Quaternary ammonium salt grafted porous calcined clay and method of making and use thereof

Abstract

A kind of quaternary ammonium salt grafted porous baking-free ceramsite and its preparation method and application.The method comprises the following steps: mixing bentonite, natural zeolite powder, fly ash and biomass ash by mass percentage; part of porous baking-free ceramsite raw material mixed powder is moved to a granulator for stirring to obtain spherical particles; water and curing agent are mixed and then sprayed into the granulator at a constant speed by high-pressure sprinkler, during which the remaining porous baking-free ceramsite raw material mixed powder is continuously added into the granulator until the diameter of the spherical particles in the granulator is 8-12 mm; the spherical particles are moved to a standard curing box for curing; the porous baking-free ceramsite matrix is subjected to amination treatment; the aminated porous baking-free ceramsite matrix is used as a carrier to graft quaternary ammonium salt bactericide on the inner pore surface to obtain quaternary ammonium salt grafted porous baking-free ceramsite.The present disclosure introduces quaternary ammonium salt bactericide groups into the activated porous baking-free ceramsite to solve the problem of residual toxicity of conventional bactericide carriers.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to the technical field of lightweight building materials, and more particularly to a kind of quaternary ammonium salt grafted porous baking-free ceramsite and its preparation method and application. BACKGROUND

[0002] Compared with traditional ceramsite, baking-free ceramsite has the following advantages: first, the production process does not need high-temperature sintering, energy consumption is reduced by 30%-50%, which is more energy-saving and environmentally friendly; second, industrial waste residues (such as fly ash and slag) are used as main raw materials, and the utilization rate of solid waste can reach more than 80%, which meets the requirements of circular economy; third, the physical properties are excellent, the adjustable range of bulk density (300-900 kg / m³) and cylinder compressive strength (1.5-6.5 MPa) is wider, and the water absorption rate (5%-15%) is lower than that of traditional ceramsite; fourth, there is no waste gas emission of sulfur dioxide, nitrogen oxides and other waste gases in the production process, and the carbon emission is reduced by more than 60%. These characteristics make the application of baking-free ceramsite in the field of lightweight concrete and wastewater treatment more sustainable.

[0003] Pathogens, ammonia nitrogen inorganic salts and other harmful substances in wastewater can cause great harm to the human body and the environment. Currently, there are studies on the use of ceramsite in the field of wastewater treatment. First, the porous characteristics of ceramsite can be used as water treatment filter material to adsorb and remove particulate matter and pathogens in wastewater through physical filtration. This can only achieve preliminary filtration. In addition, ceramsite can be used to load bactericides, including chlorine, chlorine dioxide, silver and copper ions, etc. By releasing bactericides in wastewater, the biological membrane of microorganisms can be destroyed to achieve bacteriostatic function. However, the release of these bactericides into the environment will cause environmental pollution problems, and they have the disadvantages of poor repeated practicality, poor stability and durability, and easy separation from the carrier. SUMMARY

[0004] Therefore, the present disclosure provides a kind of quaternary ammonium salt grafted porous baking-free ceramsite and its preparation method and application to solve the problem of residual toxicity of conventional bacteriostatic carrier and non-reusable bacteriostatic ceramsite.

[0005] According to one aspect of the present disclosure, a method for preparing a quaternary ammonium salt grafted porous baking-free ceramsite is provided, comprising:

[0006] S1: weigh the raw materials according to the following mass percentage: bentonite 15%-32%, natural zeolite powder 10%-15%, fly ash 15%-19%, biomass ash 10%-12%, curing agent 8%-10%, and the balance is water;

[0007] S2: mix bentonite, natural zeolite powder, fly ash and biomass ash to obtain a porous baking-free ceramsite raw material mixture powder;

[0008] S3: Move the partial porous unburned ceramsite raw material mixed powder to the granulator for stirring to obtain spherical particles;

[0009] S4: After mixing the water and the curing agent, spray them into the granulator at a constant speed through a high-pressure watering can. During this process, continuously add the remaining porous unburned ceramsite raw material mixed powder into the granulator until the diameter of the spherical particles in the granulator is 8mm-12mm, and then take them out.

[0010] S5: Move the taken-out spherical particles to a standard curing box for curing to obtain a porous unburned ceramsite matrix.

[0011] S6: Perform an amination treatment on the porous unburned ceramsite matrix to increase bactericide binding sites.

[0012] S7: Use the amination-treated porous unburned ceramsite matrix as a carrier to graft a quaternary ammonium salt bactericide on the inner pore surface to obtain a quaternary ammonium salt grafted porous unburned ceramsite.

[0013] In the above scheme, the particle size of the bentonite, the natural zeolite powder, the fly ash and the biomass ash in step S1 is not less than 200 mesh; the mass percentage content of montmorillonite in the bentonite in step S1 is 85%-90%; the mass percentage content of natural zeolite in the natural zeolite powder in step S1 is more than 50%, and the ammonia absorption value is greater than 100mmol / 100g; the fly ash in step S1 is grade II ash; the biomass ash in step S1 is one of rice husk ash, sugarcane residue ash and corn cob ash, and the silicon content is not less than 75%; and the curing agent in step S1 is solid sodium metaaluminate and solid sodium silicate, and the mass ratio is 3:1-1:2.

[0014] In the above scheme, the stirring in step S3 is performed at a stirring speed of 45-65r / min for 5-10min.

[0015] In the above scheme, the curing in step S5 is to move the spherical particles to a standard curing box for curing for 28 days.

[0016] In the above scheme, the amination treatment on the porous unburned ceramsite matrix in step S6 includes: mixing and cleaning the porous unburned ceramsite matrix with an organic solvent and deionized water to remove impurities on the surface of the ceramsite; soaking the cleaned porous unburned ceramsite matrix in a toluene solution of aminosilane for water bath reaction; washing the unreacted aminosilane on the surface and in the pores of the porous unburned ceramsite matrix with an ethanol solution, and drying it for standby use.

[0017] The organic solvent is one of ethanol or acetone; the amino silane is one of 3-aminopropyl triethoxysilane (APTES) or 3-aminopropyl trimethoxysilane (APTMS) with a mass percentage concentration of 1-5%; and the water bath reaction is performed in a 40℃ water bath for 8-12 hours.

[0018] In the above scheme, the step S7 includes: dissolving the quaternary ammonium salt in an ethanol solution to obtain a quaternary ammonium salt reaction solution; mixing the porous calcined clay aggregate substrate after the amination treatment and the quaternary ammonium salt reaction solution according to a weight ratio of 1:0.6-1.5 to perform a water bath reaction; and cleaning with anhydrous ethanol solution to remove unreacted quaternary ammonium salt and by-products, and drying to obtain the porous calcined clay aggregate grafted with the quaternary ammonium salt.

[0019] In the above scheme, the quaternary ammonium salt is one of an epoxy group quaternary ammonium salt and a halogenated alkyl quaternary ammonium salt, and the mass percentage concentration of the quaternary ammonium salt in the quaternary ammonium salt reaction solution is 1-10%; the water bath reaction is performed in a 40℃ water bath for 12-24 hours, and the pH value of the reaction environment is controlled to be 7-10; and the drying is performed at 55℃ for 0.5-1 hour.

[0020] According to another aspect of the present disclosure, there is provided a porous calcined clay aggregate grafted with a quaternary ammonium salt prepared by the method.

[0021] According to still another aspect of the present disclosure, there is provided an application of the porous calcined clay aggregate grafted with a quaternary ammonium salt prepared by the method in the fields of environmental protection filter material, sewage treatment or transportation.

[0022] The porous calcined clay aggregate grafted with a quaternary ammonium salt provided by the present disclosure and the preparation method and application thereof have the following beneficial effects compared with the prior art:

[0023] (1) The porous calcined clay aggregate grafted with a quaternary ammonium salt and the preparation method thereof provided by the present disclosure introduce the quaternary ammonium salt sterilization group into the porous calcined clay aggregate after activation treatment, and the antibacterial mode is contact sterilization rather than slow-release sterilization, which solves the problem of residual toxicity of conventional sterilization carriers and at the same time endows the sterilization clay aggregate with reusability.

[0024] (2) The porous calcined clay aggregate grafted with a quaternary ammonium salt and the preparation method thereof provided by the present disclosure use the porous calcined clay aggregate substrate as a carrier and graft the quaternary ammonium salt sterilization agent on the inner pore surface, and since the sterilization groups are concentrated on the inner pore surface of the clay aggregate, a high-concentration sterilization and disinfection area is formed, the sterilization efficiency is high, secondary pollution of water bodies is avoided, the safety is strong, and the sterilization groups can be reused (not released, but fully utilized by contacting with bacteria).

[0025] (3) The quaternary ammonium salt grafted porous unfired ceramic provided by the present disclosure and the preparation method thereof, the bentonite, the natural zeolite powder and the biomass ash are all natural light porous materials, which play a role in adsorbing organic matter, ammonia nitrogen inorganic salt and the like in sewage treatment, and under the action of a curing agent, a hydration reaction occurs to form porous ceramic with certain strength, under high porosity and high specific surface area, the bactericide can be enriched in the internal pores and the surface of the ceramic, the surface morphology of the carrier is changed to enhance the bactericidal efficiency, and the bactericidal efficiency for anaerobic bacteria is more than 90%.

[0026] (4) The quaternary ammonium salt grafted porous unfired ceramic provided by the present disclosure and the preparation method thereof, the bentonite, the natural zeolite powder and the biomass ash are all natural light porous materials, which play a role in adsorbing organic matter, ammonia nitrogen inorganic salt and the like in sewage treatment, and under the action of a curing agent, a hydration reaction occurs to form porous ceramic with certain strength, under high porosity and high specific surface area, the bactericide can be enriched in the internal pores and the surface of the ceramic, the surface morphology of the carrier is changed to enhance the bactericidal efficiency, and the bactericidal efficiency for anaerobic bacteria is more than 90%.

[0027] (5) The quaternary ammonium salt grafted porous unfired ceramic provided by the present disclosure and the preparation method thereof, before the introduction of the quaternary ammonium salt bactericide group into the porous unfired ceramic, the unfired ceramic is first soaked in an amino silane toluene solution to aminoize the internal pores and the surface of the porous ceramic, and a quaternary ammonium salt bactericide containing a reactive group (such as an epoxy group, a halogenated alkyl group and the like) is selected to facilitate the reaction with the amino group, so that the quaternary ammonium group is covalently combined in the ceramic, the bactericide group in the ceramic is more stable, is insoluble in water and organic solvents, and bacteria are inhibited or killed through direct contact with the bactericide group. It has reusability and good environmental stability. BRIEF DESCRIPTION OF DRAWINGS

[0028] The above content of the present disclosure and other purposes, features and advantages will be more apparent through the following description of the embodiments of the present disclosure with reference to the accompanying drawings, in which:

[0029] Figure 1 A flow chart of a method for preparing the quaternary ammonium salt grafted porous unfired ceramic according to the embodiments of the present disclosure is shown. DETAILED DESCRIPTION

[0030] Hereinafter, the embodiments of the present disclosure will be described with reference to the accompanying drawings. However, it should be understood that these descriptions are merely exemplary and are not intended to limit the scope of the present disclosure. In the following detailed description, many specific details are set forth in order to provide a thorough understanding of the embodiments of the present disclosure. However, it is apparent that one or more embodiments can be implemented without these specific details. Furthermore, in the following description, descriptions of well-known structures and techniques are omitted to avoid unnecessarily obscuring the concept of the present disclosure.

[0031] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the disclosure. As used herein, the terms "comprises", "comprising", "includes", "including" and the like are specifically intended to be open-ended and to mean that other features, steps, operations, and / or components can be added.

[0032] All terms used herein, including technical and scientific terms, have the meanings commonly understood by one of ordinary skill in the art unless otherwise defined herein. It should be noted that the terms used herein are defined as having meanings that are consistent with the context of the specification in which the terms are used and should not be interpreted in an idealized or overly formal way.

[0033] To solve the problem of residual toxicity of conventional sterilization carriers and the non-reusability of sterilization ceramic, the disclosure utilizes the adsorption properties of natural porous materials (bentonite, zeolite powder), the active silicon source in fly ash and biomass ash, and under the action of a curing agent (which produces more hydroxyl groups in the ceramic) and water, to first prepare a non-fired ceramic. The prepared ceramic is soaked in aminosilane for amination (hydroxyl groups as the main reaction site). The next step is to graft a quaternary ammonium salt group in the non-fired ceramic (amino groups as the main reaction site at this time).

[0034] As shown in Figure 1 , Figure 1 A flow chart of a method for preparing a quaternary ammonium salt grafted porous non-fired ceramic according to an embodiment of the disclosure is shown, which comprises the following steps:

[0035] S1: Weigh the raw materials according to the following mass percentages: bentonite 15%-32%, natural zeolite powder 10%-15%, fly ash 15%-19%, biomass ash 10%-12%, curing agent 8%-10%, and the balance is water;

[0036] In this step, the particle size of the bentonite, natural zeolite powder, fly ash, and biomass ash is not less than 200 mesh;

[0037] The mass percentage content of montmorillonite in the bentonite is 85%-90%;

[0038] The mass percentage content of natural zeolite in the natural zeolite powder is more than 50%, and the ammonia absorption value is greater than 100 mmol / 100g;

[0039] The fly ash is grade II ash;

[0040] The biomass ash is one of rice husk ash, sugarcane residue ash, and corn cob ash, and the silicon content is not less than 75%;

[0041] The curing agent is solid sodium metaaluminate and solid sodium silicate, with a mass ratio of 3:1-1:2.

[0042] S2: mixing bentonite, natural zeolite powder, fly ash and biomass ash to obtain a porous baking-free ceramsite raw material mixed powder.

[0043] S3: stirring part of the porous baking-free ceramsite raw material mixed powder in a granulator to obtain spherical particles;

[0044] In this step, the stirring is performed at a rotation speed of 45-65 r / min for 5-10 min.

[0045] S4: uniformly spraying water and a curing agent into the granulator through a high-pressure watering can, and continuously adding the remaining porous baking-free ceramsite raw material mixed powder into the granulator during this period until the diameter of the spherical particles in the granulator is 8-12 mm, and then taking out the spherical particles.

[0046] S5: moving the taken-out spherical particles to a standard curing box for curing to obtain a porous baking-free ceramsite matrix.

[0047] In this step, the curing is performed by moving the spherical particles to the standard curing box for 28 days.

[0048] S6: performing aminization treatment on the porous baking-free ceramsite matrix to increase bactericide binding sites.

[0049] In this step, the aminization treatment on the porous baking-free ceramsite matrix comprises:

[0050] S61: mixing and cleaning the porous baking-free ceramsite matrix with an organic solvent and deionized water to remove impurities on the surface of the ceramsite; optionally, the organic solvent is one of ethanol or acetone.

[0051] S62: immersing the cleaned porous baking-free ceramsite matrix in a toluene solution of aminosilane for water bath reaction; optionally, the aminosilane is one of 3-aminopropyl triethoxysilane (APTES) or 3-aminopropyl trimethoxysilane (APTMS) with a mass percentage concentration of 1%-5%; the water bath reaction is performed in a 40℃ water bath kettle for 8-12 hours.

[0052] S63: washing the unreacted aminosilane on the surface and in the pores of the porous baking-free ceramsite matrix with an ethanol solution, and drying the porous baking-free ceramsite matrix for standby use.

[0053] S7: using the aminization-treated porous baking-free ceramsite matrix as a carrier to graft a quaternary ammonium salt bactericide on the inner pore surface to obtain a quaternary ammonium salt grafted porous baking-free ceramsite, comprising:

[0054] S71: dissolving the quaternary ammonium salt in an ethanol solution to obtain a quaternary ammonium salt reaction solution; optionally, the quaternary ammonium salt is one of an epoxy group quaternary ammonium salt and a haloalkyl quaternary ammonium salt, and the mass percentage concentration of the quaternary ammonium salt in the quaternary ammonium salt reaction solution is 1% to 10%;

[0055] S72: mixing the porous unburned ceramsite matrix after the amination treatment and the quaternary ammonium salt reaction solution according to a weight ratio of 1:0.6-1.5 to perform a water bath reaction; optionally, the water bath reaction is performed in a 40°C water bath for 12 to 24 hours, and the pH value of the reaction environment is controlled to be 7 to 10;

[0056] S73: cleaning with anhydrous ethanol solution to remove unreacted quaternary ammonium salt and byproducts, and drying to obtain the quaternary ammonium salt grafted porous unburned ceramsite; optionally, the drying is performed at 55°C for 0.5 to 1 hour.

[0057] Based on the above Figure 1 The preparation method of the quaternary ammonium salt grafted porous unburned ceramsite provided by the present disclosure is described in detail below in combination with Examples 1-2 and Comparative Example 1.

[0058] Example 1:

[0059] In this example, the bactericidal group is an epoxy group quaternary ammonium salt, and the ceramsite raw materials include the following components: bentonite 18%, natural zeolite powder 12%, fly ash 17%, biomass ash 10%, curing agent 10%, and water 33%. First, the bentonite, natural zeolite powder, fly ash, rice husk ash, and curing agent are mixed to obtain a mixture of unburned ceramsite raw materials.

[0060] The light porous unburned ceramsite is prepared according to the preparation method described above, and its antibacterial performance is characterized by testing its minimum inhibitory concentration in an E. coli solution. The unburned ceramsite is soaked in deionized water, and the stability is characterized by testing the amount of quaternary ammonium groups dissolved out when the unburned ceramsite is soaked in the deionized water solution. The test results are shown in Table 1.

[0061] Example 2:

[0062] In this example, the bactericidal group is a chloroalkyl quaternary ammonium salt, and the ceramsite raw materials include the following components: bentonite 18%, natural zeolite powder 12%, fly ash 17%, biomass ash 10%, curing agent 10%, and water 33%. First, the bentonite, natural zeolite powder, fly ash, rice husk ash, and curing agent are mixed to obtain a mixture of unburned ceramsite raw materials.

[0063] The lightweight porous unfired ceramsite was prepared according to the preparation method in the foregoing, and its antibacterial performance was characterized by testing the minimum inhibitory concentration in an E. coli solution. The unfired ceramsite was soaked in deionized water, and its stability was characterized by testing the amount of quaternary ammonium group dissolved out from the unfired ceramsite soaked in the deionized water solution. The test results are shown in Table 1.

[0064] Comparative Example 1

[0065] In the present comparative example, the bactericidal group is an epoxy quaternary ammonium salt, and the ceramsite raw material comprises the following components: bentonite 18%, natural zeolite powder 12%, fly ash 17%, biomass ash 10%, curing agent 10%, and water 33%. First, the bentonite, natural zeolite powder, fly ash, rice husk ash, and curing agent are mixed to obtain an unfired ceramsite raw material mixed powder;

[0066] The lightweight porous unfired ceramsite was prepared according to the preparation method in the foregoing, but was not subjected to amination, and the remaining steps were the same. Its antibacterial performance was characterized by testing the minimum inhibitory concentration in an E. coli solution. The unfired ceramsite was soaked in deionized water, and its stability was characterized by testing the amount of quaternary ammonium group dissolved out from the unfired ceramsite soaked in the deionized water solution. The test results are shown in Table 1.

[0067]

[0068] Table 1

[0069] As can be seen from the data in Table 1, both Example 1 and Example 2 have a low minimum inhibitory concentration, indicating strong antibacterial performance, and Example 1 exhibits the best antibacterial activity, indicating that the epoxy quaternary ammonium salt has strong bactericidal ability. Comparative Example 1 has poor antibacterial performance and stability, indicating that the unfired ceramsite that has not been subjected to amination mainly combines with the quaternary ammonium salt by physical adsorption, and the chemical bonding is unstable.

[0070] It can be seen that the preparation method of the porous unfired ceramsite grafted with a quaternary ammonium salt provided by the present disclosure introduces a quaternary ammonium salt bactericidal group into the porous unfired ceramsite after activation treatment, and the antibacterial mode is contact sterilization, rather than slow-release sterilization, thereby solving the problem of residual toxicity of conventional bactericidal carriers and simultaneously imparting reusability to the bactericidal ceramsite. The preparation method of the porous unfired ceramsite grafted with a quaternary ammonium salt provided by the present disclosure uses a porous unfired ceramsite matrix as a carrier and grafts a quaternary ammonium salt bactericide on the inner pore surface. Since the bactericidal groups are concentrated on the inner pore surface of the ceramsite, a high-concentration bactericidal and disinfecting region is formed, the bactericidal efficiency is high, secondary pollution of water bodies is avoided, safety is strong, and the bactericidal ceramsite can be reused (rather than releasing bactericidal groups, but fully utilizing the concentrated bactericidal groups in the pores of the ceramsite to contact bacteria).

[0071] Further, based on the preparation method of the porous unsintered ceramic particles grafted with quaternary ammonium salt, the present disclosure also provides the porous unsintered ceramic particles grafted with quaternary ammonium salt prepared by the method, which is sintering-free, energy-saving and environment-friendly, has the characteristics of light weight, high strength, heat preservation and heat insulation, and can be widely used in the fields of light weight concrete, heat preservation block and the like.

[0072] Further, based on the preparation method of the porous unsintered ceramic particles grafted with quaternary ammonium salt, the present disclosure also provides the porous unsintered ceramic particles grafted with quaternary ammonium salt prepared by the method, which is sintering-free, energy-saving and environment-friendly, has the characteristics of light weight, high strength, heat preservation and heat insulation, and can be widely used in the fields of light weight concrete, heat preservation block and the like.

[0073] Those skilled in the art can understand that the features described in various embodiments of the present disclosure can be combined and / or integrated in various combinations, even if such combinations or integrations are not explicitly described in the present disclosure. In particular, the features described in various embodiments of the present disclosure can be combined and / or integrated in various combinations without departing from the spirit and teachings of the present disclosure. All these combinations and / or integrations fall within the scope of the present disclosure.

[0074] The above describes the embodiments of the present disclosure. However, these embodiments are only for illustrative purposes, and are not intended to limit the scope of the present disclosure. Although each embodiment is described above separately, this does not mean that the measures in each embodiment cannot be used advantageously in combination. Those skilled in the art can make various substitutions and modifications without departing from the scope of the present disclosure, and these substitutions and modifications should all fall within the scope of the present disclosure.

Claims

1. A process for the preparation of a porous, unfired, quaternary ammonium salt grafted ceramisite, characterized in that, Comprise: S1: take the raw materials according to the following mass percentage: bentonite 15%~32%, natural zeolite powder 10%~15%, fly ash 15%~19%, biomass ash 10%~12%, curing agent 8%~10%, and the balance is water; S2: the bentonite, natural zeolite powder, fly ash and biomass ash are mixed to obtain a porous unburned ceramsite raw material mixed powder; S3: part of the porous unburned ceramsite raw material mixed powder is moved to the granulator for stirring to obtain spherical particles; S4: the water and the curing agent are mixed and then uniformly sprayed into the granulator by a high-pressure watering can, and during this period, the remaining porous unburned ceramsite raw material mixed powder is continuously added to the granulator until the diameter of the spherical particles in the granulator is 8mm~12mm, and then it is taken out; S5: the spherical particles taken out are moved to a standard curing box for curing to obtain a porous unburned ceramsite matrix; S6: the porous unburned ceramsite matrix is subjected to amination treatment to increase bactericide binding sites; S7: the porous unburned ceramsite matrix after amination treatment is used as a carrier to graft quaternary ammonium salt bactericide on the inner pore surface to obtain quaternary ammonium salt grafted porous unburned ceramsite; In step S6, the amination treatment of the porous unburned ceramsite matrix comprises: mixing and cleaning the porous unburned ceramsite matrix with an organic solvent and deionized water to remove impurities on the surface of the ceramsite; the cleaned porous unburned ceramsite matrix is soaked in a toluene solution of aminosilane for water bath reaction; unreacted aminosilane on the surface and pores of the porous unburned ceramsite matrix is washed away with an ethanol solution, and then dried for standby use; the organic solvent is one of ethanol or acetone; the aminosilane is one of 3-aminopropyl triethoxysilane (APTES) or 3-aminopropyl trimethoxysilane (APTMS), and the mass percentage concentration is 1%-5%; the water bath reaction is carried out in a 40℃ water bath kettle for 8 to 12 hours.

2. The preparation method of the quaternary ammonium salt grafted porous unburned ceramsite according to claim 1, characterized in that: In step S1, the particle size of the bentonite, natural zeolite powder, fly ash and biomass ash is not less than 200 mesh; In step S1, the mass percentage content of montmorillonite in the bentonite is 85%-90%; In step S1, the mass percentage content of natural zeolite in the natural zeolite powder is more than 50%, and the ammonia adsorption value is greater than 100mmol / 100g; In step S1, the fly ash is grade II ash; In step S1, the biomass ash is one of rice husk ash, sugarcane residue ash and corn cob ash, and the silicon content is not less than 75%; In step S1, the curing agent is solid sodium metaaluminate and solid sodium silicate, and the mass ratio is 3:1~1:

2.

3. The method of making a quaternary ammonium salt grafted porous calcined clay according to claim 1, wherein, In step S3, the stirring is carried out at a speed of 45~65r / min for 5~10min.

4. The method of making a quaternary ammonium salt grafted porous calcined clay according to claim 1, wherein, In step S5, the curing is to move the spherical particles to a standard curing box for curing for 28 days.

5. The method of making a quaternary ammonium salt grafted porous calcined clay according to claim 1, wherein, In step S7, the quaternary ammonium salt bactericide is grafted on the inner pore surface of the porous unburned ceramsite matrix after amination treatment, which comprises: The quaternary ammonium salt is dissolved in an ethanol solution to obtain a quaternary ammonium salt reaction solution; The amino-treated porous unburned ceramsite matrix and the quaternary ammonium salt reaction solution are mixed according to a weight ratio of 1:0.6-1.5 to perform water bath reaction; The unreacted quaternary ammonium salt and by-products are removed by cleaning with anhydrous ethanol solution, and the quaternary ammonium salt grafted porous unburned ceramsite is obtained after drying.

6. The preparation method of the quaternary ammonium salt grafted porous unburned ceramsite according to claim 5, characterized in that, The quaternary ammonium salt is one of an epoxy group quaternary ammonium salt and a halogenated alkyl quaternary ammonium salt, and the mass percentage concentration of the quaternary ammonium salt in the quaternary ammonium salt reaction solution is 1%-10%; The water bath reaction is performed in a 40℃ water bath for 12-24 hours, and the pH value of the reaction environment is controlled to be 7-10; The drying is performed at 55℃ for 0.5-1 hour.

7. A quaternary ammonium salt grafted porous unburned ceramsite prepared by the method according to any one of claims 1-6.

8. Application of the quaternary ammonium salt grafted porous unburned ceramsite prepared by the method according to any one of claims 1-6 in the fields of environmental protection filter material, sewage treatment or transportation.

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