Method for preparing ceramsite raw balls by using solid waste

Abstract

The application provides a method for preparing ceramsite raw material balls by using solid waste, and the method can significantly improve the qualified rate of the ceramsite raw material balls, especially the ceramsite raw material balls with a particle size of 3-5 mm. The method comprises the following steps: 1) obtaining a solid waste powder, wherein the solid waste powder comprises fly ash, and the particle size of the fly ash satisfies D50>=15 mu m and D90<=150 mu m; 2) putting 1.5%-2.5% of the weight of the solid waste powder in step 1) into a granulator to perform granulation, and obtaining seed particles; 3) putting the remaining weight of the solid waste powder into the granulator in multiple times, continuously performing granulation and molding on the basis of the seed particles, polishing the obtained particles, and then drying, so as to obtain the ceramsite raw material balls with a required particle size through screening.

Description

TECHNICAL FIELD

[0001] The present application relates to a method for preparing ceramsite by using solid waste. BACKGROUND

[0002] The industrial waste in the solid waste in China is mainly coal-based solid waste and mineral waste. The comprehensive utilization of coal-based solid waste such as gasification slag and fly ash has important environmental and economic benefits.

[0003] At the same time, with the rise of sponge city and prefabricated building, ceramsite products have developed rapidly and have great market potential.

[0004] A method for preparing hydrophobic ceramsite lightweight aggregate is disclosed in Chinese patent application CN110117193A, the main method steps are raw material batching → granulation → first granule → pre-sintering → second granule → soaking and mixing modifier → second granule → coating hydrophobic agent → third granule → 900-1350℃ calcination—product. This method needs to go through three times of granulation, and the first granule needs to be pre-sintered.

[0005] A coal-based solid waste lightweight high-strength ceramsite and a preparation method thereof are disclosed in Chinese patent application CN110615689A, which requires that the coal gangue is 100-200 mesh, and the slag is 100-200 mesh. The performance of the final product is that the particle size is 5-20mm, the bulk density is ≤1000kg / m 3 ; the cylinder strength is >7MPa.

[0006] A method for preparing ceramsite and ceramsite prepared by the method are disclosed in Chinese patent application CN202010686193.6, which requires that the total amount of silicon, aluminum, iron and calcium in the gasification bottom slag is ≥82%; the residual carbon in the filter cake is ≥10%, and the silicon, aluminum, iron and calcium is ≥86%. The document does not require the granulation specification and the qualified rate of raw material balls.

[0007] The ceramsite preparation schemes provided in the above patent documents do not pay attention to the technical problem of how to improve the qualified rate of ceramsite raw material balls prepared by using solid waste, and some preparation schemes have the drawbacks of complicated process, etc. SUMMARY

[0008] The present application provides a method for preparing ceramsite raw material balls by using solid waste, which can significantly improve the qualified rate of ceramsite raw material balls, especially the ceramsite raw material balls with a particle size of 3-5mm.

[0009] To achieve the purpose, the present application provides the following technical solutions:

[0010] The present application provides a method for preparing ceramsite raw material balls by using solid waste, which includes the following steps:

[0011] 1) obtaining a solid waste powder, wherein the solid waste powder comprises fly ash, and the particle size of the fly ash satisfies D50≥15 μm and D90≤150 μm;

[0012] 2) feeding 1.5%-2.5% of the weight of the solid waste powder in step 1) into a granulator to perform granulation, and obtaining seed particles;

[0013] 3) feeding the remaining weight of the solid waste powder into the granulator in multiple times, continuously granulating and forming on the basis of the seed particles, polishing the obtained particles, and then drying and screening to obtain green balls with a desired particle size;

[0014] Preferably, the feeding of the remaining weight of the solid waste powder into the granulator in multiple times is feeding 1-15% of the remaining weight into the granulator each time.

[0015] Preferably, the particle size of the green balls is 3-5 mm.

[0016] In some embodiments, in step 1), the solid waste powder further optionally comprises gasification slag, the particle size of the gasification slag is ≤30 mesh, and the dry basis carbon content of the gasification slag is 15wt%-45wt%.

[0017] In some embodiments, based on 100 parts by weight of the solid waste powder, the parts by weight of fly ash is 10-100 parts, and the parts by weight of gasification slag is 0-90 parts.

[0018] In some embodiments, in step 1), the solid waste powder further optionally comprises other solid wastes, the other solid wastes comprise one or more of coal gangue, kaolin, clay, albite, potassium feldspar, bentonite, glass powder, sludge, and bottom slag, and the particle size of the other solid wastes satisfies D50≥15 μm and D90≤150 μm.

[0019] In some embodiments, in step 1), based on 100 parts by weight of the solid waste powder:

[0020] the parts by weight of fly ash is 10-100 parts, for example, 10-89 parts;

[0021] the parts by weight of gasification slag is 0-90 parts, for example, 10-89 parts;

[0022] the parts by weight of the other solid wastes is 0-30 parts, for example, 1-30 parts.

[0023] In some embodiments, in step 1), a binder is optionally added to the solid waste powder, and based on 100 parts by weight of the solid waste powder, the parts by weight of the binder is 0-5 parts.

[0024] In some embodiments, the binder is selected from one or more of starch ethers, glue powder, cellulose ethers, guar gum.

[0025] In some embodiments, the fly ash is selected from pulverized coal furnace fly ash and / or circulating fluidized bed fly ash.

[0026] In some embodiments, in step 2), water is sprayed during the granulation process to shape the solid waste powder into the seed particles in the granulator; preferably, the particle size of the seed particles is not more than 1 mm; preferably, in step 2), the total amount of water sprayed is 0.6wt%-1.5wt% of the total weight of the solid waste powder fed in step 2) and step 3).

[0027] In step 3), water is sprayed during the granulation process, and the total amount of water sprayed is 38.5wt%-39.4wt% of the total weight of the solid waste powder fed in step 2) and step 3).

[0028] In some preferred embodiments, in step 3), the amount of solid waste powder fed at a time gradually increases as the granulation process proceeds, and the amount of water sprayed at a time also gradually increases; and the amount of solid waste powder fed at a time is 1-15% of the remaining weight, and the total amount of water sprayed is 38.5wt%-39.4wt% of the total weight of the solid waste powder fed in step 2) and step 3).

[0029] In some embodiments, during the granulation process in step 2) and step 3), the rotation speed of the granulator is 700-800rpm.

[0030] Preferably, the granulator is a disc granulator.

[0031] The technical solution provided by the present application has the following beneficial effects:

[0032] By controlling the particle size of each component in the solid waste powder and feeding the solid waste powder in two parts in a specific ratio, the method of the present application can improve the qualified rate of ceramsite raw balls, especially ceramsite raw balls with a particle size of 3-5mm; preferably, when feeding the second part, the remaining weight of the solid waste powder is fed into the granulator in multiple times, taking 1-15% of the remaining weight each time, which is beneficial to improve the qualified rate of ceramsite raw balls, especially ceramsite raw balls with a particle size of 3-5mm. DETAILED DESCRIPTION

[0033] In order to facilitate the understanding of the present application, the present application will be further described below in conjunction with examples. It should be understood that the following examples are only for better understanding of the present application, and do not mean that the present application is limited to the following examples only.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The term "and / or" as used herein refers to and encompasses any and all combinations of one or more of the associated listed items.

[0035] Unless otherwise indicated, conventional methods of chemistry, molecular biology, recombinant DNA techniques and biochemistry used herein are those well known in the art. Unless otherwise indicated, all reagents are commercially available or are prepared according to procedures known in the art.

[0036] The present application provides a method for preparing ceramic raw balls by using solid waste, and based on the method, ceramic raw balls, especially ceramic raw balls with a particle size of 3-5 mm, can be prepared, and the qualified rate of the ceramic raw balls can be significantly improved. The method mainly comprises the following steps:

[0037] 1) obtaining a solid waste powder, wherein the solid waste powder comprises fly ash, and the particle size of the fly ash satisfies D50≥15 μm and D90≤150 μm;

[0038] 2) putting 1.5%-2.5% of the weight of the solid waste powder in step 1) into a granulator for granulation to obtain seed particles;

[0039] 3) putting the remaining weight of the solid waste powder into the granulator in multiple times, continuously granulating and forming on the basis of the seed particles, polishing the obtained particles, and then drying, and screening to obtain raw balls with a desired particle size; preferably, the particle size of the raw balls is 3-5 mm, and specifically, the raw balls with a target particle size of 3-5 mm can be obtained by screening.

[0040] In some preferred embodiments, in step 2), 1.5%-2.5% of the weight of the solid waste powder is put into the granulating disc of the granulator, and after the granulator is started, the solid waste powder rotates with the granulating disc, and water is sprayed while rotating until the solid waste powder in the granulating disc is formed into seed particles; preferably, the particle size of the seed particles is not more than 1 mm. Preferably, the used granulator is a disc granulator.

[0041] In some preferred embodiments, in step 3), the remaining weight of the solid waste powder is fed into the granulator in multiple times, i.e., 1-15% of the remaining weight of the solid waste powder is fed into the granulator each time. The present inventors have found that, by using this preferred feeding method, the green balls with uniform particle size can be obtained based on the seed particles obtained in step 2); if the proportion of the solid waste powder taken each time is not within the preferred range of 1-15%, it will adversely affect the qualified rate of the green balls with the target particle size, especially the green balls with the particle size of 3-5 mm; if the proportion of the solid waste powder taken each time exceeds 15%, new small particles are likely to be formed in the granulation disc, and these newly formed small particles are difficult to be formed into the green balls with the target particle size of 3-5 mm in step 3), which will eventually affect the qualified rate of the green balls with the particle size of 3-5 mm.

[0042] In some embodiments, in step 1), the solid waste powder comprises fly ash and optionally gasification slag, the particle size of the gasification slag is ≤30 mesh, and the dry basis carbon content of the gasification slag is 15wt%-45wt%. The present inventors have found that, when the gasification slag is introduced into the solid waste powder, the use of the gasification slag with the preferred particle size and dry basis carbon content for the preparation of the green balls, especially the green balls with the particle size of 3-5 mm, can improve the qualified rate of the green balls, especially the green balls with the particle size of 3-5 mm; if the dry basis carbon content of the gasification slag is too high, it is not easy to form a ball, and if the dry basis carbon content is too low, more large-particle-size green balls are likely to be obtained, which affects the qualified rate of the green balls with the particle size of 3-5 mm. In some embodiments, based on 100 parts by weight of the solid waste powder, the weight parts of fly ash is 10-100 parts, and the weight parts of gasification slag is 0-90 parts. In some embodiments, based on 100 parts by weight of the solid waste powder, the weight parts of gasification slag is 10-90, for example, 10-89 parts, and the balance is fly ash. In some embodiments, the gasification slag is dried in an oven, for example, at a drying temperature of 105°C±5°C, the dried gasification slag is manually crushed or crushed by a crusher, and is sieved through a 30 mesh sieve, and the undersize part, i.e., the gasification slag with a particle size of ≤30 mesh, is taken for subsequent granulation.

[0043] In some embodiments, in step 1), the solid waste powder further comprises, in addition to fly ash and optionally gasification slag, other solid waste, which comprises one or more of coal gangue, kaolin, clay, sodium feldspar, potassium feldspar, bentonite, glass powder, sludge, and furnace bottom slag, and the particle size of the other solid waste satisfies D50≥15 μm and D90≤150 μm. In some specific embodiments, the coal gangue, kaolin, clay, sodium feldspar, potassium feldspar, bentonite, waste glass powder, sludge, and / or furnace bottom slag, etc. are subjected to crushing, grinding, screening, and sorting, and the particle size is tested by a laser particle size tester, and particles with a particle size of D50≥15 μm and D90≤150 μm are selected for subsequent granulation; if the powder screened as described above does not satisfy the particle size requirement, the powder needs to be repeatedly ground, screened, and sorted until the particle size satisfies D50≥15 μm and D90≤150 μm.

[0044] In some embodiments, in step 1), based on 100 parts by weight of the solid waste powder, the weight parts of fly ash is 10-100 parts, the weight parts of gasification slag is 0-90 parts, for example 10-90 parts (for example 10-89 parts), and the weight parts of other solid waste is 0-30 parts, for example 1-30 parts. In some embodiments, based on 100 parts by weight of the solid waste powder, at least 10 parts by weight of fly ash is included, and the balance is gasification slag and / or other solid waste, for example the weight parts of gasification slag is 10-90 parts, and the weight parts of other solid waste is 1-30 parts. In some embodiments, the solid waste powder is composed of fly ash and gasification slag, for example 10-100 parts by weight of fly ash and the balance of gasification slag; in some embodiments, the solid waste powder is composed of fly ash and other solid waste, for example 0-30 parts by weight (for example 1-30 parts by weight) of other solid waste and the balance of fly ash; in some embodiments, the solid waste powder is composed of fly ash, gasification slag, and other solid waste, for example 10-100 parts by weight (for example 10-89 parts by weight) of fly ash, 0-90 parts by weight (for example 10-89 parts by weight) of gasification slag, and 0-30 parts by weight (for example 1-30 parts by weight) of other solid waste. In some embodiments, the solid waste powder is fly ash.

[0045] In some embodiments, in step 1), a binder is optionally added to the solid waste powder, and based on 100 parts by weight of the solid waste powder, the weight parts of the binder is 0-5 parts. The type of binder is not particularly limited, and a binder conventionally used in the art can be used, for example but not limited to one or more selected from the group consisting of starch ethers, glue powder, cellulose ethers, and guar gum.

[0046] In the method for preparing raw haydite balls from solid waste provided by the application, the particle size of the fly ash used in the solid waste powder needs to meet D50≥15 μm and D90≤150 μm, and the fly ash can be derived from, but is not limited to, pulverized coal furnace fly ash, circulating fluidized bed fly ash, etc. In some specific embodiments, the fly ash is tested for particle size distribution by using a laser particle size tester, and the part meeting D50≥15 μm and D90≤150 μm is obtained by screening, sorting and other processing technologies for subsequent granulation; if the screened powder does not meet the particle size requirement, the grinding, screening and sorting need to be repeated until the particle size meets D50≥15 μm and D90≤150 μm.

[0047] In some embodiments, in step 2), water is sprayed during the granulation process to form seed particles in the granulator; the particle size of the seed particles is preferably not more than 1 mm; the seed particles are preferably formed by spraying water during the above granulation process, and the total amount of water sprayed is preferably 0.6wt%-1.5wt% of the total weight of the solid waste powder fed in step 2) and step 3).

[0048] In some embodiments, in step 3), water is again sprayed during the granulation process, and the total amount of water sprayed is preferably 38.5wt%-39.4wt% of the total weight of the solid waste powder fed in step 2) and step 3).

[0049] In a preferred embodiment, in step 3), the amount of solid waste powder fed at a time gradually increases as the granulation proceeds, and the amount of water sprayed at a time also gradually increases; and the amount of solid waste powder fed at a time is 1-15% of the remaining weight (i.e. the difference between the total weight of the solid waste powder used in step 2) and step 3) and the weight of the solid waste powder fed in step 2), and the total amount of water sprayed is 38.5wt%-39.4wt% of the total weight of the solid waste powder fed in step 2) and step 3). The preferred way of performing step 3) is beneficial to improving the qualified rate of the raw haydite balls.

[0050] In some specific embodiments, the granulator used is a disc granulator. In some embodiments, in step 2) and step 3), the rotating speed of the granulator during the granulation process in the granulator is 700-800 rpm. In some embodiments, in step 3), after all the solid waste powder is fed into the granulator, the granulator continues to rotate for 10-30 min to polish the obtained raw haydite balls, and then the raw haydite balls are dried, and 3-5 mm raw haydite balls are obtained after screening. In some embodiments, in step 3), the granulator obtained by polishing is dried in a 105℃±5℃ oven, and the drying time is, for example, 1-4 h.

[0051] In some embodiments, in step 1), the components of the solid waste powder, such as fly ash meeting the corresponding particle size requirement, gasification slag and other solid waste that can be added, are uniformly mixed by manual mixing or using a mixer.

[0052] The present inventors have found that, by using the preparation process of the present application, controlling the particle size of fly ash to be D50≥15 μm and D90≤150 μm, controlling the particle size of the possibly added gasification slag to be ≤30 mesh, and using a gasification slag with a dry basis carbon content of 15wt%-45wt%, controlling the particle size of the possibly added other solid waste to be D50≥15 μm and D90≤150 μm, and feeding and granulating in two major parts in two different steps, specifically first feeding 1.5%-2.5% of the solid waste powder to obtain small particles (i.e. seed particles), and then feeding the remaining solid waste powder in multiple times, this way can significantly improve the qualified rate of 3-5 mm particle size ceramsite green balls when preparing the target particle size, especially 3-5 mm particle size ceramsite green balls. In some embodiments, the qualified rate of 3-5 mm particle size ceramsite green balls prepared by the method of the present application is ≥80%.

[0053] The following is further exemplarily illustrated by examples.

[0054] The following examples use the following balling method to prepare 3-5 mm ceramsite green balls in a disc granulator:

[0055] 1) Obtain solid waste powder:

[0056] 1a) Test the particle size distribution of fly ash with a laser particle size tester, obtain the part with D50≥15 μm and D90≤150 μm by sieving and sorting, for subsequent granulation;

[0057] 1b) For the case of using gasification slag, select gasification slag with a dry basis carbon content of 37wt%; dry the gasification slag in an oven at 105℃±5℃, manually crush or crush the dried gasification slag with a crusher, and sieve through a 30 mesh sieve, take the undersize part (i.e. the part with particle size ≤30 mesh), for subsequent granulation;

[0058] 1c) For the case of using other solid waste (in the following examples, coal gangue, kaolin, clay, albite, potassium feldspar, bentonite, waste glass powder, sludge and / or furnace bottom slag), crush, grind, sieve, and sort the other solid waste, test the particle size with a laser particle size tester, and select the particles with particle size D50≥15 μm and D90≤150 μm for subsequent granulation;

[0059] 1d) Weigh the components of the solid waste powder according to the proportions in Table 1 below, and mix the solid waste powder evenly; if a binder needs to be added, mix the binder in at this step.

[0060] 2) Take 1.5%-2.5% of the total weight of the solid waste powder (corresponding to "Step 2) solid waste powder feeding amount" in Table 1) from the uniformly mixed solid waste powder, place it in the granulating disc of the disc granulator, turn on the equipment, start the powder rotation at a speed of 800 rpm, and spray tap water (the total amount of water sprayed is shown in Table 1 as "Step 2) water spraying amount", which is a percentage of the total weight of the solid waste powder) with a watering can until the powder automatically rolls and binds into small particles of no more than 1 mm, obtaining seed particles;

[0061] 3) The remaining weight (denoted as M) of the solid waste powder is fed into the disc granulator in multiple times, and tap water is sprayed with a watering can while feeding. During this step, the single-feeding amount of the solid waste powder and the single-spraying amount of water gradually increase. The single-feeding amount of the solid waste powder is 1-15% of the remaining weight M (the single-feeding amount gradually increases from 1% of M to 15% of M), and the total amount of water sprayed is shown in Table 1 as "Step 3) water spraying amount" (which is a percentage of the total weight of the solid waste powder);

[0062] After all the powder is added to the disc granulator, continue to rotate the granulator for 10-30 min (the specific time is shown in Table 1 below as "polishing time") to polish the green balls;

[0063] Dry the prepared green ball particles in an oven at 105℃±5℃ for 1-4h;

[0064] Weigh the dried green balls, then sieve them with 3mm and 5mm round hole sieves, sieve out the 3-5mm green balls, and weigh them. Calculate the percentage of 3-5mm green balls in the total weight of the dried green balls, which is the qualified rate of 3-5mm green balls (corresponding to "3-5mm green ball ratio%" in Table 1).

[0065] The comparative examples shown in Table 1 are carried out according to the steps of the above examples, and the differences are shown in Table 1 and Table 2.

[0066] Table 1

[0067]

[0068]

[0069] Note: 1. The particle size of the gasification slag used in Comparative Example 5 in Table 1 is 25 mesh.

[0070] 2. In Table 1, during the solid waste powder feeding process in Step 3) of Comparative Example 4, the single-feeding amount of the solid waste powder gradually increases, and the single-feeding amount of the solid waste powder is controlled within the range of 1-16% of the remaining weight M, with the single-feeding amount gradually increasing from 1% of M to 16% of M.

[0071] The particle sizes of some components in Table 1 are shown in Table 2 below, wherein the suffixes "ND", "JC" and "XTY" of fly ash are the codes marked for different fly ash to facilitate the differentiation of different raw materials:

[0072] Table 2

[0073]

[0074]

[0075] From the results in Table 1 above, it can be seen that the qualified rates of the 3-5 mm raw ceramsite balls prepared by the method of the present application in the examples are all significantly higher than those of the comparative examples. In Comparative Examples 1-5, the addition amount (i.e. the first feeding amount) of the solid waste powder in step 2) of Comparative Example 1 exceeds 2.5% of the weight of the solid waste powder; the particle size of the fly ash used in Comparative Example 2 does not meet D50≥15 μm and D90≤150 μm, and the addition amount (i.e. the first feeding amount) of the solid waste powder in step 2) exceeds 2.5% of the weight of the solid waste powder; the particle size of the bottom slag used in Comparative Example 3 does not meet D50≥15 μm and D90≤150 μm; the particle size of the fly ash used in Comparative Example 4 does not meet D50≥15 μm and D90≤150 μm, and the single feeding amount of the remaining solid waste powder in step 3) is at most 15% of the weight of the remaining solid waste powder; the particle size of the gasification slag used in Comparative Example 5 does not meet ≤30 mesh; and the qualified rates of the 3-5 mm raw ceramsite balls in the raw ceramsite balls prepared in Comparative Examples 1-5 are significantly poorer than those in the examples.

[0076] It is easily understood that the above examples are only examples for clearly illustrating the present application, and do not mean that the present application is limited to this. Other different forms of changes or variations can be made on the basis of the above description by those of ordinary skill in the art. Here, it is not necessary and impossible to exhaust all the embodiments. The obvious changes or variations derived therefrom are still within the protection scope of the present application.

Claims

1. A method for preparing a raw ball of ceramsite using solid waste, characterized by, The method comprises the following steps: 1) obtaining a solid waste powder, wherein the solid waste powder comprises fly ash, and the particle size of the fly ash satisfies D50≥15 μm and D90≤150 μm; 2) feeding 1.5%-2.5% of the weight of the solid waste powder in step 1) into a granulator to perform granulation, and obtaining seed particles; 3) feeding the remaining weight of the solid waste powder into the granulator in multiple times, continuously granulating and forming on the basis of the seed particles, polishing the obtained particles, and then drying and screening to obtain green balls with a desired particle size; the feeding of the remaining weight of the solid waste powder into the granulator is feeding 1-15% of the remaining weight into the granulator each time; the particle size of the green balls is 3-5 mm.

2. The method for preparing green balls of ceramsite using solid waste according to claim 1, characterized in that, In step 1), the solid waste powder optionally further comprises gasification slag, the particle size of the gasification slag is ≤30 mesh, and the dry basis carbon content of the gasification slag is 15wt%-45wt%.

3. The method for preparing green balls of ceramsite using solid waste according to claim 2, characterized in that, Based on 100 parts by weight of the solid waste powder, the weight parts of fly ash is 10-100 parts, and the weight parts of gasification slag is 0-90 parts.

4. The method for preparing green balls of ceramsite using solid waste according to claim 2, characterized in that, In step 1), the solid waste powder optionally further comprises other solid wastes, the other solid wastes comprise one or more of coal gangue, kaolin, clay, albite, potassium feldspar, bentonite, glass powder, sludge, and furnace bottom slag, and the particle size of the other solid wastes satisfies D50≥15 μm and D90≤150 μm.

5. The method for preparing green balls of ceramsite using solid waste according to claim 4, characterized in that, In step 1), based on 100 parts by weight of the solid waste powder: the weight parts of fly ash is 10-100 parts; the weight parts of gasification slag is 0-90 parts; the weight parts of the other solid wastes is 0-30 parts.

6. The method for preparing green balls of ceramsite using solid waste according to claim 5, characterized in that, the weight parts of fly ash is 10-89 parts; the weight parts of gasification slag is 10-89 parts; and the weight parts of the other solid wastes is 1-30 parts.

7. The method of claim 5, wherein the solid waste is mixed with water in a ratio of 1: 1 to 1:

3. In step 1), a binder is optionally added to the solid waste powder, and based on 100 parts by weight of the solid waste powder, the weight parts of the binder is 0-5 parts.

8. The method for preparing green balls of ceramsite from solid waste according to claim 7, characterized in that, The binder is selected from one or more of starch ethers, glue powder, cellulose ethers, and guar gum.

9. The method for preparing green balls of ceramsite from solid waste according to any one of claims 1-8, characterized in that, The fly ash is selected from pulverized coal furnace fly ash and / or circulating fluidized bed fly ash.

10. The method for preparing green balls of ceramsite from solid waste according to any one of claims 1-8, characterized in that, In step 2), water is sprayed during the granulation process to form the seed particles in the granulator.

11. The method of claim 10, wherein the solid waste is mixed with water in a ratio of 1: 1 to 1:

3. The particle size of the seed particles is not more than 1 mm.

12. The method of claim 10, wherein the solid waste is mixed with water in a ratio of 1: 1 to 1:

3. In step 2), the total amount of water sprayed is 0.6wt%-1.5wt% of the total weight of the solid waste powder fed in steps 2) and 3).

13. The method for preparing ceramsite green balls from solid waste according to any one of claims 1-8, wherein In step 3), water is sprayed during the granulation process, and the total amount of water sprayed is 38.5wt%-39.4wt% of the total weight of the solid waste powder fed in steps 2) and 3).

14. The method for preparing ceramsite green balls from solid waste according to claim 13, wherein In step 3), the single-adding amount of the solid waste powder gradually increases, and the single-adding amount of water gradually increases as the granulation proceeds; and the single-adding amount of the solid waste powder is 1-15% of the remaining weight, and the total amount of water is 38.5wt%-39.4wt% of the total weight of the solid waste powder put into step 2) and step 3).

15. The method of claim 1-8, wherein the method of preparing green balls of ceramsite from solid waste is characterized by, In step 2) and step 3), the rotating speed of the granulator is 700-800rpm.

16. The method of claim 15, wherein the solid waste is mixed with water in a ratio of 1: 1 to 1:

3. The granulator is a disc granulator.

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