High-strength and high-density fly ash solidified body and preparation method thereof
By preparing high-strength and high-density fly ash solids, the problems of volume increase and large land occupation in fly ash treatment are solved, and efficient volume reduction and resource conservation of fly ash are achieved.
Patent Information
- Application Number
- CN202510924492.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-07-04
- Publication Date
- 2025-10-17
AI Technical Summary
The existing fly ash treatment methods have the problems of obvious volume increase, large land resource occupation and unsatisfactory volume reduction effect.
A binder is prepared by mixing polyhydroxy compounds, silane, water and fly ash, and is combined with two-dimensional sheet materials and heavy metal stabilizers to prepare a high-strength and high-density fly ash solidified body through compression molding.
The utilization rate and stacking density of fly ash are improved, the landfill space occupied during landfill is reduced, and land resources are saved.
Smart Images
Figure CN120794479A_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of waste utilization, in particular to a high-strength and high-density fly ash solidification body and a preparation method thereof. BACKGROUND
[0002] With the acceleration of urbanization, municipal solid waste incineration for power generation has become the mainstream of waste disposal. However, fly ash generated during the incineration process contains high concentrations of heavy metals (such as Pb and Cd) and dioxins, which are classified as hazardous waste (HW18). The current mainstream fly ash treatment method is mainly cement solidification and chemical agent stabilization, followed by landfill. Cement solidification has low cost, but the capacity is obviously increased (volume increased by 30%-50%). Chemical agent stabilization requires the addition of agents, and its long-term stability is questionable. Fly ash is a fine powder with low bulk density. Direct landfill of fly ash will inevitably occupy a large amount of land resources. Compression and densification of fly ash can increase its bulk density and reduce its apparent volume, thereby effectively reducing the landfill capacity and the occupation of land resources. SUMMARY
[0003] The present application provides a high-strength and high-density fly ash solidification body and a preparation method thereof, which can effectively reduce the landfill capacity and the occupation of land resources.
[0004] In a first aspect, the present application provides a preparation method of a high-strength and high-density fly ash solidification body, comprising:
[0005] S1, mixing a polyhydroxy compound, a silane, water and fly ash uniformly to obtain a binder;
[0006] S2, mixing the fly ash, the binder and a two-dimensional sheet material uniformly to obtain a solid powder;
[0007] S3, pressing and forming the solid powder to obtain a fly ash solidification body.
[0008] In a possible design, S1 comprises:
[0009] Mixing the polyhydroxy compound, the silane and the water, and stirring and reacting at 50-90℃ for 1-3h;
[0010] Adding the fly ash and stirring for 10-30min to obtain the binder.
[0011] In a possible design, S2 comprises:
[0012] Mixing the fly ash, the binder, the two-dimensional sheet material, a heavy metal stabilizer and a conditioner in a mixer to obtain a solid powder.
[0013] In a possible design, in S3, the pressure applied to the solid powder is 10-30 MPa.
[0014] In a possible design, the polyhydroxy compound comprises one or more of tannic acid, polyvinyl alcohol, cellulose derivatives, and lignin derivatives in combination.
[0015] The silane comprises one or more of KH-550, KH-540, KH-792, and KH-602 in combination.
[0016] In a possible design, in S1, the mass ratio of the polyhydroxy compound, the silane, the water, and the fly ash is (2-5):(1-3):100:(25-35).
[0017] In a possible design, the two-dimensional sheet material comprises one or more of graphene, graphite powder, and mica powder.
[0018] In a possible design, the heavy metal stabilizer comprises one or more of sodium phosphate, apatite, and dithiocarbamate, and the conditioner comprises one or more of silicate cement powder and aluminate cement powder.
[0019] In a possible design, in S2, the two-dimensional sheet material is added in an amount of 1-3% of the mass of the fly ash in S2, the binder is added in an amount of 15-25% of the mass of the fly ash in S2, the heavy metal stabilizer is added in an amount of 2-5% of the mass of the fly ash in S2, and the conditioner is added in an amount of 2-5% of the mass of the fly ash in S2.
[0020] In a second aspect, an embodiment of the present application provides a high-strength and high-density fly ash solidified body prepared according to any of the preparation methods described above.
[0021] Compared with the prior art, the present application has at least the following beneficial effects:
[0022] Mixing the polyhydroxy compound, silane, water and fly ash can prepare a high-efficiency adhesive with viscosity and fly ash in the composition, thereby improving the utilization rate of fly ash. In the high-efficiency adhesive, a large number of hydroxyl groups in the polyhydroxy compound can provide strong adhesion, and further improve the compactness of the product. The silane molecule has an active amino functional group at one end and an active Si-O-C bond at the other end. After hydrolysis, Si-OH is obtained. The functional group can combine with the hydroxyl group on the surface of the inorganic particles in the fly ash to improve the adhesion. After obtaining the adhesive with strong viscosity, the adhesive, fly ash and two-dimensional sheet material are mixed to obtain a solid powder. The obtained solid powder has high compactness, because the two-dimensional sheet material has lubricating effect. In the compression process, the fly ash particles can flow under the lubricating effect of the two-dimensional sheet material to further fill the internal gap, thereby improving the compactness of the solid powder under compression and the density of the fly ash solidification body. Because the two-dimensional sheet material is fluffy and has small bulk density, excessive addition will reduce the density of the solidification body and cause insufficient compactness. BRIEF DESCRIPTION OF DRAWINGS
[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or the prior art description. Obviously, the drawings described below are some embodiments of the present application, and those skilled in the art can obtain other drawings according to these drawings without creative labor.
[0024] Figure 1 It is a preparation method flow chart of a high-strength and high-density fly ash solidification body provided by the embodiment of the present application. DETAILED DESCRIPTION
[0025] In order to make the purpose, technical scheme and advantages of the embodiments of the present application more clear, the technical scheme in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are some embodiments of the present application, not all embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor are within the scope of protection of the present application.
[0026] As shown in Figure 1 The embodiment of the present application provides a preparation method of a high-strength and high-density fly ash solidification body, which comprises:
[0027] S1, mixing the polyhydroxy compound, silane, water and fly ash uniformly to obtain an adhesive;
[0028] S2, mixing the fly ash, adhesive and two-dimensional sheet material uniformly to obtain a solid powder;
[0029] S3, the solid powder is pressed into a shape to obtain a fly ash solidified body.
[0030] In this embodiment, the polyhydroxy compound, silane, water and fly ash are mixed to prepare a high-efficiency adhesive with viscosity and fly ash, thereby improving the utilization rate of fly ash. In the high-efficiency adhesive, a large number of hydroxyl groups in the polyhydroxy compound can provide strong adhesion, and further improve the density of the product. The silane molecule has an active amino functional group at one end and an active Si-O-C bond at the other end. After hydrolysis, Si-OH is obtained. This functional group can combine with the hydroxyl groups on the surface of the inorganic particles in the fly ash to improve the adhesion. After obtaining the adhesive with strong viscosity, the adhesive, fly ash and two-dimensional sheet material are mixed to obtain a solid powder. The obtained solid powder has high density because the two-dimensional sheet material has a lubricating effect. During compression, fly ash particles can flow and further fill internal gaps under the lubricating effect of the two-dimensional sheet material, thereby improving the density of the solid powder under compression and improving the density of the fly ash solidified body. Due to the bulkiness and low bulk density of the two-dimensional sheet material, excessive addition will reduce the density of the solidified body and cause insufficient density.
[0031] In some embodiments of the present application, S1 comprises:
[0032] The polyhydroxy compound, silane and water are mixed and stirred at 50-90°C (for example, it can be 50°C, 55°C, 60°C, 65°C, 70°C, 75°C, 80°C, 85°C or 90°C) for 1-3h (for example, it can be 1h, 1.5h, 2h, 2.5h or 3h);
[0033] The fly ash is added and stirred for 10-30min (for example, it can be 10min, 15min, 20min, 25min or 30min) to obtain an adhesive.
[0034] In this embodiment, the polyhydroxy compound, silane and water are first mixed uniformly and heated with continuous stirring to fully hydrolyze the silane, and then the fly ash is added to improve the viscosity.
[0035] In some embodiments of the present application, S2 comprises:
[0036] The fly ash, adhesive, two-dimensional sheet material, heavy metal stabilizer and conditioner are mixed in a mixer to obtain a solid powder.
[0037] In this embodiment, in order to improve the chemical stability of the fly ash solidified body product, a heavy metal stabilizer can be added to improve its stability. The conditioner can undergo hydration reaction under the participation of water to further improve the strength of the fly ash solidified body and improve the durability.
[0038] In some embodiments of the present application, the pressure applied to the solid powder in S3 is 10-30 MPa (for example, it can be 10 MPa, 11 MPa, 12 MPa, 13 MPa, 14 MPa, 15 MPa, 16 MPa, 17 MPa, 18 MPa, 19 MPa, 20 MPa, 21 MPa, 22 MPa, 23 MPa, 24 MPa, 25 MPa, 26 MPa, 27 MPa, 28 MPa, 29 MPa, or 30 MPa).
[0039] Specifically, fly ash, a binder, etc. are put into a mixer for mixing to obtain a solid powder. The solid powder is then transferred to a molding machine for pressing to obtain a fly ash solidification body. The fly ash solidification body is then transported to a stacking machine for stacking.
[0040] In some embodiments of the present application, the polyhydroxy compound includes one or more combinations of tannic acid, polyvinyl alcohol, cellulose derivatives, and lignin derivatives.
[0041] The silane includes one or more combinations of KH-550, KH-540, KH-792, and KH-602.
[0042] In some embodiments of the present application, in S1, the mass ratio of the polyhydroxy compound, the silane, water, and the fly ash is (2-5):(1-3):100:(25-35).
[0043] In the present embodiment, the proportion of the polyhydroxy compound needs to be controlled within the above range. If it is less than the above range, the adhesion is weak, which is not conducive to the durability of the fly ash solidification body. If it is higher than the above range, the cost is too high. The proportion of the silane needs to be controlled within the above range. If it is less than the above range, the adhesion is weak. If it is higher than the above range, the cost is too high.
[0044] In some embodiments of the present application, the two-dimensional sheet material includes one or more combinations of graphene, graphite powder, and mica powder.
[0045] In some embodiments of the present application, the heavy metal stabilizer includes one or more combinations of sodium phosphate, apatite, and dithiocarbamate, and the conditioner includes one or more combinations of Portland cement powder and aluminate cement powder.
[0046] In some embodiments of the present application, in S2, the amount of the two-dimensional sheet material added is 1-3% of the mass of the fly ash in S2 (for example, it can be 1%, 2% or 3%), the amount of the binder added is 15-25% of the mass of the fly ash in S2 (for example, it can be 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24% or 25%), the amount of the heavy metal stabilizer added is 2-5% of the mass of the fly ash in S2 (for example, it can be 2%, 3%, 4% or 5%), and the amount of the conditioning agent added is 2-5% of the mass of the fly ash in S2 (for example, it can be 2%, 3%, 4% or 5%).
[0047] In the present embodiment, the two-dimensional sheet material can play a lubricating role between the particles, which is conducive to the flow and filling of the particles in the process of densification of the fly ash solidified body, further improves the density of the fly ash solidified body, and improves the durability. If the amount of the two-dimensional sheet material is higher than the above range, the cost is too high, and if the amount is lower than the above range, it will not have a significant effect.
[0048] The conditioning agent can undergo a hydration reaction, further improving the strength of the fly ash solidified body and improving the durability. If the amount of the conditioning agent is higher than the above range, the cost will increase and the compatibility ratio will decrease, and if the amount is lower than the above range, it will not have a significant effect.
[0049] The present application provides a high-strength and high-density fly ash solidified body prepared according to any of the above preparation methods.
[0050] In order to more clearly illustrate the technical solutions and advantages of the present application, several embodiments will be described in detail below.
[0051] Embodiment 1
[0052] (1) Mix the polyhydroxy compound tannic acid, silane KH-550 and water uniformly, and stir and react at 50°C for 1h, then add fly ash powder, and stir for 10-30min to obtain a high-efficiency binder; wherein the mass ratio of the polyhydroxy compound, the silane, the water and the fly ash is 2:1:100:25;
[0053] (2) Put the fly ash, the high-efficiency binder, the two-dimensional sheet material graphene, the heavy metal stabilizer sodium phosphate and the conditioning agent Portland cement powder into a mixer and mix uniformly to obtain a solid powder; wherein the mass ratio of the fly ash, the high-efficiency binder, the two-dimensional sheet material, the heavy metal stabilizer and the conditioning agent is 100:15:1:2:2;
[0054] (3) Transfer the solid powder to a molding main device and press under a pressure of 10MPa to obtain a fly ash solidified body.
[0055] Embodiment 2
[0056] Example 2 is substantially the same as Example 1, except that in step (1), the polyhydroxyl compound is polyvinyl alcohol, the silane is KH-792, the stirring is performed at 70°C for 2h, the stirring is performed for 20min after the addition of fly ash, and the mass ratio of the polyhydroxyl compound, the silane, water, and is 3:2:100:30; in step (2), the two-dimensional sheet material is graphite powder, the heavy metal stabilizer is apatite, and the conditioner is aluminate cement powder, and the mass ratio of the fly ash, the high-efficiency binder, the two-dimensional sheet material, the heavy metal stabilizer, and the conditioner is 100:20:2:3:3; and the pressure in step (3) is 20MPa.
[0057] Example 3
[0058] Example 3 is substantially the same as Example 1, except that in step (1), the polyhydroxyl compound is lignin, the silane is KH-602, the stirring is performed at 90°C for 3h, the stirring is performed for 30min after the addition of fly ash, and the mass ratio of the polyhydroxyl compound, the silane, water, and is 5:3:100:35; in step (2), the two-dimensional sheet material is graphite powder, the heavy metal stabilizer is apatite, and the conditioner is aluminate cement powder, and the mass ratio of the fly ash, the high-efficiency binder, the two-dimensional sheet material, the heavy metal stabilizer, and the conditioner is 100:25:3:5:5; and the pressure in step (3) is 30MPa.
[0059] Comparative Example 1
[0060] Comparative Example 1 is substantially the same as Example 1, except that the two-dimensional sheet material graphene is not added.
[0061] Comparative Example 2
[0062] Comparative Example 2 is substantially the same as Example 1, except that the amount of the two-dimensional sheet material graphene added is 5% of the fly ash.
[0063] Comparative Example 3
[0064] Comparative Example 3 is substantially the same as Example 1, except that the silane is not added.
[0065] Comparative Example 4
[0066] Comparative Example 4 is substantially the same as Example 1, except that the mass ratio of the silane to water is 5:100.
[0067] The products of the examples and comparative examples are tested, and the test results are as follows:
[0068]
[0069] It should be pointed out finally that the above embodiments are only used to illustrate the technical solutions of the present application, but not to limit the same; and although the present application has been described in detail with reference to the foregoing embodiments, it should be appreciated by those skilled in the art that the technical solutions recorded in the foregoing embodiments can be modified, or some technical features thereof can be replaced equivalently; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the spirit and scope of the technical solutions of the embodiments of the present application.
Claims
1. A method for preparing a high-strength and high-density fly ash solidified body, characterized in that: include: S1, mixing polyol, silane, water and fly ash to obtain an adhesive; S2, mixing the fly ash, the binder, and the two-dimensional sheet material uniformly to obtain a solid powder; S3, pressing the solid powder into a shape to obtain a fly ash solidified body.
2. The preparation method according to claim 1, characterized in that S1 includes: Mix the polyol, silane and water, and stir to react at 50-90°C for 1-3 hours; Add fly ash and stir for 10 to 30 minutes to obtain the adhesive.
3. The preparation method according to claim 1, characterized in that S2 includes: The fly ash, the binder, the two-dimensional sheet material, the heavy metal stabilizer and the conditioner are placed in a mixer and mixed evenly to obtain solid powder.
4. The preparation method according to claim 1, characterized in that In S3, the pressure applied to the solid powder is 10-30 MPa.
5. The preparation method according to claim 1, characterized in that The polyhydroxy compound includes one or more combinations of tannic acid, polyvinyl alcohol, cellulose derivatives, and lignin derivatives; The silane includes one or more combinations of KH-550, KH-540, KH-792, and KH-602.
6. The preparation method according to claim 1, characterized in that In S1, the mass ratio of the polyol, silane, water and fly ash is (2-5): (1-3): 100: (25-35).
7. The preparation method according to claim 1, characterized in that The two-dimensional sheet material includes one or more combinations of graphene, graphite powder, and mica powder.
8. The preparation method according to claim 3, characterized in that The heavy metal stabilizer includes one or more combinations of sodium phosphate, apatite, and dithiocarbamate, and the conditioning agent includes one or more combinations of silicate cement powder and aluminate cement powder.
9. The preparation method according to claim 3, characterized in that In S2, the amount of the two-dimensional sheet material added is 1 to 3% of the mass of the fly ash in S2, the amount of the adhesive added is 15 to 25% of the mass of the fly ash in S2, the amount of the heavy metal stabilizer added is 2 to 5% of the mass of the fly ash in S2, and the amount of the conditioner added is 2 to 5% of the mass of the fly ash in S2.
10. A high-strength and high-density fly ash solidified body, characterized in that: Prepared according to any one of the preparation methods of claims 1-9.