Soil pollution curing material as well as preparation method and application thereof

Abstract

The invention discloses a soil pollution curing material as well as a preparation method and application thereof, relates to the technical field of soil curing, and overcomes the defects that a cement-based curing agent in the prior art is poor in adaptability to high-silicon and high-aluminum soil, pollutants are not thoroughly fixed and the strength is low. Comprising the following components in parts by mass: 40-50 parts of granulated blast furnace slag, 20-25 parts of fly ash, 15-20 parts of desulfurized gypsum, 5-8 parts of carbide slag, 3-5 parts of anhydrous sodium silicate, 2-4 parts of sodium hydroxide, 0.5-1 part of nano rare earth oxide, 3-5 parts of a micro-expanding agent, 2-4 parts of KOH activated charcoal, 1-2 parts of Al < 3 + > ion exchange modified montmorillonite and 0.5-1 part of polyvinyl alcohol. The micro-expanding agent is a compound of anhydrous calcium sulphoaluminate and gypsum. The method can be used for solidifying the high-silicon-aluminum soil.

Description

Technical Field

[0001] This invention relates to the field of soil consolidation technology, specifically to a soil pollution consolidation material, its preparation method, and its application. Background Technology

[0002] Soil is an important component of the ecosystem, but it is susceptible to pollution from heavy metals, organic matter, and other pollutants, seriously threatening the ecological environment and human health. Soil solidification technology involves adding solidifying agents to contaminated soil, which then forms a stable solidified body through physical and chemical reactions. This enhances soil strength and immobilizes pollutants, making it one of the key technologies for contaminated site remediation.

[0003] Existing soil stabilizers are mainly classified into cement-based and lime-based types. Among them, cement-based stabilizers are widely used due to their wide availability and ease of application, but they still have significant drawbacks. On the one hand, in environments with a high water-cement ratio (i.e., high moisture content), the cement hydration reaction is incomplete, resulting in a long setting time and low early strength of the stabilized soil, making it difficult to meet the time-sensitive requirements of engineering projects. On the other hand, for high-silica and alumina soils with SiO2+Al2O3 content >65%, such as sandy soils and soils with weathered rock development, cement-based materials cannot effectively activate stable silica and alumina minerals such as quartz and feldspar in the soil to participate in the hydration reaction, leading to a tendency for the stabilized body to experience strength reduction and poor stability in the later stages. In addition, existing soil stabilizers mainly fix pollutants through the physical encapsulation of hydration products, exhibiting weak retention capacity for small molecule pollutants such as heavy metal ions, resulting in a high risk of long-term leaching and making it difficult to meet national standards.

[0004] To address the aforementioned shortcomings, some studies have attempted to prepare solidifying agents using industrial wastes such as slag and fly ash as substrates through alkali activation. However, excessive use of alkali activators can easily lead to cracking of the solidified body, and there is still a problem of insufficient activation of silica and alumina activity in high-silica and alumina soils, resulting in limited strength improvement. Furthermore, pollutant fixation relies on a single physical encapsulation method, leading to poor long-term stability. Therefore, developing a soil contamination solidification material that is suitable for high-silica and alumina soils, possesses high strength, and has a low leaching risk has become an urgent need in the industry. Summary of the Invention

[0005] In order to overcome the shortcomings of existing cement-based solidifying agents in terms of poor adaptability to high silica and aluminum soils, incomplete fixation of pollutants, and low strength, this invention proposes a soil pollution solidification material, its preparation method, and its application.

[0006] The specific technical solution of the present invention is as follows: The present invention also provides a soil contamination solidification material, comprising the following components in parts by weight: Granulated blast furnace slag 40-50 parts, fly ash 20-25 parts, desulfurized gypsum 15-20 parts, carbide slag 5-8 parts, anhydrous sodium silicate 3-5 parts, sodium hydroxide 2-4 parts, nano rare earth oxides 0.5-1 parts, micro-expansion agent 3-5 parts, KOH activated biochar 2-4 parts, Al 3+ 1-2 parts of ion-exchange modified montmorillonite, 0.5-1 part of polyvinyl alcohol; The micro-expansion agent is a compound of anhydrous calcium sulfoaluminate and gypsum.

[0007] Preferably, the nano-rare earth oxide is selected from La2O3 or CeO2.

[0008] Preferably, the ratio of anhydrous calcium sulfoaluminate to gypsum is 1:0.5~2.

[0009] Preferably, the KOH-activated biochar is obtained through the following steps: The biochar after removing impurities was dried at 105°C until the moisture content dropped to <1%; The dried biochar was mixed with KOH at a mass ratio of 1:3, and after adding deionized water and stirring to dissolve, it was evaporated and dried at 80°C. Subsequently, it was activated at a high temperature of 600-800℃ for 1-2 hours under a nitrogen atmosphere; After neutralization with hydrochloric acid, the biochar was washed with deionized water until the pH reached 6-7, dried, and passed through a 100-mesh sieve to obtain KOH-activated biochar.

[0010] Preferably, the Al 3+ Ion-exchange modified montmorillonite is obtained through the following steps: Montmorillonite was added to a 0.5–1 mol / L AlCl3 solution at a ratio of 1 g: 10 mL, and stirred in a constant temperature water bath at 60–80 °C to allow the Na+ between the montmorillonite layers to react. + Ca 2+ With Al in solution 3+ An exchange occurs; After the reaction was complete, the precipitate was allowed to stand and the supernatant was discarded. The precipitate was repeatedly washed with deionized water, dried, ground, and passed through a 200-mesh sieve to obtain Al. 3+ Ion-exchange modified montmorillonite.

[0011] Preferably, the specific surface area of ​​the soil contamination solidification material is 650~700 m². 2 / kg.

[0012] The present invention also provides a method for preparing the above-mentioned soil contamination solidification material, comprising the following steps: S1, Activated biochar and Al 3+ Ion-exchange modified montmorillonite was added to a mixer and dry-mixed to obtain mixed powder A; S2. Crush and dry granulated blast furnace slag, fly ash, and desulfurized gypsum. S3. The mixed powder A is dry-mixed with granulated blast furnace slag, fly ash, desulfurized gypsum, carbide slag, anhydrous sodium silicate, sodium hydroxide, nano rare earth oxides, micro-expansion agent and polyvinyl alcohol to obtain mixed powder B. S4. Ball mill the mixed powder B to a specific surface area of ​​650~700m². 2 / kg; S5. Steam curing produces soil contamination solidification materials.

[0013] Preferably, the crushing process in step S2 is to crush the particles to a size < 5 mm; the drying process is to dry the particles to a moisture content < 1%.

[0014] Preferably, the steam curing conditions are 40~50℃ and humidity ≥90%, and the steam curing time is 12~24h.

[0015] The present invention also provides an application of the above-mentioned soil contamination solidification agent, specifically for the solidification of high silica-alumina soil, wherein the content of SiO2+Al2O3 in the high silica-alumina soil is >65%.

[0016] Preferably, the specific application method is as follows: the soil contamination solidifying agent is mixed with high silica-alumina soil at a mass ratio of 1:8 to 1:12, the moisture content is adjusted to 20 to 25%, and after compaction, it is naturally cured for 7 to 28 days.

[0017] Compared with the prior art, the specific beneficial effects of the present invention are as follows: 1. This invention utilizes the synergistic excitation of nano-rare earth oxides, whose ions can disrupt the stable structure of silicon-oxygen tetrahedra and aluminum-oxygen tetrahedra in high-silicon-aluminum soils, promoting the depolymerization of aluminum-silicon structures in the soil and forming SiO4. 4- AlO4 3- The unit, in conjunction with alkaline components, synergistically activates the activity of slag and fly ash, significantly improving the strength of the solidified body; 2. This invention uses KOH to activate biochar, which captures pollutants through pore adsorption and surface functional group complexation. Al 3+ Ion-exchange modified montmorillonite forms a dual barrier of adsorption and anchoring through interlayer domain retention and secondary ion exchange, thereby reducing the leaching rate of heavy metal ions by more than 80%. 3. The needle-like ettringite generated by the hydration of the micro-expansion agent fills the micropores of the solidified body. Combined with the bridging effect of polyvinyl alcohol, the total porosity of the solidified body is controlled at 20-25%, and the micropore ratio is >60%. This ensures strength and blocks the migration path of pollutants through capillary effect. 4. The total utilization rate of industrial waste residues (slag, fly ash, desulfurization gypsum, carbide slag) of this invention is >85%, and the raw material cost is significantly reduced compared with cement-based curing agents; the energy consumption of low-temperature steam curing is also significantly reduced compared with traditional high-temperature cement curing, which meets the needs of green and low-carbon development. Attached Figure Description

[0018] Figure 1 This is a scanning electron microscope image of KOH-activated biochar from Example 1; Figure 2 This is a scanning electron microscope image of the hydration products of the cured material in Example 1. Detailed Implementation

[0019] To make the technical solutions of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. It should be noted that the following embodiments are only used to better understand the technical solutions of the present invention and should not be construed as limiting the present invention.

[0020] Example 1. The components of the soil contamination solidification material in this embodiment are: Granulated blast furnace slag 450g, fly ash 220g, desulfurized gypsum 180g, carbide slag 60g, anhydrous sodium silicate 40g, sodium hydroxide 30g, La2O3 8g, micro-expansion agent 40g (including anhydrous calcium sulfoaluminate 20g and gypsum 20g), KOH activated biochar 30g, Al 3+ 15g of ion-exchange modified montmorillonite and 7g of polyvinyl alcohol.

[0021] The specific preparation process is as follows: (1) Preparation of KOH-activated biochar: Commercially available straw-based biochar was selected, and impurities such as stones and sawdust were removed. It was then dried in an oven at 105℃ for 12 hours until the moisture content was <1%. Add 30g KOH and 50mL deionized water to 10g of dried biochar, and stir magnetically for 20min until the KOH is completely dissolved. Pour the mixture into an evaporating dish and evaporate it in an 80°C water bath until dry to obtain a gray-black solid. The solid was placed in a tube furnace, nitrogen gas was introduced at a flow rate of 80 mL / min, and the temperature was increased to 700°C at a heating rate of 5°C / min, and held at that temperature for 1.5 h; it was then removed after naturally cooling to room temperature. Add 100 mL of 1 mol / L hydrochloric acid solution to the product and stir at room temperature for 30 min to neutralize excess KOH; then wash repeatedly with deionized water until the pH of the supernatant is 6.5. After filtration, the filter cake is dried in an oven at 105℃ for 12 hours, ground, and passed through a 100-mesh sieve to obtain KOH-activated biochar.

[0022] The scanning electron microscope test results are as follows Figure 1 As shown, under low magnification, KOH-activated biochar exhibits an irregular particle agglomeration morphology with numerous pore structures of varying sizes distributed on its surface. This is due to the etching effect of KOH on the biochar matrix during high-temperature activation, forming macroscopic macropores and mesopores, providing space for mass transport and reactions. Under magnification, the surface of the biochar particles is covered with flocculent and granular fine structures, and the outline and distribution of the pores are more clearly defined. This indicates that KOH activation not only etches macropores but also forms a large number of mesopores on the particle surface, while simultaneously exposing active sites, further increasing the specific surface area and reactivity of the material. Under high magnification, a nanoscale porous morphology is revealed, with micropores smaller than 2 μm densely distributed between the biochar particles. These micropores are the core feature of KOH activation. At high temperatures, KOH undergoes dehydration and heteroatom removal reactions with biochar, precisely etching a large number of microporous structures, greatly increasing the specific surface area of ​​the material and providing ample active sites for adsorption, catalysis, and other applications.

[0023] (2) Al 3+ Preparation of ion-exchange modified montmorillonite: Take 10g of natural montmorillonite, pass it through a 200-mesh sieve, and add 100mL of 0.8mol / L AlCl3 solution; The mixture was placed in a 70℃ constant temperature water bath and stirred at 300 rpm for 3 hours to allow Na between the montmorillonite layers to react. + Ca 2+ With Al 3+ Full exchange; After the reaction is complete, let it stand for 5 minutes and discard the supernatant. Add 200 mL of deionized water to the precipitate, stir for 10 minutes, and then let it stand and decant. Repeat the washing process 4 times until no white precipitate appears when 1 mL of the filtrate is added to 0.1 mol / L AgNO3 solution, confirming the absence of Cl. - Residue; The precipitate was dried in a 70℃ oven for 12 hours, ground, and then passed through a 200-mesh sieve to obtain Al. 3+ Ion-exchange modified montmorillonite.

[0024] (3) Preparation of soil contamination solidification materials: S1. Take 30g of the KOH-activated biochar prepared above and Al 3+ 15g of ion-exchange modified montmorillonite was added to a horizontal mixer and dry-mixed at 300r / min for 4min to obtain mixed powder A. S2. Crush 450g of granulated blast furnace slag, 220g of fly ash, and 180g of desulfurized gypsum to a particle size of <5mm, and dry them in an oven at 105℃ for 8 hours until the moisture content is <1%. S3. Add the mixed powder A together with the granulated blast furnace slag, fly ash, desulfurized gypsum and 60g of carbide slag, 40g of anhydrous sodium silicate, 30g of sodium hydroxide, 8g of La2O3, 40g of micro-expansion agent and 7g of polyvinyl alcohol after step S2 into a mixer and dry mix at 400r / min for 6min to obtain mixed powder B. S4. Pour the mixed powder B into a high-energy ball mill, add zirconium beads with a particle size of 0.2 mm, and ball mill at 700 r / min for 35 min. Take a sample and test the specific surface area, which is 680 m². 2 / kg; S5. Place the ball-milled powder in a steam curing chamber and cure it at 45°C and 95% humidity for 20 hours to obtain soil contamination solidification material.

[0025] Example 2. The components of the soil contamination solidification material in this embodiment: 500g granulated blast furnace slag, 200g fly ash, 150g desulfurized gypsum, 50g carbide slag, 30g anhydrous sodium silicate, 20g sodium hydroxide, 25g CeO, 30g micro-expansion agent (including 10g anhydrous calcium sulfoaluminate and 20g gypsum), 40g KOH activated biochar, Al 3+ 20g of ion-exchange modified montmorillonite and 5g of polyvinyl alcohol.

[0026] The specific preparation process is as follows: (1) Preparation of KOH-activated biochar: Take 10g of pretreated commercially available wood-based biochar and mix it with 30g of KOH, then evaporate and dry at 80℃. Activated at 800℃ for 2 hours under nitrogen atmosphere, neutralized with hydrochloric acid, washed until pH=6.8, dried and passed through a 100-mesh sieve.

[0027] (2) Al 3+ Preparation of ion-exchange modified montmorillonite: Take 10g of montmorillonite, add 100mL of 1mol / L AlCl3 solution, and stir in a water bath at 80℃ for 3h; Wash until Cl-free - Dry and pass through a 200-mesh sieve.

[0028] (3) Preparation of soil contamination solidification materials: S1, KOH activated biochar 40g and Al 3+ 20g of modified montmorillonite was dry-mixed at 300r / min for 5min to obtain mixed powder A; S2, slag, fly ash, and desulfurized gypsum are crushed to <5mm and dried to a moisture content of <1%; S3. Mix powder A with other components at 400 r / min for 8 min to obtain mixed powder B; S4, ball milling at 800 r / min for 30 min, specific surface area 700 m² 2 / kg; The cured material is obtained by steam curing at 50℃ and 90% humidity for 18 hours.

[0029] Example 3. The components of the soil contamination solidification material in this embodiment: Granulated blast furnace slag 400g, fly ash 250g, desulfurized gypsum 200g, carbide slag 80g, anhydrous sodium silicate 50g, sodium hydroxide 40g, La2O3 10g, micro-expansion agent 50g (including anhydrous calcium sulfoaluminate 33.3g and gypsum 16.7g), KOH activated biochar 20g, Al 3+ 10g of ion-exchange modified montmorillonite and 10g of polyvinyl alcohol.

[0030] The specific preparation process is as follows: (1) KOH activated biochar: Activate 10g of biochar with 30g of KOH at 600℃ for 1 hour, then wash until pH=6.2.

[0031] (2) Al 3+ Modified montmorillonite: Add 10g of montmorillonite to 100mL of 0.5mol / L AlCl3 solution, stir at 60℃ for 3h, wash and dry.

[0032] (3) Preparation of curing materials: S1. Dry mix 20g of biochar with 10g of montmorillonite for 3 minutes; S2, slag, etc. are crushed and dried; S3, dry mix with other components for 5 minutes; S4, ball milling at 600 r / min for 40 min, specific surface area 650 m² 2 / kg; S5, 40℃, 95% humidity, curing for 24 hours.

[0033] Comparative example. Traditional cement-based curing agents: 100g of 42.5 grade ordinary Portland cement.

[0034] Example of an effect 1. Take 100g of the soil contamination solidification material from Example 1, mix it with 1000g of high silica-alumina contaminated soil, add water to adjust the moisture content to 22%, compact it into Φ50mm×50mm specimens, and cure it naturally for 7 days; cut a 3mm×3mm×3mm small piece from the inside of the cured solidified body, soak it in anhydrous ethanol for 24h to stop the hydration reaction, and finally freeze-dry it under vacuum to retain the structure of the hydration products.

[0035] The processed sample was observed using a scanning electron microscope, and the results were as follows: Figure 2 The scanning electron microscope (SEM) images shown are as follows. Under low magnification, the hydration products exhibit a dense, interwoven structure of flocculent and needle-like crystals. Numerous flocculent CSH gels uniformly fill the interparticle gaps, while needle-like ettringite crystals are also distributed. This indicates that the activity of the slag and fly ash is fully activated, and the cementation system achieves efficient hydration, laying the foundation for improved strength and denser structure of the solidified body. Under magnification, clustered needle-like ettringite crystals can be clearly observed, interspersed within the CSH gel network. These needle-like crystals are products of micro-expansion agent hydration, effectively filling the micropores of the solidified body; combined with the bridging effect of polyvinyl alcohol, they not only refine the pore structure but also enhance the overall structural integrity. This ensures strength while blocking pollutant migration pathways through capillary effects. Under high magnification, the interfacial fusion morphology of CSH gel and KOH-activated biochar is revealed: dense flocculent CSH gel encapsulates the porous structure of biochar, preserving the micropores of the biochar while enhancing structural stability through gel encapsulation. Simultaneously, Al... 3+ The interlayer retention effect of ion-exchange modified montmorillonite and the adsorption effect of biochar work synergistically here. Pollutants are fixed in the micropores, and the densification of the cementitious products further blocks their migration pathways, theoretically significantly reducing the leaching rate of heavy metal ions.

[0036] Example of effect 2. Take 100g of the soil contamination solidification material from Example 1 and mix it with 1000g of high-silicon-alumina contaminated soil (SiO2=55%, Al2O3=20%, Pb=10%). 2+ Mix (500 mg / kg), add water to adjust the moisture content to 22%, compact into Φ50 mm × 50 mm specimens, and cure naturally (20 ± 2℃, humidity 60 ± 5%) for 7 days and 28 days, with 3 parallel samples in each group.

[0037] Take 100g of the curing material from Example 2 and mix it with 800g of high-silicon-aluminum contaminated soil (SiO2=58%, Al2O3=18%, Cd). 2+ Mix (300 mg / kg) and adjust to a moisture content of 25%, compact into specimens of the same specifications, and cure under the same conditions.

[0038] Take 100g of the curing material from Example 3 and mix it with 1200g of high-silicon-aluminum contaminated soil (SiO2=52%, Al2O3=23%, Pb). 2+ +Cd 2+ Mix (800 mg / kg) and adjust to a moisture content of 20%, compact into specimens of the same specifications, and cure under the same conditions.

[0039] Take 100g of 42.5 grade ordinary Portland cement (comparative example) and mix it with 1000g of soil used in Example 1. Adjust the moisture content to 22%, compact it into specimens of the same specifications, and cure them under the same conditions.

[0040] (I) 7-day / 28-day unconfined compressive strength test: The specimens with the corresponding curing days were placed in a pressure testing machine, and the failure load was measured at a loading rate of 1 mm / min. The compressive strength was calculated, and the average value of 3 parallel samples was taken.

[0041] (II) Test for total leaching concentration of heavy metals: The solidified body was crushed to a particle size of <5 mm. 10 g of sample was weighed and added to 100 mL of deionized water. The mixture was shaken at 25 °C and 150 r / min for 8 h. After filtration, the concentration of heavy metals in the leachate was detected by ICP-MS (Agilent 7900). The average value of three parallel tests was taken.

[0042] (III) Porosity and Micropore Ratio Testing: Mercury porosimetry was used to determine the porosity. A small piece of the freeze-dried solidified body was placed in a sample tube, and mercury was injected after vacuuming. The total porosity was calculated by measuring the pressure change: Total Porosity = (Total Pore Volume / Total Specimen Volume) × 100%. The micropore percentage was calculated as: (Volume of pores < 5 μm / Total Pore Volume) × 100%.

[0043] The test results are shown in Table 1.

[0044] Table 1

[0045] The test results show that the solidification materials of Examples 1-3 exhibit significant advantages in high silica-alumina contaminated soil: the compressive strength at 7 days and 28 days is 2.5-2.8 times and 1.8-1.9 times that of the comparative examples, respectively; the heavy metal leaching concentration is only 1 / 7 to 1 / 9 of that of the comparative examples; the total porosity is lower and the proportion of micropores is higher. The above test results demonstrate the technical advantages of this invention in terms of strength improvement, pollutant fixation, and structural optimization.

[0046] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A soil contamination solidification material, characterized in that, The components include the following parts by mass: Granulated blast furnace slag 40-50 parts, fly ash 20-25 parts, desulfurized gypsum 15-20 parts, carbide slag 5-8 parts, anhydrous sodium silicate 3-5 parts, sodium hydroxide 2-4 parts, nano rare earth oxides 0.5-1 parts, micro-expansion agent 3-5 parts, KOH activated biochar 2-4 parts, Al 3+ 1-2 parts of ion-exchange modified montmorillonite, 0.5-1 part of polyvinyl alcohol; The micro-expansion agent is a compound of anhydrous calcium sulfoaluminate and gypsum.

2. The soil contamination solidification material according to claim 1, characterized in that, The nano-rare earth oxides are selected from La2O3 or CeO2.

3. The soil contamination solidification material according to claim 1, characterized in that, The ratio of anhydrous calcium sulfoaluminate to gypsum is 1:0.5~2.

4. The soil contamination solidification material according to claim 1, characterized in that, The KOH-activated biochar was obtained through the following steps: The biochar after removing impurities was dried at 105°C until the moisture content dropped to <1%; The dried biochar was mixed with KOH at a mass ratio of 1:3, and after adding deionized water and stirring to dissolve, it was evaporated and dried at 80°C. Subsequently, it was activated at a high temperature of 600-800℃ for 1-2 hours under a nitrogen atmosphere; After neutralization with hydrochloric acid, the biochar was washed with deionized water until the pH reached 6-7, dried, and passed through a 100-mesh sieve to obtain KOH-activated biochar.

5. The soil contamination solidification material according to claim 1, characterized in that, The Al 3+ Ion-exchange modified montmorillonite is obtained through the following steps: Montmorillonite was added to a 0.5–1 mol / L AlCl3 solution at a ratio of 1 g: 10 mL, and stirred in a constant temperature water bath at 60–80 °C to allow the Na+ between the montmorillonite layers to react. + Ca 2+ With Al in solution 3+ An exchange occurs; After the reaction was complete, the precipitate was allowed to stand and the supernatant was discarded. The precipitate was repeatedly washed with deionized water, dried, ground, and passed through a 200-mesh sieve to obtain Al. 3+ Ion-exchange modified montmorillonite.

6. The soil contamination solidification material according to claim 1, characterized in that, The specific surface area of ​​the soil contamination solidification material is 650~700 m². 2 / kg.

7. A method for preparing a soil contamination solidification material as described in any one of claims 1 to 6, characterized in that, Includes the following steps: S1, Activated biochar and Al 3+ Ion-exchange modified montmorillonite was added to a mixer and dry-mixed to obtain mixed powder A; S2. Crush and dry granulated blast furnace slag, fly ash, and desulfurized gypsum. S3. The mixed powder A is dry-mixed with granulated blast furnace slag, fly ash, desulfurized gypsum, carbide slag, anhydrous sodium silicate, sodium hydroxide, nano rare earth oxides, micro-expansion agent and polyvinyl alcohol to obtain mixed powder B. S4. Ball mill the mixed powder B to a specific surface area of ​​650~700m². 2 / kg; S5. Steam curing produces soil contamination solidification materials.

8. The method for preparing soil contamination solidification material according to claim 7, characterized in that, The crushing process in step S2 is to crush the particles to a size of <5mm; the drying process is to dry the particles to a moisture content of <1%.

9. The method for preparing soil contamination solidification material according to claim 7, characterized in that, The steam curing conditions are 40~50℃ and humidity ≥90%, and the steam curing time is 12~24h.

10. The application of a soil contamination solidification agent as described in any one of claims 1 to 6, characterized in that, It is applied to the solidification of high-silica and high-alumina soil, wherein the content of SiO2+Al2O3 in the high-silica and high-alumina soil is >65%.

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