CN114920530A - A kind of sinter-free ceramsite and preparation method thereof - Google Patents

Abstract

The invention discloses a sintering-free ceramsite. The ceramsite has a core-shell structure, comprising a ceramsite core and at least one layer of a ceramsite shell; the ceramsite core is prepared from a core material, and the core material is based on a mass percentage. The calculation includes: sludge charcoal 60%-70%, cement 8%-15%, fly ash 10%-15%, gypsum 2%-5%, binder 0.1%-0.3%, and the balance is water; The ceramsite shell is prepared from shell material, and the shell material includes, in mass percentage, 30%-70% of ceramic fine powder and 30%-70% of cement. The non-sintering ceramsite has good adsorption performance and strength, and can be used as a sewage purification material and an ecological building material. The invention also discloses a method for preparing sintering-free ceramsite. The ceramsite is prepared without sintering through the steps of preparing a core material, granulating, spheroidizing, preparing a shell material mixture, wrapping the shell and curing. It has the characteristics of simple steps, energy saving and environmental protection.

Description

A kind of sinter-free ceramsite and preparation method thereof

technical field

The invention relates to the technical field of sludge treatment, in particular to a non-sintering ceramsite and a preparation method thereof.

Background technique

According to data, in 2019, the daily treatment capacity of urban sewage in China reached 192 million m ³ . If 10,000 ^m3 of domestic sewage produces 5-8 tons of sludge with a moisture content of 80%, the annual output of sludge exceeds 45.55 million tons, and the harmless treatment of urban sludge in China accounts for about 53% of the total sludge. %, which means that about 21.4 million tons of municipal sludge cannot be properly treated every year. These untreated sludges not only cannot be reasonably utilized for their useful components, resulting in low economic value, but also pollute the environment and increase the environmental impact. Difficulty of handling.

The existing sludge treatment methods mainly include incineration, land utilization, mixed landfill, and building materials utilization. Among them, the utilization of building materials includes the use of sludge to prepare sludge ceramsite, which has the treatment effects of reduction, harmlessness and resource utilization. Specifically, the sludge is first treated to be harmless, stabilized and reduced to obtain dried sludge, then the dried sludge is mixed with clay, granulated into balls, and then sintered at a temperature above 850°C to form ceramics grain. The method can not only dispose of sludge in a large amount and safely, reduce the risk of environmental pollution, but also bring considerable economic benefits.

However, the sludge ceramsite prepared by this method has the problems of low strength, high energy consumption, high carbon emission and high production cost, and has been listed as a restricted industry by many cities. How to improve the strength of ceramsite prepared from sludge, and how to reduce the energy consumption, carbon emission and production cost of the preparation process, is an urgent problem to be solved to improve the utilization rate and economic value of sludge. It can be seen that the existing technology still needs to be improved and improved.

SUMMARY OF THE INVENTION

In view of the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a sinter-free ceramsite and a preparation method thereof, aiming at solving The method has the problems of high energy consumption, high carbon emission and high production cost.

In order to achieve the above object, the present invention has adopted the following technical solutions:

A sintering-free ceramsite, wherein the ceramsite has a core-shell structure, comprising a ceramsite core and at least one layer of ceramsite shell; the ceramsite core is prepared from a core material, and the core material comprises, in mass percentage, : 60% to 70% of sludge charcoal, 8% to 15% of cement, 10% to 15% of fly ash, 2% to 5% of gypsum, 0.1% to 0.3% of binder, and the balance is water; The grain shell is prepared from shell material, and the shell material comprises, in mass percentage, 30%-70% of ceramic fine powder and 30%-70% of cement.

In the non-sintering ceramsite, the sludge charcoal is prepared from organic sludge, and the organic sludge includes one of municipal sludge, printing and dyeing sludge or papermaking sludge.

In the non-sintering ceramsite, the preparation method of the sludge charcoal is obtained by dehydrating the organic sludge through chemical reagents, deep dewatering by plate and frame filtration, sludge drying and high temperature carbonization of sludge.

In the non-sintering ceramsite, the carbon element content in the sludge charcoal is 10%-25%.

In the non-sintering ceramsite, the average particle size of the sludge charcoal is 0.624-0.660 mm, and the specific surface area is 2852-5575 cm ² /g.

In the non-sintering ceramsite, the binder includes one or more of polyvinyl acid, carboxymethyl cellulose, and epoxy resin.

In the non-sintering ceramsite, the gypsum powder is dehydrated gypsum powder.

In the non-sintering ceramsite, the fly ash is a fly ash above the second grade.

In the non-sintering ceramsite, the ceramic micropowder is powder produced by a ceramic polishing process, which is prepared by dehydration, drying and drying modification.

A preparation method of sinter-free ceramsite, wherein the preparation method comprises the following preparation steps:

Step S01. Preparation of the core material: take each component in the core material according to the proportion, first stir and mix the sludge charcoal, gypsum, fly ash, and cement, then add water and a binder, and stir and mix to obtain the core material;

Step S02. Granulation: the core material is granulated by a counter-roll granulator, and the counter-roll extrusion molding obtains an elliptical cylindrical ceramsite A of 5-20 mm;

Step S03. Forming into a ball: processing the ceramsite A into a circular or oval shape by a ball throwing machine to obtain the ceramsite B;

Step S04. Preparation of shell material mixture: take cement and ceramic micropowder according to the proportion, and mix them evenly;

Step S05. Wrap the shell: put the ceramsite B into a closed disc, and spray the shell material mixture while rolling, until the surface of the ceramsite B is evenly wrapped with a layer of shell material with a thickness of 0.15-0.5 mm, to obtain a ceramic core-shell structure. grain C;

Step S06. Curing: the ceramsite C is sent to a standard curing room for curing for 24-48 hours to obtain a sinter-free ceramsite with a sludge carbon-based core-shell structure.

Beneficial effects:

The invention provides a sintering-free ceramsite and a preparation method thereof. The sintering-free ceramsite has a core-shell structure, and the ceramsite core is prepared by using sludge charcoal with a porous structure, which has better adsorption performance and lower The ceramsite can be used as a sewage purification material, the ceramsite shell has good compressive strength, can better protect the ceramsite core, and can be used as an ecological concrete material, which has good utilization value. In addition, the core material and the shell material both use cement as the binding material, and do not need to be sintered during forming, so the energy consumption during the production of ceramsite can be greatly reduced.

The preparation method of the sintering-free ceramsite has simple steps, is easy to implement, and does not require heating and sintering in the preparation process, so the energy consumption is low and the environment is more environmentally friendly.

Detailed ways

The present invention provides a non-sintering ceramsite and a preparation method thereof. In order to make the purpose, technical solution and effect of the present invention clearer and clearer, the present invention is further described in detail with the following examples. It should be understood that the specific embodiments described herein are only used to explain the present invention, but not to limit the present invention.

The invention provides a sintering-free ceramsite. The sintering-free ceramsite has a core-shell structure, comprising a ceramsite core and at least one layer of ceramsite shells wrapped around the ceramsite core, and the ceramsite core has relatively high porosity. It can not only make the sinter-free ceramsite have better adsorption performance, but also have a lower bulk density; the ceramsite shell is wrapped outside the ceramsite core, which can improve the strength and wear resistance of the sinter-free ceramsite, and improve the Ceramic appearance.

Specifically, the ceramsite core is prepared from a core material, and the core material includes, by mass percentage: 60%-70% of sludge charcoal, 8%-15% of cement, 10%-15% of fly ash, gypsum 2% to 5%, binder 0.1% to 0.3%, and the balance is water.

In the core materials of the above proportions, the sludge charcoal is prepared by pyrolysis of organic sludge, and has a porous structure, so that the prepared ceramsite can have a porous structure inside, and the porous structure can reduce the bulk density of the ceramsite, At the same time, the adsorption performance of ceramsite is greatly improved, so that ceramsite can be used as a purification material for water treatment biological filter fillers and for making ecological concrete materials.

Specifically, the organic sludge is industrial organic sludge or municipal sludge, preferably one of municipal sludge, printing and dyeing sludge or papermaking sludge, and has a relatively high organic content. After the organic sludge is pyrolyzed, the obtained sludge char has higher porosity, better adsorption performance of activated carbon, and better purification effect.

As an embodiment, in the non-sintering ceramsite, the preparation method of the sludge charcoal is: first dewatering the organic sludge through chemical reagents, then deeply dewatering through plate and frame filter press, and then drying the sludge Treatment and high temperature carbonization of sludge to obtain sludge charcoal. Specifically, the organic sludge is first dehydrated by chemical reagents, and the sludge is separated from water to reduce its moisture content; then, it is deeply dehydrated through a plate and frame filter press device to reduce its moisture content to about 60%; The sludge after the plate and frame press filtration will be formed into lumps, and the sludge lumps will be crushed by the crusher, and then sent to the sludge thermal drying furnace for drying for 10-15 minutes, and the moisture content of the dried sludge will drop to Below 20%, the sludge dry powder is obtained; then the sludge dry powder is transported to the carbonization furnace, and the spacer is indirectly heated for 15 to 30 minutes in an anaerobic state, and the heating temperature is 450 to 600 ° C. The organic matter in the mud undergoes fracture, cracking, and deoxidation reactions to obtain sludge charcoal with a porous structure, and the small molecular organic matter produced at the same time during the pyrolysis process volatilizes into combustion-supporting gas, which can save energy.

The sludge charcoal prepared by the above method has a porous structure and can be used as a raw material for sewage purification materials.

As a preferred embodiment, in the non-sintering ceramsite, the carbon element content in the sludge charcoal is 10% to 25%. In sludge charcoal, the content of carbon element directly affects the adsorption activity and strength of non-sintering ceramsite. The higher the content of carbon element, the better the adsorption performance, but the strength will be reduced. When the content of carbon in the sludge charcoal is 10% to 25%, it has better adsorption performance and moderate strength.

As another preferred embodiment, in the non-sintering ceramsite, the average particle size of the sludge charcoal is 0.624-0.660 mm, and the specific surface area is 2852-5575 cm ² /g, which has good dispersion performance and adsorption. It can be fully mixed with other components in the core material, thereby improving the purification performance of the non-sintering ceramsite.

In the core material of the above ratio, the cement is a gel material, and each component in the core material is gelled and nucleated through a hydration reaction, and the cement can provide an alkaline environment, and then promote the hydration of fly ash and ceramic fine powder. reaction. Specifically, the cement is Portland cement with the label of P.O 42.5, which has the characteristics of high strength and good wear resistance, and can improve the strength of the ceramsite core. By using cement as the bonding material, the production of ceramsite does not require sintering, thereby greatly reducing energy consumption, simplifying the production process, and making its application widely popular.

In the above-mentioned proportioning core materials, the fly ash is fly ash above the second grade, which can replace part of the cement and reduce the production cost of the sinter-free ceramsite, and the fly ash can physically disperse the cement particles. Avoid cement accumulation and make cement more evenly distributed in the core. In addition, the fly ash can undergo a hydration reaction in an alkaline environment, thereby increasing the mechanical strength of the ceramsite.

In the above-mentioned proportioning core material, the gypsum is dehydrated gypsum powder. The dehydrated gypsum powder is helpful for the stirring and mixing of the core material, and can improve the early bonding effect of the core material, and at the same time activate the ceramic fine powder to a certain extent.

In the above-mentioned proportioning core materials, the binder is an organic binder, which can enable the core materials to be rapidly formed. The organic binder includes one or more of polyvinyl acid, carboxymethyl cellulose, epoxy resin, and has the functions of thickening and bonding.

In the sinter-free ceramsite of the above structure, the ceramsite shell is prepared from a shell material, and the shell material includes, in mass percentage, 30%-70% of ceramic fine powder and 30%-70% of cement. Wherein, the ceramic micropowder is prepared by dehydration, drying and drying modification of the sludge produced by the ceramic polishing process. It can reduce the amount of cement, reduce the bulk density of ceramsite, and enhance the hardness and wear resistance of ceramsite.

Preferably, the bulk density of the ceramic micropowder is 0.70-0.9 g/m ³ , the middle diameter is 0.015-0.018 mm, and the specific surface area is 950-1775 cm ² /g, which can better reduce the bulk density of ceramsite and enhance the hardness of ceramsite. and wear resistance.

The sinter-free ceramsite of the above structure combines the core material with adsorption performance and the shell material with good compressive strength to obtain the ceramsite with a core-shell structure, and through the adsorption performance of the core material, the ceramsite can be used as sewage It can purify the material, and at the same time use the shell material to improve its compressive strength, and then it can be used as an ecological concrete material, which has good utilization value. In addition, the core material and the shell material both use cement as the binding material, and do not need to be sintered during forming, so the energy consumption during the production of ceramsite can be greatly reduced. The sludge char in the core material is prepared from organic sludge, has a porous structure, can improve the adsorption performance of ceramsite, and has low cost and sufficient raw material sources, which can greatly improve the utilization rate and economic value of organic sludge. .

The invention also discloses a preparation method of sinter-free ceramsite, the preparation method comprising the following preparation steps:

Step S01. Preparation of the core material: take each component in the core material according to the proportion, first stir and mix the sludge charcoal, gypsum, fly ash, and cement, and then add water and a binder and stir and mix to obtain the core material;

Step S02. Granulation: the core material is granulated by a counter-roll granulator, and the counter-roll extrusion molding obtains an elliptical cylindrical ceramsite A of 5-20 mm;

Step S03. Forming into balls: Process the ceramsite A into a circular or oval shape by a ball throwing machine to obtain the ceramsite B. The shape of the ceramsite B is closer to a circle. The encapsulation of the subsequent shell material is more uniform, and the strength of the prepared sinter-free ceramsite will be better;

Step S04. the preparation of shell material mixture: get cement and ceramic micropowder according to the proportion, and mix evenly to obtain shell material mixture;

Step S05. Wrap the shell: put the ceramsite B into a closed disc, and spray the shell material mixture while rolling, until the surface of the ceramsite B is evenly wrapped with a layer of shell material with a thickness of 0.15-0.5 mm, to obtain a ceramic core-shell structure. grain C;

Step S06. Curing: the ceramsite C is sent to a standard curing room for curing for 24-48 hours to obtain a sinter-free ceramsite with a sludge carbon-based core-shell structure.

Preferably, the outer shell can be a multi-layer structure. During the specific implementation process, the ratio of the core material and the shell material can be adjusted according to actual needs. Good compressive strength.

The above-mentioned preparation method for sintering-free ceramsite has simple steps, easy realization, no need for sintering in the preparation process, energy saving, and, because the prepared ceramsite has a core-shell structure and the inner core is a porous structure, it has better adsorption performance, and the outer shell has a good adsorption performance. High strength, can enhance the strength of ceramsite, so it can be used as sewage purification material or ecological concrete building material.

To further illustrate the sinter-free ceramsite and the preparation method thereof provided by the present invention, the following examples are provided.

Example 1

A sintering-free ceramsite, the ceramsite has a core-shell structure, comprising a ceramsite core and a layer of ceramsite shell; the ceramsite core is prepared from a core material, and the core material includes, in mass percentage: sludge 60% of carbon, 13% of cement, 15% of secondary fly ash, 5% of dehydrated gypsum powder, 0.3% of polyvinyl acid, and 6.7% of water; the ceramsite shell is prepared from shell material, and the shell material is based on mass percentage Including: 30% of ceramic powder, 70% of cement.

The sludge charcoal is prepared from municipal sludge, specifically: dewatering municipal sludge through chemical reagents, then deeply dewatering through plate and frame filter press, and then performing sludge drying treatment and sludge high-temperature carbonization treatment to obtain sewage sludge. peat.

The content of carbon elements in the sludge charcoal is 25%, the average particle size of the sludge charcoal is 0.624 mm, and the specific surface area is 5575 cm ² /g.

The preparation method of the sinter-free ceramsite is:

Step S01. Preparation of the core material: take each component in the core material according to the proportion, first stir and mix the sludge charcoal, gypsum, fly ash, and cement, then add water and a binder, and stir and mix to obtain the core material;

Step S02. Granulation: the core material is granulated by a counter-roll granulator, and the counter-roll extrusion molding obtains an elliptical cylindrical ceramsite A of 5-20 mm;

Step S03. Forming into a ball: processing the ceramsite A into a circular or oval shape by a ball throwing machine to obtain the ceramsite B;

Step S04. Preparation of shell material mixture: take cement and ceramic micropowder according to the proportion, and mix them evenly;

Step S05. Wrap the shell: put the ceramsite B into a closed disc, and spray the shell material mixture while rolling, until the surface of the ceramsite B is evenly wrapped with a layer of shell material with a thickness of 0.15-0.5 mm, to obtain a ceramic core-shell structure. grain C;

Step S06. Curing: The ceramsite C is sent to a standard curing room for curing for 24 hours to obtain a sinter-free ceramsite with a sludge carbon-based core-shell structure.

Example 2

A non-sintering ceramsite, the ceramsite has a core-shell structure, including a ceramsite core and two layers of ceramsite shells; the ceramsite core is prepared from a core material, and the core material includes, in mass percentage: sludge 70% of carbon, 10% of cement, 10% of secondary fly ash, 2% of dehydrated gypsum, 0.3% of carboxymethyl cellulose, and 6.7% of water; the ceramsite shell is prepared from shell materials, and the shell materials are based on mass The percentage meter includes: 70% of ceramic powder, 30% of cement.

The sludge charcoal is prepared from printing and dyeing sludge, the content of carbon element in the sludge charcoal is 25%, the average particle size of the sludge charcoal is 0.650mm, and the specific surface area is 3350cm ² /g.

The preparation method of the sinter-free ceramsite and the preparation method of the sludge charcoal are basically the same as those in Example 1, the difference is that the shell is wrapped twice in step S05, so that the obtained sinter-free ceramsite has two layers of ceramsite shells. .

Example 3

A non-sintering ceramsite, the ceramsite has a core-shell structure, including a ceramsite core and a three-layer ceramsite shell; the ceramsite core is prepared from a core material, and the core material includes, by mass percentage: sludge 65% of carbon, 15% of cement, 12% of third-grade fly ash, 3% of dehydrated gypsum, 0.1% of epoxy resin, and 4.9% of water; the ceramsite shell is prepared from shell material, and the shell material is calculated by mass percentage Including: ceramic powder 50%, cement 50%.

The sludge charcoal is prepared from papermaking sludge, the content of carbon element in the sludge charcoal is 20%, the average particle size of the sludge charcoal is 0.630 mm, and the specific surface area is 4665 cm ² /g.

The preparation method of the sinter-free ceramsite and the preparation method of the sludge charcoal are basically the same as those in Example 1, except that the shell is wrapped three times in step S05, so that the obtained sinter-free ceramsite has three layers of ceramsite shells.

Example 4

A non-sintering ceramsite, the ceramsite has a core-shell structure, including a ceramsite core and two layers of ceramsite shells; the ceramsite core is prepared from a core material, and the core material includes, in mass percentage: sludge 62% of carbon, 12% of cement, 13% of fly ash, 4% of gypsum, 0.1% of polyvinyl acid, 0.1% of carboxymethyl cellulose, and 8.8% of water; the ceramsite shell is prepared from shell material, and the shell In terms of mass percentage, the materials include: 60% of ceramic micropowder and 40% of cement.

The sludge charcoal is prepared from municipal sludge, the content of carbon element in the sludge charcoal is 15%, the average particle size of the sludge charcoal is 0.660 mm, and the specific surface area is 2852 cm ² /g.

The preparation method of the sinter-free ceramsite and the preparation method of the sludge charcoal are basically the same as those in Example 1, the difference is that the shell is wrapped twice in step S05, so that the obtained sinter-free ceramsite has two layers of ceramsite shells. .

Example 5

A non-sintering ceramsite, the ceramsite has a core-shell structure, including a ceramsite core and two layers of ceramsite shells; the ceramsite core is prepared from a core material, and the core material includes, in mass percentage: sludge 66% of carbon, 12% of cement, 12% of secondary fly ash, 3% of dehydrated gypsum, 0.2% of polyvinyl acid, and 6.8% of water; the ceramsite shell is prepared from shell material, and the shell material is calculated by mass percentage Including: ceramic powder 65%, cement 35%.

The sludge charcoal is prepared from municipal sludge, the content of carbon elements in the sludge charcoal is 22%, the average particle size of the sludge charcoal is 0.633mm, and the specific surface area is 4887cm ² /g

The preparation method of the sinter-free ceramsite and the preparation method of the sludge charcoal are basically the same as those in Example 1, the difference is that the shell is wrapped twice in step S05, so that the obtained sinter-free ceramsite has two layers of ceramsite shells. .

Comparative Example 1

A non-sintering ceramsite, the ceramsite is a solid spherical particle prepared from a core material, and the core material comprises, in mass percentage: 66% of sludge charcoal, 12% of cement, 12% of fly ash, 3% of gypsum %, polyvinyl acid 0.2%, water 6.8%. The preparation method is as follows: taking each component in the core material according to the proportion, first stirring and mixing sludge charcoal, gypsum, fly ash and cement, then adding water and a binder, stirring and mixing to obtain the core material; then mixing the core material Granulate through a roller granulator, extrude the 5-20mm elliptical cylindrical ceramsite, and then process the elliptical ceramsite into a round ceramsite by a ball throwing machine, and then send the ceramsite into the After curing in a standard curing room for 24 hours, sinter-free ceramsite was obtained.

Comparative Example 2

A non-sintering ceramsite, the ceramsite adopts basically the same composition ratio and preparation method as in Example 5, and also has a core-shell structure, the difference is that the sludge charcoal in the core material is replaced with dried Sludge dry powder.

Comparative Example 3

A sintered ceramsite, the sintered ceramsite is mixed with 66% dried sludge and 34% clay, granulated into balls, and then sintered at a temperature above 850° C. to form ceramsite.

Performance Testing

The sinter-free ceramsites described in Examples 1-5, the sinter-free ceramsites described in Comparative Examples 1-2, and the sintered ceramsites described in Comparative Example 3 were subjected to adsorption performance and strength tests. The adsorption performance test method is as follows: put the same weight of ceramsite into water containing a certain concentration of humic acid, stir for 2 hours, measure the concentration of humic acid, and calculate the removal rate according to the initial concentration. The strength test method is carried out in accordance with "GBT4740-1999 - Test Method for Compressive Strength of Ceramic Materials". The specific test results are shown in Table 1.

Table 1. Performance test results of sinter-free ceramsite

Humic acid removal rate (%) Compressive strength (MPa) Example 1 21.2 17.01 Example 2 32.8 10.53 Example 3 25.4 14.87 Example 4 26.1 13.73 Example 5 26.6 13.59 Comparative Example 1 29.6 3.36 Comparative Example 2 6.8 10.49 Comparative Example 3 15.13 7.25

It can be seen from Table 1: the humic acid removal rate and compressive strength of Examples 1-5 have higher values, indicating that their adsorption performance and compressive performance are good, although Comparative Example 1 has a relatively high humic acid removal rate. , but its compressive strength is poor and cannot be used as a building material. Although Comparative Example 2 has good compressive strength, its adsorption performance is poor and cannot be used as a sewage purification material. Comparative Example 3 has both adsorption performance and compressive strength. The difference compared with the embodiment 1-5. It can be seen that the sinter-free ceramsite of the present invention has better comprehensive evaluation of adsorption performance and compressive performance, can be used for sewage purification materials or ecological concrete building materials, and has wide application value.

It can be understood that for those of ordinary skill in the art, equivalent replacements or changes can be made according to the technical solutions of the present invention and the inventive concept thereof, and all these changes or replacements should belong to the protection scope of the appended claims of the present invention.

Claims (10)

1. a sintering-free ceramsite, is characterized in that, described ceramsite is a core-shell structure, comprising ceramsite core and at least one layer of ceramsite shell; Described ceramsite core is prepared by core material, and described core material presses The mass percentage meter includes: sludge charcoal 60%-70%, cement 8%-15%, fly ash 10%-15%, gypsum 2%-5%, binder 0.1%-0.3%, the balance is water The ceramsite shell is prepared from shell material, and the shell material comprises, in mass percentage, 30%-70% of ceramic fine powder and 30%-70% of cement. 2. The non-sintering ceramsite according to claim 1, wherein the sludge charcoal is prepared from organic sludge, and the organic sludge comprises one of municipal sludge, printing and dyeing sludge or papermaking sludge. kind. 3. The sinter-free ceramsite according to claim 2, characterized in that, the preparation method of the sludge charcoal is: dewatering the organic sludge by chemical reagents, deep dewatering by plate and frame filtration, and drying the sludge. Treatment and high-temperature carbonization of sludge are obtained. 4. The non-sintering ceramsite according to claim 3, characterized in that, the carbon element content in the sludge charcoal is 10% to 25%. 5 . The sinter-free ceramsite according to claim 3 , wherein the average particle size of the sludge charcoal is 0.624-0.660 mm, and the specific surface area is 2852-5575 cm ² /g. 6 . 6 . The non-sintering ceramsite according to claim 1 , wherein the binder comprises one or more of polyvinyl acid, carboxymethyl cellulose, and epoxy resin. 7 . 7. The sinter-free ceramsite according to claim 1, wherein the gypsum powder is dehydrated gypsum powder. 8 . The sinter-free ceramsite according to claim 1 , wherein the fly ash is a fly ash of two or more grades. 9 . 9 . The sinter-free ceramsite according to claim 1 , wherein the ceramic micropowder is powder produced by a ceramic polishing process, and is prepared by dehydration, drying and drying modification. 10 . 10. A preparation method of the sinter-free ceramsite according to any one of claims 1-9, wherein the preparation method comprises the following preparation steps: Step S01. Preparation of the core material: take each component in the core material according to the proportion, first stir and mix the sludge charcoal, gypsum, fly ash, and cement, then add water and a binder, and stir and mix to obtain the core material; Step S02. Granulation: the core material is granulated by a counter-roll granulator, and the counter-roll extrusion molding obtains an elliptical cylindrical ceramsite A of 5-20 mm; Step S03. Forming into a ball: process the ceramsite A into a circular or oval shape by a ball throwing machine to obtain the ceramsite B; Step S04. Preparation of the shell material mixture: take the cement and the ceramic fine powder according to the proportion, and mix them uniformly; Step S05. Wrap the shell: put the ceramsite B into a closed disc, and spray the shell material mixture while rolling, until the surface of the ceramsite B is evenly wrapped with a layer of shell material with a thickness of 0.15 to 0.5 mm, to obtain a ceramic core-shell structure. grain C; Step S06. Curing: the ceramsite C is sent to a standard curing room for curing for 24-48 hours, to obtain a sinter-free ceramsite with a sludge carbon-based core-shell structure.