A method and application of modified waste incineration fly ash coupled with mineralization resource utilization

Abstract

The present invention relates to a method and application of coupled mineralization and resource utilization of modified waste incineration fly ash. The method comprises: mixing garbage with modified siliceous solid waste and a dopant and incinerating the mixture; mixing the obtained incineration product with siliceous solid waste and water; digesting and pressing the mixture into a shape; and finally performing a carbon dioxide pressurized mineralization reaction to obtain a mineralized product. Compared with the prior art, the present invention provides a method of coupled mineralization and resource utilization of modified waste incineration fly ash. The method combines the resource utilization of waste incineration fly ash, solid waste, and industrial flue gas, not only solving the problem of the activity of waste incineration fly ash in the resource utilization process, but also optimizing the composition of active components in the waste incineration fly ash by adding modified solid waste. In combination with the mineralization process, the resource utilization of waste incineration fly ash is truly realized; and the treatment process and treatment cost of the above-mentioned emissions are reduced, which is conducive to promoting industrial energy conservation and efficiency improvement and green and low-carbon development.

Description

Technical Field

[0001] The present invention belongs to the technical field of waste resource utilization, and relates to a method and application of modified waste incineration fly ash coupled with mineralization resource utilization. Background Art

[0002] Chinese Patent CN114453402A proposes a method for the efficient mineralization and harmless disposal of waste incineration fly ash. The method involves uniformly mixing the waste incineration fly ash with water and introducing flue gas containing carbon dioxide to fix the heavy metal ions in the fly ash, resulting in harmless, carbonated waste incineration fly ash blocks. Chinese Patent CN113773048A discloses a sintered brick produced from waste fly ash and solid waste, as well as a method and application thereof. The method involves solidifying and sintering waste fly ash, waste glass, and other wastes to fix the heavy metals in the fly ash, reduce dissolution, and form a strong encapsulation structure, thereby improving the strength of the sintered bricks. However, the sintering process consumes a high amount of energy. Chinese Patent CN111777345B proposes a method for the co-disposal of waste incineration fly ash in a cement kiln. The modified waste incineration fly ash is used as a sintering aid in dry-process cement production to improve the burnability and early strength of the clinker. However, the amount of waste incineration fly ash processed is only equivalent to 0.1-5.0% of the raw meal mass of the dry-process cement production line. Although the above patents have solved some of the pollutant problems of waste incineration fly ash, there are still problems such as small absorption capacity, complex process flow, high energy consumption of treatment process, loss of activity of waste incineration fly ash during the treatment process, and they have not fundamentally solved the problems of resource utilization of waste incineration fly ash. Landfill or other resource recovery paths are still required in the future; it is impossible to achieve resource utilization of waste incineration fly ash in a true sense. Summary of the Invention

[0003] The purpose of the present invention is to provide a method and application for coupled mineralization and resource utilization of modified waste incineration fly ash, which is used to solve the problems existing in the waste incineration fly ash treatment process, such as small absorption capacity, complex process flow, high energy consumption of treatment process, loss of waste incineration fly ash activity during the treatment process, low carbon fixation rate of the obtained product, and poor compressive strength.

[0004] The purpose of the present invention can be achieved by the following technical solutions:

[0005] A method for coupling modified waste incineration fly ash with mineralization for resource utilization, comprising the following steps:

[0006] S1: mixing garbage with siliceous modified solid waste and dopant and incinerating them to obtain modified garbage incineration fly ash;

[0007] S2: Mixing the modified waste incineration fly ash with siliceous solid waste and water, digesting and pressing to obtain a green body;

[0008] S3: subjecting the green body to a mineralization reaction in an atmosphere containing carbon dioxide to obtain a mineralized product.

[0009] Furthermore, in step S1, the silicon content of the siliceous modified solid waste (calculated as the mass ratio of SiO2, the same below) is not less than 55wt%.

[0010] Furthermore, in step S1, the mass ratio of the siliceous modified solid waste to the garbage is (0.01-1):100, preferably (0.1-0.5):100.

[0011] Furthermore, in step S1, the dopant is a substance containing at least one element selected from the group consisting of alkali metals, alkaline earth metals, transition metals, boron, nitrogen, aluminum, and phosphorus.

[0012] Furthermore, the dopant is at least one of BaCO3, Na2CO3 or K2CO3.

[0013] Furthermore, the amount of the dopant added is 0.001-0.5% of the mass of the garbage, preferably 0.003-0.3%, and more preferably 0.003-0.15%.

[0014] Furthermore, between step S1 and step S2, the following step is included: dechlorinating the modified waste incineration fly ash to obtain dechlorinated modified waste incineration fly ash with a chloride ion concentration of 8-12 wt%.

[0015] Furthermore, in step S2, the silicon content of the siliceous solid waste is not less than 30 wt %. Furthermore, in the mixture of modified waste incineration fly ash, siliceous solid waste, and water, the mass content of the modified waste incineration fly ash is 20-70%, the mass content of the siliceous solid waste is 15-70%, and the mass content of water is 5-30%.

[0016] Furthermore, in step S3, during the mineralization reaction, the mineralization pressure is 0.1-1.0 MPa, the mineralization time is 2-8 hours, and the volume fraction of carbon dioxide in the reaction atmosphere is 5-99%.

[0017] The invention discloses an application of a method for coupling modified waste incineration fly ash with mineralization and resource utilization, including applying the method to a resource processing process of waste incineration fly ash, solid waste and industrial flue gas.

[0018] Compared with the prior art, the present invention has the following characteristics:

[0019] 1) The present invention proposes a method for coupling modified waste incineration fly ash with mineralized resource utilization. This method combines the resource utilization of waste incineration fly ash, solid waste, and industrial flue gas, improving the resource utilization efficiency of these materials and reducing the treatment process and treatment costs of emissions, which is conducive to promoting industrial energy conservation and efficiency improvement and green and low-carbon development in my country;

[0020] 2) The resource utilization method proposed in this invention not only solves the problem of the activity of waste incineration fly ash during resource utilization, but also optimizes the composition of active components in the waste incineration fly ash by adding modified solid waste. Combined with the mineralization process, it truly realizes the resource utilization of waste incineration fly ash, providing a high-efficiency and high-value overall solution for waste incineration fly ash, and playing an important role in promoting the low-carbon and energy-saving development of my country's building materials industry.

[0021] 3) The present invention optimizes the type and dosage of dopants to reorganize the crystal structure of active substances in waste incineration fly ash. This not only increases the mineralization activity and carbon fixation rate of the fly ash, reduces the conditions for the mineralization reaction, but also improves the degree of mineralization and the mechanical strength of the mineralized product. The prepared mineralized product fully meets the requirements for use as a building material or in rail transit. DETAILED DESCRIPTION

[0022] The present invention is described in detail below with reference to specific embodiments.

[0023] A method for coupling modified waste incineration fly ash with mineralization for resource utilization, comprising the following steps:

[0024] S1: mixing garbage with siliceous modified solid waste and dopant and incinerating them to obtain modified garbage incineration fly ash;

[0025] In some specific embodiments, garbage includes but is not limited to any one or more combinations of domestic garbage, medical garbage, and other hazardous waste;

[0026] In some specific embodiments, the silicon content of the modified siliceous solid waste, calculated as SiO2, is not less than 55 wt%; the elemental silicon in the modified solid waste reacts with the active ingredient Ca(OH)2 in the incineration fly ash to form calcium silicate minerals; adjusting the addition ratio of the two can further adjust the composition of the calcium silicate minerals, which is beneficial to the hydration degree of the raw materials in the subsequent mixing step, the processing time, and the mechanical strength of the finished product in the mineralization step;

[0027] In some specific embodiments, the modified solid waste includes, but is not limited to, fly ash, coal gangue, foundry sand, construction waste, building debris, river sand, carbide slag, volcanic ash, desulfurization gypsum, contaminated soil, tailings cleaning sludge, municipal sludge, or a combination thereof;

[0028] In some specific embodiments, the mass ratio of siliceous modified solid waste to garbage is (0.01-1):100, preferably (0.1-0.5):100;

[0029] In some specific embodiments, the dopant is a substance containing at least one element selected from the group consisting of alkali metals, alkaline earth metals, transition metals, boron, nitrogen, aluminum, and phosphorus; preferably, the dopant is a combination of any one or more of the above elements, carbonates, acetates, nitrates, borates, tungstates, halides, oxides, and hydroxides;

[0030] That is, the dopant is derived from any one or more combinations of elements including but not limited to simple substances containing alkali metals, alkaline earth metals, transition metals, boron, nitrogen, aluminum, and phosphorus, carbonates, acetates, nitrates, borates, tungstates, halides, oxides, and hydroxides; preferably, any one or more combinations of carbonates, acetates, borates, nitrates, oxides, and hydroxides of the above elements;

[0031] More preferably, it is at least one of substances containing alkali metals, alkaline earth metals, boron, nitrogen, and aluminum; further preferably, it is any one or a combination of carbonates containing alkali metals or alkaline earth metals;

[0032] Still further preferably at least one of BaCO3, Na2CO3 or K2CO3;

[0033] In some specific embodiments, the amount of dopant added is 0.001-0.5% of the mass of the garbage, preferably 0.003-0.3%, and more preferably 0.003-0.15%;

[0034] Increasing the addition of dopants can improve the mechanical strength of subsequent mineralized products to a certain extent, but the present invention unexpectedly discovered that further controlling the addition amount of dopants to 0.001-0.5% of the mass of the garbage can effectively accelerate the mineralization reaction rate, improve the degree of mineralization reaction, and achieve the best strength of the mineralized product. The inventors analyzed the reason as follows: alkali metals, alkaline earth metals, transition metals, boron, nitrogen, aluminum or phosphorus elements in the dopants will enter the crystal lattice of silicate minerals during the incineration process for doping, causing the latter to produce more lattice defects. Such lattice defects significantly increase the mineralization active sites, increase the absorption of carbon dioxide by the incineration products, reduce the conditions required for mineralization and accelerate the reaction rate. When the atomic radius of the effective dopant does not match the crystal size of the silicate mineral or the doping amount is too much, part of the effective dopant does not enter the crystal lattice, but exists in other free forms, which not only fails to achieve an enhancement effect, but may also cause the strength of the mineralized product to decrease.

[0035] S2: dechlorinating the modified waste incineration fly ash to obtain dechlorinated modified waste incineration fly ash having a chloride ion concentration of 8-12 wt %;

[0036] In some specific embodiments, the dechlorination treatment adopts dry and / or wet dechlorination, including but not limited to any one or more of water washing dechlorination, biomass adsorption dechlorination, etc.;

[0037] S3: mixing the modified waste incineration fly ash with siliceous solid waste and water, digesting and pressing to obtain a green body;

[0038] In some specific embodiments, the silicon content of the siliceous solid waste is not less than 30 wt %;

[0039] Siliceous solid waste includes but is not limited to one or more of silicon-aluminum solid waste, silicon-calcium solid waste, silicon-magnesium-iron solid waste, and silicon-calcium-aluminum solid waste;

[0040] In some specific embodiments, the siliceous solid waste is siliceous-aluminous solid waste, and the total content of silicon and aluminum components is ≥90wt%; the siliceous-aluminous solid waste can be selected from at least one of fly ash, cement kiln dust, mineral powder, silica fume, kaolin, coal gangue, and construction waste;

[0041] In some specific embodiments, in the mixture of modified waste incineration fly ash, siliceous solid waste, and water, the mass content of modified waste incineration fly ash is 20-70%, the mass content of siliceous solid waste is 15-70%, and the mass content of water is 5-30%;

[0042] Preferably, the mass content of the modified waste incineration fly ash is 30-60%, the mass content of the siliceous solid waste is 20-55%, and the mass content of water is 10-20%;

[0043] In some specific embodiments, during the digestion process, the digestion time is 20-60 min; during the compression molding process, the molding pressure is 3-40 MPa, preferably 5-20 MPa;

[0044] S4: subjecting the green body to a mineralization reaction in an atmosphere containing carbon dioxide to obtain a mineralized product.

[0045] In some specific embodiments, during the mineralization reaction, the filling rate of the reactor is 5-60%, the mineralization pressure is 0.05-1.8 MPa, and the mineralization time is 1-10 h;

[0046] The carbon dioxide-containing atmosphere used can be provided by one or more of steel plant flue gas, chemical plant flue gas, cement plant flue gas, coal chemical plant flue gas, power plant flue gas, lime kiln flue gas, and gas after carbon capture and analysis, wherein the volume fraction of carbon dioxide is preferably 5-99%.

[0047] Furthermore, the product obtained after the mineralization reaction does not need to be cured to obtain a mineralized finished product.

[0048] The invention discloses an application of a method for coupling modified waste incineration fly ash with mineralization and resource utilization, comprising applying the method to the resource processing process of waste incineration fly ash, solid waste and industrial flue gas; wherein the waste incineration fly ash comes from any one or more of fly ash discharged from, including but not limited to, mechanical grate furnaces, fluidized beds and rotary kilns.

[0049] The invention relates to an application of a mineralized product obtained by a method for coupling modified waste incineration fly ash with mineralization and resource utilization, including using the mineralized product in the fields of building materials (such as housing construction, landscape architecture, industrial construction, etc.) and rail transportation.

[0050] The following examples are implemented based on the above technical solutions of the present invention, and provide detailed implementation methods and specific operating processes, but the protection scope of the present invention is not limited to the following examples.

[0051] The following examples used domestic waste from a waste-to-energy plant as raw material, foundry sand from a foundry as modified solid waste, and recycled aggregate from a building materials plant as silico-alumina solid waste. The chemical compositions of the modified solid waste and recycled aggregate were measured using X-ray fluorescence (X-ray fluorescence). Detailed information is provided in Tables 1 and 2, respectively. The composition of the captured electric field flue gas is provided in Table 3.

[0052] Table 1 Chemical composition of foundry sand

[0053] Elemental composition <![CDATA[SiO2]]> <![CDATA[Al2O3]]> <![CDATA[ZrO2]]> <![CDATA[Fe2O3]]> <![CDATA[P2O5]]> CaO LOSS Content / wt% 56.52 29.31 4.52 3.21 2.46 1.03 2.95

[0054] Table 2 Chemical composition of recycled aggregate

[0055] Elemental composition <![CDATA[SiO2]]> <![CDATA[Al2O3]]> CaO <![CDATA[CO2]]> <![CDATA[Fe2O3]]> <![CDATA[K2O]]> MgO <![CDATA[Na2O]]> LOSS Content / wt% 39.2 24.3 17.62 8.31 5.73 1.23 1.07 0.76 1.78

[0056] Table 3 Gas composition after carbon capture in waste incineration power plants (volume fraction)

[0057] Electric field flue gas composition <![CDATA[CO2]]> <![CDATA[N2]]> LOSS Content / wt% 73.1 24.4 2.5

[0058] Example 1:

[0059] A method for coupling modified waste incineration fly ash with mineralization for resource utilization, comprising the following steps:

[0060] S1. Incineration:

[0061] Before incineration, modified solid waste was added to the garbage and mixed evenly. The mass ratio of modified solid waste to garbage was 0.3:100. Before the incineration process, a dopant BaCO3 accounting for 0.03% of the garbage mass was added. After the combustion was completed, the modified garbage incineration fly ash was cooled to obtain the modified garbage incineration fly ash. The chemical composition of the obtained modified garbage incineration fly ash was measured by X-ray fluorescence detection. The test results are shown in Table 4.

[0062] Table 4 Chemical composition of the modified waste incineration fly ash obtained in step S1 of Example 1

[0063] Elemental composition CaO <![CDATA[Na2O]]> <![CDATA[SO3]]> <![CDATA[K2O]]> <![CDATA[SiO2]]> MgO <![CDATA[Fe2O3]]> <![CDATA[Al2O3]]> <![CDATA[P2O5]]> <![CDATA[TiO2]]> LOSS Content / wt% 39.32 11.37 8.37 6.13 3.72 2.13 1.32 0.91 0.61 0.53 26.13

[0064] S2, dechlorination:

[0065] The chlorine in the modified waste incineration fly ash is removed by leaching with circulating water. After dechlorination, the chloride ion content in the modified waste incineration fly ash is about 10%;

[0066] S3, mixing:

[0067] Based on the total mass of the mixture, 30% of the dechlorinated modified waste incineration fly ash, 55% of the siliceous solid waste and 15% of water are mixed and stirred to obtain a mixture, which is then sent to a powder mixing system to be evenly mixed;

[0068] S4, molding:

[0069] The mixed material is sent to the silo for static digestion for 30 minutes, and then sent to the mechanical forming system to be pressed into block green bodies under a forming pressure of 10MPa;

[0070] S5, mineralization:

[0071] The pressed green body is placed in a reactor so that the filling rate of the green body to the reactor (the percentage of the total volume of the green body to the internal space of the reactor) is 45%. The reactor door is closed, and the captured electric field flue gas containing carbon dioxide is introduced into the mineralization reaction device for mineralization reaction. The initial temperature of the mineralization reaction is 25°C, the mineralization time is 360 minutes, and the mineralization pressure is 0.6 MPa. After the reaction is completed, the gas is exhausted to normal pressure, and the mineralized product is taken out after the temperature drops to 50°C.

[0072] Example 2:

[0073] A method for coupling modified waste incineration fly ash with mineralization and resource utilization, which differs from Example 1 only in that:

[0074] In step S1, the mass ratio of modified solid waste to garbage is 0.2:100; Na2CO3 is added in an amount of 0.01% of the mass of the garbage to replace BaCO3;

[0075] In step S2, the chloride ion content in the modified waste incineration fly ash after dechlorination is about 8%;

[0076] In step S4, the digestion time is 20 min and the molding pressure is 20 MPa;

[0077] In step S5, the filling rate of the green body to the reactor is 35%, the mineralization time is 120 min, and the mineralization pressure is 1.0 MPa.

[0078] The rest is the same as Example 1.

[0079] Example 3:

[0080] A method for coupling modified waste incineration fly ash with mineralization and resource utilization, which differs from Example 1 only in that:

[0081] In step S1, the mass ratio of modified solid waste to garbage is 0.5:100; K2CO3 is added in an amount of 0.10% of the mass of the garbage to replace BaCO3;

[0082] In step S2, the chloride ion content in the modified waste incineration fly ash after dechlorination is about 12%;

[0083] In step S3, based on the total mass of the mixture, the dechlorinated modified waste incineration fly ash accounts for 60%, the siliceous solid waste accounts for 20%, and water accounts for 20%;

[0084] In step S4, the digestion time is 60 min and the molding pressure is 5 MPa;

[0085] In step S5, the filling rate of the green body to the reactor is 55%, the mineralization time is 420 min, and the mineralization pressure is 0.3 MPa.

[0086] The rest is the same as in Example 1.

[0087] Example 4:

[0088] A method for coupling modified waste incineration fly ash with mineralization and resource utilization, which differs from Example 1 only in that:

[0089] In step S3, based on the total mass of the mixture, the dechlorinated modified waste incineration fly ash accounts for 20%, the siliceous solid waste accounts for 65%, and water accounts for 15%.

[0090] The rest is the same as in Example 1.

[0091] Example 5:

[0092] A method for coupling modified waste incineration fly ash with mineralization and resource utilization, which differs from Example 1 only in that:

[0093] In step S3, based on the total mass of the mixture, the dechlorinated modified waste incineration fly ash accounts for 70%, the siliceous solid waste accounts for 15%, and water accounts for 15%.

[0094] The rest is the same as in Example 1.

[0095] Example 6:

[0096] A method for coupling modified waste incineration fly ash with mineralization and resource utilization, which differs from Example 1 only in that:

[0097] The amount of BaCO3 added accounts for 0.3% of the garbage mass.

[0098] The rest is the same as in Example 1.

[0099] Example 7:

[0100] A method for coupling modified waste incineration fly ash with mineralization and resource utilization, which differs from Example 1 only in that:

[0101] The chloride ion content in the modified waste incineration fly ash after dechlorination is about 15%;

[0102] The rest is the same as in Example 1.

[0103] Example 8:

[0104] A method for coupling modified waste incineration fly ash with mineralization and resource utilization, which differs from Example 1 only in that:

[0105] The chloride ion content in the modified waste incineration fly ash after dechlorination is about 5%;

[0106] The rest is the same as in Example 1.

[0107] Example 9:

[0108] A method for coupling modified waste incineration fly ash with mineralization and resource utilization, which differs from Example 1 only in that:

[0109] In step S1, the mass ratio of modified solid waste to garbage is 0.01:100;

[0110] The rest is the same as in Example 1.

[0111] Example 10:

[0112] A method for coupling modified waste incineration fly ash with mineralization and resource utilization, which differs from Example 1 only in that:

[0113] In step S1, the mass ratio of modified solid waste to garbage is 1:100;

[0114] The rest is the same as in Example 1.

[0115] Example 11:

[0116] A method for coupling modified waste incineration fly ash with mineralization and resource utilization, which differs from Example 1 only in that:

[0117] In step S5, the filling rate of the green body to the reactor is 30%;

[0118] The rest is the same as in Example 1.

[0119] Comparative Example 1:

[0120] A method for coupling modified waste incineration fly ash with mineralization and resource utilization, which differs from Example 1 only in that:

[0121] In step S1, no modified solid waste is added;

[0122] The rest is the same as in Example 1.

[0123] Comparative Example 2:

[0124] A method for coupling modified waste incineration fly ash with mineralization and resource utilization, which differs from Example 1 only in that:

[0125] In step S1, no dopant BaCO3 is added;

[0126] The rest is the same as in Example 1.

[0127] Comparative Example 3:

[0128] A method for coupling modified waste incineration fly ash with mineralization and resource utilization, which differs from Example 1 only in that:

[0129] In step S1, boric acid is added in an amount of 0.03% of the mass of the garbage to replace BaCO3;

[0130] The rest is the same as in Example 1.

[0131] Comparative Example 4:

[0132] A method for coupling modified waste incineration fly ash with mineralization and resource utilization, which differs from Example 1 only in that:

[0133] In step S1, tungstic acid is added in an amount of 0.03% of the mass of the waste to replace BaCO3;

[0134] The rest is the same as in Example 1.

[0135] Performance testing method:

[0136] 1. Carbon fixation rate: The specific steps for testing carbon fixation rate are the same as those in Chinese patent CN115073126A:

[0137] The mineralized products of each example were analyzed using a STA409EP comprehensive thermal analyzer from NETZSCH, Germany, to obtain a TG / DTG thermogravimetric analysis curve.

[0138] The carbon fixation rate of the mineralized product (expressed as "CO2 absorption rate of the mineralized product") = (the content of carbon dioxide absorbed by the mineralized product / the mass of the mineralized product at 105°C) × 100% = (the mass reduction of the mineralized product at 605-820°C / the mass of the mineralized product at 105°C) × 100%.

[0139] 2. Compressive strength:

[0140] In accordance with the provisions of GB / T 4111-2013 "Test Methods for Concrete Blocks and Bricks", the finished bricks (i.e., mineralized products) obtained in the examples were naturally air-dried for 24 hours and then measured for strength using a YE-30 hydraulic pressure testing machine. The average compressive strength of five test pieces was calculated for each finished brick. If the difference between the measured values ​​and their average was no more than 15%, the average was used as the compressive strength. If any value differed from the average by more than 15%, this value was discarded and the remaining values ​​were used to calculate the average.

[0141] Performance test results:

[0142] The test results are shown in Table 5.

[0143] Table 5

[0144] Sample number Carbon fixation rate / % Compressive strength / MPa Example 1 11.21 18.73 Example 2 8.97 13.55 Example 3 10.64 16.23 Example 4 8.17 8.93 Example 5 8.72 9.93 Example 6 8.51 9.20 Example 7 7.19 6.97 Example 8 8.26 8.61 Example 9 7.73 7.31 Example 10 7.59 6.93 Example 11 9.63 14.87 Comparative Example 1 0.56 2.05 Comparative Example 2 4.71 4.27 Comparative Example 3 6.12 5.94 Comparative Example 4 5.33 5.09

[0145] Result analysis:

[0146] The mineralized products prepared by the technical solution of the present invention in Examples 1-3 have a higher carbon fixation rate and higher compressive strength.

[0147] By comparing Example 1 and Examples 4-5, it can be seen that: when the content of modified waste incineration fly ash in the mineralized product raw material is too low, the calcium content is too low, the mineralization rate and mineralization degree of the test block are low, and the carbon fixation rate and compressive strength of the test block are both reduced; however, when the content of modified waste incineration fly ash is too high, the calcium content is too high, and the mineralization rate of the test block is faster after modification, the temperature is higher, and the mineralization reaction occurs rapidly on the surface, causing the internal pores of the system to block the carbon dioxide channels, and the carbon fixation rate and strength of the test block are reduced.

[0148] By comparing Example 1, Example 6 and Comparative Example 2, it can be seen that the addition of dopants can increase the lattice defects of the material and improve the mineralization degree of the test block. After mineralization, the carbon fixation rate and compressive strength of the test block are relatively high; however, excessive ion addition will lead to lattice reorganization, and the lattice defects are suppressed, so that the lattice defects of the raw material are not prominent, and the carbon fixation rate and compressive strength of the test block decrease rapidly after mineralization.

[0149] By comparing Example 1 and Examples 7-8, it can be seen that the chloride ion content in the modified waste incineration fly ash will affect the mineralization process. A certain concentration of chloride ions can stimulate mineralization, and the carbon fixation rate and compressive strength of the test block are good. However, when the chloride ion concentration is too high, the effect of mineralization stimulation is significantly enhanced, resulting in faster mineralization in the early stage. The faster mineralization rate leads to the formation of dense products on the outside of the test block, and the mineralization cannot be sustained, resulting in a decrease in the later mineralization efficiency and a decrease in the mineralization degree of the test block.

[0150] By comparing Example 1, Examples 9-10 and Comparative Example 1, it can be seen that the siliceous components in the modified solid waste can react with the active calcium components in the fly ash to generate calcium silicate minerals, which is beneficial to the mineralization reaction within the system; when the amount of modified solid waste added is small, the improvement effect on the test block is poor, only part of the calcium silicate minerals are generated, and the carbon fixation rate and mineralization degree of the test block are low; and too much modified solid waste causes the generated calcium silicate substances to be unstable and unable to stably form mineralizable calcium silicate minerals (such as dicalcium silicate, tricalcium silicate, etc.), thereby resulting in a decrease in the carbon fixation rate and compressive strength of the test block after mineralization.

[0151] By comparing Example 1 and Example 11, it can be seen that the heat released by the mineralization reaction can promote the mineralization of the test block. When the filling rate is low, there are fewer reactable substances and the heat released by the reaction is less, resulting in the system temperature rising not being obvious, and having no promoting effect on the mineralization reaction. The system mineralization reaction degree is low, resulting in a decrease in carbon fixation rate and compressive strength.

[0152] By comparing Example 1 and Comparative Examples 3-4, it can be seen that the type of dopant will affect the mineralization process and its products, because different dopants have different effects on the lattice structure and the degree of defects produced is also inconsistent. When the atomic radius of the dopant is too small, lattice defects are easily generated, but the degree of defects is low and the activation effect is relatively small; however, when the atomic radius of the dopant is too large, on the one hand, lattice doping is more difficult, and on the other hand, the crystal structure after doping may be more damaged, which in turn reduces the strength of the incineration product and its mineralized product.

[0153] The present invention provides a method for coupling modified waste incineration fly ash with mineralized resource utilization. The method combines the resource utilization of waste incineration fly ash, solid waste, and industrial flue gas, which not only solves the activity problem of waste incineration fly ash in the resource utilization process, but also optimizes the composition of active components in the waste incineration fly ash by adding modified solid waste. Combined with the mineralization process, it truly realizes the resource utilization of waste incineration fly ash; and reduces the treatment process and treatment cost of the above emissions, which is conducive to promoting industrial energy conservation and efficiency improvement and green and low-carbon development.

[0154] The above description of the embodiments is intended to facilitate understanding and use of the invention by those skilled in the art. It will be apparent that those skilled in the art can readily make various modifications to these embodiments and apply the general principles described herein to other embodiments without requiring inventive effort. Therefore, the present invention is not limited to the above-described embodiments. Improvements and modifications made by those skilled in the art based on the disclosure of the present invention, without departing from the scope of the present invention, should be within the scope of protection of the present invention.

Claims

1. A method for coupling modified waste incineration fly ash with mineralization and resource utilization, characterized in that: The following steps are involved: S1: mixing garbage with siliceous modified solid waste and a dopant and incinerating the mixture to obtain modified garbage incineration fly ash; wherein the silicon content of the siliceous modified solid waste, calculated as SiO2, is not less than 55wt%; the dopant is a substance containing at least one element selected from the group consisting of alkali metals, alkaline earth metals, transition metals, boron, nitrogen, aluminum, and phosphorus; the amount of the dopant added is 0.001-0.5% of the mass of the garbage; and the mass ratio of the siliceous modified solid waste to the garbage is (0.01-1):100; S2: Mixing the modified waste incineration fly ash with siliceous solid waste and water, digesting and pressing to obtain a green body; S3: subjecting the green body to a mineralization reaction in an atmosphere containing carbon dioxide to obtain a mineralized product.

2. The method for coupled mineralization and resource utilization of modified waste incineration fly ash according to claim 1, characterized in that: In step S1, the mass ratio of the siliceous modified solid waste to the garbage is (0.1-0.5):

100.

3. The method for coupled mineralization and resource utilization of modified waste incineration fly ash according to claim 1, characterized in that: The dopant is at least one of BaCO3, Na2CO3 or K2CO3.

4. The method for coupled mineralization and resource utilization of modified waste incineration fly ash according to claim 3, characterized in that: The added amount of the dopant is 0.003-0.3% of the mass of the garbage.

5. The method for coupled mineralization and resource utilization of modified waste incineration fly ash according to claim 4, characterized in that: The added amount of the dopant is 0.003-0.15% of the mass of the garbage.

6. The method for coupled mineralization and resource utilization of modified waste incineration fly ash according to claim 1, characterized in that: Between step S1 and step S2, the method further includes: dechlorinating the modified waste incineration fly ash to obtain dechlorinated modified waste incineration fly ash with a chloride ion concentration of 8-12 wt%.

7. The method for coupled mineralization and resource utilization of modified waste incineration fly ash according to claim 1, characterized in that: In step S2, the silicon content of the siliceous solid waste is not less than 30 wt%.

8. The method for coupled mineralization and resource utilization of modified waste incineration fly ash according to claim 1, characterized in that: In the mixture consisting of modified waste incineration fly ash, siliceous solid waste and water, the mass content of the modified waste incineration fly ash is 20-70%, the mass content of the siliceous solid waste is 15-70%, and the mass content of water is 5-30%.

9. The method for coupled mineralization and resource utilization of modified waste incineration fly ash according to claim 1, characterized in that: In step S3, during the mineralization reaction, the mineralization pressure is 0.1-1.0 MPa, the mineralization time is 2-8 hours, and the volume fraction of carbon dioxide in the reaction atmosphere is 5-99%.

10. Use of the method according to any one of claims 1 to 9, characterized in that The method is used in the resource processing process of garbage incineration fly ash, solid waste and industrial flue gas.