Method for making building materials using kitchen waste leachate sludge

Abstract

The present invention provides a method for making building materials using kitchen waste leachate sludge, comprising the following steps: S1. air-drying and activating the sludge treated with kitchen waste leachate at room temperature to obtain activated sludge; S2. heating and carbonizing the activated sludge to obtain sludge-based activated carbon; S3. preparing a water glass solution; S4. pouring the water glass solution into a whisker-shaped mullite ceramic thick film, curing and forming the film in an oven to obtain a whisker / foam porous composite material; S5. adding the sludge activated carbon and a dispersant prepared in step S2 to a polyvinylpyrrolidone solution, and then adding the solution to a polyacrylamide solution to prepare a polyacrylamide-sludge-based activated carbon suspension; S6. impregnating the whisker / foam porous composite material prepared in step S4 into the polyacrylamide-sludge and activated carbon to obtain a thermal insulation building material. The present invention combines kitchen waste leachate sludge with a high organic matter content with fly ash to prepare a high thermal insulation green building material.

Description

Technical Field

[0001] The present invention relates to the field of recycling of kitchen waste treatment agents, and in particular to a method for producing building materials by utilizing kitchen waste leachate sludge. Background Art

[0002] Kitchen waste is a type of household waste generated in daily life. It primarily comes from leftovers and food waste. Based on its composition, it is divided into raw kitchen waste and cooked kitchen waste. The former primarily refers to cooking scraps such as fruit peels, vegetable leaves, and paper towels; the latter primarily refers to leftovers from restaurants, hotels, and daily life, including rice, flour, animal and vegetable oils, fish, meat, bones, and water. Its chemical composition includes starch, cellulose, protein, fat, and inorganic salts, with a high sodium chloride content. Kitchen waste is typically treated by shredding and direct discharge into the sewer, incineration, sanitary landfill, feed conversion, composting, and resource utilization. Currently, sanitary landfill is the most widely used method for kitchen waste treatment in my country. This is due to its low investment, relatively simple technology, and ease of operation. Furthermore, the high organic content of kitchen waste provides abundant nutrients for microbial growth and reproduction, thereby accelerating waste degradation and facilitating the recovery of landfill sites. However, the kitchen waste is not further treated in landfills and the large amount of leachate generated thereby. During the stabilization process, some pollutants in the waste are degraded by squeezing and the action of microorganisms and then dissolved together with the water in the waste to form leachate.

[0003] Currently, landfill leachate treatment methods are categorized into physical, chemical, and biological methods. Among these, activated sludge-based biological treatment offers advantages such as low operating costs, excellent treatment effectiveness, and zero secondary pollution, making it widely used in landfill leachate treatment. Activated sludge contains a rich microbial community that utilizes pollutants in the leachate as a growth substrate, inducing enzyme assimilation to maintain biomass, thereby transforming and decomposing pollutants and achieving wastewater purification. However, the sludge produced by adsorption treatment of food waste leachate contains high salt content, high organic matter content, and high calorific value, making it difficult to dispose of the sludge through landfill or other resource-based methods. The use of sludge in the building materials industry offers advantages unattainable by other methods, such as stabilization, detoxification, and resource utilization. This can improve waste utilization, conserve natural resources, and contribute to sustainable development. Summary of the Invention

[0004] Technical problem to be solved: The purpose of the present invention is to provide a method for making building materials using kitchen waste leachate sludge, combining kitchen waste leachate sludge with high organic matter content and fly ash to prepare high thermal insulation green building materials.

[0005] Technical solution: A method for producing building materials using kitchen waste leachate sludge, comprising the following steps:

[0006] S1. The sludge from the kitchen waste leachate treatment was air-dried at room temperature, then dried and dehydrated to a moisture content of less than 10%. The dry sludge was ground and screened to particles less than 0.1 mm. ZnCl2 solution was then added for activation, and the activated sludge was filtered and dried to obtain the activated sludge.

[0007] S2. The activated sludge was placed in a quartz tube, nitrogen was introduced, the temperature was raised to carbonize, and then naturally cooled to room temperature. The particles were ground and screened to be less than 0.1 mm to obtain sludge-based activated carbon;

[0008] S3. Borax and sodium carbonate were added to water until completely dissolved, and the dissolved solution was added to the caustic soda solution, and mixed and stirred to obtain a water glass solution;

[0009] S4. The water glass solution is poured into the whisker-like mullite ceramic thick film and cured in an oven to obtain a whisker / foam porous composite material;

[0010] S5. The sludge activated carbon prepared in step S2 and the dispersant were added to an aqueous solution of polyvinyl pyrrolidone, and then added to the polyacrylamide solution to prepare a polyacrylamide - sludge-based activated carbon suspension;

[0011] S6. Immersing the whisker / foam porous composite material prepared in step S4 in polyacrylamide-sludge and activated carbon, and then taking it out and drying it to obtain a thermal insulation building material.

[0012] Preferably, the concentration of the ZnCl2 solution is 2-3 mol / L, and the volume ratio of the dry sludge particles to the ZnCl2 solution is 1-2:3.

[0013] Preferably, in step S2, the carbonization temperature is raised to 700° C. at a rate of 10-15° C. / min, and the carbonization time is 200-350 min.

[0014] Preferably, in step S3, the mass ratio of borax, sodium carbonate and caustic soda is 8-11:2-2.5:7-8.5.

[0015] Preferably, the preparation method of the whisker-shaped mullite ceramic thick film in step S4 is:

[0016] S11. Aluminum chloride and aluminum nitrate were mixed and added to an aqueous nitric acid solution, stirred, and then aluminum isopropoxide and aluminum powder were added, and the reaction was heated under reflux to obtain an aluminum sol;

[0017] S12 nickel oxide was added to the aluminum sol, mixed and stirred, and polyvinyl pyrrolidone was added to obtain a spinnable aluminum sol;

[0018] Aluminum sol is electrospun to obtain an aluminum oxide gel fiber membrane containing nickel oxide;

[0019] S13. The fly ash particles were added to an aqueous solution of polyvinyl pyrrolidone to obtain a fly ash solution, the fly ash solution was applied to the surface of the alumina gel fiber membrane containing nickel oxide, and then the fly ash-coated alumina gel fiber membrane was stacked and compacted under pressure to obtain a thick alumina gel film;

[0020] S14. Sintering the prepared alumina thick film to obtain a whisker-like mullite ceramic porous thick film.

[0021] Preferably, in step S5, the mass ratio of sludge activated carbon, polyvinyl pyrrolidone, polyacrylamide and water is 1-2:0.2-0.5:4-8:100.

[0022] Preferably, the drying temperature in step S6 is -20 to -10°C, and the drying time is 10 to 20 hours.

[0023] Preferably, in step S11, the molar ratio of aluminum chloride, aluminum nitrate, aluminum isopropoxide, aluminum powder and nickel oxide is 0.8-1.5:0.8-1.5:1.5-3:3.6-5:0.4-0.7.

[0024] Preferably, the sintering parameters in step S14 are: 5°C·min at room temperature -1 Raise the temperature to 200℃ and keep it for 30min, then continue heating at 5℃·min -1 Heat to 600℃ and keep it for 30 min, then heat at 3℃·min -1 The temperature was raised to 1200℃ and then the temperature was increased to 2℃·min -1 Heat to 1500 °C and keep it for 2 h, then cool naturally.

[0025] Beneficial effects: The preparation method of the present invention has the following advantages:

[0026] The landfill leachate sludge of the present invention has a high organic matter content. By activating the landfill leachate sludge and then carbonizing it to obtain sludge-based activated carbon, the sludge can be fully recycled.

[0027] In the present invention, an aluminum oxide film is prepared, and then industrial waste fly ash is loaded on the adjacent aluminum oxide film to form a thick film in the form of a multi-layer composite. The thick film is sintered to obtain a whisker-like mullite ceramic porous thick film. The film has both a hollow structure and mullite whiskers grown by sintering, and the spatial structure is diversified. The thick film is again immersed in a water glass solution to form a porous structure. Finally, the sintered sludge-based activated carbon is again loaded on the whisker / foam porous composite material to obtain a building insulation material. The composite material prepared by the present invention has an internal porous structure with a size of tens of nanometers when heat is transferred, which is smaller than the mean free path of air molecules and can effectively hinder the convective heat transfer of gas molecules. On the other hand, when the heat flow passes through the composite material, it is reflected and refracted by the internal pores and phase interfaces of the material, and the transfer path is constantly changed, which can effectively hinder the heat transfer process of the solid, thereby achieving the purpose of improving the thermal insulation effect.

[0028] In the present invention, after freeze-drying treatment, a composite three-dimensional mesh film is formed inside the pores. This structure increases the flow rate and flow resistance of air, and transforms the original large-pore structure into a mesh structure composed of multiple small pores, which means that the pore size is reduced and the thermal insulation effect is improved. DETAILED DESCRIPTION

[0029] The present invention will be further described below in conjunction with the embodiments, which are explanations of the present invention and are not limited to the following embodiments: Example 1

[0030] The preparation method of whisker-shaped mullite ceramic thick film is:

[0031] S11. Aluminum chloride and aluminum nitrate were mixed and added to an aqueous nitric acid solution, stirred, and then aluminum isopropoxide and aluminum powder were added, and the reaction was heated under reflux to obtain an aluminum sol;

[0032] S12 nickel oxide was added to the aluminum sol, mixed and stirred, and polyvinyl pyrrolidone was added to obtain a spinnable aluminum sol;

[0033] Electrospinning the aluminum sol to obtain an alumina gel fiber membrane containing nickel oxide, wherein the molar ratio of aluminum chloride, aluminum nitrate, aluminum isopropoxide, aluminum powder and nickel oxide is 0.8:0.8:1.5:3.6:0.4;

[0034] S13. Fly ash particles were added to an aqueous solution of polyvinyl pyrrolidone to obtain a fly ash solution. The fly ash solution was applied to the surface of an alumina gel fiber membrane containing nickel oxide. The fly ash-coated alumina gel fiber membranes were then stacked and compacted under pressure. The mass ratio of fly ash particles to fiber membrane was 1:1.2, resulting in a thick alumina gel film.

[0035] S14. The prepared aluminum oxide thick film was sintered at 5°C·min at room temperature. -1 Raise the temperature to 200℃ and keep it for 30 min, then continue heating at 5℃·min -1 Heat to 600℃ and keep it for 30 min, then heat at 3℃·min -1 The temperature was raised to 1200℃ and then the temperature was increased to 2℃·min -1 The temperature was raised to 1500 ℃ and kept for 2 h, and then naturally cooled to obtain a whisker-like mullite ceramic porous thick film. Example 2

[0036] The preparation method of whisker-shaped mullite ceramic thick film is:

[0037] S11. Aluminum chloride and aluminum nitrate were mixed and added to an aqueous nitric acid solution, stirred, and then aluminum isopropoxide and aluminum powder were added, and the reaction was heated under reflux to obtain an aluminum sol;

[0038] S12 nickel oxide was added to the aluminum sol, mixed and stirred, and polyvinyl pyrrolidone was added to obtain a spinnable aluminum sol;

[0039] Electrospinning the aluminum sol to obtain an alumina gel fiber membrane containing nickel oxide, wherein the molar ratio of aluminum chloride, aluminum nitrate, aluminum isopropoxide, aluminum powder and nickel oxide is 1.5:1.5:3:5:0.7;

[0040] S13. Fly ash particles were added to an aqueous solution of polyvinyl pyrrolidone to obtain a fly ash solution. The fly ash solution was applied to the surface of the alumina gel fiber membrane containing nickel oxide. The fly ash-coated alumina gel fiber membrane was then stacked and compacted under pressure. The mass ratio of fly ash particles to fiber membrane was 1:1, resulting in a thick alumina gel film.

[0041] S14. The prepared aluminum oxide thick film was sintered at 5°C·min at room temperature. -1 Raise the temperature to 200℃ and keep it for 30 min, then continue heating at 5℃·min -1 Heat to 600℃ and keep it for 30 min, then heat at 3℃·min -1 The temperature was raised to 1200℃ and then the temperature was increased to 2℃·min -1 The temperature was raised to 1500 ℃ and kept for 2 h, and then naturally cooled to obtain a whisker-like mullite ceramic porous thick film. Example 3

[0042] The preparation method of whisker-shaped mullite ceramic thick film is:

[0043] S11. Aluminum chloride and aluminum nitrate were mixed and added to an aqueous nitric acid solution, stirred, and then aluminum isopropoxide and aluminum powder were added, and the reaction was heated under reflux to obtain an aluminum sol;

[0044] S12 nickel oxide was added to the aluminum sol, mixed and stirred, and polyvinyl pyrrolidone was added to obtain a spinnable aluminum sol;

[0045] Electrospinning the aluminum sol to obtain an alumina gel fiber membrane containing nickel oxide, wherein the molar ratio of aluminum chloride, aluminum nitrate, aluminum isopropoxide, aluminum powder and nickel oxide is 1:1:2:4:0.5;

[0046] S13. Fly ash particles were added to an aqueous solution of polyvinyl pyrrolidone to obtain a fly ash solution. The fly ash solution was applied to the surface of an alumina gel fiber membrane containing nickel oxide. The fly ash-coated alumina gel fiber membranes were then stacked and compacted under pressure. The mass ratio of fly ash particles to fiber membrane was 1.5:1, resulting in a thick alumina gel film.

[0047] S14. The prepared aluminum oxide thick film was sintered at 5°C·min at room temperature. -1 Raise the temperature to 200℃ and keep it for 30 min, then continue heating at 5℃·min -1 Heat to 600℃ and keep it for 30 min, then heat at 3℃·min -1 The temperature was raised to 1200℃ and then the temperature was increased to 2℃·min -1 The temperature was raised to 1500 ℃ and kept for 2 h, and then naturally cooled to obtain a whisker-like mullite ceramic porous thick film.

[0048] Thickness of whisker mullite ceramic porous thick film Example 1 1.56cm Example 2 1.52cm Example 3 1.55cm Example 4

[0049] A method for producing building materials using kitchen waste leachate sludge comprises the following steps:

[0050] S1. The sludge from the food waste leachate treatment was air-dried at room temperature and then dried to a moisture content of less than 10%. The dry sludge was ground and screened to particles <0.1 mm. The sludge was then activated by adding a ZnCl2 solution at a concentration of 2 mol / L and a volume ratio of 1:3 between the dry sludge particles and the ZnCl2 solution. The activated sludge was then filtered and dried.

[0051] S2. The activated sludge was placed in a quartz tube and nitrogen was introduced. The sludge was heated and carbonized, and then naturally cooled to room temperature. The carbonization temperature was increased at a rate of 15°C / min to 700°C for 350 min. The sludge was ground and screened to obtain particles <0.1 mm to obtain sludge-based activated carbon.

[0052] S3 borax, sodium carbonate was added to water until completely dissolved, the dissolved solution was added to the caustic soda solution, the mass ratio of borax, sodium carbonate and caustic soda was 8:2:7, and the mixture was stirred to obtain a water glass solution;

[0053] S4. The water glass solution was poured into the whisker-like mullite ceramic thick film prepared in Example 1 and cured in an oven to obtain a whisker / porous foam composite material;

[0054] S5. The activated carbon sludge prepared in step S2 and the dispersant were added to an aqueous solution of polyvinyl pyrrolidone, and then added to the polyacrylamide solution. The mass ratio of activated carbon sludge, polyvinyl pyrrolidone, polyacrylamide and water was 1:0.2:4:100 to prepare a polyacrylamide-sludge-based activated carbon suspension.

[0055] S6. The whisker / porous foam composite material prepared in step S4 is immersed in polyacrylamide-sludge and activated carbon, and then taken out and dried at -20°C for 10 hours to obtain a thermal insulation building material. Example 5

[0056] A method for producing building materials using kitchen waste leachate sludge comprises the following steps:

[0057] S1. The sludge from the food waste leachate treatment was air-dried at room temperature and then dried to a moisture content of less than 10%. The dry sludge was ground and screened to particles <0.1 mm. The sludge was then activated by adding a ZnCl2 solution at a concentration of 3 mol / L and a volume ratio of 2:3 between the dry sludge particles and the ZnCl2 solution. The activated sludge was then filtered and dried.

[0058] S2. The activated sludge was placed in a quartz tube and nitrogen was introduced. The sludge was heated and carbonized, and then naturally cooled to room temperature. The carbonization temperature was increased at a rate of 10°C / min to 700°C for 200 min. The sludge was ground and screened to particles <0.1 mm to obtain sludge-based activated carbon.

[0059] S3 borax, sodium carbonate was added to water until completely dissolved, the dissolved solution was added to the caustic soda solution, the mass ratio of borax, sodium carbonate and caustic soda was 11:2.5:8.5, and mixed and stirred to obtain a water glass solution;

[0060] S4. The water glass solution was poured into the whisker-like mullite ceramic thick film prepared in Example 1 and cured in an oven to obtain a whisker / porous foam composite material;

[0061] S5. The activated carbon sludge and dispersant prepared in step S2 were added to an aqueous solution of polyvinyl pyrrolidone, and then added to the polyacrylamide solution. The mass ratio of activated carbon sludge, polyvinyl pyrrolidone, polyacrylamide and water was 2:0.5:8:100 to prepare a polyacrylamide-sludge-based activated carbon suspension.

[0062] S6. The whisker / porous foam composite material prepared in step S4 is immersed in polyacrylamide-sludge and activated carbon, and then taken out and dried at a temperature of -10°C for 20 hours to obtain a thermal insulation building material. Example 6

[0063] A method for producing building materials using kitchen waste leachate sludge comprises the following steps:

[0064] S1. The sludge from the food waste leachate treatment was air-dried at room temperature and then dried to a moisture content of less than 10%. The sludge was ground and screened to particles <0.1 mm. The sludge was then activated by adding a ZnCl2 solution at a concentration of 2.3 mol / L and a volume ratio of 1.2:3 between the dry sludge particles and the ZnCl2 solution. The activated sludge was then filtered and dried to obtain the activated sludge.

[0065] S2. The activated sludge was placed in a quartz tube and nitrogen was introduced. The sludge was heated and carbonized, then naturally cooled to room temperature. The carbonization temperature was increased at a rate of 11°C / min to 700°C for 260 min. The activated sludge was ground and screened to obtain particles <0.1 mm to obtain sludge-based activated carbon.

[0066] S3 borax, sodium carbonate was added to water until completely dissolved, the dissolved solution was added to the caustic soda solution, the mass ratio of borax, sodium carbonate and caustic soda was 9:2.1:7.5, and the mixture was stirred to obtain a water glass solution;

[0067] S4. The water glass solution was poured into the whisker-like mullite ceramic thick film prepared in Example 2 and cured in an oven to obtain a whisker / porous foam composite material;

[0068] S5. The activated carbon sludge and dispersant prepared in step S2 were added to an aqueous solution of polyvinyl pyrrolidone, and then added to the polyacrylamide solution. The mass ratio of activated carbon sludge, polyvinyl pyrrolidone, polyacrylamide and water was 1.2:0.:5:100 to prepare a polyacrylamide-sludge-based activated carbon suspension.

[0069] S6. The whisker / porous foam composite material prepared in step S4 is immersed in polyacrylamide-sludge and activated carbon, and then taken out and dried at -20°C for 18 hours to obtain a thermal insulation building material. Example 7

[0070] A method for producing building materials using kitchen waste leachate sludge comprises the following steps:

[0071] S1. The sludge from the food waste leachate treatment was air-dried at room temperature and then dried to a moisture content of less than 10%. The sludge was ground and screened to particles less than 0.1 mm. The sludge was then activated by adding a ZnCl2 solution at a concentration of 2.6 mol / L and a volume ratio of 1.6:3. The activated sludge was then filtered and dried.

[0072] S2. The activated sludge was placed in a quartz tube and nitrogen was introduced. The sludge was heated and carbonized, then naturally cooled to room temperature. The carbonization temperature was increased at a rate of 14°C / min to 700°C for 320 min. The activated sludge was ground and screened to obtain particles <0.1 mm to obtain sludge-based activated carbon.

[0073] S3 borax, sodium carbonate was added to water until completely dissolved, the dissolved solution was added to the caustic soda solution, the mass ratio of borax, sodium carbonate and caustic soda was 10:2.4:8.2, and the mixture was stirred to obtain a water glass solution;

[0074] S4. The water glass solution was poured into the whisker-like mullite ceramic thick film prepared in Example 3 and cured in an oven to obtain a whisker / porous foam composite material;

[0075] S5. The activated carbon sludge and dispersant prepared in step S2 were added to an aqueous solution of polyvinyl pyrrolidone, and then added to the polyacrylamide solution. The mass ratio of activated carbon sludge, polyvinyl pyrrolidone, polyacrylamide and water was 1.8:0.4:7:100 to prepare a polyacrylamide-sludge-based activated carbon suspension.

[0076] S6. The whisker / porous foam composite material prepared in step S4 is immersed in polyacrylamide-sludge and activated carbon, and then taken out and dried at a temperature of -10°C for 15 hours to obtain a thermal insulation building material. Example 8

[0077] A method for producing building materials using kitchen waste leachate sludge comprises the following steps:

[0078] S1. The sludge from the food waste leachate treatment was air-dried at room temperature and then dried to a moisture content of less than 10%. The sludge was ground and screened to particles less than 0.1 mm. The sludge was then activated by adding a ZnCl2 solution at a concentration of 2.4 mol / L and a volume ratio of 1.5:3 between the dry sludge particles and the ZnCl2 solution. The activated sludge was then filtered and dried.

[0079] S2. The activated sludge was placed in a quartz tube and nitrogen was introduced. The sludge was heated and carbonized, then naturally cooled to room temperature. The carbonization temperature was increased at a rate of 12°C / min to 700°C for 300 min. The sludge was ground and screened to particles <0.1 mm to obtain sludge-based activated carbon.

[0080] S3 borax, sodium carbonate was added to water until completely dissolved, the dissolved solution was added to the caustic soda solution, the mass ratio of borax, sodium carbonate and caustic soda was 10:2..2:8, mixed and stirred to obtain a water glass solution;

[0081] S4. The water glass solution was poured into the whisker-like mullite ceramic thick film prepared in Example 3 and cured in an oven to obtain a whisker / porous foam composite material;

[0082] S5. The activated carbon sludge and dispersant prepared in step S2 were added to an aqueous solution of polyvinyl pyrrolidone, and then added to the polyacrylamide solution. The mass ratio of activated carbon sludge, polyvinyl pyrrolidone, polyacrylamide and water was 1.6:0.3:6:100 to prepare a polyacrylamide-sludge-based activated carbon suspension.

[0083] S6. Immerse the whisker / porous foam composite material prepared in step S4 in polyacrylamide-sludge and activated carbon, then take out and dry it at -15°C for 20 hours to obtain a thermal insulation building material.

[0084] Comparative Example 1

[0085] A method for producing building materials using kitchen waste leachate sludge comprises the following steps:

[0086] S1. Borax and sodium carbonate were added to water until completely dissolved, and the dissolved solution was added to a caustic soda solution. The mass ratio of borax, sodium carbonate and caustic soda was 10:2..2:8, and the mixture was stirred to obtain a water glass solution.

[0087] S2. The water glass solution was poured into the whisker-like mullite ceramic thick film prepared in Example 3 and cured in an oven to obtain a whisker / porous foam composite material;

[0088] S3. The dried sludge and dispersant were added to an aqueous solution of polyvinyl pyrrolidone, and then added to the polyacrylamide solution. The mass ratio of sludge activated carbon, polyvinyl pyrrolidone, polyacrylamide and water was 1.6:0.3:6:100 to prepare a polyacrylamide - sludge suspension;

[0089] S4. The whisker / porous foam composite material prepared in step S4 is immersed in polyacrylamide-sludge and activated carbon, and then taken out and dried at a temperature of -15°C for 20 hours to obtain a thermal insulation building material.

[0090] Comparative Example 2

[0091] A method for producing building materials using kitchen waste leachate sludge comprises the following steps:

[0092] S1. The sludge from the food waste leachate treatment was air-dried at room temperature and then dried to a moisture content of less than 10%. The sludge was ground and screened to particles less than 0.1 mm. The sludge was then activated by adding a ZnCl2 solution at a concentration of 2.6 mol / L and a volume ratio of 1.6:3. The activated sludge was then filtered and dried.

[0093] S2. The activated sludge was placed in a quartz tube and nitrogen was introduced. The sludge was heated and carbonized, then naturally cooled to room temperature. The carbonization temperature was increased at a rate of 14°C / min to 700°C for 320 min. The activated sludge was ground and screened to obtain particles <0.1 mm to obtain sludge-based activated carbon.

[0094] S3 borax, sodium carbonate was added to water until completely dissolved, the dissolved solution was added to the caustic soda solution, the mass ratio of borax, sodium carbonate and caustic soda was 10:2.4:8.2, and the mixture was stirred to obtain a water glass solution;

[0095] S4. The water glass solution is poured into the alumina ceramic thick film and cured in an oven to obtain a whisker / porous foam composite material;

[0096] S5. The activated carbon sludge and dispersant prepared in step S2 were added to an aqueous solution of polyvinyl pyrrolidone, and then added to the polyacrylamide solution. The mass ratio of activated carbon sludge, polyvinyl pyrrolidone, polyacrylamide and water was 1.8:0.4:7:100 to prepare a polyacrylamide-sludge-based activated carbon suspension.

[0097] S6. The whisker / porous foam composite material prepared in step S4 was immersed in polyacrylamide - sludge and activated carbon, and then removed and dried at a drying temperature of -10 ° C for 15 h to obtain a thermal insulation building material;

[0098] Wherein, the preparation method of alumina ceramic thick film is:

[0099] S11. Aluminum chloride and aluminum nitrate were mixed and added to an aqueous nitric acid solution, stirred, and then aluminum isopropoxide and aluminum powder were added, and the reaction was heated under reflux to obtain an aluminum sol;

[0100] S12. Polyvinyl pyrrolidone was added to the aluminum sol to obtain a spinnable aluminum sol, which was electrospun to obtain an alumina gel fiber membrane, wherein the molar ratio of aluminum chloride, aluminum nitrate, aluminum isopropoxide, and aluminum powder was 0.8:0.8:1.5:3.6;

[0101] S13. The polyvinyl pyrrolidone solution is applied to the surface of the alumina gel fiber membrane, and then the alumina gel fiber membrane coated with the polyvinyl pyrrolidone solution is stacked and compacted under pressure to obtain a thick alumina gel film;

[0102] S14. Sintering the prepared alumina thick film to obtain a porous alumina ceramic thick film.

[0103] Comparative Example 3

[0104] A method for producing building materials using kitchen waste leachate sludge comprises the following steps:

[0105] S1. The sludge from the food waste leachate treatment was air-dried at room temperature and then dried to a moisture content of less than 10%. The sludge was ground and screened to particles <0.1 mm. The sludge was then activated by adding a ZnCl2 solution at a concentration of 2.3 mol / L and a volume ratio of 1.2:3 between the dry sludge particles and the ZnCl2 solution. The activated sludge was then filtered and dried to obtain the activated sludge.

[0106] S2. The activated sludge was placed in a quartz tube and nitrogen was introduced. The sludge was heated and carbonized, then naturally cooled to room temperature. The carbonization temperature was increased at a rate of 11°C / min to 700°C for 260 min. The activated sludge was ground and screened to obtain particles <0.1 mm to obtain sludge-based activated carbon.

[0107] S3 borax, sodium carbonate was added to water until completely dissolved, the dissolved solution was added to the caustic soda solution, the mass ratio of borax, sodium carbonate and caustic soda was 9:2.1:7.5, and the mixture was stirred to obtain a water glass solution;

[0108] S4. The activated sludge carbon prepared in step S2 was added to the water glass solution, the mass fraction of activated sludge carbon in the water glass solution was 5wt%, to obtain an activated carbon sludge water glass solution;

[0109] S5. The activated carbon sludge water glass solution is poured into the whisker-like mullite ceramic thick film prepared in Example 2, and cured in an oven to obtain a thermal insulation building material.

[0110] Performance testing:

[0111] The present invention uses the transient plane heat source method in the non-steady-state method for measurement; the compressive strength of porous ceramics is measured according to GB / T 1964-1996 Test method for compressive strength of porous ceramics. The specific results are shown in the following table:

[0112] Thermal conductivity W / (m∙K) Compressive strength MPa Example 4 0.048 0.82 Example 5 0.051 0.79 Example 6 0.046 0.85 Example 7 0.052 0.83 Example 8 0.044 0.81 Comparative Example 1 0.061 0.80 Comparative Example 2 0.075 0.75 Comparative Example 3 0.084 0.45

[0113] As can be seen from the above table, the thermal insulation effect of the thermal insulation building material obtained by the preparation method of the present invention is relatively good, and the compressive strength can also meet the requirements. This is because after high-temperature sintering, alumina and the fly ash matrix form a bonding phase with a high degree of bonding, which can absorb external forces and release stress concentration.

[0114] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A method for producing building materials using kitchen waste leachate sludge, characterized in that: The following steps are involved: S1. The sludge from the food waste leachate treatment was air-dried at room temperature, then dried and dehydrated to a moisture content of less than 10%. The dry sludge was ground and screened to particles less than 0.1 mm. The sludge was activated by adding a ZnCl2 solution, and then filtered and dried to obtain activated sludge. S2. The activated sludge was placed in a quartz tube, nitrogen was introduced, and carbonized at elevated temperature, then naturally cooled to room temperature. The activated sludge was then ground and screened to obtain particles <0.1 mm to obtain sludge-based activated carbon. S3 borax, sodium carbonate was added to water until completely dissolved, the dissolved solution was added to the caustic soda solution, mixed and stirred to obtain a water glass solution; S4. The water glass solution is poured into the whisker-like porous mullite ceramic thick film and cured in an oven to obtain a whisker / porous foam composite material; S5. The sludge-based activated carbon and dispersant prepared in step S2 were added to an aqueous solution of polyvinyl pyrrolidone and then added to the polyacrylamide solution to prepare a polyacrylamide - sludge-based activated carbon suspension; S6. The whisker / porous foam composite material prepared in step S4 is immersed in polyacrylamide-sludge-based activated carbon, and then taken out and dried to obtain a thermal insulation building material.

2. The method for producing building materials using kitchen waste leachate sludge according to claim 1, characterized in that: The concentration of the ZnCl2 solution is 2-3 mol / L, and the volume ratio of the dry sludge particles to the ZnCl2 solution is 1-2:

3.

3. The method for producing building materials using kitchen waste leachate sludge according to claim 1, characterized in that: In step S2, the carbonization temperature is raised to 700°C at a rate of 10-15°C / min, and the carbonization time is 200-350 min.

4. The method for producing building materials using kitchen waste leachate sludge according to claim 1, characterized in that: In step S3, the mass ratio of borax, sodium carbonate and caustic soda is 8-11:2-2.5:7-8.

5.

5. The method for producing building materials using kitchen waste leachate sludge according to claim 1, characterized in that: The preparation method of the whisker-shaped mullite ceramic porous thick film in the step S4 is: S11. Aluminum chloride and aluminum nitrate were mixed and added to an aqueous nitric acid solution, stirred, and then aluminum isopropoxide and aluminum powder were added, and the reaction was heated under reflux to obtain an aluminum sol; S12 nickel oxide was added to the aluminum sol, mixed and stirred, and polyvinyl pyrrolidone was added to obtain a spinnable aluminum sol; the aluminum sol was electrospun to obtain an alumina gel fiber film containing nickel oxide; S13. The fly ash particles were added to an aqueous solution of polyvinyl pyrrolidone to obtain a fly ash solution, and the fly ash solution was applied to the surface of the alumina gel fiber membrane containing nickel oxide, and then the fly ash-coated alumina gel fiber membrane was stacked and compacted under pressure to obtain a thick alumina gel film; S14. Sintering the prepared alumina thick film to obtain a whisker-like mullite ceramic porous thick film.

6. The method for producing building materials using kitchen waste leachate sludge according to claim 1, characterized in that: In step S5, the mass ratio of sludge-based activated carbon, polyvinyl pyrrolidone, polyacrylamide and water is 1-2:0.2-0.5:4-8:

100.

7. The method for producing building materials using kitchen waste leachate sludge according to claim 1, characterized in that: In step S6, the drying temperature is -20 to -10°C and the drying time is 10 to 20 hours.

8. The method for producing building materials using kitchen waste leachate sludge according to claim 5, characterized in that: In step S11, the molar ratio of aluminum chloride, aluminum nitrate, aluminum isopropoxide, aluminum powder and nickel oxide is 0.8-1.5:0.8-1.5:1.5-3:3.6-5:0.4-0.

7.

9. The method for producing building materials using kitchen waste leachate sludge according to claim 5, characterized in that: The sintering parameters in step S14 are: 5°C·min at room temperature -1 Raise the temperature to 200℃ and keep it for 30 min, then continue heating at 5℃·min -1 Heat to 600℃ and keep it for 30 min, then heat at 3℃·min -1 The temperature was raised to 1200℃ and then the temperature was increased to 2℃·min -1 Heat to 1500 °C and keep it for 2 h, then cool naturally.