Cement-based solidified material of waste incineration fly ash dechlorination residue and preparation method and application thereof

Abstract

The application belongs to the technical field of solid waste resource utilization, hazardous waste stabilization treatment and cement-based material preparation, and specifically discloses a cement-based solidification material of waste incineration fly ash dechlorination residue and a preparation method and application thereof. The low-chlorine calcium silicate residue obtained after dechlorination treatment of waste incineration fly ash is a functional powder substitute for part of cement, and is mixed with cement, aggregate and water to obtain the cement-based solidification material through molding and curing. The dechlorination residue contains calcium silicate minerals such as CaSiO3 and Ca2SiO4, which can participate in the construction of the cementitious structure through particle packing and heterogeneous nucleation. At the same time, the cement hydration product can encapsulate, adsorb, pore seal and chemically fix residual heavy metals such as Pb, Zn, Cu and Cr, realizing the secondary solidification of the heavy metals. The application realizes the conversion of waste incineration fly ash dechlorination residue from a treatment byproduct to a cement-based admixture and a solidification and stabilization material, and has good environmental benefits and application potential.

Description

Technical Field

[0001] This invention belongs to the technical fields of solid waste resource utilization, hazardous waste stabilization treatment and cement-based material preparation. Specifically, it relates to a method for preparing cement-based solidified materials using dechlorination residue from waste incineration fly ash as raw material, the cement-based solidified materials prepared by this method and their application in building material utilization and secondary solidification of heavy metals. Background Technology

[0002] Municipal solid waste incineration has become an important method for urban waste treatment due to its advantages of volume reduction, harmlessness, and high resource recovery. However, the fly ash produced during incineration is rich in soluble chloride salts, heavy metals, and dioxin-like pollutants, and is generally classified as hazardous waste. The high content of NaCl, KCl, and Ca-Cl species in fly ash can easily cause chloride ion leaching, steel corrosion, hindered cement hydration, and reduced material durability when directly used in building materials systems; at the same time, heavy metals such as Pb, Zn, Cu, and Cr pose an environmental release risk.

[0003] Existing fly ash treatment technologies mainly include water washing, acid leaching, heat treatment, molten vitrification, solidification and stabilization, and co-processing in cement kilns. Water washing is a mature process, but it generates a large amount of saline wastewater and has limited effectiveness in removing sparingly soluble chlorine and structural chlorine. Acid leaching has a strong dechlorination effect, but it suffers from equipment corrosion, reagent consumption, and the pressure of treating acidic, high-salt wastewater. High-temperature melting dechlorination is thorough, but it has high energy consumption and stringent equipment requirements. Simple solidification and stabilization can reduce leaching risk, but its resource recovery rate is limited, and its long-term stability still needs improvement.

[0004] The siliceous material-steam synergistic dechlorination treatment utilizes the combined action of siliceous materials such as waste glass powder and steam to promote chloride migration and mineral phase reconstruction in fly ash, resulting in dechlorination residues with low chloride content and high calcium silicate mineral content. This type of dechlorination residue shows a significant reduction in soluble chlorides such as NaCl and KCl, and generates calcium silicate minerals such as CaSiO3 and Ca2SiO4, while simultaneously reducing the risk of heavy metal leaching.

[0005] However, existing technologies mostly focus on the dechlorination process of waste incineration fly ash itself, or only generally propose that dechlorination residue can be used as an auxiliary cementitious material in concrete or mortar, without fully addressing the issue of the safe resource utilization of dechlorination residue in cement-based systems. In particular, for low-chlorine dechlorination residue containing calcium silicate minerals, there is a lack of feasible technical solutions regarding how to determine an appropriate low-dosage replacement rate, how to combine it with cementitious materials, aggregates, and water to form a stable cement-based solidification system, how to further reduce the leaching risk of residual heavy metals such as Pb, Zn, Cu, and Cr during cement hydration, and how to achieve a balance between compressive strength and environmental safety. Therefore, it is necessary to develop a method for preparing cement-based materials based on waste incineration fly ash dechlorination residue that combines resource utilization and secondary solidification of heavy metals. Summary of the Invention

[0006] The technical problem this invention aims to solve is as follows: While existing technologies have disclosed methods for the synergistic dechlorination of siliceous materials and steam from waste incineration fly ash and the general building material utilization of dechlorination residues, they have not clarified the safe utilization window for low-chloride calcium silicate residues in cement hydration systems at low dosages, the secondary solidification mechanism, and the synergistic control of mechanical properties and leaching risks. This invention provides a cement-based solidification material from waste incineration fly ash dechlorination residues, its preparation method, and its application. This invention does not simply pursue high-dosage cementitious utilization of dechlorination residues, but rather uses low-chloride calcium silicate dechlorination residues as a cement-based functional component with secondary heavy metal solidification capabilities. By limiting the low-dosage substitution range, the cementitious material-aggregate-water ratio, and curing conditions, it achieves synergistic control of maintaining compressive strength and reducing the risk of residual heavy metal leaching while reducing cement usage and utilizing the calcium silicate minerals in the dechlorination residues.

[0007] To solve the above-mentioned technical problems, the present invention adopts the following technical solution: The preparation method of cement-based solidification material from dechlorination residue of waste incineration fly ash includes the following steps: (1) The dechlorination residue powder of waste incineration fly ash is used as a cement substitute component to form a cementitious material together with cement, and then mixed with aggregate and water to obtain cement-based paste, mortar or mixture; the dechlorination residue powder is a low-chlorine calcium silicate residue obtained after dechlorination treatment, and the dechlorination residue powder contains CaSiO3 and / or Ca2SiO4 calcium silicate minerals; (2) The cement-based slurry, mortar or mixture from step (1) is molded and cured to obtain cement-based solidification material of dechlorination residue from waste incineration fly ash; after molding and curing, the residual heavy metals in the dechlorination residue powder are wrapped, adsorbed, sealed in the pores or chemically fixed by cement hydration products.

[0008] The dechlorination residue powder is a low-chloride calcium silicate residue obtained after dechlorination treatment, preferably the residue obtained from waste incineration fly ash after co-treatment with siliceous materials and steam. The dechlorination residue powder contains CaSiO3 and / or Ca2SiO4 calcium silicate minerals. The dechlorination residue powder is used after drying, grinding, and sieving.

[0009] The dechlorination residue powder passes through an 80–200 mesh sieve; the total chlorine content of the dechlorination residue powder is not higher than 0.5 wt%, and the water-soluble chlorine content is not higher than 0.1 wt%. In this embodiment, the total chlorine content of the CT-SG dechlorination residue is 0.072 wt%, and the water-soluble chlorine content is 0.018 wt%, which falls within the aforementioned low-chlorine residue range.

[0010] The dechlorination residue powder has a mass fraction of 5%–20%, preferably 8%–12%, and more preferably 10%, based on the total mass of cement and dechlorination residue powder. The mass ratio of the cementitious material, aggregate, and water is 1:(2–4):(0.3–0.7), preferably 1:3:0.5, wherein the cementitious material is composed of cement and dechlorination residue powder. The aggregate includes one or more of standard sand, natural sand, manufactured sand, and recycled fine aggregate.

[0011] The curing conditions are a temperature of 20±2℃ and a relative humidity of not less than 95%, with a curing time of 7–28 days.

[0012] This invention uses low-chlorine calcium silicate dechlorination residue as a cement-based curing component with secondary curing function for heavy metals, limits its substitution rate in the total mass of cement and dechlorination residue powder, and uses cement hydration products to encapsulate, adsorb, seal pores and chemically fix residual heavy metals, thereby obtaining a cement-based curing material with both compressive strength and environmental safety.

[0013] The dechlorination residue is encapsulated, embedded, or bound in the cementitious matrix by C–S–H gel, Ca(OH)2, or other cement hydration products; when the dechlorination residue accounts for no more than 20% of the total mass of cement and dechlorination residue, the leaching concentrations of Pb, Zn, Cu, and Cr in the material are no more than 0.50 mg / L, 0.70 mg / L, 0.15 mg / L, and 0.05 mg / L, respectively; when the dechlorination residue powder accounts for 8%-12% of the total mass of cement and dechlorination residue powder, the compressive strength retention rate of the obtained material is no less than 85%.

[0014] Furthermore, this invention experimentally determined that a substitution rate of 8%–12%, preferably 10%, represents a balance between mechanical properties and the risk of heavy metal leaching. This range differs from methods that simply pursue higher dosages based on cementitious activity or clinker substitution rate. Its technical objective is to achieve controllable, safe, and operable utilization of low-chlorine dechlorination residues in non-load-bearing mortars, filler materials, road base materials, brick products, and cement-based solidification and stabilization materials.

[0015] The present invention also provides a cement-based curing material prepared by the above method, and the application of the cement-based curing material in non-load-bearing mortar, filler material, road base material, brick product or cement-based curing and stabilizing material.

[0016] Compared with the prior art, the present invention has the following beneficial effects: (1) This invention transforms the dechlorination residue of low-chlorine calcium silicate from a treatment by-product or general auxiliary cementitious material into a cement-based curing material that has both cement substitution and heavy metal secondary curing functions, and clarifies the specific formula, dosage window and application form for its subsequent safe resource utilization.

[0017] (2) This invention does not simply pursue the high utilization of dechlorination residue, but uses the maintenance of compressive strength and the control of heavy metal leaching risk as dual indicators to determine the substitution rate range of 5%–20%, preferably 8%–12%, and more preferably 10%. Among them, the preferred 10% can achieve a good balance between strength retention rate and environmental safety.

[0018] (3) The calcium silicate minerals such as CaSiO3 and Ca2SiO4 in the dechlorination residue can play the role of particle filling and heterogeneous nucleation, participate in the construction of cement-based cementitious structure, and help to make up for the strength loss caused by partial cement substitution.

[0019] (4) C–S–H gel, Ca(OH)2 and other cement hydration products can encapsulate, adsorb, seal pores and chemically fix heavy metals such as Pb, Zn, Cu and Cr, so that the residual heavy metals in the uncured dechlorination residue can be further cured.

[0020] (5) The aggregate types listed in this invention are used to adapt to different engineering application scenarios; the preparation process is simple and applicable to non-load-bearing mortar, filling materials, road base materials, brick products and cement-based solidification and stabilization materials and other application scenarios. Attached Figure Description

[0021] Figure 1 Schematic diagram of the sources of CT-SG dechlorination residue.

[0022] Figure 2 Flowchart for the preparation of CT-SG-based cement-based curing materials.

[0023] Figure 3 Average failure load diagrams of mortar specimens C0, C5, C10, C15 and C20 (i.e., Comparative Example 1 and Examples 1, 2, 3 and 4).

[0024] Figure 4 Heavy metal TCLP leaching concentration diagrams for mortar specimens of C0, C5, C10, C15, and C20 (i.e., Comparative Example 1 and Examples 1, 2, 3, and 4).

[0025] Figure 5 XRD patterns of mortar blocks of C0, C10 and C20 (i.e., Comparative Example 1 and Examples 2 and 4).

[0026] Figure 6 SEM images of cross-sections of C10 and C20 (i.e., Examples 2 and 4): (a–c) C10; (d–f) C20. Detailed Implementation

[0027] The present invention will be further described below with reference to the embodiments, but the scope of protection of the present invention is not limited to the following embodiments. Conventional adjustments made by those skilled in the art to the source of raw materials, type of aggregate, size of test blocks, curing period, and morphology of engineered products without departing from the concept of the present invention shall all fall within the scope of protection of the present invention.

[0028] Sources of raw materials and dechlorination residue The implementation method uses CT-SG residue obtained after glass powder-water vapor co-dechlorination treatment as the resource utilization object. CT-SG is a low-chloride calcium silicate residue, in which the total chlorine and water-soluble chlorine content are significantly lower than that of the original waste incineration fly ash. It mainly contains mineral phases such as SiO2, CaSiO3, and Ca2SiO4, and the leaching risk of heavy metals such as Pb, Zn, Cu, and Cr is lower than that of the original fly ash. The dechlorination treatment conditions are only used to illustrate the source of the residue and do not constitute a limitation of the dechlorination process itself in this invention.

[0029] Table 1. Basic properties of CT-SG dechlorination residue

[0030] Preparation of CT-SG based cement-based curing materials Based on the total mass of cement and CT-SG dechlorination residue powder, cement was replaced with dechlorination residue powder at different mass fractions, while the total mass of cementitious materials remained constant. Cement, CT-SG, aggregate, and water were weighed according to a predetermined ratio. Laboratory verification procedure: First, cement and CT-SG were mixed evenly, then aggregate was added and mixed for 2 min; subsequently, deionized water was added and mechanically stirred for 3 min to obtain a uniform mortar. The mortar was filled into a 10 mm × 10 mm × 10 mm cubic mold, layered and gently vibrated to remove air, and allowed to stand at room temperature for 24 h before demolding. It was then cured at 20 ± 2℃ and a relative humidity of not less than 95%.

[0031] Mechanical property testing After the specimens have cured to the specified age, a compressive strength test is performed using an electronic universal testing machine. The maximum load at which the specimen fails is recorded during the loading process. The compressive strength is calculated according to formula (1): f = P / A Where f is the compressive strength (MPa); P is the failure load (N); and A is the area under pressure (mm²). For a 10 mm × 10 mm × 10 mm specimen, when the failure load is in kN, the compressive strength can be calculated using the following formula: f / MPa = 10 × P / kN Each group was set up with parallel samples, and the average value was taken as the final result. Example 1

[0032] CT-SG dechlorination residue was dried to constant weight at 105℃, ground, and passed through a 100-mesh sieve to obtain CT-SG dechlorination residue powder. 19 g of PO 42.5 ordinary Portland cement, 1 g of CT-SG dechlorination residue, 60 g of ISO standard sand, and 10 g of deionized water were used to prepare C5 mortar blocks according to the above preparation method. After curing, the average failure load was measured to be 2.77 kN, corresponding to a compressive strength of 27.73 MPa; the strength retention rate was approximately 97.06%. The concentrations of Pb, Zn, Cu, and Cr in the 28-day TCLP leachate were 0.06 mg / L, 0.11 mg / L, 0.03 mg / L, and 0.014 mg / L, respectively. The utilization rate of CT-SG dechlorination residue is low, and its use as a solid waste substitute for cement and for resource utilization is limited. Example 2

[0033] The CT-SG dechlorination residue was dried to constant weight at 105℃, ground, and passed through a 100-mesh sieve to obtain CT-SG dechlorination residue powder. 18 g of PO 42.5 ordinary Portland cement, 2 g of CT-SG dechlorination residue, 60 g of ISO standard sand, and 10 g of deionized water were used to prepare C10 mortar blocks according to the above preparation method. After curing, the average failure load was measured to be 2.59 kN, corresponding to a compressive strength of 25.87 MPa, with a strength retention rate of approximately 90.56%. The concentrations of Pb, Zn, Cu, and Cr in the 28-day TCLP leachate were 0.21 mg / L, 0.19 mg / L, 0.05 mg / L, and 0.019 mg / L, respectively. This embodiment achieves a good balance between mechanical properties and environmental safety. Example 3

[0034] The CT-SG dechlorination residue was dried to constant weight at 105℃, ground, and passed through a 100-mesh sieve to obtain CT-SG dechlorination residue powder. 17 g of PO 42.5 ordinary Portland cement, 3 g of CT-SG dechlorination residue, 60 g of ISO standard sand, and 10 g of deionized water were used to prepare C15 mortar test blocks according to the above method. After curing, the average failure load was measured to be 2.35 kN, corresponding to a compressive strength of 23.53 MPa; the strength retention rate was approximately 82.36%; the concentrations of Pb, Zn, Cu, and Cr in the 28-day TCLP leachate were 0.27 mg / L, 0.43 mg / L, 0.08 mg / L, and 0.025 mg / L, respectively. Example 4

[0035] CT-SG dechlorination residue was dried to constant weight at 105℃, ground, and passed through a 100-mesh sieve to obtain CT-SG dechlorination residue powder. 16 g of PO 42.5 ordinary Portland cement, 4 g of CT-SG dechlorination residue, 60 g of ISO standard sand, and 10 g of deionized water were used to prepare C20 mortar blocks according to the above preparation method. After curing, the average failure load was measured to be 2.05 kN, corresponding to a compressive strength of 20.53 MPa; the strength retention rate was approximately 71.86%; the concentrations of Pb, Zn, Cu, and Cr in the 28-day TCLP leachate were 0.44 mg / L, 0.62 mg / L, 0.12 mg / L, and 0.032 mg / L, respectively. Compared with the uncured CT-SG residue, the heavy metal leaching concentration was significantly reduced, indicating that the cement system has a secondary curing effect. Example 5

[0036] CT-SG dechlorination residue was dried to constant weight at 105℃, ground, and passed through an 80-mesh sieve to obtain CT-SG dechlorination residue powder. 18 g of PO 42.5 ordinary Portland cement, 2 g of the 80-mesh CT-SG dechlorination residue powder, 60 g of ISO standard sand, and 10 g of deionized water were mixed, molded, and cured using the same method as in Example 2 to obtain a CT-SG-based cementitious material. After curing, the average failure load was measured to be 2.52 kN, corresponding to a compressive strength of 25.14 MPa, with a strength retention rate of approximately 87.99%. This example illustrates that the dechlorination residue powder described in this invention can be obtained using an 80-mesh sieve. Example 6

[0037] CT-SG dechlorination residue was dried to constant weight at 105℃, ground, and passed through a 200-mesh sieve to obtain CT-SG dechlorination residue powder. 18 g of PO 42.5 ordinary Portland cement, 2 g of the 200-mesh CT-SG dechlorination residue powder, 60 g of ISO standard sand, and 10 g of deionized water were mixed, molded, and cured using the same method as in Example 2 to obtain a CT-SG-based cementitious material. After curing, the average failure load was measured to be 2.69 kN, corresponding to a compressive strength of 26.33 MPa, with a strength retention rate of approximately 92.15%. This example illustrates that the dechlorination residue powder described in this invention can be sieved using a 200-mesh sieve. As the particle size of the dechlorination residue powder decreases, its specific surface area increases, enhancing the particle filling effect and the degree of contact with cement hydration products. Therefore, the dechlorination residue powder passing through a 200-mesh sieve exhibits higher compressive strength. However, compared to passing through a 100-mesh sieve, further refining to a 200-mesh sieve offers limited performance improvement, while increasing grinding energy consumption and powder processing costs. Considering material properties, powder preparation energy consumption, and engineering feasibility, dechlorination residue powder passing through a 100-mesh sieve is preferred; in applications requiring higher mechanical properties or heavy metal solidification effects, dechlorination residue powder passing through a 200-mesh sieve can be used. Example 7

[0038] The CT-SG dechlorination residue was dried to constant weight at 105℃, ground, and passed through a 100-mesh sieve to obtain CT-SG dechlorination residue powder. 18.4 g of PO 42.5 ordinary Portland cement, 1.6 g of CT-SG dechlorination residue powder, 60 g of ISO standard sand, and 10 g of deionized water were used to prepare mortar blocks with an 8% CT-SG substitution rate according to the above preparation method. After curing, the average failure load was measured to be 2.63 kN, corresponding to a compressive strength of 26.44 MPa, with a strength retention rate of approximately 92.54%. This example illustrates that an 8% substitution rate is within the preferred substitution range of this invention. Example 8

[0039] CT-SG dechlorination residue was dried to constant weight at 105℃, ground, and passed through a 100-mesh sieve to obtain CT-SG dechlorination residue powder. 17.6 g of PO 42.5 ordinary Portland cement, 2.4 g of CT-SG dechlorination residue powder, 60 g of ISO standard sand, and 10 g of deionized water were used to prepare mortar blocks with a CT-SG substitution rate of 12% according to the above preparation method. After curing, the average failure load was measured to be 2.44 kN, corresponding to a compressive strength of 24.65 MPa, with a strength retention rate of approximately 86.27%. This example illustrates that a 12% substitution rate is within the preferred substitution range of this invention. Example 9

[0040] The CT-SG dechlorination residue was dried to constant weight at 105℃, ground, and passed through a 100-mesh sieve to obtain CT-SG dechlorination residue powder. 18 g of PO 42.5 ordinary Portland cement, 2 g of CT-SG dechlorination residue powder, 60 g of manufactured sand, and 10 g of deionized water were mixed, molded, and cured using the same method as in Example 2 to obtain a CT-SG-based cementitious material. After curing, the average failure load was measured to be 2.51 kN, corresponding to a compressive strength of 25.22 MPa, with a strength retention rate of approximately 88.27%. This example illustrates that the aggregate described in this invention is not limited to ISO standard sand; manufactured sand can also be used. Example 10

[0041] The CT-SG dechlorination residue was dried to constant weight at 105℃, ground, and passed through a 100-mesh sieve to obtain CT-SG dechlorination residue powder. 18 g of PO 42.5 ordinary Portland cement, 2 g of CT-SG dechlorination residue powder, 60 g of recycled fine aggregate, and 10 g of deionized water were mixed, molded, and cured according to the same method as in Example 2 to obtain a CT-SG-based cementitious material. After curing, the average failure load was measured to be 2.47 kN, corresponding to a compressive strength of 24.93 MPa, with a strength retention rate of approximately 87.25%. This example illustrates that the aggregate described in this invention can also be recycled fine aggregate. Example 11

[0042] C10 mortar blocks were prepared according to the formulation of Example 2. After demolding, they were cured for 7 days at 20±2℃ and relative humidity not less than 95% to obtain early-age CT-SG-based cementitious cured material. The average failure load after curing was measured to be 2.55 kN, corresponding to a compressive strength of 25.67 MPa, with a strength retention rate of approximately 89.85%. This is not significantly different from the standard-curing-age CT-SG-based cementitious cured material obtained by preparing mortar blocks with the same formulation and curing for 28 days. This example illustrates that the curing time of the present invention can be selected within the range of 7–28 days. Comparative Example 1

[0043] Without adding CT-SG dechlorination residue, 20 g of PO 42.5 ordinary Portland cement, 60 g of ISO standard sand, and 10 g of deionized water were used to prepare CO mortar blocks using the same method. After curing, the average failure load was measured to be 2.86 kN, corresponding to a compressive strength of 28.57 MPa. The concentrations of Pb, Zn, Cu, and Cr in the 28-day TCLP leachate were 0.04 mg / L, 0.07 mg / L, 0.02 mg / L, and 0.010 mg / L, respectively. This comparative example completely failed to utilize CT-SG dechlorination residue, thus failing to achieve cement substitution, solid waste resource utilization, and secondary solidification of heavy metals in the dechlorination residue. Comparative Example 2

[0044] TCLP leaching tests were conducted on CT-SG dechlorination residue that had not undergone cement-based curing treatment. The leaching concentrations of Pb, Zn, Cu, and Cr were 1.22 mg / L, 1.42 mg / L, 0.24 mg / L, and 0.11 mg / L, respectively. Compared with Examples 1-4, this comparative example demonstrates that cement hydration products have a significant secondary curing effect on residual heavy metals in CT-SG residue. Application Example 1

[0045] The CT-SG-based cementitious curing material obtained in Example 2 was used in non-load-bearing mortar or filling material. The CT-SG replacement rate was 10%. It is suitable for filling, leveling or non-load-bearing products where the structural load-bearing requirements are not high, but the resource utilization of solid waste and environmental safety need to be taken into account. Application Example 2

[0046] CT-SG dechlorination residue powder is incorporated into cement-based stabilizing materials at a 10% replacement rate, along with manufactured sand or recycled fine aggregate, for use in the preparation of road base materials or brick products. This application example illustrates that the cured material obtained by this invention is applicable to road bases, brick products, and cement-based cured and stabilized materials, among other application scenarios.

[0047] In summary, this invention further transforms the dechlorination residue of low-chlorine calcium silicate into cement-based admixtures and cement-based solidification and stabilization materials, realizing a continuous utilization path of "dechlorination-stabilization-resource recovery" for waste incineration fly ash, and has good engineering application prospects.

Claims

1. A method for preparing a cement-based solidification material from the dechlorination residue of waste incineration fly ash, characterized in that, The preparation method steps are as follows: (1) The dechlorination residue powder of waste incineration fly ash is mixed with cement to form a cementitious material, and then mixed with aggregate and water to obtain cement-based slurry, mortar or mixture; the dechlorination residue powder is a low-chlorine calcium silicate residue obtained after dechlorination treatment, and the dechlorination residue powder contains CaSiO3 and / or Ca2SiO4 calcium silicate minerals. (2) The cement-based slurry, mortar or mixture is molded and cured to obtain cement-based solidification material of dechlorination residue of waste incineration fly ash.

2. The method for preparing cement-based solidification material from dechlorination residue of waste incineration fly ash according to claim 1, characterized in that, The mass ratio of the cementitious material, aggregate, and water is 1:2-4:0.3-0.

7.

3. The method for preparing cement-based solidification material from dechlorination residue of waste incineration fly ash according to claim 1, characterized in that, The dechlorination residue powder has a mass fraction of 5%–20% based on the total mass of cement and dechlorination residue powder; the dechlorination residue powder is used after drying, grinding and sieving.

4. The method for preparing cement-based solidification material from dechlorination residue of waste incineration fly ash according to claim 1, characterized in that, The dechlorination residue powder of the waste incineration fly ash is the residue obtained after the waste incineration fly ash has been treated with siliceous materials and water vapor.

5. The method for preparing cement-based solidification material from dechlorination residue of waste incineration fly ash according to claim 1, characterized in that, The dechlorination residue powder passes through an 80–200 mesh sieve; the total chlorine content of the dechlorination residue powder is not higher than 0.5 wt%, and the water-soluble chlorine content is not higher than 0.1 wt%.

6. The method for preparing cement-based solidification material from dechlorination residue of waste incineration fly ash according to claim 1, characterized in that, The aggregate is selected from one or more of standard sand, natural sand, manufactured sand, and recycled fine aggregate.

7. The method for preparing cement-based solidification material from dechlorination residue of waste incineration fly ash according to claim 1, characterized in that, The curing conditions are: temperature 20±2℃, relative humidity not less than 95%, and curing time 7–28 days.

8. A cement-based solidification material for dechlorination residue from waste incineration fly ash prepared by the method according to any one of claims 1-7, characterized in that, The cement-based curing material is formed by mixing, molding, and curing cement, aggregate, water, and dechlorination residue powder from waste incineration fly ash.

9. The cement-based solidification material for dechlorination residue of waste incineration fly ash according to claim 8, characterized in that, When the dechlorination residue powder accounts for no more than 20% of the total mass of cement and dechlorination residue powder, the leaching concentrations of Pb, Zn, Cu and Cr in the material are no more than 0.50 mg / L, 0.70 mg / L, 0.15 mg / L and 0.05 mg / L, respectively; and when the mass fraction of the dechlorination residue powder is 8%–12% based on the total mass of cement and dechlorination residue powder, the compressive strength retention rate of the obtained material is no less than 85%.

10. The application of a cement-based solidification material for dechlorination residue from waste incineration fly ash prepared according to any one of claims 1-7, characterized in that, The curing material is used in non-load-bearing mortar, filler material, road base material, brick products, or cement-based curing and stabilizing material.

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