CN114538813A - Geopolymer artificial aggregate based on disc granulator and preparation method thereof - Google Patents

Abstract

The invention discloses a geopolymer artificial aggregate based on a disc granulator and a preparation method thereof. The method includes: adding solid material into a disc granulator, and starting the disc granulator; spraying an alkali activator solution into the rotating disc granulator to carry out a geopolymerization reaction to obtain geopolymer aggregate particles; The surface of the particles is dried and then cured to obtain a geopolymer artificial aggregate; by mass percentage, the solid material consists of 20%-100% of the main cementitious material and 0%-80% of the secondary cementitious material; the main cementitious material It is composed of 100%-80% of fly ash and 0%-20% of granulated blast furnace slag powder; the secondary cementitious material is selected from industrial by-products or waste. The artificial aggregate of the present invention provides a new possibility for the replacement of natural aggregate, and solves the environmental problems of shortage of aggregate and accumulation of industrial by-products. There is also no need to add cement during the firing process, which avoids the problem of a large amount of greenhouse gases being emitted from cement calcination.

Description

A kind of geopolymer artificial aggregate based on disc granulator and preparation method thereof

technical field

The invention relates to the technical field of building materials, in particular to a geopolymer artificial aggregate based on a disc granulator and a preparation method thereof.

Background technique

At present, the use of industrial solid by-products or solid waste to prepare artificial aggregate is a feasible way to solve the current shortage of natural aggregate resources and the environmental problems caused by solid waste landfill. There are relatively mature aggregate preparation technologies including sintering method and cold bonding method, such as sintered fly ash ceramsite and cement cold bonded aggregate. However, the sintering method needs to provide a high temperature higher than 1000 degrees Celsius, and has high cost and large emissions. The cold bonding method needs to use 10%-20% cement, but a large amount of carbon dioxide is emitted during the high temperature calcination of cement.

An alkali-excited geopolymer gelling material has become a reasonable and effective solution. Specifically, the silicon-aluminum-calcium phase material is excited by an alkaline solution, so that the material can harden quickly to form a gel with a certain strength. coagulation material. Due to the advantages of low energy consumption, excellent mechanical properties and outstanding durability, the material is a very potential building material. Fly ash and granular blast furnace slag are two very common geopolymer cementitious materials, and the prepared geopolymers have stable properties. In addition, the pressure on the environment caused by a large number of industrial solid by-products or wastes needs to be dealt with urgently, such as municipal waste incineration slag and fly ash, municipal sludge incineration ash, red mud, lithium slag, steel slag, waste glass, coal gangue, phosphorus slag, etc. .

Chinese patent document CN 108424096A discloses a kind of low-density, high-density pellets prepared by using fly ash and lime as cementitious materials, adding a small amount of cement, using light organic particles as cores, and adopting a spheroidizing process and burning at medium temperature. Ratio-strength geopolymer aggregates. However, the inventors of the present application found that the use of medium temperature calcination still consumes a large amount of energy and also generates greenhouse gas emissions.

SUMMARY OF THE INVENTION

In view of the above-mentioned deficiencies of the prior art, the purpose of the present invention is to provide a kind of geopolymer artificial aggregate based on a disc granulator and a preparation method thereof, aiming at solving the need for medium temperature calcination in the preparation method of the existing geopolymer aggregate , resulting in high energy consumption and greenhouse gas emissions.

The technical scheme of the present invention is as follows:

In a first aspect, the present invention provides a method for preparing a geopolymer artificial aggregate based on a disc granulator, comprising the steps of:

Add the solid material to the disc granulator and start the disc granulator;

Spray the alkali activator solution into the solid material in the rotating disc granulator to carry out geopolymerization reaction to obtain geopolymer aggregate particles;

drying the alkali activator solution on the surface of the prepared geopolymer aggregate particles, and then curing to obtain the geopolymer artificial aggregate;

Wherein, in terms of mass percentage, the solid material is composed of 20%-100% of the main cementing material and 0%-80% of the secondary cementing material; wherein the main cementing material is composed of 100%-80% of fly ash It is composed of 0%-20% of granulated blast furnace slag powder; the secondary cementitious material is selected from industrial by-products or industrial solid waste.

Optionally, before the step of adding the solid material to the disc granulator, it further includes the step of: fully mixing and stirring the primary gelling material and the secondary gelling material uniformly.

Optionally, after the step of adding the solid material to the disc granulator, and before the step of starting the disc granulator, it further includes the step of: uniformly spraying the solid material in the disc granulator Total mass 5% alkali activator solution.

Optionally, after the step of adding the solid material to the disc granulator, and before the step of starting the disc granulator, the step further includes the step of: setting the inclination angle of the disc granulator to 40° -50°, set the rotation speed of the disc granulator to 25-35r/min. .

Optionally, the alkali activator solution is sprayed in four stages within 6 minutes after starting the disc granulator, wherein 47.5% of the total mass of the alkali activator solution is sprayed at a uniform speed within 0-1.5 minutes, and within 1.5-3 minutes. 23.75% of the total mass of the alkali activator solution was sprayed at a uniform speed, 11.875% of the total mass of the alkali activator solution was uniformly sprayed within 3-4.5 minutes, and 11.875% of the total mass of the alkali activator solution was uniformly sprayed within 4.5-6 minutes.

Optionally, the alkali activator solution is prepared by the following method: dissolving industrial anhydrous sodium metasilicate in water, stirring and cooling to obtain the alkali activator solution;

Alternatively, sodium hydroxide is dissolved in a sodium silicate solution, stirred, and cooled to obtain the activator solution.

Optionally, the alkali activator is selected from at least one of industrial anhydrous sodium metasilicate, sodium hydroxide, and sodium carbonate.

Optionally, the step of drying the alkali activator solution on the surface of the prepared geopolymer aggregate particles, and then performing maintenance, specifically includes: placing the prepared geopolymer aggregate particles in the air at room temperature to dry. After drying until the alkali activator solution is dry, put it into an electric heating oven with a temperature of 60°C-105°C for 24-48 hours, and then perform curing in normal temperature air for 28 days or more.

Optionally, the particle size of the geopolymer artificial aggregate is 5-20 mm.

In a second aspect, the present invention provides a geopolymer artificial aggregate, which is prepared by the method for preparing a geopolymer artificial aggregate based on a disc granulator according to the present invention.

Beneficial effects: The present invention adopts industrial solid by-products (fly ash and granulated blast furnace slag powder) as the main cementing material, or supplemented by a small amount of other industrial solid by-products or wastes as the secondary cementing material, and the pellet mill is processed in a disc granulator. The alkali activator solution is sprayed while rotating, so that it aggregates to form geopolymer aggregate particles. After the surface of the geopolymer aggregate particles is dried, the alkali activator solution can be obtained with good mechanical properties and excellent durability after curing. Performance geopolymer artificial aggregates. The artificial aggregate of the invention provides a new possibility for the replacement of natural aggregates, and to a certain extent solves the environmental problems of shortage of aggregates and accumulation of industrial solid by-products and wastes. In addition, the operation of the turntable of the present invention consumes less energy and does not need to add cement, thereby avoiding the problem that cement calcination emits a large amount of greenhouse gases. In addition, the method of the present invention is convenient to operate, does not need complicated and special production equipment, has simple process and low production cost.

Detailed ways

The present invention provides a geopolymer artificial aggregate based on a disc granulator and a preparation method thereof. In order to make the purpose, technical scheme and effect of the present invention clearer and clearer, the present invention is further described below in detail. 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 embodiment of the present invention provides a method for preparing a geopolymer artificial aggregate based on a disc granulator, wherein the method includes the steps:

S10, adding the solid material to the disc granulator, and starting the disc granulator;

S20, spraying the alkali activator solution into the solid material in the rotating disc granulator to carry out a geopolymerization reaction to obtain geopolymer aggregate particles;

S30, drying the alkali activator solution on the surface of the prepared geopolymer aggregate particles, and then curing to obtain the geopolymer artificial aggregate;

Wherein, in terms of mass percentage, the solid material is composed of 20%-100% of the main cementing material and 0%-80% of the secondary cementing material; wherein the main cementing material is composed of 100%-80% of fly ash It is composed of 0%-20% of granulated blast furnace slag powder; the secondary cementitious material is selected from industrial by-products or industrial solid waste.

In this embodiment, only the main cementitious material may be added, or a part of the main cementitious material may be replaced by the secondary cementitious material, wherein the main cementitious material may be all fly ash, or granulated blast furnace slag powder may be used to replace part of the main cementitious material The addition of fly ash and granulated blast furnace slag powder can effectively improve the mechanical properties of the prepared artificial aggregate.

In this embodiment, the secondary gelling material is selected from industrial by-products or industrial solid wastes that can be excited by alkali or have weak ability to be excited by alkali or cannot be excited by alkali. In one embodiment, the secondary cementitious material is at least selected from municipal waste incineration slag and fly ash, municipal sludge incineration ash, red mud, lithium slag, steel slag, waste glass, coal gangue and phosphorus slag, etc. One, but not limited to this.

In this example, industrial solid by-products and wastes are used as the main raw materials, and the alkali activator solution is sprayed while the disc granulator is rotating, so as to aggregate them to form geopolymer aggregate particles, and the surface of the geopolymer aggregate particles is alkali excited. After the solution of the agent is dried and cured, a geopolymer artificial aggregate with good mechanical properties (including high strength, sustainable strength growth) and excellent durability can be obtained.

This embodiment has the following advantages:

1, the present embodiment uses industrial solid by-products and wastes as preparation raw materials, and uses alkaline solution as activator, the production cost is low, the reaction process does not produce toxic gas, has the advantages of environmental protection, and turns waste into treasure, greatly solving the problem of industrial Environmental issues with solid by-products and waste accumulation.

2. The artificial aggregate in this embodiment provides a new possibility for the replacement of natural aggregate, and solves the problem of shortage of aggregate to a certain extent.

3. It is very different from most of the preparation processes using cement bonding. In this embodiment, the artificial aggregate is prepared by means of alkali excitation, without adding cement, thereby avoiding the problem of calcining cement and emitting a large amount of greenhouse gases.

4. In this embodiment, the operation of the turntable has low energy consumption, convenient operation, no complicated special production device, and simple process.

5. The strength of the artificial aggregate in this embodiment increases with the increase of the placing time, because the pozzolanic properties of the fly ash can be continuously stimulated with the development of time. The aggregate strength requirements can be adjusted according to the product performance requirements. The adjustment methods can include: changing the type and proportion of raw materials, changing the inclination angle or rotation speed of the disc granulator, changing the water consumption, and changing the rate of spraying the alkali activator solution. , change the content or type of activator, change the maintenance method, etc. In addition, the properties such as alkalinity and water absorption of the aggregate can also be adjusted according to the product performance requirements, and can also be adjusted by the above-mentioned methods.

In step S10, in one embodiment, before the step of adding the solid material to the disc granulator, it further includes the step of: fully mixing and stirring the primary gelling material and the secondary gelling material evenly.

In step S10, in one embodiment, after the step of adding the solid material to the disc granulator, and before the step of starting the disc granulator, it further includes the step of: adding the solid material to the disc granulator. The solid material in the medium is evenly sprayed with a solution of alkali activator accounting for 5% of the total mass. That is to say, in terms of mass percentage, the amount sprayed in this step is 5% of the total amount of the alkali activator solution. In this embodiment, the alkali activator solution is uniformly sprayed on the solid material before starting, which can prevent the disk granulator from being filled with dust due to too small particle size of the solid material after the disk granulator is started.

In one embodiment, after the step of adding the solid material to the disc granulator, and before the step of starting the disc granulator, it further includes the step of: setting the inclination angle of the disc granulator For 40°-50°, set the rotation speed of the disc granulator to 25-35r/min. Both the inclination angle and the rotation speed provide energy for granulation, and they need to be set within a reasonable range according to the materials used. If too large, it will cause cohesion between particles, and if too small, the cohesion will be insufficient, which is not conducive to the granulation of particles. Effect.

In one embodiment, step S10 specifically includes: adding the solid material into the disc of the disc granulator, uniformly spraying the alkali activator solution on the solid material in the disc granulator, and adding the solid material to the disc granulator. Adjust to the proper inclination angle and rotation speed, and start the disc granulator.

In step S20, in one embodiment, the alkali activator solution is prepared by the following method: dissolving industrial anhydrous sodium metasilicate (as the activator) in water, stirring moderately to speed up the dissolution, cooling to room temperature , to obtain the alkali activator solution. Alternatively, sodium hydroxide is dissolved in a sodium silicate solution (water glass), moderately stirred to speed up the dissolution, and cooled to room temperature to obtain the activator solution. It should be noted that the normal temperature in this embodiment refers to a temperature of 20-30°C.

In one embodiment, the alkali activator in the alkali activator solution may be selected from at least one of sodium silicate, sodium hydroxide, sodium carbonate, and the like. In one embodiment, the content of sodium oxide in the alkali activator accounts for 5%-8% of the mass of the solid material, the molar ratio of silica and sodium oxide in the alkali activator is between 0.9-2, the water It accounts for 21%-27% of the solid material mass. The final prepared aggregate increases with the increase of the quality of sodium oxide in the alkali activator, but the quality of sodium oxide is too low, which will cause the quality of the aggregate to be low, while too high will cause the phenomenon of pan-alkali, and the cementitious material can be guaranteed within a certain range. fully motivated. The change of the molar ratio of silica and sodium oxide in the alkali activator will also change the performance of the final aggregate. If the quality of water is too small, on the one hand, the concentration of the alkali solution will be too high to block the nozzle, and on the other hand Insufficient humidity of the cementitious material. If the quality of water is too large, it is easy to cause cohesion between particles, and the effective formation of particles can be ensured within a certain range.

In one embodiment, step S20 specifically includes: loading the prepared alkali activator solution into a watering can, and spraying it in four stages within 6 minutes after starting the disc granulator, wherein within 0-1.5 minutes 47.5% of the total mass of the alkali activator solution is sprayed at a uniform speed, 23.75% of the total mass of the alkali activator solution is sprayed at a uniform speed within 1.5-3 minutes, 11.875% of the total mass of the alkali activator solution is sprayed at a uniform speed within 3-4.5 minutes, 4.5-6 minutes 11.875% of the total mass of the alkali activator solution was sprayed at a uniform speed. After 6 minutes, the alkali activator solution was no longer sprayed, the disc granulator continued to rotate, and the disc granulator was turned off after a total time of 10-15 minutes.

In step S30, the excess alkali activator solution on the surface of the prepared geopolymer aggregate particles is dried to avoid adhesion between particles due to the surface alkali activator solution.

In one embodiment, the step of drying the alkali activator solution on the surface of the prepared geopolymer aggregate particles, and then performing curing, specifically includes: placing the prepared geopolymer aggregate particles at room temperature After drying in the air until the alkali activator solution is dry, put it into an electric heating oven for curing for 24-48 hours, and then conduct curing in the air at room temperature (20-30°C) for 28 days or more. Aggregate strength increases with the extension of electric heating curing time, but the increase is limited beyond a certain range. Aggregate strength will continue to increase with curing time. In one embodiment, the temperature of the electric heating oven is 60°C-105°C. This temperature curing is beneficial to promote the geopolymer reaction.

In one embodiment, the particle size of the geopolymer artificial aggregate is 5-20 mm.

In this embodiment, industrial solid by-products and wastes are used as preparation raw materials, and inexpensive industrial alkali solution is used as an activator, the production cost is low, and no toxic gas is generated during the reaction process, which has the advantages of environmental protection. At the same time, the artificial aggregate in this embodiment provides a new possibility for the replacement of natural aggregate, and the requirements such as the strength of the artificial aggregate can also be adjusted according to product performance requirements. The adjustment method can include: changing the type and proportion of raw materials, Change the inclination angle or rotation speed of the disc granulator, change the water consumption, change the spraying rate of the alkali activator solution, change the content or type of the activator, change the maintenance method, etc.

The embodiment of the present invention provides a geopolymer artificial aggregate, which is prepared by the above-mentioned preparation method of the geopolymer artificial aggregate based on a disc granulator.

The geopolymer artificial aggregate prepared by the method in this example is a spherical coarse aggregate with a certain particle size range, and the aggregate particle size is 5-20 mm, which is suitable for providing skeleton function in self-compacting concrete. The water absorption rate of the aggregate is about 13%, which can provide good internal curing performance; the particle density is about 1900kg/m ³ , which is about 25% lighter than the natural aggregate; the average strength of a single particle can reach 6.9Mpa, which is even better than cement Strength level of chilled aggregates.

The present invention will be further described below through specific embodiments.

Example 1

Geopolymer artificial aggregate based on disc granulator, its composition is as follows:

(1) Fly ash is used as the main cementitious material; no secondary cementitious material is added;

(2) The alkali activator solution is prepared by dissolving industrial anhydrous sodium metasilicate and water, wherein the industrial anhydrous sodium silicate modulus (the mass ratio of silicon dioxide and sodium oxide in the activator) is 0.94, and the industrial anhydrous sodium silicate is 0.94. Sodium silicate accounts for 12% of the total mass of the main cementitious material, and water accounts for 22% of the total mass of the main cementitious material;

The granulation steps are as follows:

(1) Adjust the parameters of the disc granulator to a tilt angle of 45 degrees and a rotation speed of 30 r/min;

(2) adding the gelling material to the disc granulator, and evenly spraying the alkali activator solution accounting for 5% of the total mass;

(3) Start the disc granulator and spray in four stages within 6 minutes, wherein 47.5% of the total mass of the alkali activator solution is sprayed at a uniform speed within 0-1.5 minutes, and the total mass of the alkali activator solution is sprayed at a uniform speed within 1.5-3 minutes. 23.75% of the mass, 11.875% of the total mass of the alkali activator solution is uniformly sprayed within 3-4.5 minutes, and 11.875% of the total mass of the alkali activator solution is uniformly sprayed within 4.5-6 minutes. After 6 minutes, the alkali activator solution was no longer sprayed, the granulator continued to rotate, and the granulator was turned off after a total time of 10 minutes.

(4) The prepared geopolymer aggregate particles are placed in the air at room temperature until the alkali activator solution is dried, then placed in an electric heating oven (105°C) for curing for 24 hours, and then cured in the air at room temperature (25°C) for 28 sky.

The index performance of the geopolymer artificial aggregate obtained by the present embodiment is as follows:

24h water absorption: 13.1%;

Particle density: 1900kg/m ³ ;

Average single particle crush value: 6.9MPa.

Example 2

Geopolymer artificial aggregate based on disc granulator, its composition is as follows:

(1) Fly ash and granulated blast furnace slag powder are used as the main cementing materials, accounting for 80% and 20% of the total mass of the main cementing materials respectively; the secondary cementing materials are municipal solid waste incineration slag. The primary and secondary cementitious materials account for 80% and 20% of the total mass of all solid materials, respectively.

(2) The alkali activator solution is prepared by dissolving industrial anhydrous sodium metasilicate and water, wherein the industrial anhydrous sodium silicate modulus (the mass ratio of silicon dioxide and sodium oxide in the activator) is 0.94, and the industrial anhydrous sodium silicate is 0.94. Sodium silicate accounts for 12% of the solid material mass, and water accounts for 22% of the solid material mass;

The granulation steps are as follows:

(1) The municipal solid waste incineration slag is dried and ground into powder with a ball mill. This step is to increase the fineness and achieve the effect of improving the alkali excitation activity of the slag.

(2) Adjust the parameters of the disc granulator to a tilt angle of 45 degrees and a rotation speed of 30 r/min;

(3) the solid material is fully stirred and added to the disc granulator, and the 5% alkali activator solution is evenly sprayed;

(4) Start the disc granulator, spray in four stages within 6 minutes, and spray 47.5% of the mass of the total alkali activator solution at a uniform speed within 0-1.5 minutes, and spray the total alkali activator solution at a uniform speed within 1.5-3 minutes. 23.75% of the mass, 11.875% of the mass of the total alkali activator solution is uniformly sprayed within 3-4.5 minutes, and 11.875% of the mass of the total alkali activator solution is uniformly sprayed within 4.5-6 minutes. After 6 minutes, the alkali activator solution was no longer sprayed, the granulator continued to rotate, and the granulator was turned off after a total time of 10 minutes.

(5) The prepared geopolymer aggregate particles are placed in the air at room temperature to dry until the alkali activator solution is removed, then placed in an electric heating oven (105°C) for curing for 24 hours, and then cured in the air at room temperature (25°C). 28 days.

The index performance of the geopolymer artificial aggregate obtained by this embodiment is as follows:

24h water absorption: 15.1%;

Particle density: 1470kg/m ³ ;

The average crushing value of a single particle: 3.1MPa.

The particle size range of the geopolymer artificial aggregate prepared in the above embodiment is between 5-20mm; the water absorption rate is larger than that of the ordinary sand-gravel aggregate, which can provide good internal curing performance; the particle density is about 1470-1900kg/m ³ , It is about 25%-43% lighter than natural aggregate, and can be used to prepare lightweight aggregate concrete; the average strength of single particle can reach 3.1-6.9Mpa, which is even better than the strength level of cement cold aggregate. The addition of domestic waste incinerator slag reduces the strength but makes the aggregate lighter.

To sum up, the present invention provides a disc granulator-based geopolymer artificial aggregate and a preparation method thereof. The present invention uses industrial solid by-products or industrial solid wastes as raw materials, and uses powders with superior excitation performance. Coal ash and granulated blast furnace slag powder are used as the main cementing materials, and other industrial wastes with weak or no excitation performance are used as secondary cementing materials. The alkali activator solution is sprayed while the disc granulator is rotating, so as to aggregate to form geopolymer aggregate particles. After the surface of the geopolymer aggregate particles is dried, the alkali activator solution can be obtained after curing. Geopolymer artificial aggregate with mechanical properties and excellent durability properties. The artificial aggregate of the present invention provides a new possibility for the replacement of natural aggregate, and to a certain extent solves the environmental problems of shortage of aggregate and accumulation of industrial solid by-products and waste. In addition, the present invention does not need to add cement during the calcination process, thereby avoiding the problem that cement calcination emits a large amount of greenhouse gases. In addition, the present invention can prepare artificial aggregates with different strengths, alkalinities, water absorption rates, etc., according to different process parameters in the process, and has more functions than traditional natural sand. Finally, the method of the present invention is convenient to operate, does not need complicated and special production equipment, has simple process and low production cost.

It should be understood that the application of the present invention is not limited to the above examples. For those of ordinary skill in the art, improvements or transformations can be made according to the above descriptions, and all these improvements and transformations should belong to the protection scope of the appended claims of the present invention.

Claims (10)

1. A preparation method of geopolymer artificial aggregate based on a disc granulator is characterized by comprising the following steps:

adding a solid material to a disc granulator, and starting the disc granulator;

spraying an alkali activator solution into a solid material in a rotating disc granulator to carry out geological polymerization reaction to obtain geopolymer aggregate particles;

airing the alkali activator solution on the surface of the prepared geopolymer aggregate particles, and then maintaining to obtain the geopolymer artificial aggregate;

wherein, the solid material consists of 20-100% of a main cementing material and 0-80% of a secondary cementing material in percentage by mass; wherein the main cementing material consists of 100 to 80 percent of fly ash and 0 to 20 percent of granulated blast furnace slag powder; the secondary cementitious material is selected from industrial by-products or industrial solid waste.

2. The method for preparing geopolymer artificial aggregate based on a disc granulator according to claim 1, wherein the step of adding solid material into the disc granulator is preceded by the further steps of: and fully mixing and uniformly stirring the primary cementing material and the secondary cementing material.

3. The method for preparing geopolymer artificial aggregates based on a disc granulator according to claim 1, wherein the step of adding solid materials into the disc granulator is followed by the step of starting the disc granulator, and further comprising the steps of: the solid material in the disk granulator is uniformly sprayed with an alkali activator solution accounting for 5 percent of the total mass.

4. The method for preparing geopolymer artificial aggregates based on a disc granulator according to claim 1, wherein the step of adding solid materials into the disc granulator is followed by the step of starting the disc granulator, and further comprising the steps of: the inclination angle of the disc granulator is set to be 40-50 degrees, and the rotation speed of the disc granulator is set to be 25-35 r/min. .

5. The method for preparing geopolymer artificial aggregate based on the disk granulator according to claim 1, wherein the alkali-activator solution is sprayed in four stages within 6 minutes after the disk granulator is started, wherein 47.5% of the total mass of the alkali-activator solution is uniformly sprayed within 0-1.5 minutes, 23.75% of the total mass of the alkali-activator solution is uniformly sprayed within 1.5-3 minutes, 11.875% of the total mass of the alkali-activator solution is uniformly sprayed within 3-4.5 minutes, and 11.875% of the total mass of the alkali-activator solution is uniformly sprayed within 4.5-6 minutes.

6. The method for preparing geopolymer artificial aggregate based on a disc granulator according to claim 1, wherein the alkali-activator solution is prepared by the following method: dissolving industrial anhydrous sodium metasilicate in water, stirring and cooling to obtain the alkali activator solution;

or dissolving sodium hydroxide in a sodium silicate solution, stirring, and cooling to obtain the excitant solution.

7. The method for preparing geopolymer artificial aggregate based on a disc granulator according to claim 5, wherein the alkali activator is at least one selected from sodium industrial anhydrous meta-silicate, sodium hydroxide, and sodium carbonate.

8. The preparation method of the geopolymer artificial aggregate based on the disc granulator according to the claim 1, wherein the step of airing the alkali activator solution on the surface of the prepared geopolymer aggregate particles and then curing the dried geopolymer aggregate particles comprises the following steps: and placing the prepared geopolymer aggregate particles in normal-temperature air, airing until the alkali activator solution is aired, placing the geopolymer aggregate particles in an electric heating oven at the temperature of 60-105 ℃ for curing for 24-48 hours, and then curing in the normal-temperature air for 28 days or more.

9. The method for preparing geopolymer artificial aggregate based on a disc granulator according to claim 1, wherein the particle size of the geopolymer artificial aggregate is 5-20 mm.

10. A geopolymer artificial aggregate prepared by the method for preparing a geopolymer artificial aggregate based on a disc granulator according to any one of claims 1 to 9.