CN111286341A - A kind of curing strengthening agent and its preparation method and application - Google Patents

Abstract

The invention discloses a preparation method of a curing strengthening agent, which comprises the following steps: 1) mixing graphite powder and diatomite powder to obtain graphite silicon powder; 2) mixing phosphoric acid and sulfuric acid solution, and stirring evenly to obtain a sulfur-phosphorus mixed acid solution 3) Mix the graphite silicon powder and sulfur-phosphorus mixed acid solution, mix and stir evenly to obtain a silicon-ink mixed acid slurry; 4) Irradiate the mixed acid slurry with low-temperature plasma for 30-60 minutes to obtain a graphene-polysilicon-phosphorus mixed colloid 5) Take γ-mercaptopropyl trimethoxysilane and graphene polysilicon-phosphorus mixed colloid, mix, stir evenly, age for 6 to 12 hours, dry and grind to obtain a curing intensifier. The preparation method of the invention is simple, and the required raw material sources are wide. Adding 5% of the curing intensifier prepared by the invention to the traditional curing material can not only effectively reduce the leaching concentration of heavy metals in the cured body, but also effectively improve the uniaxial compressive strength, acid resistance and thawing resistance of the cured body.

Description

A kind of curing strengthening agent and its preparation method and application

technical field

The invention relates to the field of disposal of heavy metal polluted soil, in particular to a solidification and strengthening agent and a preparation method and application thereof.

Background technique

In my country, with the expansion of industry, the social problems caused by heavy metal soil pollution are prone to emerge. Heavy metal pollution has brought great challenges to the health of local residents. Heavy metals have strong biological activity and can be enriched into the human body through the biological uptake-biological chain transmission pathway. Heavy metals are extremely harmful to human health and it is difficult to excrete them from the human body through biological metabolism. For example, cadmium can accumulate in the internal organs of the human body, leading to osteoporosis and cancer. Hexavalent chromium is a carcinogen and is easily absorbed by multiple organs of the human body, which can seriously induce lung cancer. Mercury can cause irreversible damage to human organs and central nervous system after entering the human body. When lead enters the body, it can cause neurological dysfunction and lead to symptoms such as anemia and kidney damage.

At present, there are three ideas for the treatment of heavy metal-contaminated soils: natural attenuation, isolation and restoration. The solidification stabilization method is considered to be one of the most important methods for remediation of heavy metal-contaminated soils. It has the advantages of convenient operation, economic benefits, and perfect technical specifications. The solidification stabilization technology usually mixes and stirs cement and other cementitious materials with heavy metal contaminated soil to induce a hydration reaction and promote the adsorption and encapsulation of heavy metal pollutants by the hydration products. It is worth noting that the current use of solidification stabilization technology to treat polluted soil containing multiple heavy metals and high content of heavy metals still has the problems of low solidified body strength, high heavy metal leaching rate, and poor acid resistance and thawing resistance of the solidified body. In the industry, materials such as fly ash, blast furnace slag, silica fume, and bentonite are added to cement to provide cement curing properties. However, it is still difficult to effectively dispose of soil contaminated with high concentrations and heavy metals by applying this method, and it is difficult to achieve a significant improvement in multiple indicators.

Therefore, it is necessary to develop a solidification enhancer to replace traditional admixtures for effective solidification treatment of soils contaminated with high concentrations and heavy metals.

SUMMARY OF THE INVENTION

Purpose of the invention: The technical problem to be solved by the present invention is to provide a preparation method of a curing strengthening agent.

The technical problem to be solved by the present invention is to provide a curing strengthening agent and its application.

In order to solve the above-mentioned technical problems, the technical scheme adopted in the present invention is as follows: a preparation method of a curing strengthening agent, comprising the following steps:

1) graphite powder and diatomite powder are mixed to obtain graphite silicon powder;

2) Mix phosphoric acid and sulfuric acid solution, and stir to obtain sulfur-phosphorus mixed acid solution;

3) The graphite silicon powder and the sulfur-phosphorus mixed acid solution are mixed and stirred evenly to obtain a silicon-ink mixed acid slurry;

4) irradiating the silicon-ink mixed acid slurry with low-temperature plasma for 30-60 minutes to obtain a graphene-polysilicon-phosphorus mixed colloid;

5) Take the mixed colloid of γ-mercaptopropyltrimethoxysilane and graphene polysilicon phosphorus, mix, stir evenly, age for 6-12 hours, dry and grind to obtain a curing intensifier.

Wherein, the mass ratio of graphite powder and diatomite powder in the step 1) is 1-3:10.

Wherein, in the step 2) the volume ratio of phosphoric acid and sulfuric acid solution is 1-2:1; the concentration of the sulfuric acid solution is 2-6M.

Wherein, in the step 3) the solid-liquid ratio of graphite silicon powder and sulfur-phosphorus mixed acid liquid is 1:1-2 mg/mL.

Wherein, in the step 4) the low temperature plasma irradiation action voltage is 20-100KV, and the action atmosphere of the low temperature plasma is oxygen.

Wherein, the volume ratio of γ-mercaptopropyltrimethoxysilane and graphene-polysilicon-phosphorus mixed colloid in step 5) is 1-2:10.

The content of the present invention also includes the curing strengthening agent prepared by the preparation method.

The content of the present invention also includes the application of the solidifying and strengthening agent in the treatment of contaminated soil.

Wherein, the polluted soil is heavy metal polluted soil.

Wherein, the heavy metal is one or more of mercury, cadmium or arsenic.

Reaction mechanism: During the low-temperature plasma irradiation of the silicon-ink mixed acid slurry, the high-energy electrons released by the high-voltage electrode collide with the air and water to induce the ionization and dissociation of oxygen and water molecules, and release heat, electromagnetic waves and ultrasonic waves. The released heat is not only conducive to rapidly increasing the temperature of the silica-silica slurry, promoting the hydrolysis and polymerization of some phosphate radicals to generate polyphosphoric acid, but also conducive to the dissolution of graphite powder and the release of silicon in diatomite powder. At the same time, under the action of microwave, phosphoric acid can penetrate into the mineral lattice contained in diatomite, thereby promoting the dissolution of diatomite. The high-energy electron beam interacts with oxygen, water molecules and hydrogen ions to generate oxygen radicals, hydroxide radicals and hydrogen radicals. Oxygen radicals and hydroxide radicals can rapidly oxidize graphite, inducing its transformation to graphene oxide. Silicon released from diatomaceous earth generates polysilicic acid under the action of hydrogen radicals. Under the action of ultrasonic waves, polyphosphoric acid, polysilicic acid, and graphene oxide are fused and cross-linked together to form a mixed colloid. Mixing γ-mercaptopropyl trimethoxysilane and graphene polysilicon-phosphorus mixed colloid, the silicon atoms in γ-mercaptopropyl trimethoxysilane are bonded to polysilicic acid in the form of chemical bonds during the aging process, thereby forming A polysilicon-phosphorus substance mixed with thiol and graphene. During the curing process, heavy metals are first adsorbed on sulfhydryl groups and graphene through complexation, electrostatic adsorption, chemical precipitation, etc. Subsequently, the heavy metals adsorbed on thiol and graphene were gradually encapsulated by polysilicon phosphate colloids. At the same time, the mixed colloid can be filled into the pores of the original cured material, strengthen the structure of the cured body through geopolymerization and hydration reaction, and improve the strength, corrosion resistance and thawing resistance of the cured body.

Beneficial effects: the preparation method of the invention is simple, and the sources of the required raw materials are wide. Adding the curing strengthening agent prepared by the invention to the traditional curing material can not only effectively reduce the leaching concentration of heavy metals in the cured body, but also effectively improve the uniaxial compressive strength, acid resistance and thawing resistance of the cured body.

Description of drawings

Fig. 1 is a flow chart of the processing method of the present invention.

Detailed ways

The embodiments of the present invention will be described in detail below with reference to the examples, but those skilled in the art will understand that the following examples are only used to illustrate the present invention, and should not be regarded as limiting the scope of the present invention. If the specific conditions are not indicated in the examples, it is carried out according to the conventional conditions or the conditions suggested by the manufacturer. The reagents or instruments used without the manufacturer's indication are conventional products that can be obtained from the market.

The graphite powder was purchased from Qingdao Chenyang Graphite Co., Ltd. with a carbon content of 99.9% (code: LC).

The diatomite powder was purchased from Dongguan Senda Diatomite Material Co., Ltd. (model: SD30-04), composed of 91.34% SiO ₂ , 3.75% Al ₂ O ₃ , 2.26% Fe ₂ O ₃ , 1.04% CaO, 0.53% %MgO, 0.47% K ₂ O, 0.38% Na ₂ O, 0.23% organic matter composition.

Phosphoric acid is an analytically pure standard with a content greater than 99%.

The sulfuric acid is concentrated sulfuric acid with a mass fraction of 98.3%, and the sulfuric acid solution in the embodiment is obtained by diluting concentrated sulfuric acid with a corresponding amount of water.

Example 1 Influence of the mass ratio of graphite powder and diatomite powder on the performance of the prepared solidification strengthening agent to strengthen the cement solidified body

According to the mass ratio of graphite powder and diatomite powder 0.5:10, 0.7:10, 0.9:10, 1:10, 2:10, 3:10, 3.1:10, 3.3:10, 3.5:10, the graphite powder was weighed respectively Mix with diatomite powder to obtain nine groups of graphite silicon powder. Measure phosphoric acid and 2M sulfuric acid solution according to the volume ratio of 1:1, mix and stir evenly to obtain a sulfur-phosphorus mixed acid solution. According to the solid-liquid ratio of 1:1 mg/mL, the above-mentioned nine groups of graphite silicon powder and nine groups of sulfur-phosphorus mixed acid solutions were weighed, mixed, and stirred evenly to obtain nine groups of silicon-ink mixed acid slurries. The nine groups of silicon-ink mixed acid slurry mixed slurry were irradiated with low-temperature plasma for 30 minutes to obtain nine groups of graphene-polysilicon-phosphorus mixed colloid. Measure γ-mercaptopropyltrimethoxysilane and graphene polysilicon-phosphorus mixed colloids at a volume ratio of 1:10, mix, stir evenly, age for 6 hours, dry and grind to obtain nine groups of curing intensifiers.

Heavy metal-contaminated soil: The heavy metal-contaminated soil samples used were collected from the soil near an abandoned electroplating plant in Jiangsu. The sampled soil was then air-dried in a cool place for two weeks, and then the soil samples were ground and passed through a 100-mesh sieve for use. In the polluted soil, the mercury content was 202.04 mg/kg, the cadmium content was 338.62 mg/kg, and the arsenic content was 357.82 mg/kg.

Preparation of heavy metal-contaminated soil strengthening solidified body: respectively weigh nine groups of heavy metal-contaminated soils, nine groups of solidifying intensifiers prepared by the present invention, and nine groups of cement according to the mass ratio of 1:0.02:0.98, and mix them respectively to obtain nine groups of solid mixtures, wherein the cement Use the benchmark cement specified in Appendix A of "Concrete Admixtures" GB8076-2008. According to the solid-liquid ratio of 1:0.45mg/mL, water was added to the nine groups of solid mixtures, and the mixture was fully stirred until a fluid slurry was formed. Tap to form, seal the mold with polyethylene film, place it under standard curing conditions (temperature 20±2°C, relative humidity standard is more than 95%) for 1 day, and continue curing under the same conditions to 28 days after demoulding , nine groups of heavy metal-contaminated soil strengthening solidified bodies were obtained.

Uniaxial compressive strength test: The measurement of the compressive strength of the cured body is carried out according to the GB/T 17671-1999 standard of "Cement Mortar Strength Test Method (ISO Method)".

Solidified heavy metal leaching test and leaching concentration detection: The solidified heavy metal leaching test and leaching concentration detection were carried out in accordance with "Solid Waste Leaching Toxicity Leaching Method Acetic Acid Buffer Solution Method" (HJ/T 300-2007).

The test results of this example are shown in Table 1.

Table 1 Influence of the mass ratio of graphite powder and diatomite powder on the performance of the prepared solidification strengthening agent to strengthen the cement solidified body

It can be seen from the results in Table 1 that when the mass ratio of graphite powder and diatomite powder is less than 1:10 (as in Table 1, the mass ratio of graphite powder and diatomite powder = 0.9:10, 0.7:10, 0.5:10, and the 1), the graphene production is reduced, the polyphosphoric acid, polysilicic acid, and graphene oxide are fused with each other, and the cross-linking effect is poor, and the mixed colloid that can be filled into the pores of the original cured material is reduced, resulting in heavy metals The leaching concentration increased significantly with the decrease in the mass ratio of graphite powder and diatomite powder, and the uniaxial compressive strength of the solidified body decreased significantly with the decrease in the mass ratio of graphite powder and diatomite powder; when the mass ratio of graphite powder and diatomite powder decreased Equal to 1~3:10 (as shown in Table 1, when the mass ratio of graphite powder and diatomite powder = 1:10, 2:10, 3:10), the amount of graphite powder, oxygen radicals and hydroxide radicals can be Rapidly oxidize graphite to form graphene oxide. Under the action of ultrasonic waves, polyphosphoric acid, polysilicic acid, and graphene oxide are fused and cross-linked together to form a mixed colloid. During the curing process, heavy metals are first adsorbed on sulfhydryl groups and graphene through complexation, electrostatic adsorption, chemical precipitation, etc. At the same time, the mixed colloid can be filled into the pores of the original cured material, strengthen the structure of the cured body through geopolymerization and hydration reaction, and improve the strength, corrosion resistance and thawing resistance of the cured body. Finally, with the increase of the mass ratio of graphite powder and diatomite powder, the leaching concentration of heavy metals gradually decreased, and the uniaxial compressive strength of the solidified body gradually increased; when the mass ratio of graphite powder and diatomite powder was greater than 3:10 (see Table 1 , when the mass ratio of graphite powder and diatomite powder = 3.1:10, 3.3:10, 3.5:10 and higher values not listed in Table 1), excessive graphite powder, excessive graphene production, polyphosphoric acid, Polysilicic acid and graphene oxide fuse with each other, and the cross-linking effect becomes poor, and the mixed colloid that can be filled into the pores of the original cured material decreases, resulting in a further increase in the mass ratio of graphite powder and diatomite powder, and the leaching concentration of heavy metals gradually increases. Increase, the uniaxial compressive strength of the cured body gradually decreases. Therefore, in general, combining benefits and costs, when the mass ratio of graphite powder and diatomite powder is equal to 1 to 3:10, the prepared curing intensifier is most conducive to strengthening the cement solidified body.

Example 2 Influence of the solid-liquid ratio of graphite silicon powder and sulfur-phosphorus mixed acid on the performance of the prepared solidification strengthening agent to strengthen the cement solidified body

According to the mass ratio of graphite powder and diatomite powder of 3:10, the graphite powder and diatomite powder were respectively weighed and mixed to obtain graphite silicon powder. Measure phosphoric acid and 4M sulfuric acid solution according to the volume ratio of 1.5:1, mix and stir evenly to obtain a sulfur-phosphorus mixed acid solution. According to the solid-liquid ratio 1:0.5mg/mL, 1:0.7mg/mL, 1:0.9mg/mL, 1:1mg/mL, 1:1.5mg/mL, 1:2mg/mL, 1:2.1mg/mL , 1:2.3mg/mL, 1:2.5mg/mL, respectively, weigh graphite silicon powder and sulfur-phosphorus mixed acid solution, mix and stir evenly to obtain nine groups of silicon-ink mixed acid slurry. Nine groups of silicon-ink mixed acid slurries were irradiated with low-temperature plasma for 45 minutes to obtain nine groups of graphene-polysilicon-phosphorus mixed colloids. According to the volume ratio of 1.5:10, γ-mercaptopropyl trimethoxysilane and graphene polysilicon-phosphorus mixed colloids were respectively measured, mixed, stirred evenly, aged for 9 hours, dried and ground to obtain nine groups of curing intensifiers.

The preparation of heavy metal-contaminated soil, the preparation of reinforced solidified body of heavy metal-contaminated soil, the detection of uniaxial compressive strength, the leaching test of solidified heavy metals and the detection of leaching concentration are all the same as in Example 1. The test results of this embodiment are shown in Table 2.

Table 2 The effect of the solid-liquid ratio of graphite silicon powder and sulfur-phosphorus mixed acid on the performance of the prepared solidification strengthening agent to strengthen the cement solidified body

It can be seen from the results in Table 2 that when the solid-liquid ratio of graphite silicon powder and sulfur-phosphorus mixed acid liquid is greater than 1:1 (as shown in Table 2, the solid-liquid ratio of graphite silicon powder and sulfur-phosphorus mixed acid liquid=1:0.9, 1:0.7, 1:0.5 and larger values not listed in Table 2), the sulfur-phosphorus mixed acid solution is less, the dissolved amount of silicon in diatomite is reduced, the production of polyphosphoric acid and polysilicic acid is correspondingly reduced, and polyphosphoric acid, polysilicic acid , Graphene oxide fuses with each other, the cross-linking effect is poor, the generation of mixed colloids is reduced, and the mixed colloids that can be filled into the pores of the original cured material decreases, which eventually leads to the increase of the solid-liquid ratio of graphite silicon powder and sulfur-phosphorus mixed acid. increase, the leaching concentration of heavy metals increases significantly, and the uniaxial compressive strength of the solidified body decreases significantly; when the solid-liquid ratio of graphite silicon powder and sulfur-phosphorus mixed acid liquid is equal to 1:1~2 (as shown in Table 2, graphite silicon powder and sulfur-phosphorus Mixed acid-liquid solid-liquid ratio = 1:1, 1:1.5, 1:2), an appropriate amount of sulfur-phosphorus mixed acid, polyphosphoric acid and polysilicic acid are generated more frequently, and polyphosphoric acid, polysilicic acid, and graphene oxide are fully integrated , cross-linking, the mixed colloid generates enough amount, and the mixed colloid that can be filled into the pores of the original cured material is sufficient. Finally, with the decrease of the solid-liquid ratio of graphite silicon powder and sulfur-phosphorus mixed acid liquid, the leaching concentration of heavy metals gradually decreased, and the uniaxial compressive strength of the solidified body gradually increased; when the solid-liquid ratio of graphite silicon powder and sulfur-phosphorus mixed acid liquid was less than 1:2 (as shown in Table 2, when the solid-liquid ratio of graphite silicon powder and sulfur-phosphorus mixed acid = 1:2.1, 1:2.3, 1:2.5 and the smaller value not listed in Table 2), sulfur-phosphorus mixed acid When the liquid is excessive, the excess hydrogen ions react with the high-energy electron beam to generate excess hydrogen radicals. Excessive hydrogen radicals and hydrogen ions are easily combined with hydroxide radicals and oxygen radicals, thereby reducing the output of graphene oxide, and making the residual hydrogen ions in the generated strengthening agent too much, which is not conducive to the water in the curing process. As a result of the further reduction of the solid-liquid ratio of graphite silicon powder and sulfur-phosphorus mixed acid, the leaching concentration of heavy metals increases significantly, and the uniaxial compressive strength of the solidified body decreases significantly. Therefore, in general, combined with benefit and cost, when the solid-liquid ratio of graphite silicon powder and sulfur-phosphorus mixed acid liquid is equal to 1:1-2, the prepared curing intensifier is most conducive to strengthening the cement solidified body.

Example 3 The effect of low temperature plasma action voltage on the performance of the prepared solidifying agent to strengthen the cement solidified body

According to the mass ratio of graphite powder and diatomite powder of 3:10, the graphite powder and diatomite powder were respectively weighed and mixed to obtain graphite silicon powder. Measure phosphoric acid and 6M sulfuric acid solution according to the volume ratio of 2:1, mix, and stir evenly to obtain a sulfur-phosphorus mixed acid solution. According to the solid-liquid ratio of 1:2 mg/mL, the graphite silicon powder and the sulfur-phosphorus mixed acid solution were respectively weighed, mixed, and stirred evenly to obtain the silicon-ink mixed acid slurry. The nine groups of silicon-ink mixed acid slurries were respectively irradiated with low-temperature plasma for 60 minutes to obtain graphene-polysilicon-phosphorus mixed colloids, wherein the low-temperature plasma irradiation voltages of the nine groups of silicon-ink mixed acid slurries were 5KV, 10KV, 15KV, and 20KV, respectively. , 60KV, 100KV, 105KV, 110KV, 115KV, the low-temperature plasma's action atmosphere is oxygen. Measure nine groups of γ-mercaptopropyltrimethoxysilane and nine groups of graphene-polysilicon-phosphorus mixed colloids in a volume ratio of 2:10, mix, stir evenly, age for 12 hours, dry and grind to obtain nine groups of cured Enhancer.

The preparation of heavy metal-contaminated soil, the preparation of reinforced solidified body of heavy metal-contaminated soil, the detection of uniaxial compressive strength, the leaching test of solidified heavy metals and the detection of leaching concentration are all the same as in Example 1. The test results of this embodiment are shown in Table 3.

Table 3 Influence of low temperature plasma action voltage on the performance of the prepared solidifying agent to strengthen the cement solidified body

It can be seen from the results in Table 3 that when the low-temperature plasma action voltage is lower than 20KV (as in Table 3, the low-temperature plasma action voltage=15KV, 10KV, 5KV and the smaller values not listed in Table 3), the high energy released by the high-voltage electrode The electron energy is low, the high-energy electrons have low impact on air and water, and the generation of graphene oxide and polyphosphoric acid is reduced, which eventually leads to a significant increase in the leaching concentration of heavy metals with the reduction of the low-temperature plasma voltage, and the uniaxial compression resistance of the cured body. The intensity is significantly reduced; when the low-temperature plasma action voltage is equal to 20-100KV (as shown in Table 3, when the low-temperature plasma action voltage = 20KV, 60KV, 100KV), the high-energy electrons released by the high-voltage electrode collide with the air and water to induce ionization of oxygen and water molecules , dissociate and release heat, electromagnetic waves and ultrasonic waves. The released heat is not only conducive to rapidly increasing the temperature of the silica-silica slurry, promoting the hydrolysis and polymerization of some phosphate radicals to generate polyphosphoric acid, but also conducive to the dissolution of graphite powder and the release of silicon in diatomite powder. At the same time, under the action of microwave, phosphoric acid can penetrate into the mineral lattice contained in diatomite, thereby promoting the dissolution of diatomite. The high-energy electron beam interacts with oxygen, water molecules and hydrogen ions to generate oxygen radicals, hydroxide radicals and hydrogen radicals. Oxygen radicals and hydroxide radicals can rapidly oxidize graphite, inducing its transformation to graphene oxide. Finally, with the increase of the low temperature plasma voltage, the leaching concentration of heavy metals gradually decreased, and the uniaxial compressive strength of the cured body gradually increased; when the low temperature plasma voltage was higher than 100KV (as shown in Table 3, the low temperature plasma voltage = 105KV, 110KV, 115KV and the larger values not listed in Table 3), the low-temperature plasma action voltage is too high, and the high-energy electrons collide with air and water to generate excess oxygen radicals and hydroxide radicals, thus making the mixed colloid. Inactivation eventually leads to the further increase of the low-temperature plasma action voltage, the leaching concentration of heavy metals does not decrease but increases, and the uniaxial compressive strength of the solidified body does not increase but decreases. Therefore, in general, combined with benefits and costs, when the low-temperature plasma action voltage is equal to 20-100KV, the prepared curing intensifier is most conducive to strengthening the cement solidified body.

Comparative Example 1 Comparison of uniaxial compressive strength and heavy metal leaching performance between reinforced solidified body and cement solidified body

The preparation of the curing strengthening agent of the present invention: according to the mass ratio of the graphite powder and the diatomite powder of 3:10, the graphite powder and the diatomite powder are respectively weighed and mixed to obtain the graphite silicon powder. Measure phosphoric acid and 6M sulfuric acid solution according to the volume ratio of 2:1, mix, and stir evenly to obtain a sulfur-phosphorus mixed acid solution. According to the solid-liquid ratio of 1:2 mg/mL, the graphite silicon powder and the sulfur-phosphorus mixed acid solution were respectively weighed, mixed, and stirred evenly to obtain the silicon-ink mixed acid slurry. The mixed acid slurry is irradiated with low-temperature plasma for 60 minutes to obtain graphene-polysilicon-phosphorus mixed colloid. Measure γ-mercaptopropyl trimethoxysilane and graphene polysilicon-phosphorus mixed colloid according to the volume ratio of 2:10, mix, stir evenly, age for 12 hours, dry and grind to obtain a curing intensifier.

The preparation of heavy metal contaminated soil is the same as in Example 1.

Preparation of cement solidified body of heavy metal polluted soil: Weigh heavy metal polluted soil and cement according to the mass ratio of 1:1, respectively, and mix them to obtain a solid mixture, wherein the cement adopts the benchmark cement specified in Appendix A of "Concrete Admixtures" GB8076-2008. Add water to the solid mixture according to the solid-liquid ratio of 1:0.45mg/mL, stir well to form a fluid slurry, pour the slurry into a 20mm×20mm×20mm tempered mold, and tap it on a vibrating table. , seal the mold with polyethylene film, place it under standard curing conditions (temperature 20 ± 2 °C, relative humidity standard is more than 95%) for 1 day, and continue curing under the same conditions to 28 days after demoulding, get heavy metals Contaminated soil cement solidified body.

The preparation of the reinforced solidified body of heavy metal polluted soil, the detection of uniaxial compressive strength, the leaching test of solidified heavy metals and the detection of leaching concentration are all the same as in Example 1. The test results of this comparative example are shown in Table 4.

Table 4 Comparison of uniaxial compressive strength and heavy metal leaching performance between reinforced solidified body and cement solidified body

It can be seen from the results in Table 4 that the uniaxial compressive strength of the reinforced solidified body is significantly higher than that of the cement solidified body, and the leaching concentration of heavy metals in the reinforced solidified body is significantly lower than that of the cement solidified body.

Comparative example 2 Comparison of compressive strength and corrosion resistance coefficient of reinforced solidified body and cement solidified body and total mass performance of spalling per unit surface area of test piece

The preparation of the curing strengthening agent of the present invention is the same as that of Comparative Example 1.

The preparation of heavy metal-contaminated soil and the reinforced solidified body of heavy metal-contaminated soil are the same as those in Example 1.

The preparation of cement solidified body of heavy metal contaminated soil is the same as that of Comparative Example 1.

Sulfate corrosion resistance test and compressive strength corrosion resistance coefficient (%) calculation: sulfate corrosion resistance test and compressive strength corrosion resistance coefficient (%) calculation are in accordance with the "standard for long-term performance and durability of ordinary concrete test method" (GBT50082- 2009) implementation.

Freeze-thaw resistance test and specimen mass loss rate calculation: Freeze-thaw resistance test and specimen mass loss rate calculation are carried out in accordance with the "Standard for Long-term Performance and Durability Test of Ordinary Concrete" (GBT 50082-2009).

The test results of this comparative example are shown in Table 5.

Table 5 Comparison of compressive strength and corrosion resistance coefficient and mass loss rate of specimens between reinforced solidified body and cement solidified body

It can be seen from the results in Table 5 that the compressive strength and corrosion resistance coefficient of the reinforced solidified body is significantly higher than that of the cement solidified body, and the mass loss rate of the reinforced solidified body is significantly lower than that of the cement solidified body.

Claims (10)

1. a preparation method of a curing fortifier, is characterized in that, comprises the following steps: 1) Mix graphite powder and diatomite powder to obtain graphite silicon powder; 2) Mix phosphoric acid and sulfuric acid solution, stir evenly to obtain sulfur-phosphorus mixed acid solution; 3) Mix graphite silicon powder and sulfur-phosphorus mixed acid solution, mix and stir evenly to obtain silicon-ink mixed acid slurry; 4) Irradiate the silicon-ink mixed acid slurry with low-temperature plasma for 30-60 minutes to obtain a graphene-polysilicon-phosphorus mixed colloid; 5) Take the mixed colloid of γ-mercaptopropyl trimethoxysilane and graphene polysilicon phosphorus, mix, stir evenly, age for 6 to 12 hours, dry and grind to obtain a curing intensifier. 2 . The preparation method of a solidification strengthening agent according to claim 1 , wherein the mass ratio of the graphite powder and the diatomite powder in the step 1) is 1 to 3:10. 3 . 3 . The preparation method of a curing strengthening agent according to claim 1 , wherein the volume ratio of phosphoric acid and sulfuric acid solution in the step 2) is 1 to 2:1. 4 . 4 . The preparation method of a solidification strengthening agent according to claim 1 , wherein the solid-liquid ratio of the graphite silicon powder and the sulfur-phosphorus mixed acid liquid in the step 3) is 1:1-2 mg/mL. 5 . 5 . The preparation method of a curing intensifier according to claim 1 , wherein the low-temperature plasma irradiation action voltage in the step 4) is 20-100 KV, and the action atmosphere of the low-temperature plasma is oxygen. 6 . 6. The preparation method of a curing intensifier according to claim 1, wherein the volume ratio of the γ-mercaptopropyltrimethoxysilane and the graphene-polysilicon-phosphorus mixed colloid in the step 5) is 1~ 2:10. 7. The curing intensifier obtained by the preparation method of claims 1 to 6. 8. The application of the solidification strengthening agent of claim 7 in the treatment of contaminated soil. 9. The application according to claim 8, wherein the polluted soil is heavy metal polluted soil. 10. The application according to claim 9, wherein the heavy metal is one or more of mercury, cadmium or arsenic.

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