High-strength floating type fly ash-based porous ceramic and low-temperature preparation method thereof

Abstract

The invention relates to a high-strength floating type fly ash-based porous ceramic and a low-temperature preparation method thereof, belongs to the technical field of ceramics, and solves the problems that an existing preparation method of the porous ceramic needs high-temperature sintering and is high in cost; the porosity and the strength cannot be improved at the same time. The preparation method comprises the following steps: mixing the fly ash floating beads and the crushed crude pearlite, adding the sintering aid and the pore-forming agent to obtain a mixture, then adding water to dissolve the mixture, and stirring until the mixture is uniformly mixed; a monomer, a cross-linking agent and a dispersing agent are added into the slurry, then a catalyst and an initiator are added, and full stirring is conducted after the chemicals are added every time until the slurry is mixed evenly; injecting the slurry into a mold, rapidly oscillating to remove air, and standing at room temperature; the mold is put into a drying oven to be dried, and then the dried green body is taken out of the mold; and sintering the demolded green body in a sintering furnace to obtain the high-strength floating type fly ash-based porous ceramic. The porous ceramic disclosed by the invention is high in strength, small in density and good in floating durability.

Description

Technical Field

[0001] The invention relates to the technical field of porous ceramics, and in particular to a high-strength floating fly ash-based porous ceramic and a low-temperature preparation method thereof. Background Art

[0002] Floating materials have important applications in floating island landscape design, water surface marking, photocatalysis and thermoelectricity. Usually, floating materials mainly include polystyrene foam, polyimide foam, foam glass and porous ceramics. Although organic floating foam materials are widely used, they have problems such as poor weather resistance, low strength and difficult solid waste treatment. Floating foam glass is usually made by foaming the raw materials after melting at high temperature. The higher melting temperature will increase the production cost, and the strength of glass is usually lower than that of ceramics. Compared with the first two floating materials, floating porous ceramics have obvious advantages in strength and durability. As a special porous ceramic, it can still be made using the traditional preparation process of porous ceramics such as adding pore-forming agents and foaming methods.

[0003] CN111484351A discloses a method for preparing lightweight porous ceramic hollow microspheres, wherein the prepared hollow microspheres have high porosity and low density, but high sintering temperature, high energy consumption, and low compressive strength. The prior art also discloses a method of using polypropylene microspheres and polymethyl methacrylate microspheres as spherical pore-forming agents, wherein the prepared porous ceramics have low thermal conductivity, low density, and high compressive strength, but the spherical pore-forming agents used have biological toxicity and are difficult to float on the water surface for a long time.

[0004] Although some studies have been conducted on lightweight floating ceramics, their sintering temperature is relatively high, their strength is low, and their floating durability is poor. In addition, lightweight floating ceramics usually require the addition of foaming agents during the sintering process, which can cause environmental pollution or increase production costs. Summary of the invention

[0005] In view of the above analysis, the present invention aims to provide a high-strength floating fly ash-based porous ceramic and a low-temperature preparation method thereof, which is used to solve one of the following technical problems: (1) The existing preparation method of porous ceramics requires high-temperature sintering, which is costly; (2) The existing porous ceramics have high porosity but low strength, or high strength but low porosity. (3) The preparation of existing porous ceramics mostly relies on foaming agents, which is costly and causes environmental pollution.

[0006] The purpose of the present invention is mainly achieved through the following technical solutions:

[0007] The present invention provides a low-temperature preparation method of high-strength floating fly ash-based porous ceramics, comprising:

[0008] Step 1, preparing slurry: mixing fly ash beads and perlite powder, adding sintering aid and pore-forming agent to obtain a mixture, then adding water to dissolve the mixture, stirring until the mixture is uniform, and obtaining slurry;

[0009] Step 2, preparing the green body: adding monomer, crosslinking agent, dispersant, catalyst and initiator to the slurry in sequence, and stirring thoroughly after each addition of the drug until the slurry is evenly mixed; then injecting the slurry into the mold, rapidly shaking to remove air, and then standing at room temperature;

[0010] Step 3, green body drying and demoulding: putting the mold in step 2 into an oven for drying, and then removing the dried green body from the mold;

[0011] Step 4, sintering: placing the demoulded green body into a sintering furnace for sintering to obtain high-strength floating fly ash-based porous ceramics.

[0012] Furthermore, in step 1, the mass ratio of fly ash beads and perlite is controlled to be (2.5-3.5):1.

[0013] Furthermore, in step 1, the sintering aid includes one or more of sodium silicate, sodium tetraborate and glass powder.

[0014] Furthermore, in step 1, the sintering aid also includes boric acid.

[0015] Furthermore, in step 1, the mass of the sintering aid accounts for 5% to 50% of the total mass of the fly ash beads and the perlite.

[0016] Furthermore, in step 1, the pore-forming agent is one or more of silicon carbide, calcium carbonate, magnesium carbonate and sodium bicarbonate.

[0017] Furthermore, in step 1, the mass of the pore former accounts for 2.5% to 20% of the total mass of the fly ash beads and the perlite.

[0018] Furthermore, in step 3, the drying temperature of the oven is controlled to be 60-100° C., and the drying time is 12-48 hours.

[0019] Furthermore, in step 4, the sintering temperature is controlled to be 700-1000° C. and kept warm for 1-2 hours.

[0020] The present invention also provides a high-strength floating fly ash-based porous ceramic, which is prepared by the above-mentioned low-temperature preparation method.

[0021] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects:

[0022] The low-temperature preparation method of the high-strength floating fly ash-based porous ceramics of the present invention uses fly ash floating beads and perlite powder as raw materials to obtain fly ash-based porous ceramics with uniform structure and high strength, and retains the hollow structure of fly ash, thereby reducing the density of the porous ceramics and improving its floating properties. In addition, the use of fly ash floating beads as the main raw material has a wide source of materials, low cost, and realizes the solid waste utilization of fly ash.

[0023] In the low-temperature preparation method of the high-strength floating fly ash-based porous ceramics of the present invention, the sintering temperature is low, which greatly reduces the energy consumption.

[0024] In the low-temperature preparation method of the high-strength floating fly ash-based porous ceramic of the present invention, the structural collapse of the ceramic is avoided by controlling the temperature and time during the sintering process, and finally a porous ceramic with a complete structure and relatively uniform distribution of floating beads is obtained.

[0025] The high-strength floating fly ash-based porous ceramic of the present invention has a density of 0.6-0.9 g / m3, a volume shrinkage of 3%-15%, a porosity of 25%-50%, the pores are mainly closed pores, and a compressive strength of 5-21 MPa. The porous ceramic has high strength, low density, good floating durability, low preparation temperature, and better maintains the hollow structure of the fly ash floating beads. With its light and porous characteristics, it can float on the water surface for a long time.

[0026] Fly ash is a kind of solid waste. Its accumulation and storage will threaten the environment, and its resource utilization is also one of the major technical problems faced by China and abroad. Fly ash floating beads are fly ash with a hollow structure. Usually, the hollow structure is destroyed by ball milling or high pressure molding to obtain porous ceramics. The present invention uses fly ash floating beads as pore-forming agents to prepare floating porous ceramics at low temperature, thereby realizing the resource utilization of fly ash floating beads.

[0027] In the present invention, the above-mentioned technical solutions can also be combined with each other to achieve more preferred combination solutions. Other features and advantages of the present invention will be described in the subsequent description, and some advantages can become obvious from the description, or can be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained through the contents pointed out in the embodiments of the description and the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] The drawings are only for the purpose of illustrating particular embodiments and are not to be construed as limiting the invention.

[0029] Figure 1 This is an optical image of the high-strength floating fly ash-based porous ceramic of Example 1 of the present invention floating on the water surface;

[0030] Figure 2This is a micrograph of the high-strength floated fly ash-based porous ceramic of Example 2 of the present invention;

[0031] Figure 3 This is a scanning electron microscope image of the high-strength floating fly ash-based porous ceramic of Example 3 of the present invention;

[0032] Figure 4 This is an optical picture of the sample in Comparative Example 1 sinking to the bottom of water after being immersed.

[0033] Figure 5 This is an optical picture of the high-strength floating fly ash-based porous ceramic according to Example 3 of the present invention floating on the water surface. DETAILED DESCRIPTION

[0034] The preferred embodiments of the present invention will be described in detail below in conjunction with the accompanying drawings, wherein the accompanying drawings constitute a part of the present invention and are used together with the embodiments of the present invention to illustrate the principles of the present invention, but are not used to limit the scope of the present invention.

[0035] The present invention provides a low-temperature preparation method of high-strength floating fly ash-based porous ceramics, comprising:

[0036] Step 1, preparing slurry: mixing fly ash beads and perlite powder, adding sintering aid and pore-forming agent to obtain a mixture, then adding water to dissolve the mixture, stirring until the mixture is uniform, and obtaining slurry;

[0037] Step 2, preparing the green body: adding monomer, crosslinking agent, dispersant, catalyst and initiator to the slurry in sequence, and stirring thoroughly after each addition of the drug until the slurry is evenly mixed; then injecting the slurry into the mold, rapidly shaking to remove air, and then standing at room temperature;

[0038] Step 3, green body drying and demoulding: putting the mold in step 2 into an oven for drying, and then removing the dried green body from the mold;

[0039] Step 4, sintering: placing the demoulded green body into a sintering furnace for sintering to obtain high-strength floating fly ash-based porous ceramics.

[0040] Specifically, in the above step 1, the fly ash floating beads are commercially available fly ash floating beads.

[0041] Specifically, in the above step 1, the perlite powder is dry-milled with a ball-to-material ratio of 3:1.

[0042] Considering that if the mesh number of perlite powder is too high, the particle size is small, and the perlite powder is easy to agglomerate, which may cause uneven structure of the green body; if the mesh number is too low, the particle size is large, and the volume is too large due to the high temperature expansion of perlite powder under the same mass, which leads to cracking after firing and affects the integrity of the sample. Therefore, the mesh number of perlite powder is controlled to be 100-400 mesh.

[0043] Specifically, in the above step 1, when the mass ratio of fly ash floating beads to perlite is too high, the sintering temperature of the fly ash floating beads is high, which reduces the strength of the obtained sample; when the mass ratio is too low, too much perlite needs to be added, and the sintering process is prone to form too much liquid phase, which increases the density of the sample and reduces its floatability. Therefore, the mass ratio of fly ash floating beads to perlite is controlled to be (2.5-3.5):1.

[0044] Specifically, in the above step 1, the sintering aid may include one or more of sodium silicate, sodium tetraborate and glass powder. These sintering aids have low melting points, which are beneficial to reducing the sintering temperature of the porous ceramic.

[0045] Specifically, in the above step 1, excessive use of sintering aid will cause excessive shrinkage of the sample, reduced porosity, increased sample density and affect its floatability; however, too little use will cause larger pores and loose bonding between ceramic particles, reducing the mechanical strength of the finished product; therefore, the mass of the sintering aid is controlled to account for 5% to 50% of the total mass of the fly ash beads and perlite.

[0046] Specifically, in the above step 1, the sintering aid may further include boric acid, the mass of which is between 5% and 50% of the mass of the fly ash beads and the perlite. Adding boric acid can reduce the sintering temperature and increase the strength of the porous ceramic.

[0047] Specifically, in the above step 1, the pore-forming agent can be one or more of silicon carbide, calcium carbonate, magnesium carbonate and sodium bicarbonate. These pore-forming agents not only have low melting point properties, but also can generate gas to form pores during the reaction process, and can also generate liquid phase to block pores at low temperatures to improve the floatability of the prepared porous ceramic.

[0048] Specifically, in the above step 1, if the amount of pore-forming agent is too much, the porosity will increase and the strength will decrease; if the amount is too little, the density of the sample will increase and the floatation will decrease; therefore, the mass of the pore-forming agent is controlled to account for 2.5% to 20% of the total mass of the fly ash floating beads and perlite.

[0049] Specifically, in the above step 1, if the amount of water is too much, the viscosity of the slurry is too low, which will cause the sample to take a long time to dry and shrink. If the amount of water is too little, the viscosity of the slurry will be too high, which will affect the uniformity of the sample structure. Therefore, the ratio of water to the mass of fly ash beads and perlite is controlled to be 0.9-1.1:1.

[0050] Specifically, in the above step 1, the stirring time is controlled to be 5 to 10 minutes.

[0051] Specifically, in the above step 2, the monomer can be selected from one or more of methacrylamide, N-vinyl pyrrolidone, methacrylamide and acrylamide. If the amount of monomer is too much, the sample cost will increase and degumming will be difficult. If the amount is too little, the quality and strength of the porous ceramic will decrease, and deformation or cracking may occur. Therefore, the mass of the monomer is controlled to be 9% to 14% of the mass of the fly ash beads and perlite.

[0052] Specifically, in the above step 2, the cross-linking agent may be N,N'-methylenebisacrylamide and / or N-hydroxymethylacrylamide.

[0053] Specifically, in the above step 2, too much cross-linking agent will lead to too high a degree of cross-linking, which will increase the production cost of the sample and cause difficulty in subsequent debonding; too little cross-linking agent may cause the polymer to be not tightly bound, thereby reducing the strength of the sample. Therefore, the mass of the cross-linking agent is controlled to be 1% to 3% of the mass of the fly ash beads and perlite.

[0054] Specifically, in the above step 2, the dispersant can be selected from one or more of sodium polyacrylate, polyvinyl alcohol, sodium carboxymethyl cellulose, polyethylene glycol and triamine citrate. Too much dispersant will increase the preparation cost and may cause the slurry viscosity to increase again; too little may not effectively disperse the ceramic particles, resulting in instability of the suspension, and some ceramic slurries may aggregate and settle. Therefore, the mass and percentage of the dispersant to the mass of the fly ash beads and perlite is controlled to be 1% to 3%.

[0055] Specifically, in the above step 2, the catalyst may be tetramethylethylenediamine and / or N,N-dimethylaniline. Too much catalyst may form extra reaction intermediates, leading to undesirable side reactions and increasing the preparation cost; too little catalyst may limit the contact opportunities between reactant molecules and catalysts, thereby reducing the reaction rate. Therefore, the mass of the catalyst is controlled to be 1% to 2% of the mass of the fly ash beads and perlite.

[0056] Specifically, in the above step 2, the initiator can be selected from one or more of ammonium persulfate, potassium persulfate and hydrogen peroxide. Too much initiator will lead to too fast or uncontrolled reaction, reducing product quality; too little will lead to a slow reaction rate, and it may take longer to reach the expected reaction degree. Therefore, the mass of the initiator is controlled to be 1% to 2% of the mass of the fly ash beads and perlite.

[0057] Specifically, in the above step 2, if the standing time at room temperature is too long, the solid particles or the dispersed system will aggregate together to form a non-uniform structure, thereby affecting the performance of the product; if the standing time is too short, the sample microstructure may be non-uniform and produce defects such as deformation or cracking, thereby reducing the product quality. Therefore, the standing time at room temperature is controlled to be 1 to 4 hours.

[0058] Specifically, in the above step 3, the drying temperature of the oven is controlled to be 60-100° C., and the drying time is 12-48 hours.

[0059] Specifically, in the above step 4, if the sintering temperature is too high, part of the fly ash will begin to melt, the internal pore structure will collapse, the sample density will increase, and the floatability will be lost; if the temperature is too low, the sample will not be sintered and the mechanical properties will be low. Therefore, the sintering temperature is controlled to be 700-1000℃ and kept for 1-2h.

[0060] The present invention also provides a high-strength floating fly ash-based porous ceramic, which is prepared by the above-mentioned preparation method. The above-mentioned preparation method uses a sintering aid to reduce its sintering temperature and provide an appropriate amount of liquid phase, and the gas generated by the pore-forming agent at high temperature forms pores in the liquid phase, and the gas affects the fluidity of the liquid phase to form closed pores, further reducing the density of the porous ceramic to improve its floating property.

[0061] Specifically, the density of the high-strength floating fly ash-based porous ceramic of the present invention is 0.6 to 0.9 g / m 3 The volume shrinkage rate is 3% to 15%, the porosity is 25% to 50%, the pores are mainly closed cells, the compressive strength is 5 to 21 MPa, and the floating time is 40h to long-term floating.

[0062] The high-strength floating fly ash-based porous ceramics of the present invention can be used as floating catalyst carriers, underwater landscape ceramics and carriers of underwater landscapes, etc.

[0063] Compared with the prior art, the low-temperature preparation method of the high-strength floating fly ash-based porous ceramics of the present invention uses fly ash floating beads and perlite powder as raw materials to obtain fly ash-based porous ceramics with uniform structure and high strength, and retains the hollow structure of fly ash, thereby reducing the density of the porous ceramics and improving its floating properties. In addition, the use of fly ash floating beads as the main raw material has a wide source of materials, low cost, and realizes the solid waste utilization of fly ash.

[0064] In the low-temperature preparation method of the high-strength floating fly ash-based porous ceramics of the present invention, the sintering temperature is low, which greatly reduces the energy consumption.

[0065] In the low-temperature preparation method of the high-strength floating fly ash-based porous ceramic of the present invention, the temperature and time are controlled during the sintering process to avoid the structural collapse of the ceramic, and finally a ceramic with a complete structure and relatively uniform distribution of floating beads (available for use) is obtained. Figure 2 Description) of porous ceramics.

[0066] The high-strength floating fly ash-based porous ceramic of the present invention has high strength, low density, good floating durability, low preparation temperature, and better maintains the hollow structure of the fly ash floating beads. With its light weight and porous characteristics, it can float on the water surface for a long time.

[0067] Example 1

[0068] This embodiment provides a low-temperature preparation method of high-strength floating fly ash-based porous ceramics, comprising:

[0069] Select fly ash floating beads sieved with 120-200 mesh and ball-milled pearlite powder in a mass ratio of 3.2:1 as raw materials, add 25% of the raw material mass of sintering aid (sodium silicate), add 3% of the raw material mass of pore-forming agent magnesium carbonate, add water in a mass ratio of 1:1 to the raw material as solvent, and stir evenly; add 10% of the raw material mass of monomer (methacrylamide), tilt 45° and stir at a uniform speed for 2 minutes, then add 1.2% of the raw material mass of cross-linking agent (N,N'-methylenebisacrylamide), stir at a uniform speed to a low viscosity state, add 1.1% of the raw material mass of dispersant (sodium polyacrylate), stir quickly to the initial state, add 1% of the raw material mass of initiator (ammonium persulfate), speed up and stir quickly within 3 minutes to ensure full dissolution, and add 1% of the mass of catalyst (tetramethylethylenediamine);

[0070] The blank was injected into the mold and shaken quickly to remove the air inside the blank. After standing at room temperature for 2 hours, it was placed in an oven for drying at a temperature of 80°C and a drying time of 40 hours. Finally, after demolding, it was sintered in a sintering furnace at a maximum sintering temperature of 800°C and a holding time of 1 hour to obtain high-strength floating fly ash-based porous ceramics.

[0071] This embodiment carried out multiple parallel experiments. The density of the high-strength floating fly ash-based porous ceramic in this embodiment is 0.6-0.8 g / m 3 , volume shrinkage rate is 3% to 6%, compressive strength is 5 to 9 MPa, and floating time in water is 40 to 60 hours.

[0072] like Figure 1 As shown, the high-strength floating fly ash-based porous ceramics of this embodiment can float on the water surface.

[0073] Example 2

[0074] Select fly ash floating beads sieved with 120-200 mesh and ball-milled pearlite powder in a mass ratio of 3.5:1 as raw materials, add 50% of the raw material mass of sintering aid (mixture of sodium tetraborate and boric acid), add 5% of the raw material mass of pore-forming agent calcium carbonate, add water in a mass ratio of 1:1 to the raw material as solvent, and stir evenly; add 12% of the raw material mass of monomer (acrylamide), tilt 45° and stir at a uniform speed for 2 minutes, then add 1.5% of the raw material mass of cross-linking agent (N,N'-methylenebisacrylamide), stir evenly to a low viscosity state, add 1.8% of the raw material mass of dispersant (sodium polyacrylate), stir evenly to the initial state, add 1.3% of the raw material mass of initiator (potassium persulfate), stir evenly within 3 minutes to ensure full dissolution, and add 1% of the mass of catalyst (tetramethylethylenediamine);

[0075] The blank was injected into the mold and rapidly shaken to remove the air inside the blank. After standing at room temperature for 2 hours, it was placed in an oven for drying at 90°C for 30 hours. Finally, after demolding, it was sintered in a sintering furnace at a maximum sintering temperature of 800°C and a holding time of 2 hours. A high-strength floating fly ash-based porous ceramic was obtained.

[0076] This embodiment carried out multiple parallel experiments. The density of the high-strength floating fly ash-based porous ceramic in this embodiment is 0.7-0.86 g / m 3 , volume shrinkage rate 8% ~ 13.5%, compressive strength 10 ~ 15MPa, floating time 450 ~ 560h.

[0077] Example 3

[0078] Select fly ash floating beads sieved with 120-200 mesh and ball-milled pearlite powder in a mass ratio of 2.9:1 as raw materials, add 50% of the raw material weight of sintering aid (mixture of sodium silicate and boric acid), add 5% of the raw material weight of pore-forming agent silicon carbide, add water in a mass ratio of 1:1 to the raw material as solvent, and stir evenly; add 11% of the raw material weight of monomer (acrylamide), tilt 45° and stir uniformly for 2 minutes, then add 1.6% of the raw material weight of cross-linking agent (N,N'-methylenebisacrylamide), stir uniformly to a low viscosity state, add 1.7% of the raw material weight of dispersant (sodium polyacrylate), stir quickly to the initial state, add 1.1% of the raw material weight of initiator (ammonium persulfate), stir quickly within 3 minutes to ensure full dissolution, and add an appropriate amount of catalyst (tetramethylethylenediamine);

[0079] The blank was injected into the mold and rapidly shaken to remove the air inside the blank. After standing at room temperature for 2 hours, it was placed in an oven for drying at 85°C for 48 hours. Finally, after demolding, it was sintered in a sintering furnace at a maximum sintering temperature of 800°C and a holding time of 2 hours. A high-strength floating fly ash-based porous ceramic was obtained.

[0080] This embodiment carried out multiple parallel experiments. The density of the high-strength floating fly ash-based porous ceramic in this embodiment is 0.6-0.87 g / m 3 , volume shrinkage rate is 6.6%~10%, compressive strength is 14.5~21MPa, and floating time is long-term floating.

[0081] Comparative Example 1:

[0082] Comparative Example 1 discloses a porous ceramic prepared by mixing the ceramic raw material powders in Example 1 in a dry state using a conventional method, pressing the ceramic raw material powders with a tablet press at 10 MPa, and then sintering at 800°C.

[0083] Comparative Example 2:

[0084] Comparative Example 2 discloses a lightweight porous ceramic prepared by using the same method as the ceramic raw material powder in Example 1, but replacing the sintering aid (sodium silicate) therein with sodium fluoride.

[0085] Comparative Example 3

[0086] Comparative Example 3 discloses a lightweight porous ceramic prepared by using the same method as the ceramic raw material powder in Example 2, but the sintering temperature is changed from 800° C. to 900° C., and the holding time is increased from 2 h to 3 h.

[0087] The relevant parameter comparison table of Examples 1-3 and Comparative Examples 1-3 is shown in Table 1 below. It can be seen from Table 1 that the porous ceramics prepared using the same ceramic raw material powder and different sintering aids (sodium fluoride) have high porosity and low strength and cannot float on the water surface.

[0088] The relevant parameter comparison table of Examples 1-3 and Comparative Examples 1-3 is shown in Table 1 below.

[0089] Table 1 Data of Examples and Comparative Examples

[0090]

[0091] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any changes or substitutions that can be easily conceived by any technician familiar with the technical field within the technical scope disclosed by the present invention should be covered within the protection scope of the present invention.

Claims

1. A low-temperature preparation method for high-strength floating fly ash-based porous ceramics. It is characterized in that include: Step 1, preparing slurry: mixing fly ash beads and perlite powder, adding sintering aid and pore-forming agent to obtain a mixture, then adding water to dissolve the mixture, stirring until the mixture is uniform, and obtaining slurry; Step 2, preparing the green body: adding monomer, crosslinking agent, dispersant, catalyst and initiator to the slurry in sequence, and stirring thoroughly after each addition of the drug until the slurry is evenly mixed; then injecting the slurry into the mold, rapidly shaking to remove air, and then standing at room temperature; Step 3, green body drying and demoulding: putting the mold in step 2 into an oven for drying, and then removing the dried green body from the mold; Step 4, sintering: placing the demoulded green body into a sintering furnace for sintering to obtain high-strength floating fly ash-based porous ceramics.

2. The low-temperature preparation method of the high-strength floating fly ash-based porous ceramic according to claim 1, It is characterized in that In the step 1, the mass ratio of fly ash beads to perlite is controlled to be (2.5-3.5):

1.

3. The low-temperature preparation method of the high-strength floating fly ash-based porous ceramic according to claim 1, It is characterized in that In step 1, the sintering aid includes one or more of sodium silicate, sodium tetraborate and glass powder.

4. The low-temperature preparation method of the high-strength floating fly ash-based porous ceramic according to claim 3, It is characterized in that In the step 1, the sintering aid also includes boric acid.

5. The low-temperature preparation method of the high-strength floating fly ash-based porous ceramic according to claim 4, It is characterized in that In the step 1, the mass of the sintering aid accounts for 5% to 50% of the total mass of the fly ash beads and the perlite.

6. The low-temperature preparation method of the high-strength floating fly ash-based porous ceramic according to claim 1, It is characterized in that In step 1, the pore-forming agent is one or more of silicon carbide, calcium carbonate, magnesium carbonate and sodium bicarbonate.

7. The low-temperature preparation method of the high-strength floating fly ash-based porous ceramic according to claim 1, It is characterized in that In the step 1, the mass of the pore former accounts for 2.5% to 20% of the total mass of the fly ash beads and the perlite.

8. The low-temperature preparation method of the high-strength floating fly ash-based porous ceramic according to claim 1, It is characterized in that In step 3, the drying temperature of the oven is controlled to be 60-100° C., and the drying is performed for 12-48 hours.

9. The low-temperature preparation method of the high-strength floating fly ash-based porous ceramic according to any one of claims 1 to 8, It is characterized in that In step 4, the sintering temperature is controlled to be 700-1000° C. and kept warm for 1-2 hours.

10. A high-strength floating fly ash-based porous ceramic, It is characterized in that The high-strength floating fly ash-based porous ceramic is prepared by the low-temperature preparation method of the high-strength floating fly ash-based porous ceramic according to any one of claims 1 to 9.

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