ca and Mg in the first-level high-salt water is ≤100mg / L, and the sum of the mass fractions of other metal elements (e.g., Pb+Zn+Cu+Mn+Ni+Cr+Cd+As+Hg and other elements) is ≤50mg / L;

[0062] And / or, the SO4 in the secondary high-salinity water 2- The mass fraction is ≤10mg / L;

[0063] And / or, the divalent elements (e.g., SO42-) in the purified brine 2- Ca 2+ Mg 2+ Pb 2+ Zn 2+ Cu 2+ Mn 2+ Ni 2+ The sum of the mass fractions of (etc.) is ≤10mg / L.

[0064] In some embodiments, in step (5), the evaporation process is performed using multi-effect evaporation or mechanical vapor recompression (MVR) technology.

[0065] And / or, the temperature of the evaporation treatment is 95~100℃;

[0066] And / or, the temperature of the filtrate is reduced to 20~50℃ before centrifugation.

[0067] In step (5) of this embodiment, firstly, the flue gas obtained in step (2) is purified and impurities are removed by using NaOH solution and Na2CO3 solution. Since both NaOH and Na2CO3 are alkaline, they can directly absorb acidic gases such as SO2 and HCl in the flue gas, and can also capture chloride dust such as NaCl and KCl, thereby obtaining the original high-salt wastewater. The pH value in this process is usually controlled in the range of 7 to 9. Secondly, since the obtained original high-salt wastewater still contains a certain amount of heavy metals, by adding NaOH and Na2CO3 again and controlling the pH of the mixture in the range of 9 to 11, the heavy metals can be further precipitated, thereby obtaining the first-grade high-salt water. After that, BaCl2 is used to remove SO4 from the first-grade high-salt water. 2- This process yields a secondary high-salt water solution primarily composed of NaCl and KCl; finally, it is separated using fractional crystallization technology to obtain an industrial salt product that meets product standards.

[0068] The following describes a specific example of a method for the resource recovery and treatment of fly ash from waste incineration according to the present invention. Unless otherwise stated, all raw materials used in the examples are conventional commercially available products or can be prepared by known methods; experimental methods not specified in the examples are conventional methods and conditions well known in the art.

[0069] As a specific exemplary embodiment, this embodiment provides a method for the resource-based recycling and treatment of fly ash from waste incineration, including the following steps:

[0070] (1) Steam dehydration of the fly ash from waste incineration to reduce its moisture content to 1% to obtain dehydrated powdered fly ash;

[0071] (2) Dehydrated powdered fly ash, quartz sand (mixed according to the mass ratio of SiO2 to CaO in the resulting slag being 1.0) and NaCl industrial salt are mixed and then melted at 1000℃ to obtain molten salt, slag and flue gas; due to the different densities of the slag and molten salt, they are in a stratified state: the molten salt is discharged at 900℃, and the mass fraction of NaCl+KCl+CaCl2 in the molten salt is 89.42%; the slag is discharged at 900℃, and the mass ratio of SiO2 to CaO in the slag is 1.0, and the mass fraction of chlorine-containing substances in the slag is 10%;

[0072] (3) The molten salt obtained in step (2) is subjected to a first electrolytic purification treatment in a purification electrolytic cell. The cell voltage of the purification electrolytic cell is controlled to be 3.0V and the cell current density is 100mA / cm. 2A ternary molten salt, mainly composed of NaCl, KCl, and CaCl2 (with a mass fraction of 99.6% for NaCl, KCl, and CaCl2), is obtained. Impurities will form a metallic alloy on the cathode plate or the bottom of the tank. This ternary molten salt is then subjected to a second electrolytic impurity removal treatment in a sodium electrolytic cell, with the cell voltage controlled at 6.5V and the current density at 1A / cm². 2 Liquid metallic sodium is finally deposited at the cathode and stored in a kerosene-sealed tank via siphon. Chlorine gas is released at the anode and absorbed by NaOH solution. Simultaneously, a binary molten salt, mainly composed of KCl and CaCl2, is obtained at 700℃ with a NaCl mass fraction of 2.5%. This molten salt is then air-cooled to obtain binary salt particles. These particles are then placed in water to obtain a saturated binary brine at 100℃. The saturated brine is then evaporated and crystallized at 95℃ and filtered to obtain KCl product and filtrate. The filtrate is then cooled and crystallized at 10℃, centrifuged, and filtered to obtain CaCl2·2H2O product. The obtained KCl crystals and CaCl2 crystals are dried to a moisture content of 0.2%, and the purity of the KCl crystals is measured to be 96.1%, and the purity of the CaCl2 crystals is 93.6%.

[0073] (4) Quartz sand is added to the slag obtained in step (2) (SiO2 / CaO mass ratio is 1.0) for conditioning treatment. The SiO2 / CaO mass ratio in the conditioned slag is 1.8 and the chlorine mass fraction is 0.5%. Then the conditioned slag is clarified and homogenized at 1500℃ and then spun into glass fibers. The temperature is then reduced to 1300℃ to ensure melt fluidity and form uniform fibers. Then the fibers are collected, laid and adhesive is added. The fibers are then kept at 250℃ to form the final mineral wool product.

[0074] (5) The flue gas obtained in step (2) is purified and impurities are removed for the first time using NaOH solution and Na2CO3 solution. NaOH solution and Na2CO3 solution absorb acidic gases such as SO2 and HCl in the flue gas and capture chloride salt dust such as NaCl and KCl in the flue gas to obtain raw high-salt wastewater with a water temperature of 55℃. The raw high-salt wastewater contains Na + K + Ca 2+ SO4 2- The sum of their mass fractions was 12%; while the SO2 concentration of the purified flue gas was measured to be 45 mg / Nm³. 3 The concentration of HCl is 8 mg / Nm³. 3 Then, NaOH and Na2CO3 solutions were added again to the original high-salinity wastewater until the pH of the mixture reached 9.8, for a second purification process to remove heavy metals and calcium from the original high-salinity wastewater.2+ Mg 2+ Ionization, filtration, yielding sludge products and primary high-salt water, the primary high-salt water containing SO4 2- The mass fraction was 4269 mg / L, Ca 2+ The mass fraction is 11 mg / L, Mg 2+ The mass fraction is 7 mg / L, and other metallic elements (such as Pb) 2+ Zn 2+ Cu 2+ Mn 2+ Ni 2+ Cr 3+ Cd 2+ As 2+ Hg 2+ The sum of the mass fractions of (etc.) is 10.2 mg / L; then BaCl2 is added to the primary high-salt water for a third purification process to remove impurities, resulting in BaSO4 precipitate and secondary high-salt water. The SO4 in the secondary high-salt water... 2- The mass fraction of the brine was 5.6 mg / L. The secondary high-concentration brine was then filtered through a nanofiltration membrane at a controlled temperature of 35°C to further reduce the content of divalent elements, resulting in purified brine. This purified brine contained fewer divalent elements (such as SO42-). 2- Ca 2+ Mg 2+ Pb 2+ Zn 2+ Cu 2+ Mn 2+ Ni 2+ The mass fraction of NaCl was 5.9 mg / L. Finally, the purified brine was heated to 95°C by triple-effect evaporation, centrifuged and filtered to obtain NaCl crystals. The residual filtrate was cooled to 30°C and centrifuged and filtered to obtain KCl crystals. The obtained NaCl crystals and KCl crystals were dried to a water content of 0.15%, and the purity of NaCl crystals was measured to be 98.5% and that of KCl crystals to be 92.3%.

[0075] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0076] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A method for the resource-based recycling and treatment of fly ash from waste incineration, characterized in that, Includes the following steps: (1) Steam dehydration of waste incineration fly ash to obtain dehydrated powdered fly ash; (2) The dehydrated powdered fly ash is mixed with siliceous additives and NaCl and then melted at high temperature to obtain molten salt, slag and flue gas; (3) The molten salt obtained in step (2) is subjected to a first electrolytic depurification treatment in a depurification electrolytic cell to obtain ternary molten salt and impurity products; then the ternary molten salt is subjected to a second electrolytic depurification treatment in a sodium electrolytic cell to obtain binary molten salt and metallic sodium; the binary molten salt is cooled by air to obtain binary salt particles, and then the binary salt particles are placed in water to obtain binary saturated brine. Subsequently, the binary saturated brine is evaporated, crystallized, and filtered to obtain KCl product and filtrate. The filtrate is then cooled, crystallized, centrifuged, and filtered to obtain CaCl2·2H2O product. The cell voltage of the impurity removal electrolytic cell is 1.5~3.5V, and the cell current density is 20~200mA / cm². 2 The sodium electrolytic cell has a cell voltage of 6-7V and a current density of 0.5-2A / cm². 2 ; (4) Add silicon auxiliary material to the slag obtained in step (2) for conditioning treatment to obtain conditioned slag; then clarify and homogenize the conditioned slag and spin it to obtain glass fiber; Then, after collecting the cotton, laying it out, adding adhesive, and insulating it to form the mineral wool product, we obtain the mineral wool product. (5) The flue gas obtained in step (2) is purified and impurities are removed for the first time using NaOH solution and Na2CO3 solution to obtain raw high-salt wastewater; then NaOH solution and Na2CO3 solution are added to the raw high-salt wastewater again for the second purification and impurity removal, and the mixture is filtered to obtain sludge product and primary high-salt water; then BaCl2 is added to the primary high-salt water for the third purification and impurity removal to obtain BaSO4 precipitate and secondary high-salt water; then the secondary high-salt water is filtered through a nanofiltration membrane to obtain refined brine; finally, the refined brine is evaporated, centrifuged and filtered to obtain NaCl crystals, and the residual filtrate is cooled and centrifuged and filtered to obtain KCl crystals.

2. The method for resource recovery and treatment of waste incineration fly ash according to claim 1, characterized in that, In step (1), the moisture content of the dehydrated powdery fly ash is ≤1%.

3. The method for resource recovery and treatment of waste incineration fly ash according to claim 1, characterized in that, In step (2), the siliceous auxiliary material includes at least one of quartz sand, fly ash, and siliceous tailings.

4. The method for resource recovery and treatment of waste incineration fly ash according to claim 1, characterized in that, In step (2), the temperature of the high-temperature melting is 800~1300℃.

5. The method for resource recovery and treatment of waste incineration fly ash according to claim 1, characterized in that, In step (2), the discharge temperature of the molten salt is 800~1300℃, and the mass fraction of NaCl+KCl+CaCl2 in the molten salt is ≥80%.

6. The method for resource recovery and treatment of waste incineration fly ash according to claim 1, characterized in that, In step (2), the discharge temperature of the slag is 800~1300℃, the mass ratio of SiO2 to CaO in the slag is (0.8~1.2):1, and the mass fraction of chlorine-containing substances is 10~20%.

7. The method for resource recovery and treatment of waste incineration fly ash according to claim 1, characterized in that, In step (3), the mass fraction of NaCl+KCl+CaCl2 in the ternary molten salt is ≥98%; the binary molten salt is a binary molten salt mainly composed of KCl+CaCl2, and the mass fraction of NaCl in the binary molten salt is ≤5%.

8. The method for resource recovery and treatment of waste incineration fly ash according to claim 1, characterized in that, In step (3), during the second electrolytic purification process, the resulting product also includes chlorine gas released at the anode, which is absorbed by NaOH solution.

9. The method for resource recovery and treatment of waste incineration fly ash according to claim 1, characterized in that, In step (3), the sodium metal is liquid sodium metal and is stored in a kerosene-sealed tank by siphoning.

10. The method for resource recovery and treatment of waste incineration fly ash according to claim 1, characterized in that, In step (3), the temperature of the binary molten salt is 650~750℃, the temperature of the binary saturated brine is 60~100℃, the temperature of the evaporation crystallization is 80~100℃, and the temperature of the cooling crystallization is 0~20℃.

11. The method for resource recovery and treatment of waste incineration fly ash according to claim 1, characterized in that, In step (4), the slag temperature is 1400~1600℃, the mass ratio of SiO2 / CaO is ≥1.6, and the mass fraction of chlorine is ≤1.0%.

12. The method for resource recovery and treatment of waste incineration fly ash according to claim 1, characterized in that, In step (5), the Na of the original high-salinity wastewater + K + Ca 2+ SO4 2- The total mass fraction is 10-15%, and the temperature of the original high-salt wastewater is 40-100℃.

13. The method for resource recovery and treatment of waste incineration fly ash according to claim 1, characterized in that, In step (5), the sum of the mass fractions of Ca and Mg in the first-level high-salt water is ≤100mg / L, and the sum of the mass fractions of the remaining metal elements is ≤50mg / L.

14. The method for resource recovery and treatment of waste incineration fly ash according to claim 1, characterized in that, In step (5), the SO4 in the secondary high-salt water 2- The mass fraction is ≤10mg / L.

15. The method for resource recovery and treatment of waste incineration fly ash according to claim 1, characterized in that, In step (5), the sum of the mass fractions of divalent elements in the purified brine is ≤10mg / L.

16. The method for resource recovery and treatment of waste incineration fly ash according to claim 1, characterized in that, In step (5), the evaporation process is carried out by multi-effect evaporation or mechanical vapor recompression technology; the temperature of the evaporation process is 95~100℃.

17. The method for resource recovery and treatment of waste incineration fly ash according to claim 1, characterized in that, In step (5), the temperature of the filtrate is reduced to 20~50℃ before centrifugation.

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